Applications & Pathways

In this paper a kind of on-board liquid hydrogen (LH2 ) cold energy utilization system for a heavy-duty fuel cell hybrid truck is proposed. Through this system the cold energy of LH2 is used for cooling the inlet air of a compressor and the coolant of the accessories cooling system sequentially to reduce the parasitic power including the air compressor water pump and radiator fan power. To estimate the cold energy utilization ratio and parasitic power saving capabilities of this system a model based on AMESim software was established and simulated under different ambient temperatures and fuel cell stack loads. The simulation results show that cold energy utilization ratio can keep at a high level except under extremely low ambient temperature and light load. Compared to the original LH2 system without cold energy utilization the total parasitic power consumption can be saved by up to 15% (namely 1.8 kW).

The energy supply in Austria is significantly based on fossil natural gas. Due to the necessary decarbonization of the heat and energy sector a switch to a green substitute is necessary to limit CO2 emissions. Especially innovative concepts such as power-to-gas establish the connection between the storage of volatile renewable energy and its conversion into green gases. In this paper different methanation strategies are applied on syngas from biomass gasification. The investigated syngas compositions range from traditional steam gasification sorption-enhanced reforming to the innovative CO2 gasification. As the producer gases show different compositions regarding the H2/COx ratio three possible methanation strategies (direct sub-stoichiometric and over-stoichiometric methanation) are defined and assessed with technological evaluation tools for possible future large-scale set-ups consisting of a gasification an electrolysis and a methanation unit. Due to its relative high share of hydrogen and the high technical maturity of this gasification mode syngas from steam gasification represents the most promising gas composition for downstream methanation. Sub-stoichiometric operation of this syngas with limited H2 dosage represents an attractive methanation strategy since the hydrogen utilization is optimized. The overall efficiency of the sub-stoichiometric methanation lies at 59.9%. Determined by laboratory methanation experiments a share of nearly 17 mol.% of CO2 needs to be separated to make injection into the natural gas grid possible. A technical feasible alternative avoiding possible carbon formation in the methanation reactor is the direct methanation of sorption-enhanced reforming syngas with an overall process efficiency in large-scale applications of 55.9%.

An adaptive response renewable energy plant (AREP) that provides grid balancing services and XeV station fuelling services (where “X” is any type) using renewable energy located in urban centres is described. The AREP has its own primary renewable energy sources and adapts operation in the short term to changing levels of excess or deficient energy on LV and MV electricity grids. The AREP adaptively responds by (1) storing excess energy in batteries for the short term and in hydrogen tanks after energy conversion by electrolysers for the long term; (2) returning power to the grid from either the AREP’s own primary (electron-based) energy sources or batteries and/or from hydrogen via conversion in fuel cells; (3) providing electricity for fast charging BeVs and PHeVs and hydrogen for FCeVs; and (4) exporting excess stored energy as hydrogen to domestic markets. The AREP also adapts over the long term by predictive planning of charging capacity such that the type and capacity of renewable energy equipment is optimised for future operations. A key advantage of this AREP configuration is a flexible “plug and play” capability with modular extension of energy assets. If the AREP footprint is constrained interaction with neighbouring AREPs as a mini-VPP-AREP network can assist in balancing short-term operating requirements. The benefits of this grid balancing and XeV renewable energy filling station or AREP are environmental social and economic through efficient functionality of appropriately sized components. AREPs provide a net zero emissions electricity solution to an existing network with short and long-term storage options as well as a net zero emissions fuel alternative to the transport sector while leveraging existing infrastructure with minimal upfront CAPEX. AREPs can give the flexibility a grid needs to enable high levels of renewable installations while developing green hydrogen production.

