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Dr. Valter Silva
Polytechnic Institute of Portalegre, 7300-110, Portalegre, Portugal

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0 Combustion
0 Gasification
0 Pyrolysis
0 CFD
0 Statistical Design

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Gasification
Combustion
CFD
Waste-to-Energy.
Pyrolysis

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Journal article
Published: 12 June 2021 in Renewable Energy
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This work presents a technical analysis of an Integrated Biomass Direct Gasification/Gas Turbine (BIG-GT) technology within a sugarcane industry to produce electricity and thermal energy (process heat) using bagasse as fuel. Four possible configurations for the implementation of this technology were considered. A sensitivity analysis was made to assess the risks and the uncertainty level for each proposed solution. The results indicated that with the BIG-GT implementation the power generation efficiency increases for all the studied configurations as compared to the conventional system (η = 14.3%). For the configurations I, II, and III the efficiency increase was 9.1%, 11.0% and 12.6%, respectively. However, to support these configurations of the system, the fuel (bagasse) consumption is increased beyond the production capacity of the mill, and the additional amount of bagasse must be acquired to other mills. On the other hand, in configuration IV it is only considered the gasification of the bagasse produced in the mill, being the additional needs of thermal energy for the industrial process supplemented through the combustion of other biomass types (sugarcane straw produced in the mill plantations) in a Heat Recovery Steam Generator. In configuration IV, the electricity generation efficiency is only 5.9% higher than the conventional cycle, this efficiency is getting without the need for an external supply of bagasse. Ultimately, the sensitivity analysis showed that the plant's energy performance with the implementation of BIG-GT technology is particularly sensitive to variations related to the gasifier's efficiency.

ACS Style

José Ramón Copa Rey; Jorge Jadid Tamayo Pacheco; Luís António Da Cruz Tarelho; Valter Silva; João Sousa Cardoso; José Luz Silveira; Celso Eduardo Tuna. Evaluation of cogeneration alternative systems integrating biomass gasification applied to a Brazilian sugar industry. Renewable Energy 2021, 178, 318 -333.

AMA Style

José Ramón Copa Rey, Jorge Jadid Tamayo Pacheco, Luís António Da Cruz Tarelho, Valter Silva, João Sousa Cardoso, José Luz Silveira, Celso Eduardo Tuna. Evaluation of cogeneration alternative systems integrating biomass gasification applied to a Brazilian sugar industry. Renewable Energy. 2021; 178 ():318-333.

Chicago/Turabian Style

José Ramón Copa Rey; Jorge Jadid Tamayo Pacheco; Luís António Da Cruz Tarelho; Valter Silva; João Sousa Cardoso; José Luz Silveira; Celso Eduardo Tuna. 2021. "Evaluation of cogeneration alternative systems integrating biomass gasification applied to a Brazilian sugar industry." Renewable Energy 178, no. : 318-333.

Book chapter
Published: 08 June 2021 in Gasification [Working Title]
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Millions of tons of forest residues, agricultural residues, and municipal solid waste are generated in Latin America (LATAM) each year. Regularly, municipal solid waste is diverted to landfills or dumpsites. Meanwhile, forest and agricultural residues end up decomposing in the open air or burnt, releasing greenhouse gases. Those residues can be transformed into a set of energy vectors and organic/chemical products through thermochemical conversion processes, such as pyrolysis and gasification. This book chapter provides information on current examples of gasification on large scale in the world, which typically operate at 700°C, atmospheric pressure, and in a fluidized bed reactor. The produced gas is used for heat and energy generation. Whereas pyrolysis at a large scale operates around 500°C, atmospheric pressure, and in an inert atmosphere, using a fluidized bed reactor. The produced combustible liquid is used for heat and energy generation. The decision of using any of these technologies will depend on the nature and availability of residues, energy carries, techno-socio-economic aspects, and the local interest. In this regard, the particular situation of Brazil and Mexico is analyzed to implement these technologies. Its implementation could reduce the utilization of fossil fuels, generate extra income for small farmers or regions, and reduce the problem derived from the accumulation of residues. However, it is concluded that it is more convenient to use decentralized gasification and pyrolysis stations than full-scale processes, which could be an intermediate step to a large-scale process. The capabilities of numerical models to describe these processes are also provided to assess the potential composition of a gas produced from some biomass species available in these countries.

ACS Style

José Antonio Mayoral Chavando; Valter Silva; Danielle Regina Da Silva Guerra; Daniela Eusébio; João Sousa Cardoso; Luís A.C. Tarelho. Review Chapter: Waste to Energy through Pyrolysis and Gasification in Brazil and Mexico. Gasification [Working Title] 2021, 1 .

AMA Style

José Antonio Mayoral Chavando, Valter Silva, Danielle Regina Da Silva Guerra, Daniela Eusébio, João Sousa Cardoso, Luís A.C. Tarelho. Review Chapter: Waste to Energy through Pyrolysis and Gasification in Brazil and Mexico. Gasification [Working Title]. 2021; ():1.

Chicago/Turabian Style

José Antonio Mayoral Chavando; Valter Silva; Danielle Regina Da Silva Guerra; Daniela Eusébio; João Sousa Cardoso; Luís A.C. Tarelho. 2021. "Review Chapter: Waste to Energy through Pyrolysis and Gasification in Brazil and Mexico." Gasification [Working Title] , no. : 1.

