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19 pages, 1589 KiB

Open AccessArticle

Conventional and Advanced Exergy and Exergoeconomic Analysis of a Spray Drying System: A Case Study of an Instant Coffee Factory in Ecuador

by Diana L. Tinoco-Caicedo, Alexis Lozano-Medina and Ana M. Blanco-Marigorta

Energies 2020, 13(21), 5622; https://doi.org/10.3390/en13215622 - 27 Oct 2020

Cited by 14 | Viewed by 3566

Abstract

Instant coffee is produced worldwide by spray drying coffee extract on an industrial scale. This production process is energy intensive, 70% of the operational costs are due to energy requirements. This study aims to identify the potential for energy and cost improvements by [...] Read more.

Instant coffee is produced worldwide by spray drying coffee extract on an industrial scale. This production process is energy intensive, 70% of the operational costs are due to energy requirements. This study aims to identify the potential for energy and cost improvements by performing a conventional and advanced exergy and exergoeconomic analysis to an industrial-scale spray drying process for the production of instant coffee, using actual operational data. The study analyzed the steam generation unit, the air and coffee extract preheater, the drying section, and the final post treatment process. The performance parameters such as exergetic efficiency, exergoeconomic factor, and avoidable investment cost rate for each individual component were determined. The overall energy and exergy efficiencies of the spray drying system are 67.6% and 30.6%, respectively. The highest rate of exergy destruction is located in the boiler, which amounts to 543 kW. However, the advanced exergoeconomic analysis shows that the highest exergy destruction cost rates are located in the spray dryer and the air heat exchanger (106.9 $/h and 60.5 $/h, respectively), of which 47.7% and 3.8%, respectively, are avoidable. Accordingly, any process improvement should focus on the exergoeconomic optimization of the spray dryer. Full article

(This article belongs to the Special Issue Enhancement of Industrial Energy Efficiency and Sustainability)

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26 pages, 2827 KiB

Open AccessArticle

Potential and Impacts of Cogeneration in Tropical Climate Countries: Ecuador as a Case Study

by Manuel Raul Pelaez-Samaniego, Juan L. Espinoza, José Jara-Alvear, Pablo Arias-Reyes, Fernando Maldonado-Arias, Patricia Recalde-Galindo, Pablo Rosero and Tsai Garcia-Perez

Energies 2020, 13(20), 5254; https://doi.org/10.3390/en13205254 - 10 Oct 2020

Cited by 2 | Viewed by 3408

Abstract

High dependency on fossil fuels, low energy efficiency, poor diversification of energy sources, and a low rate of access to electricity are challenges that need to be solved in many developing countries to make their energy systems more sustainable. Cogeneration has been identified [...] Read more.

High dependency on fossil fuels, low energy efficiency, poor diversification of energy sources, and a low rate of access to electricity are challenges that need to be solved in many developing countries to make their energy systems more sustainable. Cogeneration has been identified as a key strategy for increasing energy generation capacity, reducing greenhouse gas (GHG) emissions, and improving energy efficiency in industry, one of the most energy-demanding sectors worldwide. However, more studies are necessary to define approaches for implementing cogeneration, particularly in countries with tropical climates (such as Ecuador). In Ecuador, the National Plan of Energy Efficiency includes cogeneration as one of the four routes for making energy use more sustainable in the industrial sector. The objective of this paper is two-fold: (1) to identify the potential of cogeneration in the Ecuadorian industry, and (2) to show the positive impacts of cogeneration on power generation capacity, GHG emissions reduction, energy efficiency, and the economy of the country. The study uses methodologies from works in specific types of industrial processes and puts them together to evaluate the potential and analyze the impacts of cogeneration at national level. The potential of cogeneration in Ecuador is ~600 MW_el, which is 12% of Ecuador’s electricity generation capacity. This potential could save ~18.6 × 10⁶ L/month of oil-derived fuels, avoiding up to 576,800 tCO₂/year, and creating around 2600 direct jobs. Cogeneration could increase energy efficiency in the Ecuadorian industry by up to 40%. Full article

(This article belongs to the Special Issue Enhancement of Industrial Energy Efficiency and Sustainability)

