Topic Editors

Institute for Research on Combustion (IRC)-CNR, P.le V. Tecchio, 80-80125 Napoli, Italy
Institute for Research on Combustion (IRC)-CNR, P.le V. Tecchio, 80-80125 Napoli, Italy

Carbon Capture, Storage and Utilisation Technologies (CCS/CCU)

Abstract submission deadline
closed (31 October 2022)
Manuscript submission deadline
closed (31 December 2022)
Viewed by
201121

Topic Information

Dear Colleagues,

This is a call for papers for the Topic “Carbon Capture, Storage and Utilisation Technologies (CCS/CCU)”. The release and accumulation of greenhouse gases (GHGs), with carbon dioxide (CO2) being one of the primary GHGs, has significantly altered the natural environment and is responsible for global warming. Reducing these CO2 emissions is, therefore, of paramount importance. In particular, aiming at keeping a global temperature rise well below 2°C by the end of this century, according to the Paris Agreement, the European Union has set a binding target to cut at least 40% of the CO2 emissions by 2030 compared to 1990, and by 30% compared to 2005.

In this framework, one of the most promising alternatives to reducing the increasing amount of CO2 released into the atmosphere and its negative impact on global climate change is represented by CO2 capture and storage (CCS), consisting of the separation of CO2 from large industrial and energy-related sources, transport to a storage location and long-term isolation from the atmosphere. Likewise, the captured CO2 can be also utilised in industrial processes for the production of value-added chemicals/fuels (CCU), in concrete curing, mineral carbonation and algae cultivation. Likewise, it can be reused and isolated permanently via enhanced oil recovery (EOR), enhanced coal bed methane (ECBM) and enhanced geothermal system (EGS) processes.

The Topic “Carbon Capture Storage and Utilisation Technologies (CCS/CCU)” seeks high-quality works focusing on the latest technical developments and scientific advances of CCS/CCU technology. Relevant themes include but are not limited to the following:

  • Carbon dioxide capture, transport (both by pipelines and ships), and sequestration;
  • Technically, environmentally, and economically viable processes for the CO2 utilisation (e.g., as a feedstock for the production of value-added chemicals/fuels, EOR, ECBM, EGS, algae cultivation, etc.);
  • Lifecycle assessment (LCA) for CCS/CCU.

Dr. Federica Raganati
Dr. Paola Ammendola
Topic Editors

Keywords

  • CCUS
  • CCS
  • CCU
  • CO2 capture
  • CO2 transportation
  • CO2 storage
  • geological sequestration
  • CO2 utilisation
  • techno-economic assessment
  • lifecycle analysis (LCA)

Participating Journals

Journal Name Impact Factor CiteScore Launched Year First Decision (median) APC
Processes
processes
3.5 4.7 2013 13.7 Days CHF 2400
C
carbon
4.1 - 2015 23.8 Days CHF 1600
Energies
energies
3.2 5.5 2008 16.1 Days CHF 2600
Applied Sciences
applsci
2.7 4.5 2011 16.9 Days CHF 2400
Sustainability
sustainability
3.9 5.8 2009 18.8 Days CHF 2400
Powders
powders
- - 2022 53.9 Days CHF 1000

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Published Papers (55 papers)

