564 research outputs found
Hydrogen & beyond:the Northern Netherlands energy transition
Get PDFThe global energy transition is at a pivotal moment, and hydrogen is emerging as a key player in reshaping our energy systems. With its potential to decarbonise industries, power homes, and fuel transportation, hydrogen is much more than just a technical challenge: it is a societal transformation. Prof. Aravind Purushothaman Vellayani has dedicated his career to exploring and advancing hydrogen and fuel cell technologies, focusing on their integration into real-world energy systems. As the head of the Energy Conversion Lab at the Energy and Sustainability Research Institute Groningen (ESRIG), he leads research on developing highly efficient, clean, and flexible energy conversion systems, ensuring that future energy solutions are not only sustainable but also practical and efficient.Hydrogen as a regional opportunityIn his inaugural lecture, Aravind P.V. will delve into the role of hydrogen in the Northern Netherlands, a region historically shaped by natural gas extraction. With the university’s strong commitment to sustainability and innovation, Groningen is uniquely positioned to lead in hydrogen research and application. As director of Hydrogen Economy at the Wubbo Ockels School for Energy and Climate, Aravind P.V. actively fosters interdisciplinary collaboration to ensure that hydrogen is not viewed in isolation but as part of a larger economic and societal shift. His research group plays a key role in this effort, focusing on system thermodynamics, fuel oxidation processes, and experimental and theoretical studies of hydrogen and other sustainable fuels such as ammonia, biogas, and biosyngas.Connecting disciplines and regionsEnergy transitions are not just about technology; they require coordinated efforts across disciplines, institutions, and regions. Aravind P.V. emphasises the importance of integrating expertise from multiple faculties: engineering, economics, social sciences, and policy studies; in order to shape informed decision-making. In addition, the Energy Conversion Lab takes this a step further by conducting cutting-edge research on combustion, electrochemical fuel oxidation, and advanced laser-based measurement techniques to study fuel conversion processes. These insights contribute to the development of ultra-high efficiency power plants, gasifier-fuel cell systems, reversible power plants, and carbon-neutral energy solutions. His work also extends beyond academia, strengthening ties with the Hydrogen Valley Campus Europe and other international knowledge hubs to share insights and accelerate the deployment of hydrogen solutions worldwide.Future PerspectivesAs the energy landscape continues to evolve, Aravind P.V. envisions a future where hydrogen is seamlessly integrated into the regional and global energy economy. His lecture will explore how advanced fuel oxidation studies, system thermodynamics, and exergy analysis—key research areas of his group—can help design the next generation of hydrogen energy systems that maximize efficiency while minimising environmental impact. By bridging academic knowledge with practical implementation, he aims to position Groningen as a key player in the hydrogen economy, both in the Netherlands and beyond
Simulation and Analysis of an Anode-Supported Solid Oxide Fuel Cell and Stack
No full textProcess and EnergyMechanical, Maritime and Materials Engineerin
Self-sufficient combined supercritical water gasification - solid oxide fuel cell system with integrated internal process waste stream recycling
No full textConfidentialSustainable Process and Energy TechnologyProcess and EnergyMechanical, Maritime and Materials Engineerin
Direct Internal Methane Steam Reforming in Operating Solid Oxide Fuel Cells: A kinetic modelling approach
No full textDirect Internal Reforming (DIR) on Solid Oxide Fuel Cell (SOFC) anodes is often considered for fuel cells systems utilising carbon based fuels. Methane Steam Reforming (MSR) is one of the most extensively studied types of DIR. The hydrogen formed by the MSR reaction can be electrochemically oxidised in the fuel cell to produce electricity, while the exothermic electrochemical reaction supplies heat to the endothermic MSR reaction. The balance is delicate and unsuitable design choices will result in operational problems and poor fuel cell performance. These issues are known for over two decades now and remain unsolved despite several attempts to capture the rate limiting kinetics of the reforming process on fuel cell anodes and modelling studies of methane fuelled SOFCs. It is not yet clear whether MSR kinetics derived from substrate measurements can be used to model SOFC performance and the influence of electrochemistry on the MSR reaction kinetics is rarely reported. In this work a rate equation is selected based on experimental observations and kinetics proposed in literature, on both industrial catalysts and SOFC anode materials. Ideal reactor models are derived for two specific test setup geometries, considering the electrochemical reactions in the anode. The ideal reactor models are then used to fit the parameters of the selected rate equation to experimental data from earlier work. The selected rate equation is of the Langmuir-Hinshelwood-Hougen-Watson type. The rate determining kinetics are characterised by the slow reaction of surface adsorbed carbon hydroxide forming carbon monoxide and atomic hydrogen. In addition surface coverage of atomic oxygen on the catalyst is limiting the available number of reaction sites. Two constants and their respective energies, associated with the activation of the rate limiting kinetics and the surface adsorption of oxygen, are fitted to experimental data. To evaluate the selected rate equation Computational Fluid Dynamics (CFD) type