Mass-produced off-the-shelf automotive air compressors cannot be directly used for boosting a fuel cell vehicle (FCV) application in the same way that they are used in internal combustion engines since the requirements are different. These include a high pressure ratio a low mass flow rate a high efficiency requirement and a compact size. From the established fuel cell types the most promising for application in passenger cars or light commercial vehicle applications is the proton exchange membrane fuel cell (PEMFC) operating at around 80 ◦C. In this case an electric-assisted turbocharger (E-turbocharger) and electric supercharger (single or two-stage) are more suitable than screw and scroll compressors. In order to determine which type of these boosting options is the most suitable for FCV application and assess their individual merits a co-simulation of FCV powertrains between GT-SUITE and MATLAB/SIMULINK is realised to compare vehicle performance on the Worldwide Harmonised Light Vehicle Test Procedure (WLTP) driving cycle. The results showed that the vehicle equipped with an E-turbocharger had higher performance than the vehicle equipped with a two-stage compressor in the aspects of electric system efficiency (+1.6%) and driving range (+3.7%); however for the same maximal output power the vehicle’s stack was 12.5% heavier and larger. Then due to the existence of the turbine the E-turbocharger led to higher performance than the single-stage compressor for the same stack size. The solid oxide fuel cell is also promising for transportation application especially for a use as range extender. The results show that a 24-kWh electric vehicle can increase its driving range by 252% due to a 5 kW solid oxide fuel cell (SOFC) stack and a gas turbine recovery system. The WLTP driving range depends on the charge cycle but with a pure hydrogen tank of 6.2 kg the vehicle can reach more than 600 km.

Ethanol and palm oil biodiesel blended with diesel fuel have the potential to reduce greenhouse gas emissions such as carbon dioxide (CO2) and can gradually decrease dependence on fossil fuels. However the combustion products from these fuels such as oxides of nitrogen (NOx) total hydrocarbons (THC) and particulate matter (PM) require to be examined and any beneficial or detrimental effect to the environment needs to be assessed. This study investigates the hydrocarbon selective catalyst reduction (HC-SCR) activities by the effect of combustion using renewable fuels (biodiesel-ethanol-diesel) blends and the effect of hydrogen addition to the catalyst with the various diesel engine operating conditions. Lower values rate of heat released were recorded as the ethanol fraction increases resulting in trade-off where lower NOx was produced while greater concentration of carbon monoxide (CO) and THC was measured in the exhaust. Consequently increasing the THC/NOx promoting the NOx reduction activity (up to 43%). Additionally the HC-SCR performance was greatly heightened when hydrogen was added into the catalyst and able to improve the NOx reduction activity up to 73%. The experiment demonstrated plausible alternatives to improve the HC-SCR performance through the aids from fuel blends and hydrogen addition.

This paper presents a new model of fuel cells for two different modes of operation: constant fuel utilization control (constant stoichiometry condition) and constant fuel flow control (constant flow rate condition). The model solves the long-standing problem of mixing reversible and irreversible potentials (equilibrium and non-equilibrium states) in the Nernst voltage expression. Specifically a Nernstian gain term is introduced for the constant fuel utilization condition and it is shown that the Nernstian gain is an irreversibility in the computation of the output voltage of the fuel cell. A Nernstian loss term accounts for an irreversibility for the constant fuel flow operation. Simulation results are presented. The model has been validated against experimental data from the literature.

Carbonate looping (CaL) has been shown to be less energy-intensive when compared to mature carbon capture technologies. Further reduction in the efficiency penalties can be achieved by employing a more efficient source of heat for the calcination process instead of oxy-fuel combustion. In this study a kW-scale solid oxide fuel cell (SOFC)-integrated calciner was designed and developed to evaluate the technical feasibility of simultaneously generating power and driving the calcination process using the high-grade heat of the anode off-gas. Such a system can be integrated with CaL systems or employed as a negative-emission technology where the calcines are used to capture CO₂ from the atmosphere. The demonstration unit consisted of a planar SOFC stack operating at 750 °C and a combined afterburner/calciner to combust hydrogen slip from the anode off-gas and thermally decompose magnesite dolomite and limestone. The demonstrator generated up to 2 kWelDC power achieved a temperature in the range of 530–550 °C at the inlet of the afterburner and up to 678 °C in the calciner which was sufficient to demonstrate full calcination of magnesite and partial calcination of dolomite. However in order to achieve the temperature required for calcination of limestone further scale-up and heat integration are needed. These results confirmed technical feasibility of the SOFC-calciner concept for production of calcined materials either for the market or for direct air capture (DAC).