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31 pages, 4161 KiB

Open AccessArticle

Establishing Energy Efficiency—Drivers for Energy Efficiency in German Manufacturing Small- and Medium-Sized Enterprises

by Werner König, Sabine Löbbe, Stefan Büttner and Christian Schneider

Energies 2020, 13(19), 5144; https://doi.org/10.3390/en13195144 - 02 Oct 2020

Cited by 20 | Viewed by 3080

Abstract

Despite strong political efforts in Europe, industrial small- and medium-sized enterprises (SMEs) seem to neglect adopting practices for energy efficiency. By taking a cultural perspective, this study investigated what drives the establishment of energy efficiency and corresponding practices in SMEs. Based on 10 [...] Read more.

Despite strong political efforts in Europe, industrial small- and medium-sized enterprises (SMEs) seem to neglect adopting practices for energy efficiency. By taking a cultural perspective, this study investigated what drives the establishment of energy efficiency and corresponding practices in SMEs. Based on 10 ethnographic case studies and a quantitative survey among 500 manufacturing SMEs, the results indicate the importance of everyday employee behavior in achieving energy savings. The studied enterprises value behavior-related measures as similarly important as technical measures. Raising awareness for energy issues within the organization, therefore, constitutes an essential leadership task that is oftentimes perceived as challenging and frustrating. It was concluded that the embedding of energy efficiency in corporate strategy, the use of a broad spectrum of different practices, and the empowerment and involvement of employees serve as major drivers in establishing energy efficiency within SMEs. Moreover, the findings reveal institutional influences on shaping the meanings of energy efficiency for the SMEs by raising attention for energy efficiency in the enterprises and making energy efficiency decisions more likely. The main contribution of the paper is to offer an alternative perspective on energy efficiency in SMEs beyond the mere adoption of energy-efficient technology. Full article

(This article belongs to the Special Issue Enhancement of Industrial Energy Efficiency and Sustainability)

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51 pages, 553 KiB

Open AccessArticle

Identification and Categorization of Factors Affecting the Adoption of Energy Efficiency Measures within Compressed Air Systems

by Andrea Trianni, Davide Accordini and Enrico Cagno

Energies 2020, 13(19), 5116; https://doi.org/10.3390/en13195116 - 01 Oct 2020

Cited by 7 | Viewed by 2457

Abstract

Understanding the factors driving the implementation of energy efficiency measures in compressed air systems is crucial to improve industrial energy efficiency, given their low implementation rate. Starting from a thorough review of the literature, it is thus clear the need to support companies [...] Read more.

Understanding the factors driving the implementation of energy efficiency measures in compressed air systems is crucial to improve industrial energy efficiency, given their low implementation rate. Starting from a thorough review of the literature, it is thus clear the need to support companies in the decision-making process by offering an innovative framework encompassing the most relevant factors to be considered when adopting energy efficiency measures in compressed air systems, inclusive of the impacts on the production resources and the operations of a company. The framework, designed following the perspective of the industrial decision-makers, has been validated, both theoretically and empirically, and preliminarily applied to a heterogeneous cluster of manufacturing industries. Results show that, beside operational, energetic, and economic factors, in particular contextual factors such as complexity, compatibility, and observability may highlight critical features of energy efficiency measures whose absence may change the outcome of a decision-making process. Further, greater awareness and knowledge over the important factors given by the implementation of the framework could play an important role in fostering the implementation of energy efficiency measures in compressed air systems. The paper concludes with further research avenues to further promote energy efficiency and sustainability oriented practices in the industrial sector. Full article

(This article belongs to the Special Issue Enhancement of Industrial Energy Efficiency and Sustainability)

22 pages, 6213 KiB

Open AccessArticle

Multi-Agent Cooperation Based Reduced-Dimension Q(λ) Learning for Optimal Carbon-Energy Combined-Flow

by Huazhen Cao, Chong Gao, Xuan He, Yang Li and Tao Yu

Energies 2020, 13(18), 4778; https://doi.org/10.3390/en13184778 - 14 Sep 2020

Cited by 1 | Viewed by 1674

Abstract

This paper builds an optimal carbon-energy combined-flow (OCECF) model to optimize the carbon emission and energy losses of power grids simultaneously. A novel multi-agent cooperative reduced-dimension Q(λ) (MCR-Q(λ)) is proposed for solving the model. Firstly, on the basis of the traditional single-objective Q(λ) [...] Read more.