Review article
Published: 08 March 2021 in Journal of Cleaner Production
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Ammonia and hydrogen carry great potential as carbon-free fuels with promising applications in energy systems. Hydrogen, in particular, has been generating massive expectations as a carbon-free economy enabler, but issues related to storage, distribution, and infrastructure deployment are delaying its full implementation. Ammonia, on the other hand, stands as a highly efficient energy vector delivering high energy density and an established and flexible infrastructure capable of mitigating hydrogen’s key drawbacks. This mature infrastructure together with the possibility of producing ammonia through renewable energy sources triggered an exploring route to the transition of ammonia as the next sustainable fuel solution for power generation. In this regard, the transportation sector as one of the main culprits for carbon emissions can benefit from ammonia-powered internal combustion engines. However, the use of pure ammonia as fuel still presents important constraints leading researchers to develop strategies such as dual-fuel concepts or novel combustion approaches. Therefore, this review covers these issues by delving into the underpinning mechanisms required for developing pure ammonia combustion in internal combustion engines. To do so, fundamentals, technical, environmental, and economic aspects associated with the use of ammonia as a transportation fuel are broadly addressed. While the emphasis is given to pure ammonia and ammonia fuel blends operation, NOx emissions control, current challenges related to the detailed and accurate understanding of the ammonia chemistry, and the lack of high-fidelity numerical models are also deeply discussed on their role into aiding the commercial deployment of this technology.

ACS Style

João Sousa Cardoso; Valter Silva; Rodolfo C. Rocha; Matthew J. Hall; Mário Costa; Daniela Eusébio. Ammonia as an energy vector: Current and future prospects for low-carbon fuel applications in internal combustion engines. Journal of Cleaner Production 2021, 296, 126562 .

AMA Style

João Sousa Cardoso, Valter Silva, Rodolfo C. Rocha, Matthew J. Hall, Mário Costa, Daniela Eusébio. Ammonia as an energy vector: Current and future prospects for low-carbon fuel applications in internal combustion engines. Journal of Cleaner Production. 2021; 296 ():126562.

Chicago/Turabian Style

João Sousa Cardoso; Valter Silva; Rodolfo C. Rocha; Matthew J. Hall; Mário Costa; Daniela Eusébio. 2021. "Ammonia as an energy vector: Current and future prospects for low-carbon fuel applications in internal combustion engines." Journal of Cleaner Production 296, no. : 126562.

Journal article
Published: 06 July 2020 in Fuel
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The present work assesses the energetic valorisation of forest biomass blends in the archipelago of the Azores, to do so, a multiphase 2-D Eulerian-Eulerian model was employed to simulate forest biomass gasification in a pilot-scale fluidized bed reactor. The numerical model was validated under experimental gasification runs performed in a 250 kWth quasi-industrial biomass gasifier. The potential use of the produced syngas as a complementary energy source for small-scale power production in the Azores was assessed based on the results. The exergy efficiency and tar production of the process were determined. A techno-economic study combining the net present value (NPV), internal rate of return (IRR), and payback period (PBP) followed by a Monte Carlo sensitivity analysis was comparatively performed for two distinct application sizes (100 and 1000 kW) so to gauge which unit size carries enhanced operative feasibility and foresee the main investment risks in conducting forest biomass blends gasification for power production in small facilities. Results revealed that the 100 kW unit was economically impracticable under current market conditions, while the 1000 kW unit showed to be economically feasible with an NPV of 486 k€, IRR of 17.44% and PBP of 7.4 years. The sensitivity analysis predicted a higher risk of failure in the NPV, being highly sensitive to the electricity sales tariff and electricity production. Indeed, forest biomass gasification projects carry great potential when applied to small facilities with economic viability in some economies of scales, withal, special concerns must always be considered regarding the project attractiveness to potential investors.

ACS Style

João Cardoso; Valter Silva; Daniela Eusébio; Inês Lima Azevedo; Luís A.C. Tarelho. Techno-economic analysis of forest biomass blends gasification for small-scale power production facilities in the Azores. Fuel 2020, 279, 118552 .

AMA Style

João Cardoso, Valter Silva, Daniela Eusébio, Inês Lima Azevedo, Luís A.C. Tarelho. Techno-economic analysis of forest biomass blends gasification for small-scale power production facilities in the Azores. Fuel. 2020; 279 ():118552.

Chicago/Turabian Style

João Cardoso; Valter Silva; Daniela Eusébio; Inês Lima Azevedo; Luís A.C. Tarelho. 2020. "Techno-economic analysis of forest biomass blends gasification for small-scale power production facilities in the Azores." Fuel 279, no. : 118552.