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14 pages, 3218 KiB  
Article
Influence of Clay Content on CO2-Rock Interaction and Mineral-Trapping Capacity of Sandstone Reservoirs
by Emad A. Al-Khdheeawi, Doaa Saleh Mahdi, Yujie Yuan and Stefan Iglauer
Energies 2023, 16(8), 3489; https://doi.org/10.3390/en16083489 - 17 Apr 2023
Cited by 5 | Viewed by 1495
Abstract
The injection of carbon dioxide (CO2) is an essential technology for maximizing the potential of hydrocarbon reservoirs while reducing the impact of greenhouse gases. However, because of the complexity of this injection, there will be many different chemical reactions between the [...] Read more.
The injection of carbon dioxide (CO2) is an essential technology for maximizing the potential of hydrocarbon reservoirs while reducing the impact of greenhouse gases. However, because of the complexity of this injection, there will be many different chemical reactions between the formation fluids and the rock minerals. This is related to the clay content of sandstone reservoirs, which are key storage targets. Clay content and clay types in sandstone can vary substantially, and the influence of these factors on reservoir-scale CO2-water-sandstone interactions has not been managed appropriately. Consequently, by simulating the process of CO2 injection in two different clay-content sandstones (i.e., high- and low-clay content), we investigated the effect of the sandstone clay concentration on CO2-water-sandstone interactions in this article. High clay content (Bandera Grey sandstone) and low clay content (Bandera Brown sandstone) were considered as potential storage reservoirs and their responses to CO2 injection were computationally assessed. Our results indicate that the mineralogical composition of the sandstone reservoir significantly varies as a result of CO2-water-sandstone interactions. Clearly, the high clay-content sandstone (Bandera Grey) had a higher maximum CO2 mineral-trapping capacity (6 kg CO2/m3 sandstone) than Bandera Brown Sandstone (low clay content), which had only 3.3 kg CO2/m3 sandstone mineral-storage capacity after 400 years of storage. Interestingly, pH was decreased by ~3 in Bandera Grey sandstone and by ~2.5 in Bandera Brown sandstone. Furthermore, porosity increased in Bandera Grey sandstone (by +5.6%), more than in Bandera Brown Sandstone (+4.4%) after a 400-year storage period. Overall, we concluded that high clay-content sandstone shows more potential for CO2 mineral-trapping. Full article
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19 pages, 3332 KiB  
Article
Experimental Study on Mineral Dissolution and Carbonation Efficiency Applied to pH-Swing Mineral Carbonation for Improved CO2 Sequestration
by Natália R. Galina, Gretta L. A. F. Arce, Mercedes Maroto-Valer and Ivonete Ávila
Energies 2023, 16(5), 2449; https://doi.org/10.3390/en16052449 - 4 Mar 2023
Cited by 7 | Viewed by 2552
Abstract
Mineral carbonation incurs high operating costs, as large amounts of chemicals and energy must be used in the process. Its implementation on an industrial scale requires reducing expenditures on chemicals and energy consumption. Thus, this work aimed to investigate the significant factors involved [...] Read more.
Mineral carbonation incurs high operating costs, as large amounts of chemicals and energy must be used in the process. Its implementation on an industrial scale requires reducing expenditures on chemicals and energy consumption. Thus, this work aimed to investigate the significant factors involved in pH-swing mineral carbonation and their effects on CO2 capture efficiency. A central composite rotatable design (CCRD) was employed for optimizing the operational parameters of the acid dissolution of serpentinite. The results showed that temperature exerts a significant effect on magnesium dissolution. By adjusting the reaction temperature to 100 °C and setting the hydrochloric acid concentration to 2.5 molar, 96% magnesium extraction was achieved within 120 min of the reaction and 91% within 30 min of the reaction. The optimal efficiency of carbon dioxide capture was 40–50%, at higher values than those found in literature, and 90% at 150 bar and high pressures. It was found that it is technically possible to reduce the reaction time to 30 min and maintain magnesium extraction levels above 90% through the present carbonation experiments. Full article
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20 pages, 3620 KiB  
Article
Exploring the Potential of Carbon Capture, Utilization, and Storage in Baltic Sea Region Countries: A Review of CCUS Patents from 2000 to 2022
by Mayur Pal, Viltė Karaliūtė and Shruti Malik
Processes 2023, 11(2), 605; https://doi.org/10.3390/pr11020605 - 16 Feb 2023
Cited by 7 | Viewed by 3084
Abstract
Carbon capture, utilization, and storage (CCUS) refers to technologies that capture carbon dioxide (CO2) emissions from sources such as power plants, industrial facilities, and transportation, and either store it underground or use it for beneficial purposes. CCUS can play a role [...] Read more.
Carbon capture, utilization, and storage (CCUS) refers to technologies that capture carbon dioxide (CO2) emissions from sources such as power plants, industrial facilities, and transportation, and either store it underground or use it for beneficial purposes. CCUS can play a role in reducing greenhouse gas emissions and mitigating climate change, as CO2 is a major contributor to global warming. In the Baltic Sea region countries (BSR), patent searches from 2000 to 2020 reveal that CCUS technologies are focused on CO2 storage, monitoring, utilization, and transport. However, the adoption and deployment of these technologies has been slow due to a variety of factors, including a lack of government action on climate change, public skepticism, increasing costs, and advances in other options such as renewables and shale gas. Overall, CCUS has the potential to significantly reduce CO2 emissions and contribute to climate change mitigation efforts, but more work is needed to overcome the barriers to its widespread adoption in the BSR and elsewhere. This could include policy measures to incentivize the use of CCUS technologies, public education and outreach efforts to increase understanding and support for CCUS, and research and development to improve the efficiency and cost-effectiveness of these technologies. Full article
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18 pages, 5048 KiB  
Article
Critical Conditions for Wellbore Failure during CO2-ECBM Considering Sorption Stress
by Hecheng Xiao, Wenda Li, Zaiyong Wang, Shuai Yang and Peng Tan
Sustainability 2023, 15(4), 3696; https://doi.org/10.3390/su15043696 - 16 Feb 2023
Cited by 1 | Viewed by 1120
Abstract
Significant stress changes caused by sorption-induced swelling raise the coal wellbore failure potential, which directly impacts the safety and sustainability of CO2 enhanced coalbed methane (CO2-ECBM). Additionally, a mixture gas (CO2/N2) injection is recommended due to [...] Read more.
Significant stress changes caused by sorption-induced swelling raise the coal wellbore failure potential, which directly impacts the safety and sustainability of CO2 enhanced coalbed methane (CO2-ECBM). Additionally, a mixture gas (CO2/N2) injection is recommended due to the sharp decline of permeability with pure CO2 injection. In this study, incorporating the impacts of mixture gas adsorption and poroelastic effects, a semi-analytical model of coal wellbore stability during mixture gas injection is proposed. Model results indicate that the stress field is significantly influenced by the boundary condition and sorption effect. In addition, parametric studies are performed to determine the influence of adsorption parameters, mechanical properties, and gas composition on the stress distribution and then on the wellbore failure index. Furthermore, mixture gas injection with a large proportion of CO2 or N2 both cause wellbore instability. Significant compressive hoop stress and shear failure are caused by the mixture gas injection with a large proportion of CO2. In contrast, the displacement of CH4 with weakly adsorptive N2 will result in less compressive and even tensile hoop stress, so shear or tensile failure may occur. Thus, mixture gas (including pure CO2/N2) injection must be controlled by coal wellbore failure, providing an accurate estimation of in-situ coal seams’ CO2 storage capacity from the perspective of wellbore stability. Full article
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14 pages, 1698 KiB  
Article
Synthesis, Characterization and Gas Adsorption of Unfunctionalized and TEPA-Functionalized MSU-2
by Xin Ying Lee, Vinosha Viriya, Thiam Leng Chew, Pei Ching Oh, Yit Thai Ong, Chii-Dong Ho and Zeinab Abbas Jawad
Processes 2022, 10(10), 1943; https://doi.org/10.3390/pr10101943 - 27 Sep 2022
Cited by 2 | Viewed by 1634
Abstract
Michigan State University-2 (MSU-2) is notable potential adsorbent for carbon dioxide (CO2) due to its intrinsic properties, which include its highly interconnected three-dimensional (3D) wormhole-like framework structure, high specific surface area, and its large total pore volume, as well as its [...] Read more.
Michigan State University-2 (MSU-2) is notable potential adsorbent for carbon dioxide (CO2) due to its intrinsic properties, which include its highly interconnected three-dimensional (3D) wormhole-like framework structure, high specific surface area, and its large total pore volume, as well as its large amount of surface silanol hydroxyl groups, which facilitate the amine functionalization process. In this study, unfunctionalized MSU-2 was synthesized via a fluoride-assisted two-step process via the solution precipitation method, using Triton X-100 as the surfactant and tetraethylorthosilicate (TEOS) as the silica precursor. Then, the synthesized MSU-2 was functionalized using varying tetraethylenepentamine (TEPA) loadings of 20–60 wt%. The effect of different TEPA loadings on the properties and CO2 adsorption capacity of the MSU samples was investigated. Studies of the CO2 adsorption of the unfunctionalized and TEPA-functionalized MSU-2 samples was conducted at 40 °C and 1 bar of pressure. Furthermore, scanning electron microscopy (SEM); surface area and porosity (SAP) analysis; carbon, hydrogen, nitrogen, and sulfur (CHNS) analysis, X-ray diffractometry (XRD); Fourier transform infrared (FTIR) spectrometry; and thermogravimetric analysis (TGA) were utilized to characterize the resultant unfunctionalized and TEPA-functionalized MSU-2 with different TEPA loadings in order to study their morphologies, pore characteristics, elemental compositions, crystallographic structures, functional groups, chemical bonding, and thermal stability, respectively. The comprehensive results obtained from the analytical instruments and the CO2 adsorption studies indicated that the TEPA-functionalized MSU-2 with 40 wt% of TEPA loading achieved the highest average CO2 adsorption capacity of 3.38 mmol-CO2/g-adsorbent. Full article
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11 pages, 1202 KiB  
Article
The Split Flow Process of CO2 Capture with Aqueous Ammonia Using the eNRTL Model
by Seung Won Jeong, Bomsock Lee and Sung Young Kim
Processes 2022, 10(9), 1839; https://doi.org/10.3390/pr10091839 - 13 Sep 2022
Viewed by 2981
Abstract
Carbon Capture and Storage (CCS) technology has attracted increasing attention as global climate change accelerates. Carbon dioxide removal processes under development include pressure swing adsorption (PSA) and chemical absorption using amine solvents. In this paper, an ammonia solvent, which is relatively inexpensive and [...] Read more.
Carbon Capture and Storage (CCS) technology has attracted increasing attention as global climate change accelerates. Carbon dioxide removal processes under development include pressure swing adsorption (PSA) and chemical absorption using amine solvents. In this paper, an ammonia solvent, which is relatively inexpensive and has good material properties, was used instead of amines in the carbon dioxide removal process simulation as a chemical absorption method. This simulation used the eNRTL thermodynamics model which has the advantage of predicting ions in the liquid phase in Aspen Plus. A case study (Case Study 1) was conducted to verify the validity of the thermodynamic model. The purpose of this research was to find the operating conditions to eliminate more than 90% of the carbon dioxide contained in the flue gas from coal-fired power stations, and to lower heat duty and operating cost conditions. A second case study (Case Study 2) was conducted to find the operating conditions by comparing various process operating conditions. Additionally, this paper determined lower operating cost conditions by manipulating the amount of steam and cooling water. The results showed that the heater’s outlet temperature should be set at under 80 ℃ to lower the operating costs. As a result of changing the flow rate of the side stream of the split flow process, energy consumption was reduced when compared to the conventional flow process. It was shown that the split flow is a superior process with 10.24% less energy use than the conventional flow. In this study, the split flow process achieved an energy saving advantage when compared to the conventional flow process, and a carbon dioxide removal rate of 95% was achieved. Full article
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19 pages, 4586 KiB  
Article
Acoustic Propagation Characteristics of Unsaturated Porous Media Containing CO2 and Oil
by Yujuan Qi, Xiumei Zhang and Lin Liu
Appl. Sci. 2022, 12(17), 8899; https://doi.org/10.3390/app12178899 - 5 Sep 2022
Viewed by 1320
Abstract
Carbon dioxide geological utilization and storage (CGUS) is an effective way to mitigate climate warming. In this paper, we resorted to Lo’s model to analyze the dispersion and attenuation characteristics of unsaturated porous media. Based on this, we analyzed the sensitivity of the [...] Read more.
Carbon dioxide geological utilization and storage (CGUS) is an effective way to mitigate climate warming. In this paper, we resorted to Lo’s model to analyze the dispersion and attenuation characteristics of unsaturated porous media. Based on this, we analyzed the sensitivity of the first compressional wave (P1) and the shear wave (S) to various physical parameters. In addition, the modified models of live oil’s velocity and density were proposed, which were verified by experimental data under the consideration of CO2 dissolution. It is shown that the velocities and attenuations of P1 and S waves are influenced by various parameters, especially CO2 saturation and pore fluid parameters, such as density and velocity. In particular, with increasing CO2 saturation, the sensitivity of P1 velocity decreases, while that of the S velocity increases. Better monitoring results can be achieved by combining P1 and S waves. Finally, the acoustic response was analyzed under the modified model. With the increase in CO2 saturation, the P1 velocity decreases, while the S velocity becomes almost constant and then linearly increases, with the trend changing at the critical saturation. The study provides a more precise basis for monitoring the security of CO2 injection in CGUS. Full article
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18 pages, 3655 KiB  
Article
Porosity and Permeability Model of a Regionally Extending Unit (Upper Miocene Sandstones of the Western Part of Sava Depression, Croatia) Based on Vintage Well Data
by Iva Kolenković Močilac, Marko Cvetković, Bruno Saftić and David Rukavina
Energies 2022, 15(16), 6066; https://doi.org/10.3390/en15166066 - 21 Aug 2022
Cited by 1 | Viewed by 2053
Abstract
The deep saline aquifer (DSA) Poljana in the Upper Pannonian Poljana Sandstones of Sava depression, the SW part of the Pannonian basin system, was identified as a potential CO2 storage object in previous works. Its boundaries have been redefined and its general [...] Read more.
