Bioenergy Technologies

Editor


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Collection Editor
1. Faculty of Engineering, Universidade Lusófona, 1749-024 Lisboa, Portugal
2. iBB – Institute for Bioengineering and Biosciences, Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, 1649-004 Lisboa, Portugal
Interests: biocatalysis; bioreactors; bioprocess engineering
Special Issues, Collections and Topics in MDPI journals

Topical Collection Information

Dear Colleagues,

The significantly escalating global energy demand is caused by industrial activity in developed and developing countries, growing transportation fuel requirements and the population increase. The scarcity of conventional sources of energy, instability in gas and oil regions and concomitant fluctuations in gas/oil-based energy prices, alarming greenhouse gas emissions and soaring air pollution have prompted dedicated and widespread research efforts in developing bioenergy technologies to cope with such an energy demand. This trend has been substantially boosted recently and is foreseen as a sustainable, environmentally friendly approach for the intended goal that, moreover, fits within the concept of the circular economy concept, later largely fostered in several contexts such as the UN 2030 Agenda for Sustainable Development.

Bioenergy processes anchor on the translation of organic material (e.g., agro-forestry, industrial and municipal waste) into either an end-product (e.g., biodiesel, hydrogen and syngas) used to produce energy, or directly into electricity (e.g., microbial fuel cells). The implementation of bioenergy processes relies on either biochemical or thermochemical-based approaches, both  having recently experienced major advances.

This Topical Collection looks for original contributions regarding technological developments focused on the production of energy from biomass or/and organic waste, and its assessment in a circular economy context. Topics include, but are not limited to, bio-based processes for the conversion of organic material, e.g., alcoholic fermentation, anaerobic digestion, microbial fuel cells, photobiologic hydrogen synthesis and transesterification; the thermo-chemical conversion of organic materials, e.g., direct combustion, gasification, liquefaction and pyrolysis; bioenergy production and the economic/environmental impacts.

Dr. Pedro Fernandes
Collection Editor

Manuscript Submission Information

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Keywords

  • bioenergy
  • biofuels
  • bioelectricity
  • circular bioeconomy
  • life cycle assessment

Published Papers (4 papers)

2024

Jump to: 2023, 2022

18 pages, 1889 KiB  
Article
Biogas as Alternative to Liquefied Petroleum Gas in Mauritania: An Integrated Future Approach for Energy Sustainability and Socio-Economic Development
by Sidahmed Sidi Habib and Shuichi Torii
Clean Technol. 2024, 6(2), 453-470; https://doi.org/10.3390/cleantechnol6020023 - 11 Apr 2024
Viewed by 548
Abstract
The global shift from conventional energy sources to sustainable alternatives has garnered significant attention, driven by the promise of economic benefits and environmental sustainability. The current study rigorously investigated the economic advantages and sustainability achieved from the transition of households in Mauritania from [...] Read more.
The global shift from conventional energy sources to sustainable alternatives has garnered significant attention, driven by the promise of economic benefits and environmental sustainability. The current study rigorously investigated the economic advantages and sustainability achieved from the transition of households in Mauritania from liquefied petroleum gas (LPG) to biogas utilization. The study constitutes a robust case study that centers on assessing the multifaceted impacts of this transition on household finances and overall quality of life in Mauritania. This case focuses on biogas technology adoption and its role as a competitor of LPG in Mauritania. The energy poverty portfolio of the nation has been explored and livestock waste generation and biogas production potential have been estimated at 2451 million cubic meters annually. Biogas production can fulfill 50% of the energy requirement for cooking purposes within the country. The community scale fixed-dome-type biogas digesters have been recommended for Mauritania by considering a community of 100 families. The calculated payback period for the community project is 74 months, and after the payback period, continuous monthly benefits of USD 1750 will be started. Livestock manure is directly utilized for farming practices in Mauritania, which produces 10.7 Gg of methane emissions per year. Biogas production is a clean and economically viable option for Mauritania, which can also be beneficial for reducing the methane emissions footprints of the livestock sector. This case study will prove as a vital project for other African nations if successfully implemented. Multiple recommendations for the policy-makers of Mauritania have also been formulated, like tariffs on biogas production facilities and swift financing schemes, which can further strengthen the biogas production on a national scale. International funders should also take part in coping with the energy demand of Mauritania and its mission to mitigate climate change rather than utilizing LPG on a national scale. Biogas production and utilization are much cheaper compared with the fluctuating prices of LPG and ensure health when cooking. Full article
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2023