Journal article
Published: 15 June 2020 in Energies
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The focus of this study is to provide a comparative techno-economic analysis concerning the deployment of small-scale gasification systems in dealing with various fuels from two countries, Portugal and Brazil, for electricity generation in a 15 kWe downdraft gasifier. To quantify this, a mathematical model was implemented and validated against experimental runs gathered from the downdraft reactor. Further, a spreadsheet economic model was developed combining the net present value (NPV), internal rate of return (IRR) and the payback period (PBP) over the project’s lifetime set to 25 years. Cost factors included expenses related to electricity generation, initial investment, operation and maintenance and fuel costs. Revenues were estimated from the electricity sales to the grid. A Monte Carlo sensitivity analysis was used to measure the performance of the economic model and determine the investment risk. The analysis showed an electricity production between 11.6 to 15 kW, with a general system efficiency of approximately 13.5%. The viability of the projects was predicted for an NPV set between 18.99 to 31.65 k€, an IRR between 16.88 to 20.09% and a PBP between 8.67 to 12.61 years. The risk assessment yielded favorable investment projections with greater risk of investment loss in the NPV and the lowest for IRR. Despite the feasibility of the project, the economic performance proved to be highly reliant on the electricity sales prices subdue of energy market uncertainties. Also, regardless of the broad benefits delivered by these systems, their viability is still strikingly influenced by governmental decisions, subsidiary support and favorable electricity sales prices. Overall, this study highlights the empowering effect of small-scale gasification systems settled in decentralized communities for electric power generation.

ACS Style

J. R. Copa; C. E. Tuna; J. L. Silveira; R. A. M. Boloy; P. Brito; V. Silva; J. Cardoso; D. Eusébio. Techno-Economic Assessment of the Use of Syngas Generated from Biomass to Feed an Internal Combustion Engine. Energies 2020, 13, 3097 .

AMA Style

J. R. Copa, C. E. Tuna, J. L. Silveira, R. A. M. Boloy, P. Brito, V. Silva, J. Cardoso, D. Eusébio. Techno-Economic Assessment of the Use of Syngas Generated from Biomass to Feed an Internal Combustion Engine. Energies. 2020; 13 (12):3097.

Chicago/Turabian Style

J. R. Copa; C. E. Tuna; J. L. Silveira; R. A. M. Boloy; P. Brito; V. Silva; J. Cardoso; D. Eusébio. 2020. "Techno-Economic Assessment of the Use of Syngas Generated from Biomass to Feed an Internal Combustion Engine." Energies 13, no. 12: 3097.

Chapter
Published: 31 May 2020 in Nanomaterial Biointeractions at the Cellular, Organismal and System Levels
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Computational fluid dynamics (CFD) analysis has recently been applied to study the performance of waste-to-energy systems, with a broad literature range dedicated to this topic. However, there is still a lack of guidance, particularly for new researchers, concerning a broad and detailed discussion on the current routes available to appropriately make use of these numerical models to describe waste combustion and gasification processes. In this sense, this chapter contributes with theoretical considerations that are crucial to understanding the practical implementation within the ANSYS Fluent framework. The main required features to solve the solution, the main settings and the insights about the process flow are fully addressed. Overall, the guidelines here provided intend to guide the reader throughout the complete implementation process while clarifying many aspects of performing a suitable waste-to-energy analysis in CFD.

ACS Style

João Cardoso; Valter Bruno Silva; Daniela Eusébio. Implementation Guidelines for Modelling Gasification Processes in Computational Fluid Dynamics: A Tutorial Overview Approach. Nanomaterial Biointeractions at the Cellular, Organismal and System Levels 2020, 359 -379.

AMA Style

João Cardoso, Valter Bruno Silva, Daniela Eusébio. Implementation Guidelines for Modelling Gasification Processes in Computational Fluid Dynamics: A Tutorial Overview Approach. Nanomaterial Biointeractions at the Cellular, Organismal and System Levels. 2020; ():359-379.

Chicago/Turabian Style

João Cardoso; Valter Bruno Silva; Daniela Eusébio. 2020. "Implementation Guidelines for Modelling Gasification Processes in Computational Fluid Dynamics: A Tutorial Overview Approach." Nanomaterial Biointeractions at the Cellular, Organismal and System Levels , no. : 359-379.

Journal article
Published: 13 January 2020 in Energy Conversion and Management
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In this work, direct (air) co-gasification of refused derived fuel with biomass was demonstrated in an 80kWth pilot-scale bubbling fluidized bed reactor. The influence of the process operating parameters, namely average bed temperature between 785 and 829 °C, equivalence ratio between 0.21 and 0.36 and refused derived fuel weight percentage in the fuel mixture (0, 10, 20, 50 and 100 wt%) was analyzed. For the operating conditions used, the process was demonstrated as autothermal and operating under steady-state conditions, with no defluidization phenomena observed. The increase of the refused derived fuel weight percentage in the fuel mixture led to an increase of the methane and ethylene concentration in the producer gas and, consequently, an increase of the producer gas lower heating value, reaching a maximum value of 6.4 MJ/Nm3. In terms of efficiency parameters, cold gas efficiency was found between 32.6 and 53.5% and carbon conversion efficiency between 56.0 and 84.1%. A slight increase of the cold gas efficiency was observed with the increase of the refused derived fuel weight percentage in the fuel mixture. Thus, refused derived fuel co-gasification with biomass was shown as a highly promising process for the valorization of wastes as an energetic resource.

ACS Style

D.T. Pio; L.A.C. Tarelho; A.M.A. Tavares; M.A.A. Matos; V. Silva. Co-gasification of refused derived fuel and biomass in a pilot-scale bubbling fluidized bed reactor. Energy Conversion and Management 2020, 206, 112476 .

