E-Mail Alert

Add your e-mail address to receive forthcoming issues of this journal:

Journal Browser

Journal Browser

Special Issue "Selected Papers from SDEWES 2018 Conferences on Sustainable Development of Energy, Water and Environment Systems"

A special issue of Energies (ISSN 1996-1073).

Deadline for manuscript submissions: closed (31 December 2018)

Special Issue Editors

Guest Editor
Prof. Dr. Neven Duić

Faculty of Mechanical Engineering and Naval Architecture, University of Zagreb, Croatia
Website | E-Mail
Interests: energy planning of energy systems with high penetration of renewables; sustainable communities; energy policy; energy economics; mitigation of climate change; energy efficiency; combustion engineering
Guest Editor
Prof. Dr. Mário Manuel Gonçalves da Costa

Instituto Superior Técnico, University of Lisbon, Portugal
Website | E-Mail
Interests: energy; combustion
Guest Editor
Prof. Dr. Qiuwang Wang

Key Laboratory of Thermo-Fluid Science and Engineering (Ministry of Education), Xi’an Jiaotong University, Xi’an, Shaanxi 710049, China
Website | E-Mail
Interests: heat transfer enhancement and its applications to engineering problems; high-temperature heat transfer and fluid flow; transport phenomena in porous media; numerical simulation; prediction and optimization
Guest Editor
Prof. Francesco Calise

Department of Industrial Engineering, University of Naples Federico II, 80125 Naples, Italy
Website | E-Mail
Interests: fuel cells; advanced optimization techniques; solar thermal systems; concentrating photovoltaic/thermal photovoltaic systems; energy saving in buildings; solar heating and cooling; organic Rankine cycles; geothermal energy; dynamic simulations of energy systems; renewable polygeneration systems
Guest Editor
Prof. Dr. Poul Alberg Østergaard

Department of Planning, Aalborg University, Denmark
Website | E-Mail
Phone: +45 9940 8424
Interests: energy systems; energy scenarios; renewable energy system integration; energy and development; environmental impacts from energy development

Special Issue Information

Dear Colleagues,

One of the main issues of the coming decades is the need to improve efficiencies by integrating various life supporting systems, using waste from one as a resource in another, in the exact moment when it is beneficial to all, integrating electricity, heating, cooling, transport, water, buildings, waste, wastewater, industry, forestry, and agriculture systems. Sustainability is also a perfect field for the interdisciplinary and multi-cultural evaluation of complex systems. The SDEWES conferences have become a significant venue for researchers in those areas to meet and originate, discuss, share, and disseminate new ideas.

Energy has been and is the key-factor in human development. However, it is also one of the main—if not the main—human environmental fingerprints. Even with the significant attention paid to the importance and merits of sustainable energy supply over the past several decades, there are still significant gaps to be filled with respect to how to design and implement technically optimal energy systems at the lowest costs.

This Special Issue aims to provide an important contribution by presenting state-of-the-art knowledge with sustainable energy supply solutions ranging from the technical analyses of energy components on both supply and demand sides to energy scenarios and pathways. This Special Issue particularly welcomes SDEWES papers that address the energy system without traditional sector boundaries between electricity, heating, cooling, transportation, and industrial demands, and rather considers the integration and synergies between these sectors.

Three conferences on the Sustainable Development of Energy, Water and Environment Systems (SDEWES Conferences) were held in 2018: the 1st Latin American SDEWES in Rio de Janeiro, Brazil in January, the 3rd Southeast European SDEWES in Novi Sad, Serbia in July, and the 13th SDEWES in Palermo, Italy in October, were dedicated to the improvement and dissemination of knowledge on methods, policies, and technologies for increasing the sustainability of development by de-coupling growth from natural resources and replacing them with knowledge-based economy, taking into account economic, environmental, and social pillars.