models are developed for the two experimental setups, one with a Ni?GDC anode and the other utilising a Ni?YSZ anode. These model are used to solve fluid dynamics, heat transfer, species transport, and electrochemistry. To model methane steam reforming in the fuel cell anode the selected rate equation is implemented in the CFD models. The obtained models are used to simulate MSR on the fuel cell anode for the experimental conditions. The modelled methane conversions and I-V characteristics are compared to the experimental values. The spatial distributions in the anode predicted with the selected rate equation and a power law model, fitted to the same experimental data, are compared to evaluate the use of global reaction models. For the Ni?GDC anode setup the model predicts the experimental methane conversions with good accuracy: the R2 value is with 0.987 close to unity. The experimental and modelled I-V characteristics are in good agreement. The model adopting a power law reaction mechanism underestimates the gradients in the anode. However, the model shows poor agreement with the experimental results obtained on the Ni?YSZ test setup. Large deviations with the temperatures and concentrations assumed in the ideal reactor model are found which might explain the inaccuracy of the model. The good agreement on the Ni?GDC anode suggests that MSR kinetics in SOFCs can be modelled for both open and closed circuit conditions with an appropriate intrinsic rate equation. This was not confirmed for the Ni?YSZ anode. Therefore further investigation with a combined experimental and modelling ap- proach, preferably on similar setups, is required.Sustainable Process and Energy TechnologyProcess and EnergyMechanical, Maritime and Materials Engineerin
Analysis and Simulation of an Anode Supported Solid Oxide Fuel Cell Single Channel for Operation with Biosyngas and Methane
No full textA three-dimensional thermo-fluid model coupled with electrochemical reaction for an anode-supported planar SOFC has been developed to investigate the internal processes and temperature distribution within a single cell unit for the design proposed by the Energy research Center of the Netherlands (ECN) in cooperation with TU Delft. The SOFC developed is for operation with natural gas. In this work, operation with biosyngas is evaluated. The electrochemical reactions, heat and mass transfer phenomena between the solid and gas phases have all been included in the cell model. The object is to investigate the complete cell using the models developed and make comparisons for the cell performance when fed with hydrogen, methane and different biosyngas compositions, come up with suggestions for efficient and ideal SOFC operation conditions when fed with different fuels and investigate safety issues under different working conditions. In order to clarify the goals of this work, the following questions have to be answered \u95 Is operation with biosyngas safe for the SOFC (Ni oxidation, carbon deposition)? \u95 Is operation with methane safe for the SOFC (Ni oxidation, carbon deposition)? \u95 What is the impact of different fuel compositions on SOFC performance? \u95 What is the impact of the steam reforming reaction of methane on the SOFC performance for operation with biosyngas and methane? \u95 What constructive suggestions can be made for further development of SOFCs?MSc Sustainable Energy TechnologyProcess and EnergyMechanical, Maritime and Materials Engineerin
3D reconstruction and electrochemical characterization of SOFC anode
No full textMechanical, Maritime and Materials EngineeringProcess and EnergySustainable Energy Technology (SET
Helio tracker: P.V. integrated shading device
No full textThe EU is committed to reducing the energy used and Co2 produced by 2050. Every component plays an important part in building an energy efficient building. This thesis looks at P.V. integrated shading devices.Shading devices are designed to block the excess solar radiation coming into the building to reduce the energy load of a building. This surface can be utilized to generate electricity by adding P.V. panels. P.V. panels are more efficient if they track the sun’s movement to increase the amount of solar radiation falling on the surface. The existing solar tracking devices fail due to multiple gears and the load of the panel on the rotational device.To tackle this problem heliotropic plants were studied. Heliotropic plants follow the sun’s movement to receive more solar radiation for photosynthesis. The internal mechanisms and forces of a sunflower (heliotropic plant) that cause this movement was analysed through an experiment and digital image correlation. The analysis showed that the sunflower’s stem utilizes water to expand and contract the sides of the stem in a diurnal pattern so that the stem can track the sun. This expansion and contraction curves the stem to move it 14 degrees which is sufficient to increase the solar radiation on the plant. This property of expansion and contraction was taken forward to design a sun tracking P.V. integrated shading to produce more energy. The expansion and contraction of the device were enabled by utilizing segments that were moved by piezo electric actuators. The Piezo electric actuator uses the energy generated from the P.V. panel and converts it to mechanical energy which enables the rotation of the device.To find the angle for rotation a simulation was made to find the angle at which the P.V. panel produces the most energy and the angle at which the shading device reduces the load on the heating or cooling device. The device is designed to track the change in the sun's altitude as this rotation produces the most energy for a P.V. panel and a shading device. The device responds to the change in altitude four times a year as this corresponds to the seasons to which the shading device rotates. There were two simulations made for the energy saved by the P.V. integrated shading device. The first simulation was for the Netherlands, factoring the energy saved by the shading device and the energy losses by the mechanical parts the device produces 196kW/ year and reduces the heating and cooling load by 16%. In Abu Dhabi, the same device produces 777kW/ year which reduces the cooling load by 15%.<br/