AMA Style

D.T. Pio, L.A.C. Tarelho, A.M.A. Tavares, M.A.A. Matos, V. Silva. Co-gasification of refused derived fuel and biomass in a pilot-scale bubbling fluidized bed reactor. Energy Conversion and Management. 2020; 206 ():112476.

Chicago/Turabian Style

D.T. Pio; L.A.C. Tarelho; A.M.A. Tavares; M.A.A. Matos; V. Silva. 2020. "Co-gasification of refused derived fuel and biomass in a pilot-scale bubbling fluidized bed reactor." Energy Conversion and Management 206, no. : 112476.

Journal article
Published: 20 November 2019 in Energies
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The first part of the current reported work presents experimental results of brewers’ spent grains gasification in a pilot-scale downdraft gasifier. The gasification procedure is assessed through various process characteristics such as gas yield, lower heating value, carbon conversion efficiency, and cold gas efficiency. Power production was varied from 3.0 to 5.0 kWh during the gasification experiments. The produced gas was supplied to an internal combustion engine coupled to a synchronous generator to produce electricity. Here, 1.0 kWh of electricity was obtained for about 1.3 kg of brewers’ spent grains pellets gasified, with an average electrical efficiency of 16.5%. The second part of the current reported work is dedicated to the development of a modified thermodynamic equilibrium model of the downdraft gasification to assess the potential applications of the main Portuguese biomasses through produced gas quality indices. The Portuguese biomasses selected are the main representative forest residues (pine, eucalyptus, and cork) and agricultural residues (vine prunings and olive bagasse). A conclusion can be drawn that, using air as a gasifying agent, the biomass gasification provides a produced gas with enough quality to be used for energy production in boilers or turbines.

ACS Style

Sérgio Ferreira; Eliseu Monteiro; Luís Calado; Valter Silva; Paulo Brito; Cândida Vilarinho. Experimental and Modeling Analysis of Brewers´ Spent Grains Gasification in a Downdraft Reactor. Energies 2019, 12, 4413 .

AMA Style

Sérgio Ferreira, Eliseu Monteiro, Luís Calado, Valter Silva, Paulo Brito, Cândida Vilarinho. Experimental and Modeling Analysis of Brewers´ Spent Grains Gasification in a Downdraft Reactor. Energies. 2019; 12 (23):4413.

Chicago/Turabian Style

Sérgio Ferreira; Eliseu Monteiro; Luís Calado; Valter Silva; Paulo Brito; Cândida Vilarinho. 2019. "Experimental and Modeling Analysis of Brewers´ Spent Grains Gasification in a Downdraft Reactor." Energies 12, no. 23: 4413.

Conference paper
Published: 27 September 2019 in WEENTECH Proceedings in Energy
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Municipal solid waste provides an opportunity for electricity production. This strategy provides the rural communities a potential waste-to-energy opportunity to manage its costly residues problem, turning them into a valuable recycled asset. To address this issue, a techno-economic study of an integrated system comprising gasification of Acacia residues and Portuguese Municipal Solid Waste (PMSW) with an Internal Combustion Engine-Generator (ICEG) for electricity generation at small-scale (100 kW) was developed. Current studies only devote attention to biomass residues and do not explore MSW potential to eschew biomass supply shortage. Conventional systems are generally part of biomass supply chains, limiting flexibility and all year operation for their operators. Experimental data was gathered at a downdraft gasifier to provide a clear assessment of particle and tar concentration in the syngas and levers conditioning a satisfactory ICE operation. Once the potential of using Acacia residues and PMSW has been proven during gasification runs testing, and validation, a set of new conditions was also explored through a high-fidelity CFD model. We find that residues blends have the highest potential to generate high-quality syngas and smallest exposure to supply disruption. Despite both substrates showing potential at specific conditions, they also present individual drawbacks which will be best mitigated by executing a hybrid supply comprising the mix of substrates. An economic model coupling the financial indicators of net present value (NPV), internal rate of return (IRR) and the payback period (PBP) considering a project lifetime of 25 years was developed. Cost factors include expenses with electricity generation, initial investment, amortizations and operation and maintenance (containing fuels costs). Revenues were estimated from electricity generated and sales to the national grid. A sensitivity analysis based on the Monte Carlo method was used to measure the economic model performance and to determine the risk in investing in such venture. The risk appraisal yielded favorable investment projections, with an NPV reaching positive values, an IRR superior to the discount rate and PBP lower than the project life span. This work allowed to confirm the positive effect of the generation of energy from downdraft gasification plants on a small-scale. Regardless of the project’s feasibility, the economic performance depended to a large extent on the electricity prices which present considerable variability and are subject to political decisions.

ACS Style

Valter Silva; João Cardoso; Paulo Brito; Luís Tarelho; José Luz. Municipal Solid Waste as a valuable recycled asset for small-scale electricity production in rural communities. WEENTECH Proceedings in Energy 2019, 92 -106.

AMA Style

Valter Silva, João Cardoso, Paulo Brito, Luís Tarelho, José Luz. Municipal Solid Waste as a valuable recycled asset for small-scale electricity production in rural communities. WEENTECH Proceedings in Energy. 2019; ():92-106.