Prof. Dr. Neven Duić
Prof. Dr. Mário Costa
Prof. Dr. Qiuwang Wang
Prof. Dr. Francesco Calise
Prof. Dr. Poul Alberg Østergaard
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Energies is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1800 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • sustainability comparisons and measurements
  • smart energy systems
  • energy policy
  • water–energy nexus
  • energy system analysis
  • renewable energy resources
  • primary energy resources
  • renewable electricity generation systems
  • thermal power plants
  • district heating and/or cooling
  • advanced sustainable energy conversion systems
  • renewable heat systems
  • biofuels and biorefineries
  • alternative fuels
  • hybrid and electric vehicles
  • water treatment for drinking water
  • modelling for pollution avoidance and energy efficiency
  • cogeneration, trigeneration, polygeneration
  • energy storage
  • electricity transmission and distribution
  • gas security of supply
  • energy efficiency in industry and mining
  • energy-efficient appliances
  • energy efficiency in buildings
  • energy markets

Published Papers (12 papers)

View options order results:
result details:
Displaying articles 1-12
Export citation of selected articles as:

Research

Open AccessArticle Temperature Disturbance Management in a Heat Exchanger Network for Maximum Energy Recovery Considering Economic Analysis
Energies 2019, 12(4), 594; https://doi.org/10.3390/en12040594
Received: 31 December 2018 / Revised: 1 February 2019 / Accepted: 11 February 2019 / Published: 13 February 2019
PDF Full-text (7342 KB) | HTML Full-text | XML Full-text
Abstract
The design of heat exchanger networks (HEN) in the process industry has largely focused on minimisation of operating and capital costs using techniques such as pinch analysis or mathematical modelling. Aspects of operability and flexibility, including issues of disturbances affecting downstream processes during [...] Read more.
The design of heat exchanger networks (HEN) in the process industry has largely focused on minimisation of operating and capital costs using techniques such as pinch analysis or mathematical modelling. Aspects of operability and flexibility, including issues of disturbances affecting downstream processes during the operation of highly integrated HEN, still need development. This work presents a methodology to manage temperature disturbances in a HEN design to achieve maximum heat recovery, considering the impact of supply temperature fluctuations on utility consumption, heat exchanger sizing, bypass placement and economic performance. Key observations have been made and new heuristics are proposed to guide heat exchanger sizing to consider disturbances and bypass placement for cases above and below the HEN pinch point. Application of the methodology on two case studies shows that the impact of supply temperature fluctuations on downstream heat exchangers can be reduced through instant propagation of the disturbances to heaters or coolers. Where possible, the disturbances have been capitalised upon for additional heat recovery using the pinch analysis plus-minus principle as a guide. Results of the case study show that the HEN with maximum HE area yields economic savings of up to 15% per year relative to the HEN with a nominal HE area. Full article
Figures

Graphical abstract

Open AccessArticle Thermodynamic and Technical Issues of Hydrogen and Methane-Hydrogen Mixtures Pipeline Transmission
Energies 2019, 12(3), 569; https://doi.org/10.3390/en12030569
Received: 27 December 2018 / Revised: 31 January 2019 / Accepted: 4 February 2019 / Published: 12 February 2019
PDF Full-text (6261 KB) | HTML Full-text | XML Full-text
Abstract
The use of hydrogen as a non-emission energy carrier is important for the innovative development of the power-generation industry. Transmission pipelines are the most efficient and economic method of transporting large quantities of hydrogen in a number of variants. A comprehensive hydraulic analysis [...] Read more.
The use of hydrogen as a non-emission energy carrier is important for the innovative development of the power-generation industry. Transmission pipelines are the most efficient and economic method of transporting large quantities of hydrogen in a number of variants. A comprehensive hydraulic analysis of hydrogen transmission at a mass flow rate of 0.3 to 3.0 kg/s (volume flow rates from 12,000 Nm3/h to 120,000 Nm3/h) was performed. The methodology was based on flow simulation in a pipeline for assumed boundary conditions as well as modeling of fluid thermodynamic parameters for pure hydrogen and its mixtures with methane. The assumed outlet pressure was 24 bar (g). The pipeline diameter and required inlet pressure were calculated for these parameters. The change in temperature was analyzed as a function of the pipeline length for a given real heat transfer model; the assumed temperatures were 5 and 25 C. The impact of hydrogen on natural gas transmission is another important issue. The performed analysis revealed that the maximum participation of hydrogen in natural gas should not exceed 15%–20%, or it has a negative impact on natural gas quality. In the case of a mixture of 85% methane and 15% hydrogen, the required outlet pressure is 10% lower than for pure methane. The obtained results present various possibilities of pipeline transmission of hydrogen at large distances. Moreover, the changes in basic thermodynamic parameters have been presented as a function of pipeline length for the adopted assumptions. Full article
Figures