Green hydrogen for mobility represents an alternative to conventional fuel to decarbonize the transportation sector. Nevertheless the thermodynamic properties make the transport and the storage of this energy carrier at standard conditions inefficient. Therefore this study deploys a georeferenced optimal transport infrastructure for four base case scenarios in France and Germany that differs by production distribution based on wind power potential and demand capacities for the mobility sector at different penetration shares for 2030 and 2050. The restrained transport network to the road infrastructure allows focusing on the optimum combination of trucks operating at different states of aggregations and storage technologies and its impact on the annual cost and hydrogen flow using linear programming. Furthermore four other scenarios with production cost investigate the impact of upstream supply chain cost and eight scenarios with daily transport and storage optimization analyse the modeling method sensitivity. The results show that compressed hydrogen gas at a high presser level around 500 bar was on average a better option. However at an early stage of hydrogen fuel penetration substituting compressed gas at low to medium pressure levels by liquid organic hydrogen carrier minimizes the transport and storage costs. Finally in France hydrogen production matches population distribution in contrast to Germany which suffers from supply and demand disparity.

The need to reduce the climate impact of the transport sector has led to an increasing interest in the utilisation of alternative fuels. Producing advanced fuels through the integration of anaerobic digestion and power-to-fuel technologies may offer a solution to reduce greenhouse gas emissions from difficult to decarbonise modes of transport such as heavy goods vehicles shipping and commercial aviation while also offering wider system benefits. This paper investigates the energy balance of power-to-fuel (power-to-methane power-to-methanol power-to-Fischer-Tropsch fuels) production integrated with a biogas facility co-digesting grass silage and dairy slurry. Through the integration of power-to-methane with anaerobic digestion an increase in system gross energy of 62.6% was found. Power-to-methanol integration with the biogas system increased the gross energy by 50% while power-to-Fischer-Tropsch fuels increased the gross energy yield by 32%. The parasitic energy demand for hydrogen production was highlighted as the most significant factor for integrated biogas and power-to-fuel facilities. Consuming electricity that would otherwise have been curtailed and optimising the anaerobic digestion process were identified as key to improving the energetic efficiency of all system configurations. However the broad cross-sectoral benefits of the overarching cascading circular economy system such as providing electrical grid stability and utilising waste resources must also be considered for a comprehensive perspective on the integration of anaerobic digestion and power-to-fuel.

Solid oxide fuel cells (SOFCs) produce electricity with high electrical efficiency and fuel flexibility without pollution for example CO₂ NO_x SO_x and particles. Still numerous issues hindered the large‐scale commercialization of fuel cell at a large scale such as fuel storage mechanical failure catalytic degradation electrode poisoning from fuel and air for example lifetime in relation to cost. Computational fluid dynamics (CFD) couples various physical fields which is vital to reduce the redundant workload required for SOFC development. Modeling of SOFCs includes the coupling of charge transfer electrochemical reactions fluid flow energy transport and species transport. The Butler‐Volmer equation is frequently used to describe the coupling of electrochemical reactions with current density. The most frequently used is the activation‐ and diffusion‐controlled Butler‐Volmer equation. Three different electrode reaction models are examined in the study which is named case 1 case 2 and case 3 respectively. Case 1 is activation controlled while cases 2 and 3 are diffusion‐controlled which take the concentration of redox species into account. It is shown that case 1 gives the highest reaction rate followed by case 2 and case 3. Case 3 gives the lowest reaction rate and thus has a much lower current density and temperature. The change of activation overpotential does not follow the change of current density and temperature at the interface of the anode and electrolyte and interface of cathode and electrolyte which demonstrates the non‐linearity of the model. This study provides a reference to build electrochemical models of SOFCs and gives a deep understanding of the involved electrochemistry.

