Conceptual design of alternative energy systems from biomass

El sector energético se está dirigiendo hacia un nuevo paradigma, favoreciendo la aparición de procesos de conversión más eficientes, el uso de las fuentes de energía renovables y la micro-generación. La bioenergía es una solución prometedora para la futura combinación de energías. Los conceptos de ingeniería deben de integrarse junto con los aspectos económicos, ambientales y sociales en el desarrollo de proyectos. Los sistemas de energía centralizados y distribuidos necesitan enfoques a medida para explotar las características de cada posible sistema. Esta tesis investiga el potencial del sector bioenergético, mediante el estudio de la gasificación de biomasa a través de técnicas avanzadas de modelización de procesos y de la incorporación de la gestión de la cadena de suministro, en el marco del diseño conceptual para la toma de decisiones. Los sistemas estudiados son: (i) gasificación integrada con ciclo combinado y con métodos de captura y almacenamiento de CO2 (IGCC-CCS, 285 MWe) para los sistemas de energía centralizados, y (ii) un gasificador de biomasa combinada con un motor de gas (BG-GE, 14 kWe) para los sistemas de energía distribuidos. La superestructura concebida puede ser utilizada en el diseño preliminar de alternativas para los diferentes procesos considerados, para adaptar los ya existentes y para adquirir conocimiento sobre las condiciones de operación de plantas de gasificación. El problema de optimización multi-objetivo considerado evalúa el equilibrio entre los criterios técnico-económicos y ambientales de 25 escenarios, con mezclas de diferentes materias primas y cambios topológicos: mezclas de carbón, coque y biomasa y la generación de electricidad a partir de gas de síntesis, la generación de electricidad a partir de H2 y la producción de H2 puro, considerando o no el uso del gas de purga del PSA en el ciclo combinado. El análisis de Pareto revela que como mejores escenarios el que utiliza coque de petróleo como materia prima para producir H2, con reciclo del gas de purga del PSA y el que utiliza biomasa residual sin reaprovechamiento del gas de purga del PSA. La implementación de la tecnología CCS conlleva una penalización en la eficiencia de un 8,7% en términos de potencia neta, si el H2 se utiliza en el ciclo combinado. La gestión de cadenas de suministro de sistemas centralizados, señalan que España tiene potencial de biomasa residual, invirtiendo en nuevas centrales IGCC-CCS, o para producir electricidad mediante co-combustión en las centrales térmicas de carbón ya existentes. Para el primer caso, el valor actual neto óptimo es 230 millones de € para un periodo considerado de 25 años. Para el segundo caso, se ha calculado que las políticas de subvención en este tipo de proyectos deben de tener en cuenta la sostenibilidad económica, cubriendo en un rango de 5,84% a 20,25% el aumento de los precios de la electricidad. El caso de estudio propuesto y optimizado como ejemplo de un sistema distribuido tiene en cuenta una comunidad de Ghana en el marco de la electrificación rural, a abastecer con peladuras de yuca y mediante sistemas BG-GE. Los resultados revelan una red inviable. De las cadenas de suministro resultantes como óptimas, se puede deducir que cierto nivel de centralización es necesario para que las propuestas sean sostenibles en el tiempo. El sector de la bioenergía cumple ofrece ventajas en términos de impacto ambiental y social. Su implementación es posible con el apoyo de las tecnologías actuales de conversión de energía. Los principales retos están en la mejora de los procesos de pretratamiento de la biomasa y en su almacenamiento. La conversión de la biomasa, junto con los métodos de captura y almacenamiento de CO2, necesitan de incentivos políticos para poder penetrar definitivamente en el mercado, como sería el caso de cualquier otra tecnología alternativa de conversión de energíaThe energy sector faces a new energy paradigm, with more efficient conversion processes, renewable sources and micro-generation. Bioenergy is a promising solution. Engineering aspects must be integrated with economic, environmental and social aspects in bioenergy projects. Biomass properties enhancement is crucial. It concerns energy and matter densifications, for stabilisation and easier transport. Tailor-made approaches are needed to account for the characteristics of each potential system, being it centralised or distributed. This thesis has assessed the bioenergy potential using advanced modelling techniques, enlarged with supply chain management strategies, in the framework of conceptual design for decision-making. The studied energy systems are (i) an integrated gasification combined cycle power plant combined with carbon capture and storage (IGCC-CCS, 285 MWe) for centralised energy systems, and (ii) a biomass gasifier with a gas engine (BG-GE, 14 kWe) for distributed energy systems. Process system modelling and optimisation approaches are integrated with supply chain management to analyse co-gasification and co-production of electricity and hydrogen alternatives in IGCC-CCS, and co-combustion of biomass and coal in pulverised coal power plants in the light of economic and environmental considerations. Process modelling is integrated with supply chain management optimisation for rural electrification by BG-GE systems, considering economic, environmental and social issues. The superstructure can be used for the design of process alternatives, retrofit of existing ones and to gain knowledge on operation of IGCC-CCS. The multi-objective optimisation problem evaluates the trade-off between techno-economic and environmental criteria of 25 scenarios. Considerations comprise different coal, petcoke and biomass combinations and electricity generation from syngas, electricity generation from H2 and purified H2 production without and with PSA purge gas use in the combined cycle. The Pareto frontier analyses reveals that the scenario with petcoke as feedstock for H2 production with PSA flue gas profit is the best in terms of techno-economic optimisation. The scenario with residual biomass without PSA flue gas profit is the best in terms of environmental optimisation. CCS technology implementation leads to an efficiency penalty of 8.7% in net power terms if H2 is used in the IGCC. To maintain the same power level than that obtained with the combustion of syngas, the feedstock should be increased by 21% on a mass basis. Supply chain studies highlight, for Spain, a huge biomass waste potential for electricity and H2 production by investing on new IGCC-CCS power plants, or adaptation of existing plants. For the first case, the optimal NPV is around 230M€ for a period of 25 years. The sensitivity of the optimal solutions to changes in prices is demonstrated. For the second case, policy subsidies or alternatively price increases range from 5.84% to 20.25%. The investment is within 549M€ and 1640M€. A supply chain in a specific community from Ghana is proposed for rural electrification using cassava peels. Optimisations considers 9 communities and an overall electricity demand of 118 MWh/yr. The results reveal an unviable network. From the resulting networks, distributed approaches need a certain level of centralisation to be feasible on time. Bioenergy offers decisive advantages in terms of environmental and social impacts. Its deployment is straightforward to support with current energy conversion technologies. Challenges concern the biomass pre-treatment and storage. Despite all the striking advantages, political incentives are needed for definitive market entry, as would be the case for any energy conversion alternative.Postprint (published version