This paper builds an optimal carbon-energy combined-flow (OCECF) model to optimize the carbon emission and energy losses of power grids simultaneously. A novel multi-agent cooperative reduced-dimension Q(λ) (MCR-Q(λ)) is proposed for solving the model. Firstly, on the basis of the traditional single-objective Q(λ) algorithm, the solution space is reduced effectively to shrink the size of Q-value matrices. Then, based on the concept of ant cooperative cooperation, multi-agents are used to update the Q-value matrices iteratively, which can significantly improve the updating rate. The simulation in the IEEE 118-bus system indicates that the proposed technique can decrease the convergence speed by hundreds of times as compared with conventional Q(λ), keeping high global stability, which is very suitable for dynamic OCECF in a large and complex power grid compared with other algorithms. Full article

(This article belongs to the Special Issue Enhancement of Industrial Energy Efficiency and Sustainability)

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40 pages, 2789 KiB

Open AccessArticle

Roadmap for Decarbonization of the Building and Construction Industry—A Supply Chain Analysis Including Primary Production of Steel and Cement

by Ida Karlsson, Johan Rootzén, Alla Toktarova, Mikael Odenberger, Filip Johnsson and Lisa Göransson

Energies 2020, 13(16), 4136; https://doi.org/10.3390/en13164136 - 10 Aug 2020

Cited by 25 | Viewed by 8722

Abstract

Sweden has committed to reducing greenhouse gas (GHG) emissions to net-zero by 2045. Around 20% of Sweden’s annual CO₂ emissions arise from manufacturing, transporting, and processing of construction materials for construction and refurbishment of buildings and infrastructure. In this study, material and [...] Read more.

Sweden has committed to reducing greenhouse gas (GHG) emissions to net-zero by 2045. Around 20% of Sweden’s annual CO₂ emissions arise from manufacturing, transporting, and processing of construction materials for construction and refurbishment of buildings and infrastructure. In this study, material and energy flows for building and transport infrastructure construction is outlined, together with a roadmap detailing how the flows change depending on different technical and strategical choices. By matching short-term and long-term goals with specific technology solutions, these pathways make it possible to identify key decision points and potential synergies, competing goals, and lock-in effects. The results show that it is possible to reduce CO₂ emissions associated with construction of buildings and transport infrastructure by 50% to 2030 applying already available measures, and reach close to zero emissions by 2045, while indicating that strategic choices with respect to process technologies and energy carriers may have different implications on energy use and CO₂ emissions over time. The results also illustrate the importance of intensifying efforts to identify and manage both soft and hard barriers and the importance of simultaneously acting now by implementing available measures (e.g., material efficiency and material/fuel substitution measures), while actively planning for long-term measures (low-CO₂ steel or cement). Full article

(This article belongs to the Special Issue Enhancement of Industrial Energy Efficiency and Sustainability)

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18 pages, 2457 KiB

Open AccessArticle

Pathways for Low-Carbon Transition of the Steel Industry—A Swedish Case Study

by Alla Toktarova, Ida Karlsson, Johan Rootzén, Lisa Göransson, Mikael Odenberger and Filip Johnsson

Energies 2020, 13(15), 3840; https://doi.org/10.3390/en13153840 - 27 Jul 2020

Cited by 64 | Viewed by 7735

Abstract

The concept of techno-economic pathways is used to investigate the potential implementation of CO₂ abatement measures over time towards zero-emission steelmaking in Sweden. The following mitigation measures are investigated and combined in three pathways: top gas recycling blast furnace (TGRBF); carbon capture [...] Read more.

