Plasma and Fluidic Assisted Electrocatalysis for Chemical Storage of Renewable Electricity

Our ambition is to couple electrocatalysis, plasma catalysis and fluidic oscillation to create a highly efficient energy conversion device and a paradigm shift in the ability to store renewable energy in chemical form.

The reduction in carbon emissions required for a sustainable future, and the resultant necessary decarbonisation of energy generation, inevitably lead to an increased focus on renewable energy sources. The natural intermittency of renewable electricity, such as wind and solar, mean that other technologies, such as energy storage, must play an increasingly fundamental role by smoothing the natural fluctuations in electricity production. Reversible Solid Oxide Cells (SOCs) are widely seen as a leading technology for future clean power generation, chemicals production and energy storage. Renewable electricity can be utilised directly in electrolysis mode to reduce CO2 and/or H2O which can then be further reacted to produce a myriad of hydrocarbon related products. In times of low or no renewable electricity generation, the SOC can be run in reverse, in fuel cell mode, to produce electricity.
There are currently no subsidy-free, commercially viable SOC companies anywhere in the world. Whilst single SOCs are easy to operate on a small scale in the laboratory, larger systems have found it difficult to compete with alternative energy technologies on cost, performance and durability. In particular, it is necessary to develop methods for lifetime extension of SOCs, minimisation of losses such as concentration polarisation, and faster chemical activation of CO2, using energy inputs close to the thermodynamic minimum.

Non-thermal plasma catalysis has shown great potential for CO2 reduction in its own right due to the promotion of strongly endothermic reactions with low activation energy, so that little or no excess energy is required from the plasma for activation and thermodynamic efficiencies are high. The challenges are to dynamically control the reaction and to achieve high conversion. Fluidic oscillation can disrupt boundary layer formation and therefore minimise, or remove completely, concentration polarisation. Fluidic oscillation has never before been coupled to an SOC.

We propose a novel, hybrid, plasma and fluidic assisted electrolysis system, in which the plasma is used to radically improve the kinetics and energy efficiency of CO2 dissociation. The system would be designed to reduce concentration polarisation, a cause of lowered mass transfer, at the electrode through fluidic oscillation to disrupt the gas boundary layer and by use of the ionic wind formed in plasmas (the gas flow generated by movement of ions in the plasma). Ultimately the aim is to create a completely new design of chemical reactor for strongly endothermic reactions. A significant reduction in overall energy use and cell failure rate will be achieved as a result of this feasibility research.

The project management and dissemination plans are designed to maximise impact. The research team has significant experience in promoting their research to a wide range of stakeholders. Using the RCUK Typology we see this project as having impact in at least ten fields covering economic, societal and academic impact.

Improving social welfare; Environmental sustainability, protection and impact:
The social and economic impact, nationally and globally, of sustainable, high energy density, economically viable energy storage for renewable electricity could hardly be overestimated. Decarbonisation of energy generation is essential for a sustainable future and efficient, reversible solid oxide cells could do this reliably.

Commercialisation & exploitation; Enhancing industrial research capacity:
Our work on microbubbles to date has demonstrated a track record for commercialisation. We will invite relevant industry and academics to a one-day symposium on plasma and fluidic assisted electrolysis. We will be assisted in this by the CO2Chem Network (>1100 members, 30% Overseas) and will also work with the Energy KTN to attract appropriate industry. This will not only disseminate project results but will engage industry in the research and provide valuable feedback to the project. In particular we will invite renewable energy producers and large to medium scale CO2 emitters (steel, cement, oil etc) with the will to collaborate to tackle their carbon emission issues. Interaction with the Advisory Board of the Energy Storage CDT, jointly hosted by Sheffield and Southampton, and the UK Centre for Carbon Dioxide Utilization, hosted by Sheffield, both of which the investigators are already actively involved with, will enhance industrial engagement. In addition we will produce an industry facing report on the project.

Increasing public awareness and understanding of science and energy issues:
Rothman is Director for Women in Engineering at Sheffield, leading all Equality and Diversity initiatives, as well as numerous engagement and outreach activities to inspire and educate future generations of engineers. She recently launched Sheffield's "Engineering Is..." campaign in the Houses of Parliament and regularly presents on her research to the public. We will capitalise on these and other public engagement activities, such as the Engineering Imagination (designed to inspire primary school children), Festival of the Mind (bringing together engineering, science and art) and British Science Week to ensure that the potential of solid oxide cells for renewable energy storage is fully understood. Two-way engagement will be ensured through careful design of activities. The PDRA employed by the project will also be actively involved in public engagement. Rothman will use her expertise in equality, diversity and inclusion to ensure all engagement activities are fully inclusive, in line with the ambition set out in RCUK's 2016 Action Plan for Equality, Diversity and Inclusion.

Enhancing knowledge; Global research position; Innovative methodologies, technologies and cross-disciplinary approaches; Health of the chemistry/chemical engineering interface; Training of highly skilled researchers:
The UK is regarded as being a leading nation in carbon dioxide utilisation and energy storage. This multidisciplinary project, covering engineering, chemistry and materials will help ensure we retain this position. Coupling of three technologies in which Sheffield and the UK are world leading will drive forward a potential economic, efficient solution for renewable energy storage. A clear priority is communication of the work at international conference and workshops and in high quality journals. This project will also provide a highly trained researcher with the vast ranging skill set necessary for the R&D programmes required for market innovation to occur. Interaction with Project Partners will further enhance knowledge and skill acquisition.