Graphical abstract

Open AccessArticle Fuel Switch to LNG in Heavy Truck Traffic
Energies 2019, 12(3), 515; https://doi.org/10.3390/en12030515
Received: 27 December 2018 / Revised: 30 January 2019 / Accepted: 2 February 2019 / Published: 6 February 2019
PDF Full-text (2652 KB) | HTML Full-text | XML Full-text
Abstract
Liquefied natural gas (LNG) use as a fuel in road and maritime traffic has increased rapidly, and it is slowly entering railroad traffic as well. The trend was pushed by the state administrations of mainly EU countries and international organizations seeing LNG as [...] Read more.
Liquefied natural gas (LNG) use as a fuel in road and maritime traffic has increased rapidly, and it is slowly entering railroad traffic as well. The trend was pushed by the state administrations of mainly EU countries and international organizations seeing LNG as a cost-effective and environmentally friendly alternative to diesel. Different infrastructural projects for the widespread use of LNG in transport have been launched around the world. The main goal of this paper was to analyze use of LNG as a fuel for heavy trucks. Different aspects of LNG chain were analyzed along with economical and ecological benefits of LNG application. Filling stations network for LNG were described for the purpose of comparative analysis of diesel and LNG heavy trucks. Conclusion has shown that using LNG as propellant fuel has numerous advantages over the use of conventional fuels. The higher initial investment of the LNG road vehicles could be amortized in their lifetime use, and in the long-term they are more affordable than the classic diesel vehicles. In addition to cost-effectiveness, LNG road vehicles reduce CO2 emissions. Therefore, the environmental goals in transport, not only of the member states but worldwide, could not be met without LNG in heavy truck traffic. Full article
Figures

Graphical abstract

Open AccessArticle Modelling of the Biomass mCHP Unit for Power Peak Shaving in the Local Electrical Grid
Energies 2019, 12(3), 458; https://doi.org/10.3390/en12030458
Received: 21 December 2018 / Revised: 24 January 2019 / Accepted: 29 January 2019 / Published: 31 January 2019
PDF Full-text (3688 KB) | HTML Full-text | XML Full-text
Abstract
In the article, the method and algorithm for a control strategy of the operation of a micro combined heat and power (mCHP) unit and for reducing the power consumption peaks (peak shaving) are proposed and analyzed. Two scenarios of the mCHP’s operation, namely [...] Read more.
In the article, the method and algorithm for a control strategy of the operation of a micro combined heat and power (mCHP) unit and for reducing the power consumption peaks (peak shaving) are proposed and analyzed. Two scenarios of the mCHP’s operation, namely with and without the control strategy, are discussed. For calculation purposes, a boiler fired with wood pellets coupled with a Stirling engine, manufactured by ÖkoFEN, was used. These results were used to analyze two scenarios of the control strategy. In this study, the operation of mCHP was simulated using the energyPRO software. The application of this control strategy to dispersed mCHP systems allows for a very effective “peak shaving” in the local power grid. The results of calculation using the new algorithm show that the electricity generated by the mCHP system covers the total demand for power during the morning peak and reduces the evening peak by up to 71%. The application of this method also allows for a better reduction of the load of conventional grids, substations, and other equipment. Full article
Figures

Figure 1

Open AccessArticle Numerical Study on Heat Transfer Performance in Packed Bed
Energies 2019, 12(3), 414; https://doi.org/10.3390/en12030414
Received: 17 December 2018 / Revised: 18 January 2019 / Accepted: 22 January 2019 / Published: 28 January 2019
PDF Full-text (6803 KB) | HTML Full-text | XML Full-text
Abstract
Packed beds are widely used in industries and it is of great significance to enhance the heat transfer between gas and solid states inside the bed. In this paper, numerical simulation method is adopted to investigate the heat transfer principle in the bed [...] Read more.
Packed beds are widely used in industries and it is of great significance to enhance the heat transfer between gas and solid states inside the bed. In this paper, numerical simulation method is adopted to investigate the heat transfer principle in the bed at particle scale, and to develop the direct enhanced heat transfer methods in packed beds. The gas is treated as continuous phase and solved by Computational Fluid Dynamics (CFD), while the particles are treated as discrete phase and solved by the Discrete Element Method (DEM); taking entransy dissipation to evaluate the heat transfer process. Considering the overall performance and entransy dissipation, the results show that, compared with the uniform particle size distribution, radial distribution of multiparticle size can effectively improve the heat transfer performance because it optimizes the velocity and temperature field, reduces the equivalent thermal resistance of convection heat transfer process, and the temperature of outlet gas increases significantly, which indicates the heat quality of the gas has been greatly improved. The increase in distribution thickness obviously enhances heat transfer performance without reducing the equivalent thermal resistance in the bed. The result is of great importance for guiding practical engineering applications. Full article
Figures