The concept of techno-economic pathways is used to investigate the potential implementation of CO₂ abatement measures over time towards zero-emission steelmaking in Sweden. The following mitigation measures are investigated and combined in three pathways: top gas recycling blast furnace (TGRBF); carbon capture and storage (CCS); substitution of pulverized coal injection (PCI) with biomass; hydrogen direct reduction of iron ore (H-DR); and electric arc furnace (EAF), where fossil fuels are replaced with biomass. The results show that CCS in combination with biomass substitution in the blast furnace and a replacement primary steel production plant with EAF with biomass (Pathway 1) yield CO₂ emission reductions of 83% in 2045 compared to CO₂ emissions with current steel process configurations. Electrification of the primary steel production in terms of H-DR/EAF process (Pathway 2), could result in almost fossil-free steel production, and Sweden could achieve a 10% reduction in total CO₂ emissions. Finally, (Pathway 3) we show that increased production of hot briquetted iron pellets (HBI), could lead to decarbonization of the steel industry outside Sweden, assuming that the exported HBI will be converted via EAF and the receiving country has a decarbonized power sector. Full article

(This article belongs to the Special Issue Enhancement of Industrial Energy Efficiency and Sustainability)

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12 pages, 4780 KiB

Open AccessArticle

Heat Transfer Characteristics of High-Temperature Dusty Flue Gas from Industrial Furnaces in a Granular Bed with Buried Tubes

by Shaowu Yin, Feiyang Xue, Xu Wang, Lige Tong, Li Wang and Yulong Ding

Energies 2020, 13(14), 3589; https://doi.org/10.3390/en13143589 - 11 Jul 2020

Viewed by 1930

Abstract

Experimental heat transfer equipment with a buried tube granular bed was set up for waste heat recovery of flue gas. The effects of flue gas inlet temperature (1096.65–1286.45 K) and cooling water flow rate (2.6–5.1 m³/h) were studied through experiment and [...] Read more.

Experimental heat transfer equipment with a buried tube granular bed was set up for waste heat recovery of flue gas. The effects of flue gas inlet temperature (1096.65–1286.45 K) and cooling water flow rate (2.6–5.1 m³/h) were studied through experiment and computational fluid dynamics’ (CFD) method. On the basis of logarithmic mean temperature difference method, the total heat transfer coefficient of the granular bed was used to characterize its heat transfer performance. Experimental results showed that the waste heat recovery rate of the equipment exceeded 72%. An increase in the cooling water flow rate and inlet gas temperature was beneficial to recovering waste heat. The cooling water flow rate increases from 2.6 m³/h to 5.1 m³/h and the recovery rate of waste heat increases by 1.9%. Moreover, the heat transfer coefficient of the granular bed increased by 4.4% and the inlet gas temperature increased from 1096.65 K to 1286.45 K. The recovery rate of waste heat increased by 1.7% and the heat transfer coefficient of the granular bed rose by 26.6%. Therefore, experimental correlations between the total heat transfer coefficient of a granular bed and the cooling water flow rate and inlet temperature of dusty gas were proposed. The CFD method was used to simulate the heat transfer in the granular bed, and the effect of gas temperature on the heat transfer coefficient of granular bed was studied. Results showed that the relative error was less than 2%. Full article

(This article belongs to the Special Issue Enhancement of Industrial Energy Efficiency and Sustainability)

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23 pages, 3642 KiB

Open AccessArticle

Operability and Technical Implementation Issues Related to Heat Integration Measures—Interview Study at an Oil Refinery in Sweden

by Sofie Marton, Elin Svensson and Simon Harvey

Energies 2020, 13(13), 3478; https://doi.org/10.3390/en13133478 - 05 Jul 2020

Cited by 6 | Viewed by 2319

Abstract

In many energy-intensive industrial process plants, significant improvements in energy efficiency can be achieved through increased heat recovery. However, retrofitting plants for heat integration purposes can affect process operability. The aim of this paper is to present a comprehensive overview of such issues [...] Read more.