The deep saline aquifer (DSA) Poljana in the Upper Pannonian Poljana Sandstones of Sava depression, the SW part of the Pannonian basin system, was identified as a potential CO2 storage object in previous works. Its boundaries have been redefined and its general model further developed, including the areal distribution of porosity based on analyses of 23 well logs. The sandstones were deposited in turbiditic and deltaic facies that caused considerable variations of porosity, which was further influenced by diagenetic processes. A comparison of altogether 355 pairs of porosity and permeability measurements on core plugs from 16 wells indicated 2 different sets of samples: impermeable samples with effective porosities reaching 18% and permeable samples which showed correlation between porosity and permeability. Accordingly, the permeability model was developed as semi-categorical with two categories: the first category comprising parts of DSA Poljana with porosity values exceeding 18%, where permeability was correlated with porosity, although with limited reliability, and the second category comprising model cells with porosity values below the threshold of 18%, where permeability should not be correlated with porosity due to the appearance of impermeable values. This approach enabled delineation of areas where permeability can be estimated with greater certainty, which is of utmost importance for the planning and development of CO2 storage projects and/or energy storage projects with respect to fluid injectivity. This approach can be used in areas with similar geological settings and limited datasets as an important step from regional capacity estimations towards the detailed, local-scale investigations. Full article
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18 pages, 3513 KiB  
Article
Clay Mineral Type and Content Control Properties of Fine-Grained CO2 Caprocks—Laboratory Insights from Strongly Swelling and Non-Swelling Clay–Quartz Mixtures
by Mohammad Nooraiepour
Energies 2022, 15(14), 5149; https://doi.org/10.3390/en15145149 - 15 Jul 2022
Viewed by 1858
Abstract
Understanding and predicting sealing characteristics and containment efficiency as a function of burial depth across sedimentary basins is a prerequisite for safe and secure subsurface storage. Instead of estimators and empirical relationships, this study aimed to delineate data-driven variability domains for non-cemented fine-grained [...] Read more.
Understanding and predicting sealing characteristics and containment efficiency as a function of burial depth across sedimentary basins is a prerequisite for safe and secure subsurface storage. Instead of estimators and empirical relationships, this study aimed to delineate data-driven variability domains for non-cemented fine-grained clastic caprocks. Constant rate-of-strain uniaxial compression experiments were performed to measure changes in properties of brine-saturated quartz–clay mixtures. The binary mixtures were prepared by mixing quartz with strongly swelling (smectite) and non-swelling (kaolinite) clays representing end-member clay mineral characteristics. The primary objective was to evaluate the evolution of mudstone properties in the first 2.5 km of burial depth before chemical compaction and cementation. By conducting systematic laboratory tests, variability domains, normal compaction trends, and the boundaries in which characteristics of fine-grained argillaceous caprocks may vary were identified, quantified, and mathematically described. The results showed distinct domains of properties, where kaolinite-rich samples showed higher compressibility, lower total porosity, higher vertical permeability, and higher Vp and Vs. Two discrepancies were discovered in the literature and resolved regarding the compaction of pure kaolinite and the ultimate lowest porosity for quartz–clay mixtures. The present experimental study can provide inputs for numerical simulation and geological modeling of candidate CO2 storage sites. Full article
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18 pages, 3487 KiB  
Article
The Spatiotemporal Evolution and Prediction of Carbon Storage in the Yellow River Basin Based on the Major Function-Oriented Zone Planning
by Jinfeng Wang, Lingfeng Li, Qing Li, Sheng Wang, Xiaoling Liu and Ya Li
Sustainability 2022, 14(13), 7963; https://doi.org/10.3390/su14137963 - 29 Jun 2022
Cited by 10 | Viewed by 2122
Abstract
Land use/cover change is the main reason for the variation of ecosystem carbon storage. The study of the impact of land use on carbon storage has certain reference values for realizing high-quality development in the Yellow River Basin. In this paper, the InVEST [...] Read more.
Land use/cover change is the main reason for the variation of ecosystem carbon storage. The study of the impact of land use on carbon storage has certain reference values for realizing high-quality development in the Yellow River Basin. In this paper, the InVEST model was used to simulate the variation of carbon storage in the Yellow River Basin in 2000, 2005, 2010, 2015, and 2020, and to predict the carbon storage in 2030 in combination with the CA-Markov model, as well as to discuss the impact of land use on carbon storage. The results showed that: (1) The variation trend of carbon storage for different land use types in the Yellow River Basin was different and was mainly manifested as a decrease of cultivated land and unused land, and an increase of forest land, grassland, water, and construction land. The carbon storage in the provincial key development prioritized zone, national development optimized zone, and provincial development optimized zone showed decreasing trends, while the national key development prioritized zone and national major grain producing zone presented a fluctuating downward trend. (2) The ecosystem carbon storage function weakened after 2000, and part of the carbon sink area transformed into a carbon source area. The area with low carbon storage was distributed in the west of the provincial key ecological function zone, and the area with high carbon storage was concentrated in the south and middle of national key ecological function zone and the east of the provincial key ecological function zone. (3) The carbon loss was largest in the urban expansion scenario (UES), followed by the natural development scenario (NDS) and ecological protection scenario (EPS). The carbon storage of different scenarios presented significant positive correlations with land use intensity. Full article
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38 pages, 6749 KiB  
Review
Recent Advances on CO2 Mitigation Technologies: On the Role of Hydrogenation Route via Green H2
by Georgios Varvoutis, Athanasios Lampropoulos, Evridiki Mandela, Michalis Konsolakis and George E. Marnellos
Energies 2022, 15(13), 4790; https://doi.org/10.3390/en15134790 - 29 Jun 2022
Cited by 13 | Viewed by 3875
Abstract
The increasing trend in global energy demand has led to an extensive use of fossil fuels and subsequently in a marked increase in atmospheric CO2 content, which is the main culprit for the greenhouse effect. In order to successfully reverse this trend, [...] Read more.
The increasing trend in global energy demand has led to an extensive use of fossil fuels and subsequently in a marked increase in atmospheric CO2 content, which is the main culprit for the greenhouse effect. In order to successfully reverse this trend, many schemes for CO2 mitigation have been proposed, taking into consideration that large-scale decarbonization is still infeasible. At the same time, the projected increase in the share of variable renewables in the future energy mix will necessitate large-scale curtailment of excess energy. Collectively, the above crucial problems can be addressed by the general scheme of CO2 hydrogenation. This refers to the conversion of both captured CO2 and green H2 produced by RES-powered water electrolysis for the production of added-value chemicals and fuels, which are a great alternative to CO2 sequestration and the use of green H2 as a standalone fuel. Indeed, direct utilization of both CO2 and H2 via CO2 hydrogenation offers, on the one hand, the advantage of CO2 valorization instead of its permanent storage, and the direct transformation of otherwise curtailed excess electricity to stable and reliable carriers such as methane and methanol on the other, thereby bypassing the inherent complexities associated with the transformation towards a H2-based economy. In light of the above, herein an overview of the two main CO2 abatement schemes, Carbon Capture and Storage (CCS) and Carbon Capture and Utilization (CCU), is firstly presented, focusing on the route of CO2 hydrogenation by green electrolytic hydrogen. Next, the integration of large-scale RES-based H2 production with CO2 capture units on-site industrial point sources for the production of added-value chemicals and energy carriers is contextualized and highlighted. In this regard, a specific reference is made to the so-called Power-to-X schemes, exemplified by the production of synthetic natural gas via the Power-to-Gas route. Lastly, several outlooks towards the future of CO2 hydrogenation are presented. Full article
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15 pages, 2150 KiB  
Article
Investigation of Hydrodynamic Parameters in an Airlift Photobioreactor on CO2 Biofixation by Spirulina sp.
by Zahra Zarei, Peyman Malekshahi, Antoine P. Trzcinski and Mohammad Hossein Morowvat
Sustainability 2022, 14(12), 7503; https://doi.org/10.3390/su14127503 - 20 Jun 2022
Cited by 2 | Viewed by 2190
Abstract
The rise of CO2 concentration on Earth is a major environmental problem that causes global warming. To solve this issue, carbon capture and sequestration technologies are becoming more and more popular. Among them, cyanobacteria can efficiently sequestrate CO2, which is [...] Read more.
The rise of CO2 concentration on Earth is a major environmental problem that causes global warming. To solve this issue, carbon capture and sequestration technologies are becoming more and more popular. Among them, cyanobacteria can efficiently sequestrate CO2, which is an eco-friendly and cost-effective way of reducing carbon dioxide, and algal biomass can be harvested as valuable products. In this study, the hydrodynamic parameters of an airlift photobioreactor such as gas holdup, mean bubble diameter and liquid circulation velocity were measured to investigate CO2 biofixation by Spirulina sp. The total gas holdup was found to increase linearly with the increase in the gas velocity from 0.185 to 1.936 cm/s. The mean bubble velocities in distilled water only and in the cyanobacterial culture on the first and sixth days of cultivation were 109.97, 87.98, and 65.89 cm/s, respectively. It was found that shear stress at gas velocities greater than 0.857 cm/s led to cyanobacterial death. After 7 days of batch culture, the maximum dry cell weight reached 1.62 g/L at the gas velocity of 0.524 cm/s, whereas the highest carbon dioxide removal efficiency by Spirulina sp. was 55.48% at a gas velocity of 0.185 cm/s, demonstrating that hydrodynamic parameters applied in this study were suitable to grow Spirulina sp. in the airlift photobioreactor and remove CO2. Full article
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20 pages, 2924 KiB  
Article
Carbon Capture Utilisation and Storage Technology Development in a Region with High CO2 Emissions and Low Storage Potential—A Case Study of Upper Silesia in Poland
by Anna Śliwińska, Aleksandra Strugała-Wilczek, Piotr Krawczyk, Agnieszka Leśniak, Tomasz Urych, Jarosław Chećko and Krzysztof Stańczyk
Energies 2022, 15(12), 4495; https://doi.org/10.3390/en15124495 - 20 Jun 2022
Cited by 2 | Viewed by 2455
Abstract
The region of Upper Silesia, located in southern Poland, is characterised by very high emissions of carbon dioxide into the air—the annual emission exceeds 33 Mt CO2 and the emission ‘per capita’ is 7.2 t/y in comparison to the EU average emission [...] Read more.
The region of Upper Silesia, located in southern Poland, is characterised by very high emissions of carbon dioxide into the air—the annual emission exceeds 33 Mt CO2 and the emission ‘per capita’ is 7.2 t/y in comparison to the EU average emission per capita 6.4 t/y and 8.4 t/y for Poland in 2019. Although in the region there are over 100 carbon dioxide emitters covered by the EU ETS, over 90% of emissions come from approximately 15 large hard coal power plants and from the coke and metallurgical complex. The CCUS scenario for Upper Silesia, which encompasses emitters, capture plants, transport routes, as well as utilisation and storage sites until 2050, was developed. The baseline scenario assumes capture of carbon dioxide in seven installations, use in two methanol plants and transport and injection into two deep saline aquifers (DSA). The share of captured CO2 from flue gas was assumed at the level of 0.25–0.9, depending mainly on the limited capacity of storage. To recognise the views of society on development of the CCUS technologies in Upper Silesia, thirteen interviews with different types of stakeholders (industry, research and education, policy makers) were conducted. The respondents evaluated CCU much better than CCS. The techno-economic assessment of CCUS carried out on a scenario basis showed that the economic outcome of the scenario with CCUS is EUR 3807.19 million more favourable compared to the scenario without CO2 capture and storage. Full article
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16 pages, 1235 KiB  
Article
Fixed Amidst Change: 20 Years of Media Coverage on Carbon Capture and Storage in Germany
by Danny Otto, Maria Pfeiffer, Mariana Madruga de Brito and Matthias Gross
Sustainability 2022, 14(12), 7342; https://doi.org/10.3390/su14127342 - 15 Jun 2022
Cited by 5 | Viewed by 2533
Abstract
Carbon capture and storage (CCS) technologies are controversially discussed worldwide. Germany is no exception. Here, CO2 storage is banned, although successful pilot plants were installed in the late 2000s. However, the recent burgeoning political interest in this technology prompts us to investigate [...] Read more.
Carbon capture and storage (CCS) technologies are controversially discussed worldwide. Germany is no exception. Here, CO2 storage is banned, although successful pilot plants were installed in the late 2000s. However, the recent burgeoning political interest in this technology prompts us to investigate why and how the (public) image of CCS technologies has changed over time and with regard to different CCS applications. For this purpose, we examine the coverage of CCS in German newspapers over the last 20 years on the basis of a quantitative analysis of about 4000 newspaper articles. A sample of 571 articles with different political orientations was studied qualitatively to analyse reporting on different CCS frames and actors. We find evidence that the media debate is shifting towards the application of CCS for negative emissions technologies and carbon removal. However, the negative image of CCS connected to coal fired power plants persists, suggesting that public and political support remain a problem for a technology fixed in binary negotiations for or against it. Full article
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16 pages, 837 KiB  
Article
The Impact of Carbon Emission Trading Policies on Enterprises’ Green Technology Innovation—Evidence from Listed Companies in China
by Hong Tian, Jiaen Lin and Chunyuan Jiang
Sustainability 2022, 14(12), 7207; https://doi.org/10.3390/su14127207 - 13 Jun 2022
Cited by 11 | Viewed by 2751
Abstract
At present, the Chinese government has successively launched various policies to control the emission standards of greenhouse gases. As one of the most important standards, carbon emission trading policies were implemented in some provinces and regions in China in 2013, aiming to restrict [...] Read more.
At present, the Chinese government has successively launched various policies to control the emission standards of greenhouse gases. As one of the most important standards, carbon emission trading policies were implemented in some provinces and regions in China in 2013, aiming to restrict the carbon emissions of enterprises. However, the government’s control of corporate carbon emissions restricts their rapid economic growth to some extent. Enterprises’ green technology innovation can be an effective means to ensure the implementation of low-carbon policies and promote sustainable economic growth simultaneously. The Porter hypothesis holds that reasonable environmental regulations can stimulate enterprises’ green technology innovation. Based on the Porter hypothesis, this paper examines the impact of China’s carbon emission trading policies on local enterprises’ green technology innovation from a micro perspective, taking China’s listed companies from 2007 to 2020 as samples and adopting the differential method. The differences in the impact of carbon emission trading policies on green technology innovation in the context of different corporate environmental strategies are also studied. Our study found that China’s carbon emissions trading policies can effectively stimulate green technology innovation, as carbon emissions trading policies under different environmental strategies have a positive influence on the technical innovation of enterprises and, compared with reactive environmental strategies, promote a greater role for enterprises’ proactive environmental strategies. The conclusions of this study not only provide relevant suggestions for the Chinese government to enact environmental regulation policies but also provide references for enterprises to choose appropriate environmental strategies and achieve sustainable development under the constraints of environmental regulation. Full article