Bi-directional Solid Oxide Cells used as SOFC for Aircraft APU system and as SOEC to produce fuel at the airport
No full textLeaders of European union and G8 have set the target of 80% reduction in greenhouse gases emissions by 2050 by decarbonizing the power and transport sector. There are several pathways to achieve this, some of them being a) use of renewable power and biomass b) improvement in transport and building energy efficiency and c) replacement of fossil based fuel with sustainable fuel. This thesis is focussed on some of the measures which can be taken by Air Transportation Industry to reduce GHG emissions and carbon footprint. Although, there are many ways in which air transport industry can achieve this goal, this work mainly discusses a) increase in power generation efficiency of aircraft systems b) use of sustainable fuels for aircrafts and c) some ways for sustainable fuel production for aircrafts in an efficient and economic way. However, it is only starting point for discussion and can be further extended to include more efficient and cheaper technologies with reduced carbon foot-print. In this study, use of bi-directional Solid-Oxide Cells (SOC) as auxiliary power unit (APU) on-board commercial aircraft is explored. These bi-directional SOC APU units can be used in the airport energy network either to produce cleaner energy or to produce sustainable fuels depending on the energy demand. This work focusses on use of these bi-directional SOCs as fuel cells during flight operations and as electrolysers to produce sustainable fuel at the airport when the aircrafts are parked. Hence, complete fuel production plant is designed to be situated at the airport. The scope of this thesis is limited to production of fuel for aircraft APU use only. Further extension of this project can include use of these bi-directional SOCs for providing electricity to the airport and fuel for other purposes. For analysis, medium range aircrafts like A320 and B737 are considered. This system is designed and dimensioned for producing 500KW of electric power on-board aircarft. Jet fuel and ammonia are considered as fuel options for Solid Oxide Fuel Cell-Gas Turbine (SOFC-GT) based APU. Small scale airports like Eindhoven are studied to understand the flight frequency and parking duration for the aircrafts. These bi-directional SOCs are operational as Solid Oxide Electrolyzer Cell (SOEC) only when the aircraft is parked. Co-electrolysis is performed to produce syngas and steam electrolysis is done to produce hydrogen at the airport. Jet fuel is synthesized from syngas through Fischer Tropsch process and ammonia is synthesized from H2 and N2 through Haber Bosch process. Fuel synthesis plants are also designed as part of stationary fuel production plant at the airport. The fact that electrolyzer operates on excess available renewable electricity only, needs a special mention here. Intermittent nature of excess renewable electricity requires implementation of another source of sustainable syngas for fuel production so that sufficient capacity to supply all demand is ensured and robustness against delivery risks is achieved. Biomass gasification is one other method for generating fossil-free fuel. It uses biomass (birch wood) to produce syngas for sustainable fuel production at the aiport alongwith electrolysers. This leads to three cases of fuel production: - Case-1: Gasifier+fuel synthesis - Case-2: SOEC+fuel synthesis - Case-3: Gasifier+SOEC+Fuel synthesis ASPEN PLUS is used for modelling SOFC and stationary fuel production plant models with both jet fuel and ammonia. Modelling procedure for all the models is explained in detail with input parameters and process conditions. Thermodynamic analysis is carried out to compare the exergy efficiency of jet fuel and ammonia based SOFC-GT systems. It is observed that both jet fuel and ammonia based SOFC-GT systems give 62% and 58% exergy efficiency respectively which is higher than the conventional APU systems. Similarly, section by section exergy analysis is carried out for jet fuel and ammonia production plants to understand the exergy destructing processes. Comparison is made between exergy efficiency of jet fuel and ammonia production plants at the airport to understand thermodynamic behavior of both. Jet fuel synthesis produces significant amount of hydrogen and gasoline alongwith jet fuel as product. Therefore, two scenarios are analysed for exergy comparisons. a) Ammonia and jet fuel considered as product: Ammonia shows higher exergy efficiency than jet fuel production for all three cases enumerated above. b) Ammonia and (jet fuel, gasoline, hydrogen) are considered as useful products: For case-1 and case-3, jet fuel plant is exergetically more favorable than ammonia plant. However, for case-2, ammonia plant has higher exergy efficiency than jet fuel plant.SPETProcess and EnergyMechanical, Maritime and Materials Engineerin
Modeling a solid oxide fuel-assisted electrolysis cell in cycle tempo