Figure 1

Open AccessArticle District Cooling Versus Individual Cooling in Urban Energy Systems: The Impact of District Energy Share in Cities on the Optimal Storage Sizing
Energies 2019, 12(3), 407; https://doi.org/10.3390/en12030407
Received: 25 December 2018 / Revised: 25 January 2019 / Accepted: 26 January 2019 / Published: 28 January 2019
PDF Full-text (795 KB) | HTML Full-text | XML Full-text
Abstract
The energy transition of future urban energy systems is still the subject of an ongoing debate. District energy supply can play an important role in reducing the total socio-economic costs of energy systems and primary energy supply. Although lots of research was done [...] Read more.
The energy transition of future urban energy systems is still the subject of an ongoing debate. District energy supply can play an important role in reducing the total socio-economic costs of energy systems and primary energy supply. Although lots of research was done on integrated modelling including district heating, there is a lack of research on integrated energy modelling including district cooling. This paper addressed the latter gap using linear continuous optimization model of the whole energy system, using Singapore for a case study. Results showed that optimal district cooling share was 30% of the total cooling energy demand for both developed scenarios, one that took into account spatial constraints for photovoltaics installation and the other one that did not. In the scenario that took into account existing spatial constraints for installations, optimal capacities of methane and thermal energy storage types were much larger than capacities of grid battery storage, battery storage in vehicles and hydrogen storage. Grid battery storage correlated with photovoltaics capacity installed in the energy system. Furthermore, it was shown that successful representation of long-term storage solutions in urban energy models reduced the total socio-economic costs of the energy system for 4.1%. Full article
Figures

Figure 1

Open AccessArticle Renewable Energy Generation Scenarios Using 3D Urban Modeling Tools—Methodology for Heat Pump and Co-Generation Systems with Case Study Application
Energies 2019, 12(3), 403; https://doi.org/10.3390/en12030403
Received: 24 December 2018 / Revised: 18 January 2019 / Accepted: 24 January 2019 / Published: 28 January 2019
PDF Full-text (3564 KB) | HTML Full-text | XML Full-text
Abstract
In the paper, a method was developed to automatically dimensionalize and calculate central energy generation and supply scenarios with a district heating system for cities based on 3D building models in the CityGML format and their simulated heat demand. In addition, the roof [...] Read more.
In the paper, a method was developed to automatically dimensionalize and calculate central energy generation and supply scenarios with a district heating system for cities based on 3D building models in the CityGML format and their simulated heat demand. In addition, the roof geometry of every individual building is used to model photovoltaic energy generation potential. Two types of supply systems, namely a central heat pump (HP) system and a large co-generation (combined heat and power-CHP) system (both with a central storage and district distribution system), are modeled to supply the heat demand of the area under investigation. Both energy generation models are applied to a case study town of 1610 buildings. For the HP scenario, it can be shown that the case study town’s heat demand can be covered by a monovalent, low-temperature system with storage, but that the PV only contributes 15% to the HP electricity requirement. For the CHP scenario, only 61% of the heat demand can be covered by the CHP, as it was designed for a minimum of 4000 operating hours. Both the PV and the CHP excess electricity are fully injected into the grid. As a result, the primary energy comparison of both systems strongly depends on the chosen primary energy factors (PEF): with given German regulations the CHP system performs better than the HP system, as the grid-injected electricity has a PEF of 2.8. In the future, with increasingly lower PEFs for electricity, the situation reverses, and HPs perform better, especially if the CHP continues to use natural gas. Even when renewable gas from a power to gas (P2G) process is used for the CHP, the primary energy balance of the HP system is better, because of high conversion losses in the P2G process. Full article
Figures