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21 pages, 2328 KiB  
Article
EnviroCoin: A Holistic, Blockchain Empowered, Consensus-Based Carbon Saving Unit Ecosystem
by Amin Shokri, Ali Shokri, Dean White, Richard Gelski, Yosse Goldberg, Stephen Harrison and Taha Hossein Rashidi
Sustainability 2022, 14(12), 6979; https://doi.org/10.3390/su14126979 - 7 Jun 2022
Cited by 3 | Viewed by 2058
Abstract
The capacity of the greenhouse gas recycling mechanism in nature has long reached its limit, resulting in a sharply increasing trend in the marginal cost of recycling one unit of human-produced carbon and other greenhouse gas emissions. Externalities associated with the marginal cost [...] Read more.
The capacity of the greenhouse gas recycling mechanism in nature has long reached its limit, resulting in a sharply increasing trend in the marginal cost of recycling one unit of human-produced carbon and other greenhouse gas emissions. Externalities associated with the marginal cost of greenhouse gas emissions affect health, climate, and the economy, which have urged global authorities and governments to request urgent actions to slow down the production of such pollutants. Nonetheless, without public awareness and a holistic mechanism to monetise the impact of pollutants, a universal strategy to reduce greenhouse gas emissions is condemned to failure. This paper presents an overview of emerging technologies that can come together to offer an innovative solution for monetising, incentivising and realising the reduction of greenhouse gas emissions. Through a brief review of the literature, an innovative ecosystem is proposed for the first time, accounting for a unified platform for carbon verification, validation and monetisation, which can be adopted as a business model to validate and monetise the amount of incentivising businesses and people for carbon saving on a decentralised blockchain platform. Full article
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20 pages, 5391 KiB  
Article
Exergetic Analysis of DME Synthesis from CO2 and Renewable Hydrogen
by Marcello De Falco, Gianluca Natrella, Mauro Capocelli, Paulina Popielak, Marcelina Sołtysik, Dariusz Wawrzyńczak and Izabela Majchrzak-Kucęba
Energies 2022, 15(10), 3516; https://doi.org/10.3390/en15103516 - 11 May 2022
Cited by 8 | Viewed by 2747
Abstract
Carbon Capture and Utilization (CCU) is a viable solution to valorise the CO2 captured from industrial plants’ flue gas, thus avoiding emitting it and synthesizing products with high added value. On the other hand, using CO2 as a reactant in chemical [...] Read more.
Carbon Capture and Utilization (CCU) is a viable solution to valorise the CO2 captured from industrial plants’ flue gas, thus avoiding emitting it and synthesizing products with high added value. On the other hand, using CO2 as a reactant in chemical processes is a challenging task, and a rigorous analysis of the performance is needed to evaluate the real impact of CCU technologies in terms of efficiency and environmental footprint. In this paper, the energetic performance of a DME and methanol synthesis process fed by 25% of the CO2 captured from a natural gas combined cycle (NGCC) power plant and by the green hydrogen produced through an electrolyser was evaluated. The remaining 75% of the CO2 was compressed and stored underground. The process was assessed by means of an exergetic analysis and compared to post-combustion Carbon Capture and Storage (CCS), where 100% of the CO2 captured was stored underground. Through the exergy analysis, the quality degradation of energy was quantified, and the sources of irreversibility were detected. The carbon-emitting source was a 189 MW Brayton–Joule power plant, which was mainly responsible for exergy destruction. The CCU configuration showed a higher exergy efficiency than the CCS, but higher exergy destruction per non-emitted carbon dioxide. In the DME/methanol production plant, the main contribution to exergy destruction was given by the distillation column separating the reactor outlet stream and, in particular, the top-stage condenser was found to be the component with the highest irreversibility (45% of the total). Additionally, the methanol/DME synthesis reactor destroyed a significant amount of exergy (24%). Globally, DME/methanol synthesis from CO2 and green hydrogen is feasible from an exergetic point of view, with 2.276 MJ of energy gained per 1 MJ of exergy destroyed. Full article
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22 pages, 3960 KiB  
Article
Carbon Soil Storage and Technologies to Increase Soil Carbon Stocks in the South American Savanna
by Gabriel Ribeiro Castellano, Landerlei Almeida Santos and Amauri Antonio Menegário
Sustainability 2022, 14(9), 5571; https://doi.org/10.3390/su14095571 - 6 May 2022
Cited by 2 | Viewed by 2863
Abstract
The expansion of the agricultural frontiers that occurred in the last decades in the South American savanna (Cerrado), the second-largest biome in Brazil (covering an area of 204 million hectares), has accounted for a substantial portion of South America’s CO2 [...] Read more.
The expansion of the agricultural frontiers that occurred in the last decades in the South American savanna (Cerrado), the second-largest biome in Brazil (covering an area of 204 million hectares), has accounted for a substantial portion of South America’s CO2 emissions. In this context, our research investigated the potential for soil carbon storage in the biome. The analysis of previous data (n = 197) shows a vertical distribution pattern of soil carbon stock: 26.17% for the upper 0–30 cm layer, 37.67% for the 30–100 cm layer, and 36.15% for the 100–200 cm layer. The total soil carbon storage for the biome is 13.5 ± 6.7 gigatons (n = 71) for the upper 0–30 cm layer, 30.5 ± 18.9 Gt (n = 64) for the 0–100 cm layer, and 47.8 ± 4.3 (n = 9) for the 0–200 cm layer. The results indicate that the soil carbon stock up to 1 m deep in the Cerrado ranges from 0.5% to 2.29% of the global soil organic carbon storage for this depth. Further research is necessary to investigate what happens at a depth of at least 2 m. The results also indicate that the soil under pasture lands constitutes the largest manageable pool for increasing soil carbon stocks via the restoration of degraded pastures. Full article
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13 pages, 1280 KiB  
Article
Soil Organic Carbon Sequestration under Long-Term Chemical and Manure Fertilization in a Cinnamon Soil, Northern China
by Yun Xiang, Man Cheng, Yongli Wen and Frédéric Darboux
Sustainability 2022, 14(9), 5109; https://doi.org/10.3390/su14095109 - 23 Apr 2022
Cited by 4 | Viewed by 2015
Abstract
To mitigate climate change and improve food security, it is essential to understand how fertilizer strategies impact the dynamics of soil organic carbon and its fractions. The soil organic carbon (SOC), light fraction organic carbon (LFOC), and particulate organic carbon (POC) were investigated [...] Read more.
To mitigate climate change and improve food security, it is essential to understand how fertilizer strategies impact the dynamics of soil organic carbon and its fractions. The soil organic carbon (SOC), light fraction organic carbon (LFOC), and particulate organic carbon (POC) were investigated every five years in a corn (Zea mays L.) cropping system with chemical fertilization and manuring over twenty-four years (1992–2016) in a semiarid area of northern China. There were four treatments with chemical fertilizer (i.e., N1P1, N2P2, N3P3, N4P4), three treatments with chemical fertilizer plus manure (i.e., N2P1M1, N3P2M3, N4P2M2), and one treatment with manure alone (i.e., M6), and an unfertilized treatment (control). The carbon sequestration rate (CSR) and efficiency (CSE) of SOC, POC, and LFOC were identified. The results revealed that the fertilization treatments (N2P2, N3P3, N2P1M1, N3P2M3, N4P2M2, and M6) promoted SOC sequestration, with a sequestration rate of 0.19~1.29 Mg ha−1 y−1. The excess application of chemical fertilizer caused a reduction in POC, whereas the application of NP, NPM or manure resulted in greater POC sequestration in soil, with a carbon sequestration rate of 0.04~0.24 Mg ha−1 y−1. The LFOC stocks were 1.43~2.24 Mg ha−1 under the NP treatments, 2.47~6.68 Mg ha−1 under the NPM treatments and 8.12 Mg ha−1 under the M treatment; these stocks were all higher than that of the control treatment. Different fertilization strategies affected the pools of SOC with different sequestration rates. We found the carbon sequestration rates of SOC and LFOC were logarithmically correlated with the annual carbon input. When the annual C input is approximately 1.39 Mg ha−1 y−1, the SOC level will be maintained; when the annual C input is higher than 0.8 Mg ha−1 y−1, the LFOC level increases. This study describes the relationship between carbon inputs and the SOC(LFOC) sequestration rates under continuous fertilization in arid cropland. The results further evidence that the long-term fertilization of NPM and M increases the potential for SOC sequestration and quantifies the amount of exogenous carbon input required for soil organic matter enhancement. Full article
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21 pages, 1058 KiB  
Review
Sewage-Water Treatment and Sewage-Sludge Management with Power Production as Bioenergy with Carbon Capture System: A Review
by Israel Bernardo S. Poblete, Ofélia de Queiroz F. Araujo and José Luiz de Medeiros
Processes 2022, 10(4), 788; https://doi.org/10.3390/pr10040788 - 17 Apr 2022
Cited by 12 | Viewed by 6809
Abstract
Sewage-water treatment comprehends primary, secondary, and tertiary steps to produce reusable water after removing sewage contaminants. However, a sewage-water treatment plant is typically a power and energy consumer and produces high volumes of sewage sludge mainly generated in the primary and secondary steps. [...] Read more.
Sewage-water treatment comprehends primary, secondary, and tertiary steps to produce reusable water after removing sewage contaminants. However, a sewage-water treatment plant is typically a power and energy consumer and produces high volumes of sewage sludge mainly generated in the primary and secondary steps. The use of more efficient anaerobic digestion of sewage water with sewage sludge can produce reasonable flowrates of biogas, which is shown to be a consolidated strategy towards the energy self-sufficiency and economic feasibility of sewage-water treatment plants. Anaerobic digestion can also reduce the carbon footprint of energy sources since the biogas produced can replace fossil fuels for electricity generation. In summary, since the socio-economic importance of sewage treatment is high, this review examined works that contemplate: (i) improvements of sewage-water treatment plant bioenergy production and economic performances; (ii) the exploitation of technology alternatives for the energy self-sufficiency of sewage-water treatment plants; (iii) the implementation of new techniques for sewage-sludge management aiming at bioenergy production; and (iv) the implementation of sewage-water treatment with bioenergy production and carbon capture and storage. Full article
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13 pages, 1981 KiB  
Technical Note
Recycling of Industrial Waste Gypsum Using Mineral Carbonation
by Chan-Ung Kang, Sang-Woo Ji and Hwanju Jo
Sustainability 2022, 14(8), 4436; https://doi.org/10.3390/su14084436 - 8 Apr 2022
Cited by 8 | Viewed by 3274
Abstract
Direct mineral carbonation (MC) is used to mitigate carbon dioxide (CO2) emissions. This method has the great advantages of reducing the amount of industrial residues and creating valuable materials by incorporating CO2. Waste gypsum, industrial waste including flue gas [...] Read more.
Direct mineral carbonation (MC) is used to mitigate carbon dioxide (CO2) emissions. This method has the great advantages of reducing the amount of industrial residues and creating valuable materials by incorporating CO2. Waste gypsum, industrial waste including flue gas desulfurization (FGD) gypsum (25.27–53.40 wt% of CaO), and phosphogypsum (30.50–39.06 wt% of CaO) can be used for direct MC (conversion rate up to 96%). Mineral carbonation converts waste gypsum into calcium carbonate (CaCO3), which can be recycled during desulfurization. Furthermore, ammonium sulfate ((NH4)2SO4), which is used as a fertilizer, can be prepared as a by-product when the carbonation reaction is performed using ammonia (NH3) as a base. In this study, recent progress in the carbonation kinetics and preparation of CaCO3 using FGD gypsum and phosphogypsum with NH3 was investigated. Temperature, CO2 partial pressure, CO2 flow rate, and NH3 concentration were reviewed as factors affecting carbonation kinetics and efficiency. The factors influencing the polymorphs of the prepared CaCO3 were also reviewed and summarized. A state-of-the-art bench-scale plant study was also proposed. In addition, economic feasibility was investigated based on a bench-scale study to analyze the future applicability of this technology. Full article
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26 pages, 1259 KiB  
Review
Industrial CO2 Capture by Algae: A Review and Recent Advances
by Tatyana Iglina, Pavel Iglin and Dmitry Pashchenko
Sustainability 2022, 14(7), 3801; https://doi.org/10.3390/su14073801 - 23 Mar 2022
Cited by 55 | Viewed by 21869
Abstract
The problem of global warming and the emission of greenhouse gases is already directly affecting the world’s energy. In the future, the impact of CO2 emissions on the world economy will constantly grow. In this paper, we review the available literature sources [...] Read more.
The problem of global warming and the emission of greenhouse gases is already directly affecting the world’s energy. In the future, the impact of CO2 emissions on the world economy will constantly grow. In this paper, we review the available literature sources on the benefits of using algae cultivation for CO2 capture to decrease CO2 emission. CO2 emission accounts for about 77% of all greenhouse gases, and the calculation of greenhouse gas emissions is 56% of all CO2 imports. As a result of the study of various types of algae, it was concluded that Chlorella sp. is the best at capturing CO2. Various methods of cultivating microalgae were also considered and it was found that vertical tubular bioreactors are emerging. Moreover, for energy purposes, thermochemical methods for processing algae that absorb CO2 from flue gases were considered. Of all five types of thermochemical processes for producing synthesis gas, the most preferred method is the method of supercritical gasification of algae. In addition, attention is paid to the drying and flocculation of biofuels. Several different experiments were also reviewed on the use of flue gases through the cultivation of algae biomass. Based on this literature review, it can be concluded that microalgae are a third generation biofuel. With the absorption of greenhouse gases, the growth of microalgae cultures is accelerated. When a large mass of microalgae appears, it can be used for energy purposes. In the results, we present a plan for further studies of microalgae cultivation, a thermodynamic analysis of gasification and pyrolysis, and a comparison of the results with other biofuels and other algae cultures. Full article
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12 pages, 3701 KiB  
Article
Pilot-Scale Experimental Study of a New High-Loading Absorbent for Capturing CO2 from Flue Gas
by Yi Ye, Xinglei Zhao, Jian Chen and Mengxiang Fang
Processes 2022, 10(3), 599; https://doi.org/10.3390/pr10030599 - 19 Mar 2022
Cited by 5 | Viewed by 2204
Abstract
Chemical absorbents with low-energy requirements have become the primary focus of the research on CO2 capture from flue gas in power plants. To verify the absorption performance of the NICE absorbent developed by the National Institute of Clean-and-Low-Carbon Energy in China, a [...] Read more.