The Australian transport sector is under increasing pressure to reduce carbon emissions whilst also managing a fuel supply chain that relies heavily on foreign import partners.



Transport in Australia equates to a significant proportion (approximately 18%) of the country’s total greenhouse gas emissions. Due to ongoing population growth these emissions have been steadily rising with the increase of cars on our roads and freight trucks in transit. Coupled with this the transport fuel supply chain is highly reliant on overseas partners – Australia currently imports 90% of its liquid fuel. These two challenges present an interesting dichotomy for the industry incentivising research and development into new technologies that can address one or both of these issues.



Hydrogen is one technology that has the potential to provide a reduction in greenhouse gas emissions as well as a more reliable domestic fuel supply. Hydrogen fuel cell electric vehicles (FCEVs) are an emerging zero-emission alternative for the transport sector which offer a variety of benefits.



Available from the Energy Ministers Website link here

A research is under development at the Department of Agro-Environmental Sciences of the University of Bari “Aldo Moro” in order to investigate the suitable solutions of a power system based on solar energy (photovoltaic) and hydrogen integrated with a geothermal heat pump for powering a self sustained heated greenhouse. The electrical energy for heat pump operation is provided by a purpose-built array of solar photovoltaic modules which supplies also a water electrolyser system controlled by embedded pc; the generated dry hydrogen gas is conserved in suitable pressured storage tank. The hydrogen is used to produce electricity in a fuel cell in order to meet the above mentioned heat pump power demand when the photovoltaic system is inactive during winter night-time or the solar radiation level is insufficient to meet the electrical demand. The present work reports some theoretical and observed data about the electrolyzer operation. Indeed the electrolyzer has required particular attention because during the experimental tests it did not show a stable operation and it was registered a performance not properly consistent with the predicted performance by means of the theoretical study.

The House of Lords Science and Technology Committee will hear from leading researchers about anticipated developments in batteries and fuel cells over the next ten years that could contribute to meeting the net-zero target.

The Committee continues its inquiry into the Role of batteries and fuel cells in achieving Net Zero. It will ask a panel of experts about batteries hearing about the current state-of-the-art in technologies that are currently in deployment primarily lithium-ion batteries. It will also explore the potential of next generation technologies currently in development and the challenges in scaling them up to manufacture.

The Committee will then question a second panel about fuel cells hearing about the different types available and their applications. It will explore challenges that need to be overcome in the development of the technology and will consider the UK’s international standing in the sector.

Meeting details

At 10.00am: Oral evidence

Professor Serena Corr Chair in Functional Nanomaterials and Director of Research Department of Chemical and Biological Engineering at University of Sheffield

Professor Paul Shearing Professor in Chemical Engineering at University College London

Dr Jerry Barker Founder and Chief Technology Officer at Faradion Limited

Dr Melanie Loveridge Associate Professor Warwick Manufacturing Group at University of Warwick

At 11.00am: Oral evidence

Professor Andrea Russell Professor of Physical Electrochemistry at University of Southampton

Professor Anthony Kucernak Professor of Physical Chemistry Faculty of Natural Sciences at Imperial College London

Professor John Irvine Professor School of Chemistry at University of St Andrews

Possible questions

• What contribution are battery and fuel cell technologies currently making towards decarbonization in the UK?
• What advances do we expect to see in battery and fuel cell technologies and over what timeframes?
• How quickly can UK battery and fuel cell manufacture be scaled up to meet electrification demands?
• What are the challenges facing technological innovation and deployment in heavy transport?
• Are there any sectors where battery and fuel cell technologies are not currently used but could contribute to decarbonisation?
• What are the life cycle environmental impacts of batteries and fuel cells?

Parliament TV video of the meeting

This is part two of a three part enquiry.

Part one can be found here and part three can be found here.