In many energy-intensive industrial process plants, significant improvements in energy efficiency can be achieved through increased heat recovery. However, retrofitting plants for heat integration purposes can affect process operability. The aim of this paper is to present a comprehensive overview of such issues by systematically relating different types of heat recovery retrofit measures to a range of technical barriers associated with process operability and practical implementation of the measures. The paper presents a new approach for this kind of study, which can be applied in the early-stage screening of heat integration retrofit measures. This approach accounts for the importance of a number of selected operability factors and their relative significance. The work was conducted in the form of a case study at a large oil refinery. Several conceptual heat exchanger network retrofit design proposals were prepared and discussed during semi-structured interviews with technical staff at the refinery. The results show that many operability and practical implementation factors, such as spatial limitations, pressure drops and non-energy benefits, influence the opportunities for implementation of different types of heat exchanger network retrofit measures. The results indicate that it is valuable to consider these factors at an early stage when designing candidate heat exchanger network retrofit measures. The interview-based approach developed in this work can be applied to other case studies for further confirmation of the results. Full article

(This article belongs to the Special Issue Enhancement of Industrial Energy Efficiency and Sustainability)

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28 pages, 5203 KiB

Open AccessArticle

Energy-Saving Strategies and their Energy Analysis and Exergy Analysis for In Situ Thermal Remediation System of Polluted-Soil

by Tian-Tian Li, Yun-Ze Li, Zhuang-Zhuang Zhai, En-Hui Li and Tong Li

Energies 2019, 12(20), 4018; https://doi.org/10.3390/en12204018 - 22 Oct 2019

Cited by 5 | Viewed by 3074

Abstract

The environmental safety of soil has become a severe problem in China with the boost of industrialization. Polluted-soil thermal remediation is a kind of suitable remediation technology for large-scale heavily contaminated industrial soil, with the advantages of being usable in off-grid areas and [...] Read more.

The environmental safety of soil has become a severe problem in China with the boost of industrialization. Polluted-soil thermal remediation is a kind of suitable remediation technology for large-scale heavily contaminated industrial soil, with the advantages of being usable in off-grid areas and with a high fuel to energy conversion rate. Research on energy-saving strategies is beneficial for resource utilization. Focused on energy saving and efficiency promotion of polluted-soil in situ thermal remediation system, this paper presents three energy-saving strategies: Variable-condition mode (VCM), heat-returning mode (HRM) and air-preheating mode (APM). The energy analysis based on the first law of thermodynamics and exergy analysis based on the second law of thermodynamics are completed. By comparing the results, the most effective part of the energy-saving strategy for variable-condition mode is that high savings in the amount of natural gas (NG) used can be achieved, from 0.1124 to 0.0299 kg·s⁻¹ in the first stage. Energy-saving strategies for heat-returning mode and air-preheating mode have higher utilization ratios than the basic method (BM) for the reason they make full use of waste heat. As a whole, a combination of energy-saving strategies can improve the fuel savings and energy efficiency at the same time. Full article

(This article belongs to the Special Issue Enhancement of Industrial Energy Efficiency and Sustainability)

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Review

Jump to: Research

21 pages, 758 KiB

Open AccessReview

A Review of Energy Management Assessment Models for Industrial Energy Efficiency

by A S M Monjurul Hasan and Andrea Trianni

Energies 2020, 13(21), 5713; https://doi.org/10.3390/en13215713 - 01 Nov 2020

Cited by 27 | Viewed by 3421

Abstract

The necessity to ensure energy efficiency in the industries is of significant importance to attain reduction of energy consumption and greenhouse gases emissions. Energy management is one of the effective features that ensure energy efficiency in the industries. Energy management models are the [...] Read more.

The necessity to ensure energy efficiency in the industries is of significant importance to attain reduction of energy consumption and greenhouse gases emissions. Energy management is one of the effective features that ensure energy efficiency in the industries. Energy management models are the infancy in the industrial energy domain with practical guidelines towards implementation in the organizations. Despite the increased interest in energy efficiency, a gap exists concerning energy management literature and present application practices. This paper aims to methodologically review the energy management assessment models that facilitate the assessment of industrial energy management. In this context, the minimum requirements model, maturity model, energy management matrix model, and energy efficiency measures characterization framework are discussed with implications. The study concludes with interesting propositions for academia and industrial think tanks delineating few further research opportunities. Full article

(This article belongs to the Special Issue Enhancement of Industrial Energy Efficiency and Sustainability)

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