Chemical absorbents with low-energy requirements have become the primary focus of the research on CO2 capture from flue gas in power plants. To verify the absorption performance of the NICE absorbent developed by the National Institute of Clean-and-Low-Carbon Energy in China, a performance optimization test was conducted in Zhejiang University’s pilot-scale platform, and the effects of the liquid–gas ratio, regeneration pressure, rich liquid fractional flow, and interstage cooling on the absorption performance and regeneration energy consumption were investigated. The results showed that in the CO2 pilot test, the optimized minimum regeneration energy consumption was 2.85 GJ/t CO2, and the corresponding process parameters were as follows: a liquid–gas ratio of 1.82 L/m3, regeneration pressure of 191 kPa, an interstage cooling temperature of 40 °C, and a rich liquid fractional flow ratio of 0.18. This study preliminarily verified the low-energy consumption performance of the NICE absorbent and showed its good potential for industrial applications. Additionally, the NICE absorbent showed promise for capital and operating cost savings because of its low liquid–gas ratio. Full article
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11 pages, 1737 KiB  
Article
Direct Dry Carbonation of Mining and Industrial Wastes in a Fluidized Bed for Offsetting Carbon Emissions
by Antonio Coppola, Fabrizio Scala and Mehdi Azadi
Processes 2022, 10(3), 582; https://doi.org/10.3390/pr10030582 - 17 Mar 2022
Cited by 7 | Viewed by 2409
Abstract
The direct dry mineral carbonation of selected mining and industrial wastes, using carbon dioxide derived from combustion flue gas, was evaluated. Specifically, coal fly ash from two Australian brown coal-fired power plants, red mud from the refinement of bauxite into alumina, and diamond [...] Read more.
The direct dry mineral carbonation of selected mining and industrial wastes, using carbon dioxide derived from combustion flue gas, was evaluated. Specifically, coal fly ash from two Australian brown coal-fired power plants, red mud from the refinement of bauxite into alumina, and diamond tailings were considered, due to their relevant residual alkali content. These materials were tested in a laboratory-scale fluidized bed reactor at different temperatures (300–450 °C), in a reactive environment that simulated the typical CO2 concentration in a combustion flue gas. The experimental results showed a low, but still appreciable, CO2 capture capacity for three of the tested materials, which appears to be more favorable in the lower temperature range and with relatively fast kinetics, indicating the practical relevance of the process. One of the fly ashes exhibited a different behavior; starting at 350 °C, the sorbent began to release CO2, rather than absorb it. This suggested that the sorbent was already extensively carbonated by weathering before the tests. This study provides some evidence for the possible viability of recycling mining waste and for the circular economy in offsetting carbon emissions in the mining industry. Full article
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13 pages, 2253 KiB  
Review
Analysis of Korea’s Green Technology Policy and Investment Trends for the Realization of Carbon Neutrality: Focusing on CCUS Technology
by Seok-ho Jung, Hongjin Kim, Youngjun Kang and Eunhoo Jeong
Processes 2022, 10(3), 501; https://doi.org/10.3390/pr10030501 - 2 Mar 2022
Cited by 4 | Viewed by 4676
Abstract
In 2008, the Republic of Korea announced the Low Carbon Green Growth vision as the national growth engine. This Green Growth vision invested in developing state-of-the-art green technologies to minimize greenhouse gas and pollutant emissions. Following a change in administration, Korean green technologies [...] Read more.
In 2008, the Republic of Korea announced the Low Carbon Green Growth vision as the national growth engine. This Green Growth vision invested in developing state-of-the-art green technologies to minimize greenhouse gas and pollutant emissions. Following a change in administration, Korean green technologies were re-categorized into six core technologies for climate change response in 2014, and ten core technologies for carbon-neutrality in 2021. The government proposed the realization of an inclusive green state in the 3rd Five-Year Green Growth Plan announced in 2019. Following the Green New Deal announced in 2020, green technology policies and investments continue, with the declaration of 2050 carbon neutrality. In the past two years, government policies from the 2050 Carbon Neutrality Strategy to the 2050 Carbon-Neutral Scenario consider Carbon Capture Utilization and Storage (CCUS) as an important technology to reduce CO2 and meet carbon-neutral goals. This study examines major green technology policy trends, focusing on CCUS, beginning with the Green Growth era in 2008 to today. R&D investment costs related to green technology during the green growth period and CCUS-related investment costs over the past 10 years (2011–2020) are utilized in statistical analyses (correlation, trend) to investigate and analyze investment volatility in green and CCUS technologies related to climate change. Finally, the study will provide basic information for establishing CCUS-related R&D policies, which will continue to increase in achieving carbon neutrality. Full article
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27 pages, 10117 KiB  
Article
Holistic View on Synthetic Natural Gas Production: A Technical, Economic and Environmental Analysis
by Estefania Vega Puga, Gkiokchan Moumin, Nicole Carina Neumann, Martin Roeb, Armin Ardone and Christian Sattler
Energies 2022, 15(5), 1608; https://doi.org/10.3390/en15051608 - 22 Feb 2022
Cited by 10 | Viewed by 3073
Abstract
Synthetic Natural Gas (SNG) is the most researched option for a Power-to-Fuel pathway in Germany after hydrogen, having the advantage of being compatible with the existing infrastructure. However, it is not clear under which conditions SNG is economically and environmentally advantageous compared to [...] Read more.
Synthetic Natural Gas (SNG) is the most researched option for a Power-to-Fuel pathway in Germany after hydrogen, having the advantage of being compatible with the existing infrastructure. However, it is not clear under which conditions SNG is economically and environmentally advantageous compared to natural gas usage, since this is determined by a complex interplay of many factors. This study analyzes the technical, economic and environmental aspects of a pilot SNG plant to determine the key parameters for profitable and sustainable operation. The SNG plant was simulated in Aspen Plus® with CO2 from biogas production as a feedstock and with hydrogen provided by a 1 MWel electrolyzer unit. A life cycle analysis (LCA) was undertaken considering several impact categories with a special focus on global warming potential (GWP). An SNG cost of 0.33–4.22 €/kWhth was calculated, depending on factors such as operational hours, electricity price and type of electrolyzer. It was found that the CO2 price has a negligible effect on the SNG cost, while the electricity is the main cost driver. This shows that significant cost reductions will be needed for SNG to be competitive with natural gas. For the investigated scenarios, a CO2 tax of at least 1442 €/t was determined, calling for more drastic measures. Considering the global warming potential, only an operation with an emission factor of electricity below 121 g CO2-eq/kWhel leads to a reduction in emissions. This demonstrates that unless renewable energies are implemented at a much higher rate than predicted, no sustainable SNG production before 2050 will be possible in Germany. Full article
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24 pages, 4760 KiB  
Article
CO2 Sequestration through Mineral Carbonation: Effect of Different Parameters on Carbonation of Fe-Rich Mine Waste Materials
by Verma Loretta M. Molahid, Faradiella Mohd Kusin, Sharifah Nur Munirah Syed Hasan, Noor Allesya Alis Ramli and Ahmad Makmom Abdullah
Processes 2022, 10(2), 432; https://doi.org/10.3390/pr10020432 - 21 Feb 2022
Cited by 14 | Viewed by 4625
Abstract
Mineral carbonation is an increasingly popular method for carbon capture and storage that resembles the natural weathering process of alkaline-earth oxides for carbon dioxide removal into stable carbonates. This study aims to evaluate the potential of reusing Fe-rich mine waste for carbon sequestration [...] Read more.
Mineral carbonation is an increasingly popular method for carbon capture and storage that resembles the natural weathering process of alkaline-earth oxides for carbon dioxide removal into stable carbonates. This study aims to evaluate the potential of reusing Fe-rich mine waste for carbon sequestration by assessing the influence of pH condition, particle size fraction and reaction temperature on the carbonation reaction. A carbonation experiment was performed in a stainless steel reactor at ambient pressure and at a low temperature. The results indicated that the alkaline pH of waste samples was suitable for undergoing the carbonation process. Mineralogical analysis confirmed the presence of essential minerals for carbonation, i.e., magnetite, wollastonite, anorthite and diopside. The chemical composition exhibited the presence of iron and calcium oxides (39.58–62.95%) in wastes, indicating high possibilities for carbon sequestration. Analysis of the carbon uptake capacity revealed that at alkaline pH (8–12), 81.7–87.6 g CO2/kg of waste were sequestered. Furthermore, a particle size of <38 µm resulted in 83.8 g CO2/kg being sequestered from Fe-rich waste, suggesting that smaller particle sizes highly favor the carbonation process. Moreover, 56.1 g CO2/kg of uptake capacity was achieved under a low reaction temperature of 80 °C. These findings have demonstrated that Fe-rich mine waste has a high potential to be utilized as feedstock for mineral carbonation. Therefore, Fe-rich mine waste can be regarded as a valuable resource for carbon sinking while producing a value-added carbonate product. This is in line with the sustainable development goals regarding combating global climate change through a sustainable low-carbon industry and economy that can accelerate the reduction of carbon dioxide emissions. Full article
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19 pages, 4352 KiB  
Article
Amine-Functionalized Mesoporous Silica Adsorbent for CO2 Capture in Confined-Fluidized Bed: Study of the Breakthrough Adsorption Curves as a Function of Several Operating Variables
by Rossella Girimonte, Flaviano Testa, Maria Turano, Giuseppe Leone, Marta Gallo and Giovanni Golemme
Processes 2022, 10(2), 422; https://doi.org/10.3390/pr10020422 - 21 Feb 2022
Cited by 6 | Viewed by 3151
Abstract
Carbon capture, utilization, and storage (CCUS) is one of the key promising technologies that can reduce GHG emissions from those industries that generate CO2 as part of their production processes. Compared to other effective CO2 capture methods, the adsorption technique offers [...] Read more.
Carbon capture, utilization, and storage (CCUS) is one of the key promising technologies that can reduce GHG emissions from those industries that generate CO2 as part of their production processes. Compared to other effective CO2 capture methods, the adsorption technique offers the possibility of reducing the costs of the process by setting solid sorbent with a high capacity of adsorption and easy regeneration and, also, controlling the performance of gas-solid contactor. In this work, an amine-functionalized mesoporous sorbent was used to capture CO2 emissions in a confined-fluidized bed. The adoption of a confined environment allows the establishment of a homogeneous expansion regime for the sorbent and allows to improve the exchange of matter and heat between gas and solid phase. The results illustrate how the different concentration of the solution adopted during the functionalization affects the adsorption capacity. That, measured as mg of CO2 per g of sorbent, was determined by breakthrough curves from continuous adsorption tests using different concentrations of CO2 in air. Mesoporous silica functionalized with a concentration of 20% of APTES proves to be the best viable option in terms of cost and ease of preparation, low temperature of regeneration, and effective use for CO2 capture. Full article
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24 pages, 1146 KiB  
Review
Using Real Options Thinking to Value Investment Flexibility in Carbon Capture and Utilization Projects: A Review
by Hanne Lamberts-Van Assche and Tine Compernolle
Sustainability 2022, 14(4), 2098; https://doi.org/10.3390/su14042098 - 12 Feb 2022
Cited by 9 | Viewed by 2702
Abstract
Carbon capture and utilization (CCU) is one of the key technologies that may help to reduce industrial emissions. However, the deployment of CCU is hampered by various barriers, including high levels of technical, policy and market uncertainty. The real options theory (ROT) provides [...] Read more.
Carbon capture and utilization (CCU) is one of the key technologies that may help to reduce industrial emissions. However, the deployment of CCU is hampered by various barriers, including high levels of technical, policy and market uncertainty. The real options theory (ROT) provides a method to account for these uncertainties and introduce flexibility in the investment decision by allowing decisions to be changed in response to the evolution of uncertainties. ROT is already being applied frequently in the evaluation of renewable energy or carbon capture and storage (CCS) projects, e.g., addressing the uncertainty in the price of CO2. However, ROT has only found a few applications in the CCU literature to date. Therefore, this paper investigates the specific types of uncertainty that arise with the utilization of CO2, identifies the types of real options present in CCU projects and discusses the applied valuation techniques. Research gaps are identified in the CCU literature and recommendations are made to fill these gaps. The investment decision sequence for CCU projects is shown, together with the uncertainties and flexibility options in the CCU projects. This review can support the real options-based evaluations of the investment decisions in CCU projects to allow for flexibility and uncertainty. Full article
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21 pages, 4343 KiB  
Article
CO2 Capture and Crystallization of ATH Using Sodium Aluminate Solution in a Bubble Column Scrubber
by Pao-Chi Chen, Shiun-Huang Zhuo and Jyun-Hong Jhuang
Energies 2022, 15(3), 1031; https://doi.org/10.3390/en15031031 - 29 Jan 2022
Cited by 1 | Viewed by 2847
Abstract
In this work, sodium aluminate alkaline solution was used to capture CO2 in a continuous bubble column scrubber and aluminum tri-hydrate (ATH) precipitates were produced. As the sodium carbonate could be recycled after the filtrated solution was crystallized by evaporation, a novel [...] Read more.
In this work, sodium aluminate alkaline solution was used to capture CO2 in a continuous bubble column scrubber and aluminum tri-hydrate (ATH) precipitates were produced. As the sodium carbonate could be recycled after the filtrated solution was crystallized by evaporation, a novel CO2 capture process was developed successfully. There were five experimental operation variables, including solution flow rate (A), concentration of the solution (B), gas flow rate (C), CO2 gas concentration (D), and liquid temperature (E), with four levels to each variable. The influence of each variable on absorption efficiency (EF), absorption rate (RA), absorption factor (φ), mass transfer coefficient (KGa), and precipitation rate (RP) in a steady state was explored in this study. The Taguchi experimental design was adopted, and 16 experiments were performed; as the optimum operating conditions found in Taguchi analysis required further verification, there were a total of 21 experiments in the end. According to S/N analysis, the overall order of importance was D > A = B > C > E, meaning D (CO2 concentration) was most important and E (liquid temperature) was least important. In addition, the result also showed that the Rp was 1.25–2.0 times higher than the RA. The obtained powder was mainly ATH according to XRD analysis, with the crystal size ranging between 8.14 and 27.97 nm. However, the BET analysis showed its particle size range being 17.6–283.7 nm, indicating agglomeration for primary particles. The SEM analysis showed that there were flower-like, irregular, urchin-like, elongated, and amorphous particles. The solutions from five groups of optimum conditions were used to recycle the sodium carbonate experiments. After evaporation and crystallization of the filtrated solutions, the energy loading was found to be 1.70–2.56 GJ/t-solvent, illustrating the superiorities of low energy consumption. The precipitated powders were verified to be sodium carbonate by FTIR, which is a valuable constituent. Full article