No full textThis research forms a basis for the process of quantifying and simulating the reactions occurring within a Solid Oxide Fuel-Assisted Electrolysis Cell and the results emanating from it. This relatively new alternative application within the known SOFC is a subject of great interest. Initial laboratory tests predict it's highly efficient hydrogen production ability. A summation of previous works will be followed by a detailed explanation of the theory behind the SOFEC. In the whole report, comparisons will constantly be made with a SOFC, in an attempt to better understand the processes involved. This theoretical knowledge is expanded with a mathematical description of the internal processes involving the cell voltage, current density, resistance and voltage drop. These variables are linked together through a single equation. Based on the known SOFC equation, a SOFEC variant is proposed. This is done by breaking down the steps performed within Cycle Tempo. These are analyzed individually, an alterations are made. Afterwards, the actual programming code is analyzed, and all alterations are summarized. They are changed according to the proposed theory. With a working program, the results are finally analyzed and compared to the theory. This is followed by a chapter covering explaining the basics of the hydrogen economy. The advantages and problems occurring from this are summarized and a possible future implementation of the SOFEC is given. The report end with a conclusion and recommendations.Energy TechnologyProcess and EnergyMechanical, Maritime and Materials Engineerin
Modeling Of Radiative Heat Transfer In Solid Oxide Fuel Cells
No full textSolid Oxide Fuel Cells operate at high temperatures, which places stringent requirements on the ceramic materials in these devices. Optimizing the design by thermal stress minimization could increase the life expectancy of a fuel cell. In order to do this it is important to have a detailed understanding of the heat flows and temperature profiles in SOFCs. Because of the high temperatures it is expected that radiative heat transfer plays an important role in the thermal behavior of the cell. This phenomenon is however often neglected in SOFC modeling. Arguments often used for neglecting thermal radiation is the lack of knowledge of material properties or to save computational time. A literature study on thermal radiation in solid oxide fuel cells shows that the results from past research are not always in agreement. Some articles about radiation in the anode, cathode and electrolyte (or PEN-structure) even show completely contradictory results. Modeling studies have been performing in multiple steps, all simulations are performed using Ansys Fluent. The SOFC models are all hydrogen fueled. To study the effects of thermal radiation in the anode, cathode and electrolyte simplified 2D representations of the PEN-structure were developed. Because the material properties are not well known the results are obtained for a wide range of optical properties, on two different geometries. The results show that in the limit of high optical thickness of the anode and cathode the entire PEN-structure can be considered opaque, which means only radiation emitting from the anode and cathode surface will be important. Thermal radiation in the electrolyte has a negligible effect on the temperature profiles in the PEN-structure. To study the effect of surface-to-surface radiation a 2D model of a planar SOFC is developed. In this model uniform heat sources are used to account for the heat released due to electrochemical reactions and irreversibilities. Since the surface properties are not well known the temperature profiles throughout the domain are obtained for a wide range of optical properties, for both a co-flow and a counter-flow arrangement. The results show that thermal radiation has a very small effect on the temperature profiles in the domain. It was also found that the results are not very sensitive to the surface emissivities. The results are also obtained with the PEN-structure participating in radiative heat transfer, which verifies the statement that these materials can be considered opaque. To obtain more accurate results and to check the assumption of uniform heat sources a 3D-model of a single channel planar SOFC is developed. This model is also used to study the influence of participating gases. Instead of assuming uniform heat sources the ‘Fuel Cell and Electrolysis’ add-on module is used to model the relevant fuel cell phenomena. The model outputs show that using uniform heat sources is not an accurate assumption. The results also show that radiation has a very small effect on the temperature profiles in the domain, and that the ratio of radiative heat flux to total heat flux is not higher than 9%. Similar to the 2D planar cell model, the results are not sensitive to surface emissivities. The effect of participating gases is studied by considering water vapor as a participating component for the radiative transfer equation. The results show this participating gas has a negligible effect on the temperature profiles in the domain. The reason for small radiation effects is because temperature gradients are small in the direction were radiation has the most effect. Temperature gradients are shown to be dominant in axial direction, or in the direction of the flow, which is important for further studies on thermal stress minimization. To study the effect of radiative heat transfer in a completely different fuel cell design, a 3D model of an anode supported tubular SOFC is developed. The ‘SOFC with Unresolved Electrolyte’ add-on module is used to model the relevant fuel cell phenomena. It is expected that radiation effects are slightly more important in this tubular SOFC model. However this model does not work optimal yet, and no results with radiative heat transfer have been obtained yet. The results in this thesis show that radiative heat transfer in single channel SOFCs can be neglected when the temperature field has to be determined for thermal stress minimization.Sustainable Process And Energy TechnologiesProcess and EnergyMechanical, Maritime and Materials Engineerin
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