Jump to: 2024, 2022

12 pages, 1254 KiB  
Article
Eco-Friendly Cement Mortar with Wastewater Treatment Plant Sludge Upcycling
by Thais Theomaris Grabowski, Juliana Martins Teixeira de Abreu Pietrobelli and Ramiro José Espinheira Martins
Clean Technol. 2023, 5(3), 961-972; https://doi.org/10.3390/cleantechnol5030048 - 02 Aug 2023
Viewed by 1606
Abstract
This study aimed to investigate the technical feasibility of replacing cement in mortar production with sludge generated in wastewater treatment plants (WWTPs), prepared using different treatments. The sludge used in the experiments was processed using four different methods to investigate the effect of [...] Read more.
This study aimed to investigate the technical feasibility of replacing cement in mortar production with sludge generated in wastewater treatment plants (WWTPs), prepared using different treatments. The sludge used in the experiments was processed using four different methods to investigate the effect of processing on the mechanical strength of the specimens. The sludge was then mixed with mortar in different proportions, and samples were produced for flexural and compressive strength tests. The results showed that specimens with 7% sludge from the burned treatment exhibited the highest resistance, surpassing the standard. Specimens with sludge from the drying treatments showed similar results. This study found that using sludge in mortar production could lead to energy savings compared to traditional cement production methods. Moreover, the incorporation of sludge resulted in mortars that met the specifications of the EN 998-1:2018 standard, thereby indicating their technical feasibility. Therefore, this study demonstrated the potential of using sludge from WWTPs as a substitute for cement in mortar production, which could contribute to the reduction in the environmental impacts caused by civil construction and the development of sustainable alternatives for the disposal of sludge generated in WWTPs. Full article
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15 pages, 7040 KiB  
Article
Use of Propyl Gallate in Cardoon Biodiesel to Keep Its Main Properties during Oxidation
by Sergio Nogales-Delgado, Agustina Guiberteau Cabanillas, Juan Pedro Moro and José María Encinar Martín
Clean Technol. 2023, 5(2), 569-583; https://doi.org/10.3390/cleantechnol5020029 - 02 May 2023
Cited by 2 | Viewed by 1681
Abstract
The use of alternatives for petroleum-based products is becoming more and more important, especially considering the new and constantly changing geopolitical context, where excessive energy dependence is not desirable. Thus, biodiesel could play an important role in contributing to the implementation of biorefineries, [...] Read more.
The use of alternatives for petroleum-based products is becoming more and more important, especially considering the new and constantly changing geopolitical context, where excessive energy dependence is not desirable. Thus, biodiesel could play an important role in contributing to the implementation of biorefineries, which represent desirable goals in terms of sustainability, green chemistry and the circular economy. However, one challenge related to biodiesel based on vegetable oils is its low oxidative stability, which can alter the properties of these products during storage. To avoid this problem, interesting antioxidants, such as propyl gallate (PG), could be added to biodiesel to allow it to keep its main properties during oxidation. Additionally, monitoring PG content during oxidation is interesting, and the use of voltammetry could be suitable for this purpose. The aim of this work was to assess the effectiveness of PG during cardoon biodiesel oxidation, while monitoring the process through cyclic voltammetry (CV). As a result, it was proven that PG was highly effective, increasing the length of oxidative stability to more than 10 h at low concentrations (600 mg·L−1) and retaining its main properties (viscosity and acidity) during oxidation. Regarding CV, this technique was successfully optimized to determine PG concentration in cardoon biodiesel during oxidation. Full article
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2022

Jump to: 2024, 2023

18 pages, 6927 KiB  
Article
Steam Explosion Pre-Treatment of Sawdust for Biofuel Pellets
by Peyman Alizadeh, Tim Dumonceaux, Lope G. Tabil, Edmund Mupondwa, Majid Soleimani and Duncan Cree
Clean Technol. 2022, 4(4), 1175-1192; https://doi.org/10.3390/cleantechnol4040072 - 15 Nov 2022
Cited by 6 | Viewed by 2702
Abstract
The current study explores steam explosion pre-treatment of wood sawdust to develop high-quality biofuel pellets. In order to determine optimized conditions (temperature and residence time) for steam-treated biomass, seven test responses were chosen, including bulk, particle and pellet densities as well as tensile [...] Read more.
The current study explores steam explosion pre-treatment of wood sawdust to develop high-quality biofuel pellets. In order to determine optimized conditions (temperature and residence time) for steam-treated biomass, seven test responses were chosen, including bulk, particle and pellet densities as well as tensile strength, dimensional stability, ash content and higher heating value (HHV). Parameters tested for steam treatment process included the combination of temperatures 180, 200 and 220 °C and durations of 3, 6 and 9 min. Results showed that when the severity of steam pre-treatment increased from 2.83 to 4.49, most of the qualities except HHV and ash content were favorable for steam pretreated materials. The pellet density of pretreated sawdust in comparison to raw sawdust resulted in 20% improvement (1262 kg/m3 for pretreated material compared with 1049 kg/m3 for non-treated material). Another important factor in determining the best pellet quality is tensile strength, which can be as high as 5.59 MPa for pretreated pellets compared with 0.32 MPa for non-treated pellets. As a result, transportation and handling properties can be enhanced for steam pretreated biomass pellets. After optimization, the selected treatment was analyzed for elemental and chemical composition. Lower nitrogen and sulfur contents compared with fossil fuels make steam pretreated pellets a cleaner option for home furnaces and industrial boilers. High-quality pellets were produced based on optimized pre-treatment conditions and are therefore suggested for bioenergy applications. Full article
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