Figure 1

Open AccessArticle Numerical Simulation and Optimization of Waste Heat Recovery in a Sinter Vertical Tank
Energies 2019, 12(3), 385; https://doi.org/10.3390/en12030385
Received: 26 December 2018 / Revised: 18 January 2019 / Accepted: 21 January 2019 / Published: 25 January 2019
PDF Full-text (5286 KB) | HTML Full-text | XML Full-text
Abstract
In this paper, a two-dimensional steady model is established to investigate the gas-solid heat transfer in a sinter vertical tank based on the porous media theory and the local thermal non-equilibrium model. The influences of the air flow rate, sinter flow rate, and [...] Read more.
In this paper, a two-dimensional steady model is established to investigate the gas-solid heat transfer in a sinter vertical tank based on the porous media theory and the local thermal non-equilibrium model. The influences of the air flow rate, sinter flow rate, and sinter particle diameter on the gas-solid heat transfer process are investigated numerically. In addition, exergy destruction minimization is used as a new principle for heat transfer enhancement. Furthermore, a multi-objective genetic algorithm based on a Back Propagation (BP) neural network is applied to obtain a combination of each parameter for a more comprehensive performance, with the exergy destruction caused by heat transfer and the one caused by fluid flow as the two objectives. The results show that the heat dissipation and power consumption both gradually increase with an increase of the air mass flow rate. Additionally, the increase of the sinter flow rate results in a decrease of the heat dissipation and an increase of the power consumption. In addition, both heat dissipation and power consumption gradually decrease with an increase of the sinter particle diameter. For the given structure of the vertical tank, the optimal operating parameters are 2.99 kg/s, 0.61 kg/s, and 32.8 mm for the air flow rate, sinter flow rate, and sinter diameter, respectively. Full article
Figures

Figure 1

Open AccessArticle Techno-Economic Assessment of Solar Hydrogen Production by Means of Thermo-Chemical Cycles
Energies 2019, 12(3), 352; https://doi.org/10.3390/en12030352
Received: 20 December 2018 / Revised: 18 January 2019 / Accepted: 22 January 2019 / Published: 23 January 2019
PDF Full-text (5222 KB) | HTML Full-text | XML Full-text
Abstract
This paper presents the system analysis and the techno-economic assessment of selected solar hydrogen production paths based on thermochemical cycles. The analyzed solar technology is Concentrated Solar Power (CSP). Solar energy is used in order to run a two-step thermochemical cycle based on [...] Read more.
This paper presents the system analysis and the techno-economic assessment of selected solar hydrogen production paths based on thermochemical cycles. The analyzed solar technology is Concentrated Solar Power (CSP). Solar energy is used in order to run a two-step thermochemical cycle based on two different red-ox materials, namely nickel-ferrite and cerium dioxide (ceria). Firstly, a flexible mathematical model has been implemented to design and to operate the system. The tool is able to perform annual yield calculations based on hourly meteorological data. Secondly, a sensitivity analysis over key-design and operational techno-economic parameters has been carried out. The main outcomes are presented and critically discussed. The technical comparison of nickel-ferrite and ceria cycles showed that the integration of a large number of reactors can be optimized by considering a suitable time displacement among the activation of the single reactors working in parallel. In addition the comparison demonstrated that ceria achieves higher efficiency than nickel-ferrite (13.4% instead 6.4%), mainly because of the different kinetics. This difference leads to a lower LCOH for ceria (13.06 €/kg and 6.68 €/kg in the base case and in the best case scenario, respectively). Full article
Figures

Figure 1

Open AccessArticle High-Efficiency Cogeneration Systems: The Case of the Paper Industry in Italy
Energies 2019, 12(3), 335; https://doi.org/10.3390/en12030335
Received: 20 December 2018 / Revised: 16 January 2019 / Accepted: 18 January 2019 / Published: 22 January 2019
PDF Full-text (3623 KB) | HTML Full-text | XML Full-text
Abstract
In January 2011, the introduction of high-efficiency cogeneration in Europe radically modified the incentive scheme for combined heat and power (CHP) plants. Since then, the techno-economic feasibility of new cogeneration plants in different areas of application (industry, service, residential, etc.), along with the [...] Read more.
In January 2011, the introduction of high-efficiency cogeneration in Europe radically modified the incentive scheme for combined heat and power (CHP) plants. Since then, the techno-economic feasibility of new cogeneration plants in different areas of application (industry, service, residential, etc.), along with the definition of their optimal operation, have inevitably undergone a radical change. In particular, with reference to the Italian case and according to the most recent ministerial guidelines following the new EU regulation, in the event that cogeneration power plants do not reach an established value in terms of overall efficiency, their operation has to be split into a CHP and a non-CHP portion with incentives proportional to the energy quantities pertaining to the CHP portion only. In the framework of high-efficiency cogeneration, the present study compares different CHP solutions to be coupled with the paper industry that, among all the industrial processes, appears to be the best suited for cogeneration applications. With reference to this particular industrial reality, energy, environmental, and economic performance parameters have been defined, analysed, and compared with the help of GateCycle software. Among the proposed CHP alternatives, results show that gas turbines are the most appropriate technology for paper industry processes. Full article
Figures