Chicago/Turabian Style

Valter Silva; João Cardoso; Paulo Brito; Luís Tarelho; José Luz. 2019. "Municipal Solid Waste as a valuable recycled asset for small-scale electricity production in rural communities." WEENTECH Proceedings in Energy , no. : 92-106.

Research article
Published: 10 May 2019 in International Journal of Energy Research
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In this work, a computational fluid dynamics (CFD) model was coupled with an advanced statistical strategy combining design of experiments (DoE) and the Monte Carlo method to comparatively optimize and test the robustness of two municipal solid waste (MSW) gasification processes one using air‐carbon dioxide (CO2) mixtures as a gasifying agent and the other using air alone. A 3k full factorial design of 18 computer simulations was performed using as input factors for air‐CO2 mixtures the equivalence ratio and CO2‐to‐MSW ratio, while MSW feeding rate and air flow rate were used for air gasification. The selected responses were CO2, H2, CO, and CnHm generation, CH4/H2 and H2/CO ratios, carbon conversion, and cold gas efficiency (CGE). Findings were that DoE allowed determining the best‐operating conditions to achieve optimal syngas quality. Monte Carlo identified the best‐operating conditions reaching a more stable high‐quality syngas. Air‐CO2 mixture gasification showed enhanced responses with major improvements in CO2 conversion and CGE, both up to a 13% increase. The optimal operating conditions that set the optimized responses showed to not always imply the most stable set of values to operate the system. Finally, this combined optimization process performance revealed to grant professionals the ability to make smarter decisions in an industrial environment.

ACS Style

João Cardoso; Valter Silva; Daniela Eusébio. Process optimization and robustness analysis of municipal solid waste gasification using air‐carbon dioxide mixtures as gasifying agent. International Journal of Energy Research 2019, 43, 4715 -4728.

AMA Style

João Cardoso, Valter Silva, Daniela Eusébio. Process optimization and robustness analysis of municipal solid waste gasification using air‐carbon dioxide mixtures as gasifying agent. International Journal of Energy Research. 2019; 43 (9):4715-4728.

Chicago/Turabian Style

João Cardoso; Valter Silva; Daniela Eusébio. 2019. "Process optimization and robustness analysis of municipal solid waste gasification using air‐carbon dioxide mixtures as gasifying agent." International Journal of Energy Research 43, no. 9: 4715-4728.

Journal article
Published: 19 March 2019 in Applied Energy
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In this paper, the influence of activation procedure on the long-term performance of membrane electrode assembly (MEA) is investigated. The MEAs are activated by most commonly used procedures; constant voltage and constant current. After activation, MEAs are implemented under 9000 aging cycles. During aging process, MEAs performance is evaluated using polarization curves, electrochemical impedance spectroscopy and cyclic voltammetry. The obtained results show that the activated MEA by constant current method shows an average voltage decay of 11.33 µV/cycle at 1 A/cm2, compared to 4.4 µV/cycle for the activated MEA by constant voltage procedure. This is due to the more reduction of electrochemical surface area for the activated MEA by constant current method (32% vs. 19%). Also, after 9000 degradation cycles, more severe platinum nanoparticles agglomeration is seen in the cathode catalyst layer of activated MEA by constant current procedure. This shows that MEA activation by constant current activation method not only need to the longer activation time, but also causes higher catalyst layer degradation.

ACS Style

Mohammad Mohammadi Taghiabadi; Mohammad Zhiani; Valter Silva. Effect of MEA activation method on the long-term performance of PEM fuel cell. Applied Energy 2019, 242, 602 -611.

AMA Style

Mohammad Mohammadi Taghiabadi, Mohammad Zhiani, Valter Silva. Effect of MEA activation method on the long-term performance of PEM fuel cell. Applied Energy. 2019; 242 ():602-611.

Chicago/Turabian Style

Mohammad Mohammadi Taghiabadi; Mohammad Zhiani; Valter Silva. 2019. "Effect of MEA activation method on the long-term performance of PEM fuel cell." Applied Energy 242, no. : 602-611.

Journal article
Published: 01 January 2019 in Thermal Science
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A mathematical model approach was employed to simulate olive pomace gasification in a bubbling fluidized bed reactor. To validate the model a set of gasification experiments were performed in a 250 kW quasi-industrial gasifier. The cold gas efficiency of the th gasifier and tar production were evaluated to assess the energy potential of olive pomace while determining its most suitable end-use applications. A techno-economic analysis addressing the comparison of two different commercially manufactured gasifying unit sizes (100 kW and 1000 kW) and a Monte-Carlo sensitivity analysis were employed to assess both the feasibility of each application size and also foresee the main investment risks in conducting olive pomace gasification in small rural facilities. Olive pomace gasification showed to be more suitable for personal household purposes. The low cold gas efficiency (around 20%) makes this producer gas more appropriate for small cogeneration facilities applications. The use of olive pomace residues in gasification showed viable economic performance in small cogeneration solutions at a scale of 1000 kW for agriculture waste-to-energy recovery in olive oil agriculture cooperatives, while 100 kW showed to be unable to reach an economically sustainable scenario. Final remarks point out that despite the feasibility of the venture at a scale of 1000 kW special concerns must be considered regarding the study attractiveness to potential investors.