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11 pages, 3595 KiB  
Article
Activated Carbon and Coconut Coir with the Incorporation of ABR System as Greywater Filter: The Implications for Wastewater Treatment
by Zakir Sabara, Aswariani Anwar, Setyawati Yani, Kusnul Prianto, Rahmad Junaidi, Rofiqul Umam and Rizqi Prastowo
Sustainability 2022, 14(2), 1026; https://doi.org/10.3390/su14021026 - 17 Jan 2022
Cited by 8 | Viewed by 6735
Abstract
Greywater refers to wastewater generated from domestic activities, which do not contain fecal contamination. Therefore, this study aims to treat greywater in Makassar city to speed up the water cycle and enable reuse, as an environmental conservation strategy. The water parameters measured were [...] Read more.
Greywater refers to wastewater generated from domestic activities, which do not contain fecal contamination. Therefore, this study aims to treat greywater in Makassar city to speed up the water cycle and enable reuse, as an environmental conservation strategy. The water parameters measured were pH, Turbidity, Total Suspended Solid (TSS), Biological Oxygen Demand (BOD), and Chemical Oxygen Demand (COD). According to the results, the greywater’s BOD, COD, and TTS contents were 49.98 to 54.88 mg/L, 509 to 655 mg/L, and 404.40 to 464.65 mg/L, respectively, all of which exceed WHO wastewater quality standards. The use of a wastewater treatment installation comprising a combination of Activated Carbon (AC) and Coconut Coir (CC) with the incorporation of the Anaerobic Baffle Reactor (ABR) system as a greywater filter successfully reduced the city’s greywater pollution. In addition, the new BOD content fulfills the environmentally safe wastewater standards, while the new COD and TSS contents were 152 mg/L to 184 mg/L and 59.68 mg/L to 77.42 mg/L, respectively, which are close to the WHO domestic wastewater quality standards. Full article
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40 pages, 6916 KiB  
Article
Cost and Emissions Reduction in CO2 Capture Plant Dependent on Heat Exchanger Type and Different Process Configurations: Optimum Temperature Approach Analysis
by Solomon Aforkoghene Aromada, Nils Henrik Eldrup and Lars Erik Øi
Energies 2022, 15(2), 425; https://doi.org/10.3390/en15020425 - 7 Jan 2022
Cited by 8 | Viewed by 2769
Abstract
The performance of a plate heat exchanger (PHE), in comparison with the conventional shell and tube types, through a trade-off analysis of energy cost and capital cost resulting from different temperature approaches in the cross-exchanger of a solvent-based CO2 capture process, was [...] Read more.
The performance of a plate heat exchanger (PHE), in comparison with the conventional shell and tube types, through a trade-off analysis of energy cost and capital cost resulting from different temperature approaches in the cross-exchanger of a solvent-based CO2 capture process, was evaluated. The aim was to examine the cost reduction and CO2 emission reduction potentials of the different heat exchangers. Each specific heat exchanger type was assumed for the cross-exchanger, the lean amine cooler and the cooler to cool the direct contact cooler’s circulation water. The study was conducted for flue gases from a natural-gas combined-cycle power plant and the Brevik cement plant in Norway. The standard and the lean vapour compression CO2 absorption configurations were used for the study. The PHE outperformed the fixed tube sheet shell and tube heat exchanger (FTS-STHX) and the other STHXs economically and in emissions reduction. The optimal minimum temperature approach for the PHE cases based on CO2 avoided cost were achieved at 4 °C to 7 °C. This is where the energy consumption and indirect emissions are relatively low. The lean vapour compression CO2 capture process with optimum PHE achieved a 16% reduction in CO2 avoided cost in the cement plant process. When the available excess heat for the production of steam for 50% CO2 capture was considered together with the optimum PHE case of the lean vapour compression process, a cost reduction of about 34% was estimated. That is compared to a standard capture process with FTS-STHX without consideration of the excess heat. This highlights the importance of the waste heat at the Norcem cement plant. This study recommends the use of plate heat exchangers for the cross-heat exchanger (at 4–7 °C), lean amine cooler and the DCC unit’s circulation water cooler. To achieve the best possible CO2 capture process economically and in respect of emissions reduction, it is imperative to perform energy cost and capital cost trade-off analysis based on different minimum temperature approaches. Full article
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16 pages, 4455 KiB  
Article
Spectral and Soil Quality Index for Monitoring Environmental Rehabilitation and Soil Carbon Stock in an Amazonian Sandstone Mine
by Paula Godinho Ribeiro, Gabriel Caixeta Martins, Markus Gastauer, Ediu Carlos da Silva Junior, Diogo Corrêa Santos, Cecílio Frois Caldeira Júnior, Rosane Barbosa Lopes Cavalcante, Douglas Silva dos Santos, Marco Aurélio Carbone Carneiro, Rafael Borges da Silva Valadares, Wilson da Rocha Nascimento Junior, Guilherme Oliveira, Pedro Walfir Martins e Souza Filho and Silvio Junio Ramos
Sustainability 2022, 14(2), 597; https://doi.org/10.3390/su14020597 - 6 Jan 2022
Cited by 7 | Viewed by 3075
Abstract
Rehabilitation is the key factor for improving soil quality and soil carbon stock after mining operations. Monitoring is necessary to evaluate the progress of rehabilitation and its success, but the use of repeated field surveys is costly and time-consuming at a large scale. [...] Read more.
Rehabilitation is the key factor for improving soil quality and soil carbon stock after mining operations. Monitoring is necessary to evaluate the progress of rehabilitation and its success, but the use of repeated field surveys is costly and time-consuming at a large scale. This study aimed to monitor the environmental/soil rehabilitation process of an Amazonian sandstone mine by applying spectral indices for predicting soil organic carbon (SOC) stock and comparing them to soil quality index. The studied area has different chronological rehabilitation stages: initial, intermediate, and advanced with 2, 10, and 12 years of onset rehabilitation activities, respectively. Non-rehabilitated (NR) and two native forest areas (RA) were used as controls. Soil samples were analyzed for physical, chemical, and biological attributes. After determination of Normalized Difference Vegetation Index and Bare Soil Index, simple regression analysis comparing these indices with SOC stock showed a good fit (R2 = 0.82). Rehabilitated areas presented higher soil quality index (~1.50-fold) and SOC stock (~10.6-fold) than NR; however, they did not differ of RA. The use of spectral indices was effective for monitoring the soil quality in this study, with a positive correlation between the predicted SOC stock and the calculated soil quality index. Full article
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65 pages, 9368 KiB  
Review
Application of Porous Materials for CO2 Reutilization: A Review
by Amir Masoud Parvanian, Nasrin Sadeghi, Ahmad Rafiee, Cameron J. Shearer and Mehdi Jafarian
Energies 2022, 15(1), 63; https://doi.org/10.3390/en15010063 - 22 Dec 2021
Cited by 13 | Viewed by 4898
Abstract
CO2 reutilization processes contribute to the mitigation of CO2 as a potent greenhouse gas (GHG) through reusing and converting it into economically valuable chemical products including methanol, dimethyl ether, and methane. Solar thermochemical conversion and photochemical and electrochemical CO2 reduction [...] Read more.
CO2 reutilization processes contribute to the mitigation of CO2 as a potent greenhouse gas (GHG) through reusing and converting it into economically valuable chemical products including methanol, dimethyl ether, and methane. Solar thermochemical conversion and photochemical and electrochemical CO2 reduction processes are emerging technologies in which solar energy is utilized to provide the energy required for the endothermic dissociation of CO2. Owing to the surface-dependent nature of these technologies, their performance is significantly reliant on the solid reactant/catalyst accessible surface area. Solid porous structures either entirely made from the catalyst or used as a support for coating the catalyst/solid reactants can increase the number of active reaction sites and, thus, the kinetics of CO2 reutilization reactions. This paper reviews the principles and application of porous materials for CO2 reutilization pathways in solar thermochemical, photochemical, and electrochemical reduction technologies. Then, the state of the development of each technology is critically reviewed and evaluated with the focus on the use of porous materials. Finally, the research needs and challenges are presented to further advance the implementation of porous materials in the CO2 reutilization processes and the commercialization of the aforementioned technologies. Full article
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23 pages, 6778 KiB  
Article
Influence of Injection Well Location on CO2 Geological Storage Efficiency
by Katarzyna Luboń
Energies 2021, 14(24), 8604; https://doi.org/10.3390/en14248604 - 20 Dec 2021
Cited by 8 | Viewed by 2659
Abstract
An analysis of the influence of injection well location on CO2 storage efficiency was carried out for three well-known geological structures (traps) in deep aquifers of the Lower Jurassic Polish Lowlands. Geological models of the structures were used to simulate CO2 [...] Read more.
An analysis of the influence of injection well location on CO2 storage efficiency was carried out for three well-known geological structures (traps) in deep aquifers of the Lower Jurassic Polish Lowlands. Geological models of the structures were used to simulate CO2 injection at fifty different injection well locations. A computer simulation showed that the dynamic CO2 storage capacity varies depending on the injection well location. It was found that the CO2 storage efficiency for structures with good reservoir properties increases with increasing distance of the injection well from the top of the structure and with increasing depth difference to the top of the structure. The opposite is true for a structure with poor reservoir properties. As the quality of the petrophysical reservoir parameters (porosity and permeability) improves, the location of the injection well becomes more important when assessing the CO2 storage efficiency. Maps of dynamic CO2 storage capacity and CO2 storage efficiency are interesting tools to determine the best location of a carbon dioxide injection well in terms of gas storage capacity. Full article
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21 pages, 8159 KiB  
Article
Thermodynamic and Kinetic Description of the Main Effects Related to the Memory Effect during Carbon Dioxide Hydrates Formation in a Confined Environment
by Federico Rossi, Yan Li and Alberto Maria Gambelli
Sustainability 2021, 13(24), 13797; https://doi.org/10.3390/su132413797 - 14 Dec 2021
Cited by 24 | Viewed by 2369
Abstract
This article consists of an experimental description about how the memory effect intervenes on hydrates formation. In particular, carbon dioxide hydrates were formed in a lab–scale apparatus and in presence of demineralized water and a pure quartz porous medium. The same gas-water mixture [...] Read more.
This article consists of an experimental description about how the memory effect intervenes on hydrates formation. In particular, carbon dioxide hydrates were formed in a lab–scale apparatus and in presence of demineralized water and a pure quartz porous medium. The same gas-water mixture was used. Half of experiments was carried out in order to ensure that the system retained memory of previous processes, while in the other half, such effect was completely avoided. Experiments were characterized thermodynamically and kinetically. The local conditions, required for hydrates formation, were compared with those of equilibrium. Moreover, the time needed for the process completion and the rate constant trend over time, were defined. The study of these parameters, together with the observation that hydrates formation was quantitatively similar in both types of experiments, allowed to conclude that the memory effect mainly acted as kinetic promoter for carbon dioxide hydrates formation. Full article
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19 pages, 5234 KiB  
Article
Simulation and Performance Comparison for CO2 Capture by Aqueous Solvents of N-(2-Hydroxyethyl) Piperazine and Another Five Single Amines
by Simeng Li, Han Li, Yanmei Yu and Jian Chen
Processes 2021, 9(12), 2184; https://doi.org/10.3390/pr9122184 - 3 Dec 2021
Cited by 3 | Viewed by 3344
Abstract
N-(2-Hydroxyethyl) piperazine (HEPZ) has a chemical structure similar to PZ and has less volatility. It is not easy to volatilize in a continuous operation device. It is studied to replace PZ as a promotor to increase the CO2 capture rate. This [...] Read more.
N-(2-Hydroxyethyl) piperazine (HEPZ) has a chemical structure similar to PZ and has less volatility. It is not easy to volatilize in a continuous operation device. It is studied to replace PZ as a promotor to increase the CO2 capture rate. This paper researches the lowest energy consumption and absorbent loss of HEPZ/H2O in the absorption-regeneration process, and compares it with another five amines, including PZ, MEA, 1-MPZ, AMP and DMEA. Based on the thermodynamic model, this work establishes a process simulation based on the equilibrium stage, assuming that all stages of the absorption and desorption towers reach thermodynamic equilibrium and CO2 recovery in the absorption tower is 90%. By optimizing the process parameters, the lowest thermodynamic energy consumption and absorbent loss of process operation are obtained. Our results show that HEPZ as a promotor to replace PZ and MEA has significant economic value. The lowest reboiler energy consumption of HEPZ with the optimal process parameters is 3.018 GJ/tCO2, which is about 35.2% lower than that of PZ and about 11.6% lower than that of MEA, and HEPZ has the lowest solvent loss. The cyclic capacity is 64.7% higher than PZ and 21.6% lower than primary amine MEA. Full article
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18 pages, 315 KiB  
Article
Macroeconomic Factors Influencing Public Policy Strategies for Blue and Green Hydrogen
by Roberto Fazioli and Francesca Pantaleone
Energies 2021, 14(23), 7938; https://doi.org/10.3390/en14237938 - 26 Nov 2021
Cited by 10 | Viewed by 3124
Abstract
The aim of this paper is to analyze the factors affecting hydrogen and Carbon Capture and Storage Technologies (“CCS”) policies, taking into consideration Fossil Fuel Consumption, Oil Reserves, the Debt/GDP Ratio, the Trilemma Index and other variables with respect to OECD countries. STATA [...] Read more.
The aim of this paper is to analyze the factors affecting hydrogen and Carbon Capture and Storage Technologies (“CCS”) policies, taking into consideration Fossil Fuel Consumption, Oil Reserves, the Debt/GDP Ratio, the Trilemma Index and other variables with respect to OECD countries. STATA 17 was used for the analysis. The results confirm the hypothesis that countries with high fossil fuel consumption and oil reserves are investing in blue hydrogen and CCS towards a “zero-carbon-emission” perspective. Moreover, countries with a good Debt/GDP ratio act most favorably to green policies by raising their Public Debt, because Foreign Direct Investments are negatively correlated with those kinds of policies. Future research should exploit Green Finance policy decision criteria on green and blue hydrogen. Full article
12 pages, 601 KiB  
Article
The Kinetics Investigation of CO2 Absorption into TEA and DEEA Amine Solutions Containing Carbonic Anhydrase
by Bin Liu, Zhe Cui and Wende Tian
Processes 2021, 9(12), 2140; https://doi.org/10.3390/pr9122140 - 26 Nov 2021
Cited by 5 | Viewed by 2203
Abstract
Tertiary amines have been used as alternative absorbents for traditional primary and secondary amines in the process of carbon capture. However, the carbon dioxide (CO2) absorption rates in these kinds of amine are relatively slow, which implies greater investment and construction costs and [...] Read more.