The House of Lords Science and Technology Committee will question experts on the role of batteries and fuel cells for decarbonisation and how much they can contribute to meeting the net-zero target.

Tuesday’s evidence session will be the first of the committee’s new decarbonisation inquiry which was launched on Wednesday 3 March and is currently accepting written evidence submissions.

The session will give an overview of battery and fuel cell technologies and their applications in transport and other sectors. The Committee will ask how battery manufacture can be scaled up to meet wide-scale deployment of electric vehicles and whether technical challenges can be overcome to allow batteries and fuel cells to be used in HGVs and trains. The Committee will also investigate the wider use of batteries and fuel cells in various sectors including integration into power grids and heating systems.

Inquiry Role of batteries and fuel cells in achieving Net Zero

Professor Nigel Brandon Dean of the Faculty of Engineering at Imperial College London

Professor Mauro Pasta Associate Professor of Materials at University of Oxford

Professor Pam Thomas CEO at Faraday Institution and Pro Vice Chancellor for Research at University of Warwick

Mr Amer Gaffar Director of Manchester Fuel Cell Innovation Centre at Manchester Metropolitan University



Possible questions

What contribution are battery and fuel cell technologies currently making towards decarbonization in the UK?

What advances do we expect to see in battery and fuel cell technologies and over what timeframes?

How quickly can UK battery and fuel cell manufacture be scaled up to meet electrification demands?

What are the challenges facing technological innovation and deployment in heavy transport?

Are there any sectors where battery and fuel cell technologies are not currently used but could contribute to decarbonisation?

What are the life cycle environmental impacts of batteries and fuel cells?

Parliament TV video of the meeting​​​

This is part one of a three part enquiry.

Part two can be found here and part three can be found here.

The House of Lords Science and Technology Committee will hear from officials research funders and leading research consortia about the UK’s strategy for research and development of batteries and fuel cells to help meet the net-zero target.



The Committee will question officials from government departments and research councils about the UK’s increased support for battery development and how the initiatives and funding will evolve. The Committee will compare the support given to fuel cell research and ask how this technology will be developed for applications such as heavy transport. For both technologies it will ask how training will be delivered to provide a skilled workforce.



The Committee will also hear from leaders of research consortia asking them about support for their research sectors and how this compares with countries leading the development of the technologies. The Committee will explore coordination between research into batteries fuel cells and wider strategies such as for hydrogen and whether research for transport can be transferred to applications in other sectors such as power grids and heating.



At 10.00am: Oral evidence 

Mr Tony Harper Industrial Strategy Challenge Director Faraday Battery Challenge at UK Research and Innovation (UKRI) at University of Central Lancashire

Dr Lucy Martin Deputy Director of Cross-Council Programmes and lead for Net Zero at University of Central Lancashire

Dr Bob Moran Deputy Director Head of Environment Strategy at University of Central Lancashire

Professor Paul Monks Chief Scientific Adviser at University of Central Lancashire



At 11.00am: Oral evidence

Professor Philip Taylor Director at EPSRC Supergen Energy Networks Hub and Pro-Vice Chancellor for Research and Enterprise at University of Bristol

Professor David Greenwood CEO High Value Manufacturing Catapult at University of Central Lancashire Director Industrial Engagement at University of Central Lancashire and Professor of Advanced Propulsion Systems at University of Warwick

Professor Paul Dodds Professor of Energy Systems at University of Central Lancashire



Possible questions

• On which aspects of battery and fuel cell research and development is the UK focusing and why?
• How successful have the UK’s new research initiatives been in advancing battery science and application?
• Does battery research receive greater public funding than fuel cell research? If so why?
• What technologies are seen as the most likely options for heavy transport i.e. HGVs buses and trains?
• What is the Government’s strategy for supporting the growth of skilled workers for battery and fuel cell research and development?
• To what extent is battery and fuel cell research and development coordinated in the UK? If so who is responsible for this coordination?