ACS Style

João Cardoso; Valter Silva; Daniela Eusebio; Marta Trninic; Tiago Carvalho; Paulo Brito. Techno-economic analysis of olive pomace gasification for cogeneration applications in small facilities. Thermal Science 2019, 23, 1487 -1498.

AMA Style

João Cardoso, Valter Silva, Daniela Eusebio, Marta Trninic, Tiago Carvalho, Paulo Brito. Techno-economic analysis of olive pomace gasification for cogeneration applications in small facilities. Thermal Science. 2019; 23 (Suppl. 5):1487-1498.

Chicago/Turabian Style

João Cardoso; Valter Silva; Daniela Eusebio; Marta Trninic; Tiago Carvalho; Paulo Brito. 2019. "Techno-economic analysis of olive pomace gasification for cogeneration applications in small facilities." Thermal Science 23, no. Suppl. 5: 1487-1498.

Journal article
Published: 01 January 2019 in Chemical Industry and Chemical Engineering Quarterly
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A 2-D numerical simulation approach was implemented to describe the gasification process of olive pomace in a bubbling fluidized bed reactor. The numerical model was validated under experimental gasification runs performed in a 250 kWth quasi-industrial biomass gasifier. The producer gas composition, H2/CO ratio, CH4/H2 ratio, cold gas efficiency and tar content were evaluated. The most suitable applications for the potential use of olive pomace as an energy source in Portugal were assessed based on the results. A techno-economic study and a Monte Carlo sensitivity analysis were performed to assess the feasibility and foresee the main investment risks in conducting olive pomace gasification in small facilities. Results indicated that olive pomace gasification is more suitable for domestic purposes. The low cold gas efficiency of the process (around 20%) turns the process more appropriate for producer gas production in small cogeneration facilities. Olive pomace gasification solutions showed viable economic performance in small cogeneration solutions for agriculture waste-to-energy recovery in olive oil agriculture cooperatives. However, the slender profitability may turn the project unattractive for most investors from a financial standpoint.

ACS Style

João Cardoso; Valter Silva; Daniela Eusébio; Tiago Carvalho; Paulo Brito. Modelling and experimental analysis of a small-scale olive pomace gasifier for cogeneration applications: A techno-economic assessment. Chemical Industry and Chemical Engineering Quarterly 2019, 25, 329 -339.

AMA Style

João Cardoso, Valter Silva, Daniela Eusébio, Tiago Carvalho, Paulo Brito. Modelling and experimental analysis of a small-scale olive pomace gasifier for cogeneration applications: A techno-economic assessment. Chemical Industry and Chemical Engineering Quarterly. 2019; 25 (4):329-339.

Chicago/Turabian Style

João Cardoso; Valter Silva; Daniela Eusébio; Tiago Carvalho; Paulo Brito. 2019. "Modelling and experimental analysis of a small-scale olive pomace gasifier for cogeneration applications: A techno-economic assessment." Chemical Industry and Chemical Engineering Quarterly 25, no. 4: 329-339.

Journal article
Published: 10 December 2018 in Journal of Cleaner Production
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In 2017, deadly wildfires flared across central and north of Portugal. Following these events, the Government released a set of forestry policies promoting the increase of the currently installed forest biomass combustion thermal power plant capacity. In this study, we conduct a techno-economic analysis of an 11 MW gasification power plant, as a cleaner alternative to traditional combustion plants, dealing with forest biomass blends in Portugal central region. The analysis is built based on existing literature review and evaluation reports concerning investment projects in biomass-to-energy power plants. A spreadsheet economic model combining net present value (NPV), internal rate of return (IRR) and payback period (PBP) is developed over the plant’s lifetime period of 25 years. Cost factors incurred in initial investment, amortizations, fixed assets and working capital investments, financial income, operation and maintenance costs, employees and structure costs. Revenues are generated from selling electricity to the grid. A Monte Carlo sensitivity analysis is employed to gauge the economic model performance and investment risk. Lastly, an assessment of the environmental impact, noxious emissions and future prospects to this biomass-based energy conversion process are addressed. Results predict the feasibility of the project, with an NPV of 2.367 M€, an IRR of 8.66% and PBP of 23.1 years. Sensitivity analysis foresees affordable risks for investors, and that the project’s NPV is highly sensitive to the electricity sales price and electricity production. Despite the viability of the project delivered by the economic model, the economic performance is strongly reliant on revenues from electricity sales regulated by uncertain tariffs and reimbursements. Thus, special concerns must be considered regarding the project attractiveness to potential investors.

ACS Style

João Cardoso; Valter Silva; Daniela Eusébio. Techno-economic analysis of a biomass gasification power plant dealing with forestry residues blends for electricity production in Portugal. Journal of Cleaner Production 2018, 212, 741 -753.

AMA Style

João Cardoso, Valter Silva, Daniela Eusébio. Techno-economic analysis of a biomass gasification power plant dealing with forestry residues blends for electricity production in Portugal. Journal of Cleaner Production. 2018; 212 ():741-753.