Tertiary amines have been used as alternative absorbents for traditional primary and secondary amines in the process of carbon capture. However, the carbon dioxide (CO2) absorption rates in these kinds of amine are relatively slow, which implies greater investment and construction costs and limits the large-scale application of carbon capture. Carbonic anhydrase (CA) is considered to be an ideal homogeneous catalyst for accelerating the rate of CO2 into aqueous amine solution. In this work, CO2 absorption combining CA with two single aqueous tertiary amines, namely triethanolamine (TEA) and 2-(diethylamino)ethanol (DEEA), was studied by use of the stopped-flow apparatus over temperature ranging from 293 to 313 K. The concentrations of selected aqueous amine solution and CA used in the experiment were ranging among 0.1–0.5 kmol/m3 and 0–50 g/m3 , respectively. Compared to the solution without the addition of CA, the pseudo first-order reaction rate in the presence of CA (k0,withCA) is significantly increased. The values of k0,withCA have been calculated by a new kinetics model. The results of experimental and calculated k0,amine and k0,withCA in CO2-amine-H2O solutions were also investigated,respectively. Full article
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13 pages, 2282 KiB  
Article
An Electrochemical Platform for the Carbon Dioxide Capture and Conversion to Syngas
by Alessio Mezza, Angelo Pettigiani, Nicolò B. D. Monti, Sergio Bocchini, M. Amin Farkhondehfal, Juqin Zeng, Angelica Chiodoni, Candido F. Pirri and Adriano Sacco
Energies 2021, 14(23), 7869; https://doi.org/10.3390/en14237869 - 24 Nov 2021
Cited by 5 | Viewed by 2743
Abstract
We report on a simple electrochemical system able to capture gaseous carbon dioxide from a gas mixture and convert it into syngas. The capture/release module is implemented via regeneration of NaOH and acidification of NaHCO3 inside a four-chamber electrochemical flow cell employing [...] Read more.
We report on a simple electrochemical system able to capture gaseous carbon dioxide from a gas mixture and convert it into syngas. The capture/release module is implemented via regeneration of NaOH and acidification of NaHCO3 inside a four-chamber electrochemical flow cell employing Pt foils as catalysts, while the conversion is carried out by a coupled reactor that performs electrochemical reduction of carbon dioxide using ZnO as a catalyst and KHCO3 as an electrolyte. The capture module is optimized such that, powered by a current density of 100 mA/cm2, from a mixture of the CO2–N2 gas stream, a pure and stable CO2 outlet flow of 4–5 mL/min is obtained. The conversion module is able to convert the carbon dioxide into a mixture of gaseous CO and H2 (syngas) with a selectivity for the carbon monoxide of 56%. This represents the first all-electrochemical system for carbon dioxide capture and conversion. Full article
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11 pages, 866 KiB  
Article
Acceptance Sampling Plans from Life Tests Based on Percentiles of New Weibull–Pareto Distribution with Application to Breaking Stress of Carbon Fibers Data
by Mansour Shrahili, Amer I. Al-Omari and Naif Alotaibi
Processes 2021, 9(11), 2041; https://doi.org/10.3390/pr9112041 - 15 Nov 2021
Cited by 6 | Viewed by 1841
Abstract
In this paper, acceptance sampling plans (ASPs) are proposed for the new Weibull-Pareto distribution (NWPD) percentiles assuming truncated life tests at a pre-determined time. The minimum sample sizes essential to assert the specified percentile are calculated for a given consumer’s risk. The operating [...] Read more.
In this paper, acceptance sampling plans (ASPs) are proposed for the new Weibull-Pareto distribution (NWPD) percentiles assuming truncated life tests at a pre-determined time. The minimum sample sizes essential to assert the specified percentile are calculated for a given consumer’s risk. The operating characteristic function values of the developed ASPs and producer’s risk are provided. A real data set related to the breaking stress of carbon fibers data are presented for illustration. Full article
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14 pages, 9240 KiB  
Article
Measurement of Solubility of CO2 in NaCl, CaCl2, MgCl2 and MgCl2 + CaCl2 Brines at Temperatures from 298 to 373 K and Pressures up to 20 MPa Using the Potentiometric Titration Method
by Bo Liu, Barham Sabir Mahmood, Erfan Mohammadian, Abbas Khaksar Manshad, Nor Roslina Rosli and Mehdi Ostadhassan
Energies 2021, 14(21), 7222; https://doi.org/10.3390/en14217222 - 2 Nov 2021
Cited by 14 | Viewed by 3121
Abstract
Understanding the carbon dioxide (CO2) solubility in formation brines is of great importance to several industrial applications, including CO2 sequestration and some CO2 capture technologies, as well as CO2-based enhanced hydrocarbon recovery methods. Despite years of study, [...] Read more.
Understanding the carbon dioxide (CO2) solubility in formation brines is of great importance to several industrial applications, including CO2 sequestration and some CO2 capture technologies, as well as CO2-based enhanced hydrocarbon recovery methods. Despite years of study, there are few literature data on CO2 solubility for the low salinity range. Thus, in this study, the solubility of CO2 in distilled water and aqueous ionic solutions of NaCl, MgCl2, CaCl2 and MgCl2 + CaCl2 were obtained in a low salinity range (0–15,000 ppm) at temperatures from 298–373 K and pressures up to 20 MPa using an accurate and unconventional method called potentiometric titration. An experimental data set of 553 data points was collected using this method. The results of the experiments demonstrate that increasing pressure increases the solubility of CO2 in various brines, whereas increasing temperature and salinity reduces the solubility. The role of different ions in changing the solubility is elaborated through a detailed discussion on the salting-out effect of different ionic solutions. To verify the experimental results of this research, the solubility points obtained by the potentiometric titration method were compared to some of the well-established experimental and analytical data from the literature and a very good agreement with those was obtained. Full article
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25 pages, 5761 KiB  
Review
Circular Carbon Economy (CCE): A Way to Invest CO2 and Protect the Environment, a Review
by Latifah M. Alsarhan, Alhanouf S. Alayyar, Naif B. Alqahtani and Nezar H. Khdary
Sustainability 2021, 13(21), 11625; https://doi.org/10.3390/su132111625 - 21 Oct 2021
Cited by 45 | Viewed by 10150
Abstract
Increased levels of carbon dioxide have revolutionised the Earth; higher temperatures, melting icecaps, and flooding are now more prevalent. Fortunately, renewable energy mitigates this problem by making up 20% of human energy needs. However, from a “green environment” perspective, can carbon dioxide emissions [...] Read more.
Increased levels of carbon dioxide have revolutionised the Earth; higher temperatures, melting icecaps, and flooding are now more prevalent. Fortunately, renewable energy mitigates this problem by making up 20% of human energy needs. However, from a “green environment” perspective, can carbon dioxide emissions in the atmosphere be reduced and eliminated? The carbon economic circle is an ideal solution to this problem, as it enables us to store, use, and remove carbon dioxide. This research introduces the circular carbon economy (CCE) and addresses its economic importance. Additionally, the paper discusses carbon capture and storage (CCS), and the utilisation of CO2. Furthermore, it explains current technologies and their future applications on environmental impact, CO2 capture, utilisation, and storage (CCUS). Various opinions on the best way to achieve zero carbon emissions and on CO2 applications and their economic impact are also discussed. The circular carbon economy can be achieved through a highly transparent global administration that is supportive of advanced technologies that contribute to the efficient utilisation of energy sources. This global administration must also provide facilities to modernise and develop factories and power stations, based on emission-reducing technologies. Monitoring emissions in countries through a global monitoring network system, based on actual field measurements, linked to a worldwide database allows all stakeholders to track the change in greenhouse gas emissions. The process of sequestering carbon dioxide in the ocean is affected by the support for technologies and industries that adopt the principle of carbon recycling in order to maintain the balance. This includes supporting initiatives that contribute to increasing vegetation cover and preserving oceans from pollutants, especially chemicals and radioactive pollutants, which will undoubtedly affect the process of sequestering carbon dioxide in the oceans, and this will contribute significantly to maintaining carbon dioxide at acceptable levels. Full article
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40 pages, 6258 KiB  
Review
New Solvents for CO2 and H2S Removal from Gaseous Streams
by Laura A. Pellegrini, Matteo Gilardi, Fabio Giudici and Elvira Spatolisano
Energies 2021, 14(20), 6687; https://doi.org/10.3390/en14206687 - 15 Oct 2021
Cited by 28 | Viewed by 4429
Abstract
Acid gas removal from gaseous streams such as flue gas, natural gas and biogas is mainly performed by chemical absorption with amines, but the process is highly energy intensive and can generate emissions of harmful compounds to the atmosphere. Considering the emerging interest [...] Read more.
Acid gas removal from gaseous streams such as flue gas, natural gas and biogas is mainly performed by chemical absorption with amines, but the process is highly energy intensive and can generate emissions of harmful compounds to the atmosphere. Considering the emerging interest in carbon capture, mainly associated with increasing environmental concerns, there is much current effort to develop innovative solvents able to lower the energy and environmental impact of the acid gas removal processes. To be competitive, the new blends must show a CO2 uptake capacity comparable to the one of the traditional MEA benchmark solution. In this work, a review of the state of the art of attractive solvents alternative to the traditional MEA amine blend for acid gas removal is presented. These novel solvents are classified into three main classes: biphasic blends—involving the formation of two liquid phases, water-lean solvents and green solvents. For each solvent, the peculiar features, the level of technological development and the main expected pros and cons are discussed. At the end, a summary on the most promising perspectives and on the major limitations is provided. Full article
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13 pages, 2352 KiB  
Article
Control Strategies for Energy Efficiency at PNU’s Metro System
by Wafaa Saleh, Shekaina Justin, Ghada Alsawah, Tasneem Al Ghamdi and Maha M. A. Lashin
Energies 2021, 14(20), 6660; https://doi.org/10.3390/en14206660 - 14 Oct 2021
Cited by 2 | Viewed by 2141
Abstract
It is broadly acknowledged that there is an urgent need to reduce carbon-based mobility systems and increase renewable energy alternatives. The automotive industry is one of the greatest consumers of energy in the world. It is fronted with many challenges that aim at [...] Read more.
It is broadly acknowledged that there is an urgent need to reduce carbon-based mobility systems and increase renewable energy alternatives. The automotive industry is one of the greatest consumers of energy in the world. It is fronted with many challenges that aim at reducing carbon emissions. Renewable energy costs are getting cheaper and more cost effective. However, well devised design and control strategies are also needed in order to optimize any systems that are adopted in this field. Previous research shows that the energy consumption for non-traction purposes may be of the same scale as the energy used to move rolling stock, and in some cases even larger. The Kingdom of Saudi Arabia is very interested in the implementation of policies that aim at reducing energy consumption and encouraging renewable energy programs. Under its Vision 2030 development program, the Kingdom of Saudi Arabia is looking to produce 30% of its energy from renewables and other sources, with solar energy playing an important role. The work presented in this paper is aimed at an investigation of design and control strategies to reduce energy consumption and to propose a cleaner source of energy to power Princess Nourah Bint Abdulrahman University’s Automated People Mover (PNU-APM). Two areas of applications have been investigated for adopting these types of technology. Firstly, a p-v solar energy option that could be adopted for implementation in potential applications since the metro system is already in full operation using electricity. Secondly, design and control strategies including exploiting solar energy for a metro operation are discussed and investigated. A number of strategies to reduce heating, ventilation, and air conditioning (HVAC) load, which happens to be the biggest energy consumer, have been discussed. Results show great potential in energy savings with adopting p-v solar sources as well as implementation of few suggested control strategies. Some deliberations of some of the drawbacks of solar energy are also offered. Full article
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5 pages, 10729 KiB  
Project Report
The Use of CO2 in the Production of Bioplastics for an Even Greener Chemistry
by Drault Fabien, Youssef Snoussi, Ivaldo Itabaiana, Jr. and Robert Wojcieszak
Sustainability 2021, 13(20), 11278; https://doi.org/10.3390/su132011278 - 13 Oct 2021
Cited by 3 | Viewed by 2200
Abstract
The high life expectancy of the world population provokes increase in demand for food and energy. As a result, the intense industrialization and the application of fossil sources is responsible for high levels of CO2 emission and waste generation. To mitigate the [...] Read more.
The high life expectancy of the world population provokes increase in demand for food and energy. As a result, the intense industrialization and the application of fossil sources is responsible for high levels of CO2 emission and waste generation. To mitigate the CO2 emission a practical solution at the very short term is urgently needed. The capture of CO2 and its application in chemical processes for the valorization of residual biomass are of great importance nowadays. The application of CO2 in the selective carboxylation of furoic acid for the production of 2,5-furandicarboxylic acid (FDCA), a bio-based monomer, has been an important step towards obtaining biopolymers to replace petroleum-based plastics such as polyethylene terephthalate (PET). In this project report, we discuss on the current challenges for obtaining the 2,5-FDCA precursor from the furfural in two main routes involving oxidation and carboxylation via heterogeneous catalysis. We present the main objectives and discuss the importance of this research for the development of more sustainable processes. Full article
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23 pages, 6135 KiB  
Article
A Decarbonization Roadmap for Singapore and Its Energy Policy Implications
by Hon Chung Lau, Seeram Ramakrishna, Kai Zhang and Mohamed Ziaudeen Shahul Hameed
Energies 2021, 14(20), 6455; https://doi.org/10.3390/en14206455 - 9 Oct 2021
Cited by 23 | Viewed by 9749
Abstract
As a signatory to the Paris Agreement, Singapore is committed to achieving net-zero carbon emissions in the second half of the century. In this paper, we propose a decarbonization roadmap for Singapore based on an analysis of Singapore’s energy landscape and a technology [...] Read more.
As a signatory to the Paris Agreement, Singapore is committed to achieving net-zero carbon emissions in the second half of the century. In this paper, we propose a decarbonization roadmap for Singapore based on an analysis of Singapore’s energy landscape and a technology mapping exercise. This roadmap consists of four major components. The first component, which also underpins the other three components, is using centralized post-combustion carbon capture technology to capture and compress CO2 emitted from multiple industrial sources in Jurong Island. The captured CO2 is then transported by ship or an existing natural gas pipeline to a neighboring country, where it will be stored permanently in a subsurface reservoir. Important to the success of this first-of-a-kind cross-border carbon capture and storage (CCS) project is the establishment of a regional CCS corridor, which makes use of economies of scale to reduce the cost of CO2 capture, transport, and injection. The second component of the roadmap is the production of hydrogen in a methane steam reforming plant which is integrated with the carbon capture plant. The third component is the modernizing of the refining sector by introducing biorefineries, increasing output to petrochemical plants, and employing post-combustion carbon capture. The fourth component is refueling the transport sector by introducing electric and hydrogen fuel cell vehicles, using biofuels for aviation and hydrogen for marine vessels. The implications of this roadmap on Singapore’s energy policies are also discussed. Full article