Parliament TV video of the meeting



This is part three of a three part enquiry.

Part one can be found here and part two can be found here.

Current developments of non-relativistic quantum mechanics appear to predict and reveal counter-intuitive dynamical effects of hydrogen in nanostructured materials that are of considerable importance for basic research as well as for technological applications. In this review the experimental focus is on H₂O and H molecules in carbon nanotubes and other nanocavities that have been experimentally investigated using the well-established technique of incoherent inelastic neutron scattering (INS). For instance the momentum and energy transfers as obtained from the commonly used standard data analysis techniques from a

(I) H₂ molecule in a C-nanotube resulting in a roto-translational motion along the nanotube axis seems to (1) either violate the standard conservation laws or (2) to attribute to the H molecule undergoing translation the effective mass a.m.u. (atomic mass units) instead of the expected 2 a.m.u. A similar striking anomalous effect has been found in the neutron-H scattering from the

(II) H₂O molecules in nano-channels of some solid materials in which O-H stretching vibrations along the channel axis are created.

The results of this scattering process seem to once again either violate the standard conservation laws or to attribute to the effective mass of the struck H₂ molecule as a.m.u. instead of the expected value of 1 a.m.u. We show that these counterintuitive observations from the INS studies have no conventional interpretation within the standard non-relativistic scattering theory. However they can be qualitatively interpreted “from first principles” within the framework of modern theories of

(III) time-symmetric quantum dynamics as provided by the weak values (WV) and two-state- vector formalism (TSVF)

and/or

(IV) quantum correlations especially quantum discord (QD) and quantum thermodynamics (QTD).

The theoretical analysis provides an intuitive understanding of the experimental results gives strong evidence that the nano-structured cavities do represent quantum systems which participate significantly in the dynamics of the neutron-H scattering and surprisingly shows that new physical information can be derived from the experimental data. This latter point may also have far-reaching consequences for technology and material sciences (e.g. fuel cells H storage materials etc.). Moreover novel insights into the short-lived quantum dynamics and/or quantum information theory can be gained.

A compact air-breathing jet hybrid-electric engine coupled with solid oxide fuel cells (SOFC) is proposed to develop the propulsion system with high power-weight ratios and specific thrust. The heat exchanger for preheating air is integrated with nozzles. Therefore the exhaust in the nozzle expands during the heat exchange with compressed air. The nozzle inlet temperature is obviously improved. SOFCs can directly utilize the fuel of liquid natural gas after being heated. The performance parameters of the engine are acquired according to the built thermodynamic and mass models. The main conclusions are as follows. 1) The specific thrust of the engine is improved by 20.25% compared with that of the traditional jet engine. As pressure ratios rise the specific thrust increases up to 1.7 kN/(kg·s⁻¹). Meanwhile the nozzle inlet temperature decreases. However the temperature increases for the traditional combustion engine. 2) The power-weight ratio of the engine is superior to that of internal combustion engines and inferior to that of turbine engines when the power density of SOFC would be assumed to be that predicted for 2030. 3) The total pressure recovery coefficients of SOFCs combustors and preheaters have an obvious influence on the specific thrust of the engine and the power-weight ratio of the engine is strongly affected by the power density of SOFCs.

Europe has built up one of the best gas distribution infrastructures in the world. There’s one problem though. It distributes natural gas a fuel that we will hardly be able to use if we’re to reach our net zero targets. Can we use the infrastructure instead for clean hydrogen – either blended with natural gas as a stepping stone or with pure hydrogen in the future? In this episode we put aside discussion on the extent to which we should do this – and focus on whether or not we can do this and what’s involved in doing so.

Jon Slowe is joined by Eva Hennig Head of Department for EU Energy Policy at Thüga an alliance of German municipal energy companies (as well as chair of Eurogas’s distribution committee); Keith Owen Head of Systems Development and Energy Strategy at Northern Gas Networks in the UK; and Delta-EE expert Rob Castek.  