Chicago/Turabian Style

João Cardoso; Valter Silva; Daniela Eusébio. 2018. "Techno-economic analysis of a biomass gasification power plant dealing with forestry residues blends for electricity production in Portugal." Journal of Cleaner Production 212, no. : 741-753.

Journal article
Published: 23 October 2018 in ChemEngineering
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A volume-of-fluid (VOF) finite volume model under the ANSYS® Fluent framework was coupled with the response surface method (RSM) to find the best operating conditions within a jettability window for two selected responses in a drop-on-demand inkjet printing process. Twenty-five runs were generated using a face centred design and numerical simulations were carried out using viscosity, surface tension, nozzle diameter, and inlet velocity as input factors. A mesh study was first conducted to establish the necessary number of cells to best combine accuracy and expended time. Selected runs were discussed, identifying the underpinning mechanisms behind the droplet generation at different time periods. Each one of the responses was evaluated under different input factors and their effects were identified. Finally, the desirability function concept was advantageously used to proceed with a multiple optimization where all the responses were targeted under usual jettability/printability conditions.

ACS Style

Nuno Couto; Valter Silva; João Cardoso; Leo M. González-Gutiérrez; Antonio Souto-Iglesias. Coupled CFD-Response Surface Method (RSM) Methodology for Optimizing Jettability Operating Conditions. ChemEngineering 2018, 2, 51 .

AMA Style

Nuno Couto, Valter Silva, João Cardoso, Leo M. González-Gutiérrez, Antonio Souto-Iglesias. Coupled CFD-Response Surface Method (RSM) Methodology for Optimizing Jettability Operating Conditions. ChemEngineering. 2018; 2 (4):51.

Chicago/Turabian Style

Nuno Couto; Valter Silva; João Cardoso; Leo M. González-Gutiérrez; Antonio Souto-Iglesias. 2018. "Coupled CFD-Response Surface Method (RSM) Methodology for Optimizing Jettability Operating Conditions." ChemEngineering 2, no. 4: 51.

Book chapter
Published: 03 October 2018 in Low Carbon Transition - Technical, Economic and Policy Assessment
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ACS Style

João Cardoso; Valter Bruno Reis E Silva; Daniela Eusébio. Introductory Chapter: Low Carbon Economy. An Overview. Low Carbon Transition - Technical, Economic and Policy Assessment 2018, 1 .

AMA Style

João Cardoso, Valter Bruno Reis E Silva, Daniela Eusébio. Introductory Chapter: Low Carbon Economy. An Overview. Low Carbon Transition - Technical, Economic and Policy Assessment. 2018; ():1.

Chicago/Turabian Style

João Cardoso; Valter Bruno Reis E Silva; Daniela Eusébio. 2018. "Introductory Chapter: Low Carbon Economy. An Overview." Low Carbon Transition - Technical, Economic and Policy Assessment , no. : 1.

Journal article
Published: 23 July 2018 in Renewable Energy
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2D and 3D simulations were carried out to predict the whole gasification process behaviour in a pilot-scale bubbling fluidized bed reactor. Special concern for the complex hydrodynamics phenomena within the fluidized bed was undertaken. The implemented multiphase Eulerian-Eulerian mathematical model was validated by comparison to experimental gasification runs and fluidization curves gathered from the pilot-scale fluidized bed. Appropriate 2D and 3D computational domains were achieved by applying a mesh sensitivity study. Solids distribution within the fluidized bed, mixing and segregation phenomena and binary mixture heat transfer were comparatively studied for both configurations. 3D simulations showed improved predicting performance with the experimental results. Also, 3D simulations presented improved segregation degree, while 2D simulations showed improved mixing index, alongside with a tendency to underestimate the reactor heat transfer behaviour. Main findings point to a general good agreement with some close resemblances in the solids distribution between the 2D and 3D simulations whenever quantitative values were considered, while in absolute terms larger discrepancies were seen. The bed expansion was misrepresented at higher superficial gas velocities to a great extent by the 2D configuration. Moreover, it was found that higher superficial gas velocity will induce higher differences between both configurations. Lastly, both configurations successfully described the general tendencies, however, 2D simulations are appropriate every time accuracy is not demanding, whereas 3D simulations should be considered for accurate predictions.

ACS Style

João Cardoso; Valter Silva; Daniela Eusébio; Paulo Brito; Ronney Mancebo Boloy; Luís Tarelho; José Luz Silveira. Comparative 2D and 3D analysis on the hydrodynamics behaviour during biomass gasification in a pilot-scale fluidized bed reactor. Renewable Energy 2018, 131, 713 -729.

AMA Style

João Cardoso, Valter Silva, Daniela Eusébio, Paulo Brito, Ronney Mancebo Boloy, Luís Tarelho, José Luz Silveira. Comparative 2D and 3D analysis on the hydrodynamics behaviour during biomass gasification in a pilot-scale fluidized bed reactor. Renewable Energy. 2018; 131 ():713-729.

Chicago/Turabian Style

João Cardoso; Valter Silva; Daniela Eusébio; Paulo Brito; Ronney Mancebo Boloy; Luís Tarelho; José Luz Silveira. 2018. "Comparative 2D and 3D analysis on the hydrodynamics behaviour during biomass gasification in a pilot-scale fluidized bed reactor." Renewable Energy 131, no. : 713-729.