Economic evaluation of bio-based supply chains with CO2 capture and utilisation

Carbon capture and storage (CCS) and carbon capture and utilisation (CCU) are acknowledged as important R&D priorities to achieve environmental goals set for next decades. This work studies biomass-based energy supply chains with CO2 capture and utilisation. The problem is formulated as a mixed-integer linear program. This study presents a flexible supply chain superstructure to answer issues on economic and environmental benefits achievable by integrating biomass-coal plants, CO2 capture and utilisation plants; i.e. location of intermediate steps, fraction of CO2 emissions captured per plant, CO2 utilisation plants' size, among others. Moreover, eventual incentives and environmental revenues will be discussed to make an economically feasible project. A large-size case study located in Spain will be presented to highlight the proposed approach. Two key scenarios are envisaged: (i) Biomass, capture or utilisation of CO2 are not contemplated; (ii) Biomass, capture and CO2 utilisation are all considered. Finally, concluding remarks are drawn.Peer ReviewedPostprint (author's final draft

Integrated tool for IGCC power plants design.

Expanding economies and global warming are increasingly important and interrelated challenging issues which require cleaner and more efficient power plants designs to comply with sustainable energy demand are required. Integrated Gasification Combined Cycle (IGCC) power plants have an important role, because of their more efficient way of producing energy from fossil fuels. Actions are focused on clean power and H2 from coal, and bioproducts. So, one of the future of coal-based power generation strategies should be CO2 transport and storage in order to obtain a purer hydrogen stream. This paper proposes a methodology and supporting tool for estimating plant performance in terms of power effiency and environmental compliance and making an economic assessment for different scenarios. The technical performance has been modeled in Aspen Hysys and Aspen Plus, and models have been validated with real power plant data from ELCOGAS. Comparisons, in terms of power, emissions, efficiencies and costs between a wide variety of plant designs are presented: they enhance differences in raw material, purification units layout, and hydrogen obtention. Results obtained are examined and discussed towards future work.Peer ReviewedPostprint (author’s final draft