The Fuel Cells and Hydrogen Joint Undertaking (FCH JU) has supported a range of initiatives in recent years designed to develop hydrogen fuel cell buses to a point where they can fulfil their promise as a mainstream zero emission vehicle for public transport.<br/>Within this study 90 different European cities and regions have been supported in understanding the business case of fuel cell bus deployment and across these locations. The study analyses the funding and financing for fuel cell bus deployment to make them become a mainstream zero emission choice for public transport providers in cities and regions across Europe. It also outlines possible solutions for further deployment of FC buses beyond the subsidised phase.<br/>In the light of the experience of the joint tender process in the UK and in Germany the study highlights best practices for ordering fuel cell buses. Other innovative instruments explored in other countries for the orders of large quantities of fuel cells buses are presented: Special Purpose Vehicles and centralised purchase office. Finally the study deeply analyses the funding and financing for fuel cell bus deployment to make them become a mainstream zero emission choice for public transport providers in cities and regions across Europe.

With the rapid development of hydrogen vehicle technology and large scale fuel cell vehicle (FCV) demonstration project worldwide more hydrogen refueling stations need to be built. Safety distances of hydrogen refueling stations have always been a public concern and have become a critical issue to further implementation of hydrogen station. In this paper safety distances for 35MPa and 70MPa gaseous hydrogen refueling station are evaluated on the basis of the maximum consequences likely to occur. Four typical consequences of hydrogen release are considered in modeling: physical explosion jet fire flash fire and confined vapor cloud explosion. Results show that physical explosion and the worst case of confined vapor cloud explosion produce the longest harm effect distances for instantaneous and continuous release respectively indicating that they may be considered as leading consequences for the determination of safety distances. For both 35MPa station and 70MPa station safety measures must be implemented because the calculated safety distances of most hydrogen facilities can not meet the criteria in national code if without sufficient mitigation measures. In order to reduce the safety distances to meet the national code some mitigation measures are investigated including elevation of hydrogen facilities using smaller vessel and pipe work and setting enclosure around compressors. Results show that these measures are effective to improve safety but each has different effectiveness on safety distance reduction. The combination of these safety measures may effectively eliminate the hazard of 35MPa station however may be not enough for 70MPa station. Further improvements need to be studied for compressors inside 70MPa station.

Protonic ceramic fuel cells (PCFCs) are promising electrochemical devices for the efficient and clean conversion of hydrogen and low hydrocarbons into electrical energy. Their intermediate operation temperature (500–800 °C) proffers advantages in terms of greater component compatibility unnecessity of expensive noble metals for the electrocatalyst and no dilution of the fuel electrode due to water formation. Nevertheless the lower operating temperature in comparison to classic solid oxide fuel cells places significant demands on the cathode as the reaction kinetics are slower than those related to fuel oxidation in the anode or ion migration in the electrolyte. Cathode design and composition are therefore of crucial importance for the cell performance at low temperature. The different approaches that have been adopted for cathode materials research can be broadly classified into the categories of protonic–electronic conductors oxide-ionic–electronic conductors triple-conducting oxides and composite electrodes composed of oxides from two of the other categories. Here we review the relatively short history of PCFC cathode research discussing trends highlights and recent progress. Current understanding of reaction mechanisms is also discussed.

Hydrogen and its energy carriers such as liquid hydrogen (LH2) methylcyclohexane (MCH) and ammonia (NH3) are essential components of low-carbon energy systems. To utilize hydrogen energy the complete environmental merits of its supply chain should be evaluated. To understand the expected environmental benefit under the uncertainty of hydrogen technology development we conducted life-cycle inventory analysis and calculated CO2 emissions and their uncertainties attributed to the entire supply chain of hydrogen and NH3 power generation (co-firing and mono-firing) in Japan. Hydrogen was assumed to be produced from overseas renewable energy sources with LH2/MCH as the carrier and NH3 from natural gas or renewable energy sources. The Japanese life-cycle inventory database was used to calculate emissions. Monte Carlo simulations were performed to evaluate emission uncertainty and mitigation factors using hydrogen energy. For LH2 CO2 emission uncertainty during hydrogen liquefaction can be reduced by using low-carbon fuel. For MCH CO2 emissions were not significantly affected by power consumption of overseas processes; however it can be reduced by implementing low-carbon fuel and waste-heat utilization during MCH dehydrogenation. Low-carbon NH3 production processes significantly affected power generation whereas carbon capture and storage during NH3 production showed the greatest reduction in CO2 emission. In conclusion reducing CO2 emissions during the production of hydrogen and NH3 is key to realize low-carbon hydrogen energy systems.