Figure 1

Open AccessArticle Environmental Performance of Effluent Conditioning Systems for Reuse in Oil Refining Plants: A Case Study in Brazil
Energies 2019, 12(2), 326; https://doi.org/10.3390/en12020326
Received: 12 December 2018 / Revised: 12 January 2019 / Accepted: 14 January 2019 / Published: 21 January 2019
PDF Full-text (1134 KB) | HTML Full-text | XML Full-text
Abstract
This study aims to evaluate the environmental and energy effects of the reuse of 1.0 m³ of water in a cooling tower obtained from an oil refinery effluent. An arrangement comprising reverse osmosis (RO), evaporation (EV), and crystallization (CR) was created for water [...] Read more.
This study aims to evaluate the environmental and energy effects of the reuse of 1.0 m³ of water in a cooling tower obtained from an oil refinery effluent. An arrangement comprising reverse osmosis (RO), evaporation (EV), and crystallization (CR) was created for water desalination. Six process routes were evaluated; for this purpose, each of them was converted into an specific scenario of analysis: S1: pre-treatment with Ethylenediaminetetraacetic acid (EDTA) + RO + EV (multi-effect distillation) + CR; S2: S1 with pre-treatment by BaSO4; S3: with Ca(OH)2/CaCO3/HCl; S4: S3 with waste heat to supply the thermal demand of EV; S5: S3 with steam recompression in EV; and, S6: S3 with HNO3 in place of HCl. The analysis was carried out by attributional LCA for primary energy demand (PED) and global warming (GW) impacts. The comparison was carried out for a reference flow (RF) of: add 1.0 m3 of reused water to a cooling tower with quality to proper functioning of this equipment. S4 presented the best performance among the analyzed possibilities (PED: 11.9 MJ/RF; and GW: 720 gCO2,eq/RF). However, dependence on other refinery sectors makes it inadvisable as a regular treatment option. Thus, S5 appears as the lowest impact scenario in the series (PED: 17.2 MJ/RF; and GW: 1.24 kgCO2,eq/RF), given the pre-treatment technique of RO-fed effluent, and the exclusive use of steam recompression to meet total EV energy demands. Finally, an intrinsic correlation was identified between RO water recovery efficiency and the accumulated PED and GW impacts on the arrangements that operate with heat and electricity. Full article
Figures

Figure 1

Open AccessArticle Torrefaction as a Valorization Method Used Prior to the Gasification of Sewage Sludge
Energies 2019, 12(1), 175; https://doi.org/10.3390/en12010175
Received: 30 November 2018 / Revised: 29 December 2018 / Accepted: 2 January 2019 / Published: 6 January 2019
PDF Full-text (2733 KB) | HTML Full-text | XML Full-text
Abstract
The gasification and torrefaction of sewage sludge have the potential to make the thermal utilization of sewage sludge fully sustainable, thus limiting the use of expensive fossil fuels in the process. This includes sustainability in terms of electricity consumption. Although a great deal [...] Read more.
The gasification and torrefaction of sewage sludge have the potential to make the thermal utilization of sewage sludge fully sustainable, thus limiting the use of expensive fossil fuels in the process. This includes sustainability in terms of electricity consumption. Although a great deal of work has been performed so far regarding the gasification of sewage sludge and some investigations have been performed in the area of its torrefaction, there is still a gap in terms of the influence of the torrefaction of the sewage sludge on its subsequent gasification. This study presents the results from the torrefaction tests, performed on a pilot scale reactor, as well as two consecutive steam gasification tests, performed in an allothermal fixed bed gasifier, in order to determine if torrefaction can be deemed as a primary method of the reduction of tar content for the producer gas, from the aforementioned gasification process. A comparative analysis is performed based on the results obtained during both tests, with special emphasis on the concentrations of condensable compounds (tars). The obtained results show that the torrefaction of sewage sludge, performed prior to gasification, can indeed have a positive influence on the gas quality. This is beneficial especially in terms of the content of heavy tars with melting points above 40 °C. Full article
Figures

Figure 1

Energies EISSN 1996-1073 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top