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23 pages, 12030 KiB  
Article
Analysis of Reservoir Fluid Migration in the Process of CO2 Sequestration in a Partially Depleted Gas Reservoir
by Wiesław Szott and Krzysztof Miłek
Energies 2021, 14(19), 6398; https://doi.org/10.3390/en14196398 - 6 Oct 2021
Cited by 1 | Viewed by 2129
Abstract
This paper addresses problems of reservoir fluid migrations in the process of CO2 sequestration in a partially depleted petroleum reservoir. A detailed analysis of the migrations is required to obtain fundamental characteristics of a sequestration structure, including estimation of its sequestration capacity [...] Read more.
This paper addresses problems of reservoir fluid migrations in the process of CO2 sequestration in a partially depleted petroleum reservoir. A detailed analysis of the migrations is required to obtain fundamental characteristics of a sequestration structure, including estimation of its sequestration capacity and leakage risks. The paper presents a general discussion of the relevant mechanisms and their contributions to the analysed issues. The proposed approach to solve the problems relies on the usage of numerical structure modelling and simulations of the sequestration processes on numerical models of the structure. It is applied to a selected geological structure comprising a partially depleted gas reservoir. The modelling includes key types of reservoir fluid migrations: viscous multiphase transport and convection transport. It also takes into account other phenomena that affect fluid migrations including injected gas solubility in the formation water and gas trapping by capillary forces. Correspondingly, the leakage risks are associated with distinct leakage pathways (beyond the structural trap, to the caprock, via activated fractures). All these cases are separately modelled and their detailed characteristics are presented and discussed. The final results of the fluid migrations and their consequences for the leakage events are discussed and some generalized conclusions are drawn from the approach employed in the study. Full article
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15 pages, 9050 KiB  
Article
Effects of Bi Substitution on the Cobalt-Free 60wt.%Ce0.9Pr0.1O2−δ-40wt.%Pr0.6Sr0.4Fe1−xBixO3−δ Oxygen Transport Membranes
by Chao Zhang, Yanhao Huang, Lingyong Zeng, Yiyi He, Peifeng Yu and Huixia Luo
Processes 2021, 9(10), 1767; https://doi.org/10.3390/pr9101767 - 1 Oct 2021
Cited by 4 | Viewed by 1767
Abstract
The mixed ionic-electronic conducting (MIEC) oxygen transport membrane (OTM) can completely selectively penetrate oxygen theoretically and can be widely used in gas separation and oxygen-enriched combustion industries. In this paper, dual-phase MIEC OTMs doped with Bi are successfully prepared by a sol-gel method [...] Read more.
The mixed ionic-electronic conducting (MIEC) oxygen transport membrane (OTM) can completely selectively penetrate oxygen theoretically and can be widely used in gas separation and oxygen-enriched combustion industries. In this paper, dual-phase MIEC OTMs doped with Bi are successfully prepared by a sol-gel method with high-temperature sintering, whose chemical formulas are 60wt.%Ce0.9Pr0.1O2−δ-40wt.%Pr0.6Sr0.4Fe1−xBixO3−δ (60CPO-40PSF1−xBxO, x = 0.01, 0.025, 0.05, 0.10, 0.15, 0.20). The dual-phase structure, element content, surface morphology, oxygen permeability, and stability are studied by XRD, EDXS, SEM, and self-built devices, respectively. The optimal Bi-doped component is 60wt.%Ce0.9Pr0.1O2−δ-40wt.%Pr0.6Sr0.4Fe0.99Bi0.01O3−δ, which can maintain 0.71 and 0.62 mL·min−1·cm−2 over 50 h under He and CO2 atmospheres, respectively. The oxygen permeation flux through these Bi-doped OTMs under air/CO2 gradient is 12.7% less than that under air/He gradient, which indicates that the Bi-doped OTMs have comparable oxygen permeability and excellent CO2 tolerance. Full article
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19 pages, 7484 KiB  
Article
Fuel Reactor CFD Multiscale Modelling in Syngas-Based Chemical Looping Combustion with Ilmenite
by Vlad-Cristian Sandu, Ana-Maria Cormos and Calin-Cristian Cormos
Energies 2021, 14(19), 6059; https://doi.org/10.3390/en14196059 - 23 Sep 2021
Cited by 4 | Viewed by 1754
Abstract
As global power generation is currently relying on fossil fuel-based power plants, more anthropogenic CO2 is being released into the atmosphere. During the transition period to alternative energy sources, carbon capture and storage seems to be a promising solution. Chemical-looping combustion (CLC) [...] Read more.
As global power generation is currently relying on fossil fuel-based power plants, more anthropogenic CO2 is being released into the atmosphere. During the transition period to alternative energy sources, carbon capture and storage seems to be a promising solution. Chemical-looping combustion (CLC) is an energy conversion technology designed for combustion of fossil fuel with advantageous carbon capture capabilities. In this work, a 1D computational fluid dynamics (CFD) multiscale model was developed to study the reduction step in a syngas-based CLC system and was validated using literature data (R=0.99). In order to investigate mass transfer effects, flow rate and particle dimension studies were carried out. Sharper mass transfer rates were seen at lower flow rates and smaller granule sizes due to suppression of diffusion limitations. In addition, a 3D CFD particle model was developed to investigate in depth the reduction within an ilmenite particle, with focus on heat transfer effects. Minor differences of 1 K were seen when comparing temperature changes predicted by the two models during the slightly exothermic reduction reaction with syngas. Full article
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34 pages, 3602 KiB  
Review
The Review of Carbon Capture-Storage Technologies and Developing Fuel Cells for Enhancing Utilization
by Nehil Shreyash, Muskan Sonker, Sushant Bajpai, Saurabh Kr Tiwary, Mohd Ashhar Khan, Subham Raj, Tushar Sharma and Susham Biswas
Energies 2021, 14(16), 4978; https://doi.org/10.3390/en14164978 - 13 Aug 2021
Cited by 26 | Viewed by 7467
Abstract
The amount of CO2 released in the atmosphere has been at a continuous surge in the last decade, and in order to protect the environment from global warming, it is necessary to employ techniques like carbon capture. Developing technologies like Carbon Capture [...] Read more.
The amount of CO2 released in the atmosphere has been at a continuous surge in the last decade, and in order to protect the environment from global warming, it is necessary to employ techniques like carbon capture. Developing technologies like Carbon Capture Utilization and Storage aims at mitigating the CO2 content from the air we breathe and has garnered immense research attention. In this review, the authors have aimed to discuss the various technologies that are being used to capture the CO2 from the atmosphere, store it and further utilize it. For utilization, researchers have developed alternatives to make profits from CO2 by converting it into an asset. The development of newer fuel cells that consume CO2 in exchange for electrical power to drive the industries and produce valuable hydrocarbons in the form of fuel has paved the path for more research in the field of carbon utilization. The primary focus on the article is to inspect the environmental and economic feasibility of novel technologies such as fuel cells, different electrochemical processes, and the integration of artificial intelligence and data science in them, which are designed for mitigating the percentage of CO2 in the air. Full article
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21 pages, 6812 KiB  
Article
Characterization of Gold Mining Waste for Carbon Sequestration and Utilization as Supplementary Cementitious Material
by Sharifah Nur Munirah Syed Hasan, Faradiella Mohd Kusin, Nik Norsyahariati Nik Daud, Muhammad Anwar Saadon, Ferdaus Mohamat-Yusuff and Zulfa Hanan Ash’aari
Processes 2021, 9(8), 1384; https://doi.org/10.3390/pr9081384 - 9 Aug 2021
Cited by 6 | Viewed by 3126
Abstract
This study aims to identify the potential of gold mining waste for CO2 sequestration and its utilization for carbon storage in cementitious material. Samples of mine waste were identified from a gold mine for mineralogical and chemical composition analysis using X-ray diffractogram [...] Read more.
This study aims to identify the potential of gold mining waste for CO2 sequestration and its utilization for carbon storage in cementitious material. Samples of mine waste were identified from a gold mine for mineralogical and chemical composition analysis using X-ray diffractogram and scanning electron microscopy with energy-dispersive X-ray. Mine waste was utilized in a brick-making process as supplementary cementitious material and as an agent for CO2 capture and storage in bricks. Carbonation curing was incorporated in brick fabrication to estimate CO2 uptake of the brick product. Results indicated that the mine wastes were composed of silicate minerals essential for mineral carbonation such as muscovite and illite (major) and chlorite-serpentine, aerinite, albite and stilpnomelane (moderate/minor phases). The mine wastes were identified as belonging to the highly pozzolanic category, which has a great role in improving the strength properties of brick products. Carbonated minerals served as an additional binder that increased the strength of the product. CO2 uptake of the product was between 0.24% and 0.57% for bricks containing 40–60% of gold mine waste, corresponding to 7.2–17.1 g CO2/brick. Greater performance in terms of compressive strength and water adsorption was observed for bricks with 3 h carbonation curing. The carbonation product was evidenced by strong peaks of calcite and reduced peaks for calcium hydroxide from XRD analysis and was supported by a densified and crystalline microstructure of materials. It has been demonstrated that gold mine waste is a potential feedstock for mineral carbonation, and its utilization for permanent carbon storage in brick making is in line with the concept of CCUS for environmental sustainability. Full article
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16 pages, 2462 KiB  
Article
CO2-Derived Carbon Capture Using Microalgae and Sodium Bicarbonate in a PhotoBioCREC Unit: Kinetic Modeling
by Maureen Cordoba-Perez and Hugo de Lasa
Processes 2021, 9(8), 1296; https://doi.org/10.3390/pr9081296 - 27 Jul 2021
Cited by 3 | Viewed by 2625
Abstract
By converting bicarbonates via Chlorella vulgaris photosynthesis, one can obtain valuable biofuel products and find a route toward carbon-derived fossil fuel conversion into renewable carbon. In this research, experiments were carried out in the PhotoBioCREC prototype under controlled radiation and high mixing conditions. [...] Read more.
By converting bicarbonates via Chlorella vulgaris photosynthesis, one can obtain valuable biofuel products and find a route toward carbon-derived fossil fuel conversion into renewable carbon. In this research, experiments were carried out in the PhotoBioCREC prototype under controlled radiation and high mixing conditions. Sodium bicarbonate (NaHCO3) was supplied as the inorganic carbon-containing species, at different concentrations, in the 18 to 60 mM range. Both the NaHCO3 concentrations and the organic carbon concentrations were quantified periodically during microalgae culture, with the pH being readjusted every day to the 7.00 level. It was found that sodium bicarbonate was converted with a selectivity up to 33.0% ± 2.0 by Chlorella vulgaris. It was also observed that the reaction rate constant for inorganic carbon conversion was 0.26 ± 0.09 day1, while the maximum reaction rate constant for organic carbon formation was achieved with a 28 mM NaHCO3 concentration and displayed a 1.18 ± 0.05 mmole L1day1 value. Full article
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12 pages, 5350 KiB  
Article
Co-Production of Hydrogen and Methanol Using Fuel Mix Systems: Technical and Economic Assessment
by Usama Ahmed, Umer Zahid, Sagheer A. Onaizi, Abdul Gani Abdul Jameel, Nauman Ahmad, Nabeel Ahmad and Hamad AlMohamadi
Appl. Sci. 2021, 11(14), 6577; https://doi.org/10.3390/app11146577 - 17 Jul 2021
Cited by 7 | Viewed by 2968
Abstract
With the increase in global energy requirements, the utilization of fossil fuels has also increased, which has caused global warming. In this study, a process integration framework based on an energy mix system is proposed to simultaneously produce two cleaner fuels (methanol and [...] Read more.
With the increase in global energy requirements, the utilization of fossil fuels has also increased, which has caused global warming. In this study, a process integration framework based on an energy mix system is proposed to simultaneously produce two cleaner fuels (methanol and H2). Aspen Plus is used to develop process models followed by their techno-economic assessment. Case 1 is considered the base case process, where the coal–biomass gasification process is used to produce the synthesis gas, which is further converted into H2 and methanol. Conversely, the case 2 design represents the novel process configuration framework, where the coal–biomass gasification technology in case 1 is sequentially integrated with the methane reforming technology to minimize the energy penalties while increasing the net fuel production. To perform the technical analysis, the fuel production rates, carbon conversion efficiencies and specific energy requirements are compared for both models. It is analyzed from the results that the case 2 design offers higher methanol and H2 production rates with lower energy requirements. Additionally, the specific energy requirement for case 2 is 29% lower compared to the case 1 design, leading to an increase in the process efficiency of case 2 by 3.5%. Full article
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24 pages, 5198 KiB  
Article
Environmental Performance of Alternative Green Polyol Synthesis Routes: A Proposal for Improvement
by Kaccnny Carvalho, Rita M. B. Alves and Luiz Kulay
Processes 2021, 9(7), 1122; https://doi.org/10.3390/pr9071122 - 28 Jun 2021
Cited by 5 | Viewed by 3353
Abstract
This study verified the environmental effectiveness of potentially less aggressive routes for the synthesis of poly(propylene/ethylene oxide) glycol (PPG). The analysis was developed in two stages. Firstly, the environmental performance of the conventional PPG processing route was compared to alternative variants—vegetal PPG and [...] Read more.
This study verified the environmental effectiveness of potentially less aggressive routes for the synthesis of poly(propylene/ethylene oxide) glycol (PPG). The analysis was developed in two stages. Firstly, the environmental performance of the conventional PPG processing route was compared to alternative variants—vegetal PPG and CO2-based PPG—applying the life cycle assessment technique to measure the primary energy demand, global warming potential, acidification, photochemical oxidation, and freshwater ecotoxicity impact categories. The synthesis of vegetable polyols from bio-based assets, such as vegetable oils, and the application of CO2 conversion routes as an alternative to technologies supported by petroleum and natural gas were studied. The use of CO2 recovered through carbon capture and usage practices resulted in environmental gains for PPG production. The processing routes within vegetal assets were not an environmentally attractive option as the performance was worse than the conventional arrangement by 144% for the global warming impact category, an increase related to the deforestation carried out to expand soybean cultivation in Brazil. Secondly, improvement scenarios to mitigate the environmental impacts of alternative routes were performed. The hypothesis of using cleaner inputs to obtain a more ecofriendly route was tested. The analysis concluded that the use of high-purity CO2 brings fewer benefits compared to other capturing sources that need a purification process before feeding the PPG synthesis. Full article
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