Many Unmanned Air Vehicle (UAV) applications require vertical take-off and landing and very long-range capabilities. Fixed-wing aircraft need long runways to land and electric energy is still a bottleneck for helicopters which are not range efficient. In this paper we introduce the NederDrone a hybrid lift hybrid energy hydrogen-powered UAV that can perform vertical take-off and landings using its 12 propellers while flying efficiently in forward flight thanks to its fixed wings. The energy is supplied from a combination of hydrogen-driven Polymer Electrolyte Membrane fuel-cells for endurance and lithium batteries for high-power situations. The hydrogen is stored in a pressurized cylinder around which the UAV is optimized. This work analyses the selection of the concept the implemented safety elements the electronics and flight control and shows flight data including a 3h38 flight at sea while starting and landing from a small moving ship.

Managing the concentration of atmospheric CO₂ requires a multifaceted engineering strategy which remains a highly challenging task. Reducing atmospheric CO₂ (CO2R) by converting it to value-added chemicals in a carbon neutral footprint manner must be the ultimate goal. The latest progress in CO2R through either abiotic (artificial catalysts) or biotic (natural enzymes) processes is reviewed herein. Abiotic CO2R can be conducted in the aqueous phase that usually leads to the formation of a mixture of CO formic acid and hydrogen. By contrast a wide spectrum of hydrocarbon species is often observed by abiotic CO2R in the gaseous phase. On the other hand biotic CO2R is often conducted in the aqueous phase and a wide spectrum of value-added chemicals are obtained. Key to the success of the abiotic process is understanding the surface chemistry of catalysts which significantly governs the reactivity and selectivity of CO2R. However in biotic CO2R operation conditions and reactor design are crucial to reaching a neutral carbon footprint. Future research needs to look toward neutral or even negative carbon footprint CO2R processes. Having a deep insight into the scientific and technological aspect of both abiotic and biotic CO2R would advance in designing efficient catalysts and microalgae farming systems. Integrating the abiotic and biotic CO2R such as microbial fuel cells further diversifies the spectrum of CO2R.

This paper discusses the numerical modeling of an automobile fuel cell system using a two-stage turbo-compressor for air supply. The numerical model incorporates essential input parameters for air and hydrogen flow. The model also performed mass and energy balances across different components such as pump fan heat-exchanger air compressor and keeps in consideration the pressure losses across flow pipes and various mechanical parts. The compressor design process initiates with numerical analysis of the preliminary design of a highly efficient two-stage turbo compressor with an expander as a single-stage compressor has several limitations in terms of efficiency and pressure ratio. The compressor’s design parameters were carefully studied and analyzed with respect to the highly efficient fuel cell stack (FCS) used in modern hydrogen vehicles. The model is solved to evaluate the overall performance of PEM FCS. The final compressor has a total pressure and temperature of 4.2 bar and 149.3°C whereas the required power is 20.08kW with 3.18kW power losses and having a combined efficiency of 70.8%. According to the FC model with and without expander the net-power outputs are 98.15kW and 88.27kW respectively and the maximum efficiencies are 65.1% and 59.1% respectively. Therefore it can be concluded that a two-stage turbo compressor with a turbo-expander can have significant effects on overall system power and efficiency. The model can be used to predict and optimize system performance for PEM FCS at different operating conditions.