Conference paper
Published: 03 June 2018 in Lecture Notes in Electrical Engineering
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A two dimensional CFD model for MSW gasification has been used to predict and analyze the viability of the hydrogen generation from MSW gasification. The model is based in an Eulerian-Eulerian approach to describe the transport of mass, momentum and energy for the solid and gas phases. The model is applied to a fluidized bed gasifier to full predict and analyze the viability of the hydrogen generation from MSW gasification taking into account the equivalence ratio and steam-to-waste ratio. Conclusion could be drawn that the increase of equivalence ratio has a negative effect on hydrogen production because the oxidation reactions are favored. The introduction of steam to MSW gasification is favorable for improving hydrogen yield, because it increases the partial pressure of steam inside the reactor which favors the gas-phase reactions.

ACS Style

Eliseu Monteiro; Nuno Couto; Valter Silva; Abel Rouboa. Assessment of Municipal Solid Wastes Gasification Through CFD Simulation. Lecture Notes in Electrical Engineering 2018, 662 -667.

AMA Style

Eliseu Monteiro, Nuno Couto, Valter Silva, Abel Rouboa. Assessment of Municipal Solid Wastes Gasification Through CFD Simulation. Lecture Notes in Electrical Engineering. 2018; ():662-667.

Chicago/Turabian Style

Eliseu Monteiro; Nuno Couto; Valter Silva; Abel Rouboa. 2018. "Assessment of Municipal Solid Wastes Gasification Through CFD Simulation." Lecture Notes in Electrical Engineering , no. : 662-667.

Journal article
Published: 01 May 2018 in Energy
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This paper presents a comparative scaling analysis of two different sized pilot-scale fluidized bed reactors operating with biomass substrates. A multiphase Eulerian-Eulerian 2-D mathematical model was implemented, coupled with in-house user-defined functions (UDF) built to enhance hydrodynamics and heat transfer phenomena. The model validation was attained by comparison to experimental data gathered from both reactors. A grid refinement study was carried out for both geometries to achieve an appropriate computational domain. Hydrodynamics was deeply studied for both reactors concerning the scale-up effect. Mixing and segregation phenomena, solid particle distribution and biomass velocity were matters of great concern. Results showed that UDF implementation successfully minimized deviations and increased the model’s predictability. The largest deviations measured between experimental and numerical results for syngas composition were of about 20%. Solids mixing and segregation was found to be directly affected by the particles size, density, and superficial gas velocity, with the larger reactor revealing improved mixing ability. Improved mixing occurred for smaller particles size ratio (dbiomass=3 mm), smaller particles density ratio (ρbiomass=950 kg/m3), and higher dimensionless superficial gas velocities (=3.5). The larger unit showed an increase in near-wall velocity, lateral dispersion, and bubble size. As for the smaller reactor, higher velocities were obtained at the center region due to a more pronounced wall boundary layer. Similarities were found between the two reactors regarding the bubble distribution, dimensionless average bed pressure drop and biomass velocity vector profiles when dimensionless parameters were employed.

ACS Style

J. Cardoso; V. Silva; D. Eusébio; P. Brito; M.J. Hall; L. Tarelho. Comparative scaling analysis of two different sized pilot-scale fluidized bed reactors operating with biomass substrates. Energy 2018, 151, 520 -535.

AMA Style

J. Cardoso, V. Silva, D. Eusébio, P. Brito, M.J. Hall, L. Tarelho. Comparative scaling analysis of two different sized pilot-scale fluidized bed reactors operating with biomass substrates. Energy. 2018; 151 ():520-535.

Chicago/Turabian Style

J. Cardoso; V. Silva; D. Eusébio; P. Brito; M.J. Hall; L. Tarelho. 2018. "Comparative scaling analysis of two different sized pilot-scale fluidized bed reactors operating with biomass substrates." Energy 151, no. : 520-535.

Book chapter
Published: 07 March 2018 in Statistical Approaches With Emphasis on Design of Experiments Applied to Chemical Processes
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Introductory Chapter: How to Use Design of Experiments Methodology to Get Most from Chemical Processes | IntechOpen, Published on: 2018-03-07. Authors: Valter Bruno Reis e Silva, Daniela Eusébio and João Cardoso

ACS Style

Valter Bruno Reis E Silva; Daniela Eusébio; João Cardoso. Introductory Chapter: How to Use Design of Experiments Methodology to Get Most from Chemical Processes. Statistical Approaches With Emphasis on Design of Experiments Applied to Chemical Processes 2018, 1 .

AMA Style

Valter Bruno Reis E Silva, Daniela Eusébio, João Cardoso. Introductory Chapter: How to Use Design of Experiments Methodology to Get Most from Chemical Processes. Statistical Approaches With Emphasis on Design of Experiments Applied to Chemical Processes. 2018; ():1.

Chicago/Turabian Style

Valter Bruno Reis E Silva; Daniela Eusébio; João Cardoso. 2018. "Introductory Chapter: How to Use Design of Experiments Methodology to Get Most from Chemical Processes." Statistical Approaches With Emphasis on Design of Experiments Applied to Chemical Processes , no. : 1.