Characteristics and outcomes of adult patients in the PETHEMA registry with relapsed or refractory FLT3-ITD mutation-positive acute myeloid leukemia

This retrospective study investigated outcomes of 404 patients with relapsed/refractory (R/R) FMS-like tyrosine kinase 3 (FLT3)-internal tandem duplication (ITD) acute myeloid leukemia (AML) enrolled in the PETHEMA registry, pre-approval of tyrosine kinase inhibitors. Most patients (63%) had received first-line intensive therapy with 3 + 7. Subsequently, patients received salvage with intensive therapy (n = 261), non-intensive therapy (n = 63) or supportive care only (n = 80). Active salvage therapy (i.e., intensive or non-intensive therapy) resulted in a complete remission (CR) or CR without hematological recovery (CRi) rate of 42%. More patients achieved a CR/CRi with intensive (48%) compared with non-intensive (19%) salvage therapy (p < 0.001). In the overall population, median overall survival (OS) was 5.5 months; 1- and 5-year OS rates were 25% and 7%. OS was significantly (p < 0.001) prolonged with intensive or non-intensive salvage therapy compared with supportive therapy, and in those achieving CR/CRi versus no responders. Of 280 evaluable patients, 61 (22%) had an allogeneic stem-cell transplant after they had achieved CR/CRi. In conclusion, in this large cohort study, salvage treatment approaches for patients with FLT3-ITD mutated R/R AML were heterogeneous. Median OS was poor with both non-intensive and intensive salvage therapy, with best long-term outcomes obtained in patients who achieved CR/CRi and subsequently underwent allogeneic stem-cell transplant.This study was supported by Centro de Investigación Biomédica en Red Cáncer (CIBERONC), Valencia, Spain [CB16/12/00284]

Co-production of electricity and hydrogen from coal and biomass gasification

This work addresses the techno-economic and environmental analysis of an Integrated Gasification Combined Cycle power plant (IGCC) of 308 MWe of gross power, giving particular attention to co-gasification and co-production of electricity and H2. Products, sub-products and effluents distributions are estimated by means of an ad-hoc developed superstructure for conceptual design of syngas generation and treatment, delivering preliminary fiowsheets targeted to co-production. The resulting multi-objective optimization problem evaluates the trade-off between the cost of energy (COE), the total energy efficiency of the plant and the environmental impact evaluated through Impact 2002+ indicator. Sixteen scenarios are considered: 4 different feedstock's combined with 4 alteruative plant topologies; electricity generation from syngas, electricity generation from H2, and purified H2 production from fiue gas in a Pressure Swing Adsorption (PSA) unit in the Combined Cycle (CC). The case studies environmental boundary has been drawn from cradle to gateo The Pareto Frontiers (PF) for the Key Performance Indicators (KPIs) trade-off evaluation reveals that the scenario with petcoke as feedstock and H2 production with PSA fiue gas profit is the best one in terms of eHíciency maximization and COE minimization. Scenario with residual biomass without PSA fiue gas profit is the best in terms of environmental impact

Advanced simulation environment for clean power production in IGCC plants

Oxygen-blown biomass integrated gasification combined cycle (IGCC) plants are one of the most promising options for clean energy generation with CO2 abatement potential. However, the integrated nature of IGCC leads to difficult design problems. In this study, we present an advanced simulation environment for the preliminary design and retrofit of IGCC plants. We describe the modelling approach, the model validation strategy and the plant behaviour, as determined by sensitivity analyses. The simulation environment uses Pareto curves to examine various co-gasification and co-production case studies in terms of technical, economic and environmental performance. It serves as a decision support tool in the design stage, which can be used to explore ways to improve plant performance and to analyse the influence of raw materials and the unit’s operational parameters. The test and validation results are discussed.Peer ReviewedPostprint (published version

