Investigating carbon formation in solid oxide fuel cell range extenders operating on sustainable alcohol fuels for electric vehicles

Energy costs are rising and the UK must address both energy security and climate change. Transport is a concern as it is particularly challenging to reduce its dependence upon fossil derived liquid fuels. In the transport sector there are three alternative energy carriers that are most often considered, biofuels, hydrogen and fuel cells, and battery electric vehicles. However, vehicles are complex consumer products and the replacement technology must in an ideal world have the following characteristics: good lifecycle efficiency, low cost, good availability, zero net CO2 emissions, high energy density, low cost of energy conversion device, and be easy to handle, transport and refuel. None of the three technologies fulfil all these requirements on their own. However, it is clear that the utilisation of biofuels in existing infrastructure and the electrification of road vehicles via plug in hybrids can deliver the quickest reductions in CO2 emissions from road transport in the near term. However, in the long run alternative technologies will be required. Full electrification and hydrogen fuel cells are often considered. However a fourth alternative, sustainable liquid alcohol fuels and solid oxide fuel cells (SOFCs) are often overlooked. The approach is synergistic as SOFCs can be used as range extenders for electric vehicles and the alcohol fuel with its high energy density can overcome some of the disadvantages of electric vehicles. It is also possible to make the alcohol fuels from renewable energy using a closed carbon cycle via atmospheric sequestration (or in the short term CO2 capture from flue gas) and reduction of CO2. Electrochemical reduction of CO2 is possible using SOFCs as solid oxide electrolysers (SOEC) to produce syngas (carbon monoxide and hydrogen) which is the first step in making a fuel via Fischer-Tropsch synthesis. Success will therefore offer a potential alternative to a hydrogen economy using sustainable liquid fuels and SOFCs with the advantage of higher energy densities and the ability to be transported in and used with existing fuel infrastructure and engine technologies, significantly reducing the risk and cost of transferring to a new energy carrier.Major challenges that need to be overcome to realise this are understanding carbon deposition in low cost intermediate temperature SOFCs, where carbon formation is a problem. A detailed understanding of the reaction kinetics involving carbon is therefore necessary in order to develop both SOFCs capable of operating on alcohol fuels and SOECs that can electrochemically reduce CO2. Existing electrode materials are also insufficient for this application, and developing a scientific understanding of carbon formation will enable new materials and electrode structures to be developed to mitigate carbon deposition. Investigations will involve emerging techniques such as in-situ Raman spectroscopy and the development of new in-situ techniques, alongside molecular modelling of reaction mechanisms and the development of new electrode materials and structures with controlled micro and nano morphologies.The development of solid oxide technology for this purpose will be groundbreaking, and investigating the mechanism for electrochemical reduction of CO2 in an SOEC entirely novel. In addition, the successful demonstration of electrochemical reduction of CO2 in SOECs will be transferrable to other areas, such as future robotic and even manned missions to Mars, where the atmosphere is over 95% CO2, and where fuel to power missions or a return trip will most likely have to generated in-situ from solar energy and local resources.

The innovation proposed in this proposal could have significant commercial impact. The development of solid oxide fuel cell range extenders for electric vehicles and solid oxide electrolysers for CO2 reduction could benefit solid oxide fuel cell developers such as Ceres Power; renewable fuel companies such as BioMCN and Greenergy; and automotive supply chain and automotive companies such as Lotus Engineering, Jaguar Land Rover, Lotus, Nissan, Frazer-Nash, Radical, Caterpillar and Toyota, with all of whom Imperial College has strong relationships. The principle advantage of a solid oxide fuel cell range extender over other fuel cell types is the potential to operate on liquid hydrocarbon and alcohol fuels with minimal reforming enabling them to facilitate and participate in a transitional shift to a low carbon economy. In addition the principle advantage of a solid oxide electrolyser over other electrolysers is the ability to reduce CO2 and therefore produce a syngas suitable for the production of a liquid fuel, and if combined with a carbon capture or sequestration technology represent a closed carbon cycle for renewable transport fuels. As a result the innovations in this proposal could benefit the wider UK community, both in terms of air quality improvements and therefore health, and also contributing to wealth generation and job creation by working with the fuel cell, fuel production and automotive supply chains. Given that the innovations proposed in this proposal could have significant commercial impact I will ensure that the necessary IP is protected by patents, filed through Imperial Innovations. Once IP is protected we will then engage in discussions with industry partners under appropriate non-disclosure agreements to protect IP sensitive material. My aim will be to ensure that Imperial is in a position to exploit the innovation through partnership between Imperial Innovations and the fuel cell, fuel production and automotive supply chain. Subsequent to patent filing, non-confidential outputs from the project will be widely disseminated via peer reviewed publication, presentations at major international conferences and the UK low carbon vehicle partnership, of which Imperial is an active participant. UK and International policy makers will also benefit from a greater understanding of the potential of these technologies to contribute to a low carbon economy. In particular the Dept of Energy & Climate Change and the Dept of Transport both of which I have very good links. The fundamental understanding, models and improved materials and fabrication techniques are likely to benefit the solid oxide fuel cell community as a whole, including those involved in the development of SOFCs for stationary power such as Rolls Royce Fuel Cell Systems. These partners will be engaged through the presentation of results at conferences and through peer reviewed publications. The realistic timescales for the scientific benefits, feasibility studies and policy guidance of the research are throughout the duration of the project. The timescales for commercial impacts will be towards the end of the project, therefore within 3-5 years of commencement of the project. Research and professional staff working on the project will develop an understanding of some of the main challenges facing the fuel cell, fuel production and automotive sectors in the transition to a low carbon economy. These skills are likely to be transferrable to all sectors of a low carbon economy.