Co-production of electricity and hydrogen from coal and biomass gasification

This work addresses the techno-economic and environmental analysis of an Integrated Gasification Combined Cycle power plant (IGCC) of 308 MWe of gross power, giving particular attention to co-gasification and co-production of electricity and H2. Products, sub-products and effluents distributions are estimated by means of an ad-hoc developed superstructure for conceptual design of syngas generation and treatment, delivering preliminary fiowsheets targeted to co-production. The resulting multi-objective optimization problem evaluates the trade-off between the cost of energy (COE), the total energy efficiency of the plant and the environmental impact evaluated through Impact 2002+ indicator. Sixteen scenarios are considered: 4 different feedstock's combined with 4 alteruative plant topologies; electricity generation from syngas, electricity generation from H2, and purified H2 production from fiue gas in a Pressure Swing Adsorption (PSA) unit in the Combined Cycle (CC). The case studies environmental boundary has been drawn from cradle to gateo The Pareto Frontiers (PF) for the Key Performance Indicators (KPIs) trade-off evaluation reveals that the scenario with petcoke as feedstock and H2 production with PSA fiue gas profit is the best one in terms of eHíciency maximization and COE minimization. Scenario with residual biomass without PSA fiue gas profit is the best in terms of environmental impact.Postprint (published version

Advanced simulation environment for clean power production in IGCC plants

Oxygen-blown biomass integrated gasification combined cycle (IGCC) plants are one of the most promising options for clean energy generation with CO2 abatement potential. However, the integrated nature of IGCC leads to difficult design problems. In this study, we present an advanced simulation environment for the preliminary design and retrofit of IGCC plants. We describe the modelling approach, the model validation strategy and the plant behaviour, as determined by sensitivity analyses. The simulation environment uses Pareto curves to examine various co-gasification and co-production case studies in terms of technical, economic and environmental performance. It serves as a decision support tool in the design stage, which can be used to explore ways to improve plant performance and to analyse the influence of raw materials and the unit’s operational parameters. The test and validation results are discussed.Peer Reviewe

Co-production of electricity and hydrogen from coal and biomass gasification

This work addresses the techno-economic and environmental analysis of an Integrated Gasification Combined Cycle power plant (IGCC) of 308 MWe of gross power, giving particular attention to co-gasification and co-production of electricity and H2. Products, sub-products and effluents distributions are estimated by means of an ad-hoc developed superstructure for conceptual design of syngas generation and treatment, delivering preliminary fiowsheets targeted to co-production. The resulting multi-objective optimization problem evaluates the trade-off between the cost of energy (COE), the total energy efficiency of the plant and the environmental impact evaluated through Impact 2002+ indicator. Sixteen scenarios are considered: 4 different feedstock's combined with 4 alteruative plant topologies; electricity generation from syngas, electricity generation from H2, and purified H2 production from fiue gas in a Pressure Swing Adsorption (PSA) unit in the Combined Cycle (CC). The case studies environmental boundary has been drawn from cradle to gateo The Pareto Frontiers (PF) for the Key Performance Indicators (KPIs) trade-off evaluation reveals that the scenario with petcoke as feedstock and H2 production with PSA fiue gas profit is the best one in terms of eHíciency maximization and COE minimization. Scenario with residual biomass without PSA fiue gas profit is the best in terms of environmental impact

Towards a carbon-neutral energy sector: Opportunities and challenges of coordinated bioenergy supply Chains-A PSE approach

The electricity generation sector needs to reduce its environmental impact and dependence on fossil fuel, mainly from coal. Biomass is one of the most promising future options to produce electricity, given its potential contribution to climate change mitigation. Even though biomass is an old source of energy, it is not yet a well-established commodity. The use of biomass in large centralised systems requires the establishment of delivery channels to provide the desired feedstock with the necessary attributes, at the right time and place. In terms of time to deployment and cost of the solution, co-combustion/co-gasification of biomass and coal are presented as transition and short-medium term alternatives towards a carbon-neutral energy sector. Hence, there is a need to assess an effective introduction of co-combustion/co-gasification projects in the current electricity production share. The purpose of this work is to review recent steps in Process Systems Engineering towards bringing into reality individualised and ad-hoc solutions, by building a common but adjustable design platform to tailored approaches of biomass-based supply chains. Current solutions and the latest developments are presented and future needs under study are also identified.Peer Reviewe