Process Intensification of Biological Methanation (BM) Systems

This project seeks to explore the idea of using biological enzymes immobilised on a biochar framework to convert carbon dioxide (CO2) to methanol (CH3OH). Biological enzymes present a powerful and sustainable alternative to inorganic catalysis; however, they also present a challenge. Enzymes must be robust enough to work within adverse environments, such as CO2 exhaust outflows. Free enzymes in solution also create unfeasibly high operational costs due to low recovery rates.

One of the most effective ways to solve these issues is through immobilization; unfortunately, many studies are limited by complex methodology and loss of enzyme activity. Biochar has recently emerged as a stable, inert, and economical matrix for enzyme immobilisation that could overcome these limitations. As opposed to being bound onto the matrix - which impacts activity - enzymes are instead held in place on the biochar by surface functional groups. This could create a bio-catalytic system that provides enzyme stability without affecting functionality; offering industries struggling to decarbonise a CO2-capture technology that generates an economic return on the significant investment required to implement capture-based solutions.

This study will begin by engineering biochar from sustainable UK-based forestry products to ensure its physiochemistry facilitates optimal enzyme attachment and activity. Then, it will determine the optimal conditions (pH, time, temperature, enzyme and ionic concentration) for enzyme binding. It will then test bio-catalysis of CO2 to methanol in pure CO2 and flue gas. Finally, if the study proof-of-concept is achieved, I hope to conduct lifecycle, technoeconomic and pathways-to-market analyses to determine process sustainability and identify pathways to accelerate technology uptake and adoption.

In 2018 alone, methanol production from fossil fuels contributed 211 million tonnes of CO2 emissions into the atmosphere. If proof of concept is achieved; this novel technology could replace the use of fossil fuels in methanol manufacturing, demand for which has reached 98 million tonnes in 2018 and is increasing. It could also create an opportunity for CCUS investment in growing industries struggling to eliminate CO2 emissions, such as the cement and steel industry, which contribute over 9% of global CO2 emissions. Methanol will also continue to be in demand in the future as a source of hydrogen for fuel cell vehicles and for conversion to dimethyl ether - a super clean diesel fuel for transport. This provision of sustainable methanol could assist in transport decarbonisation, transport is currently responsible for 6% of global CO2 output.

The leading method for CO2 capture and conversion to methanol is via rare-metal catalysis, which is associated with expense and sustainability concerns. This biocatalytic method will overcome these barriers by utilising biochar as the reaction matrix, to which the enzymes are attached. Biochar and enzymes are renewable, widely available, and affordable, which could result in a lower carbon footprint and a more competitive process. Also, the enzyme-mediated conversion performs optimally at lower temperatures and pressures, making it more energy-efficient.

This would be the first study of its kind to use biochar in a multi-enzyme cascade system. It is hoped that proof of the system's concept will incentivise further investigations into enzyme-mediated carbon capture.

The proposed Centre will benefit the following groups

1. Students - develop their professional skills, a broad technical and societal knowledge of the sector and a wider appreciation of the role decarbonised fuel systems will play in the UK and internationally. They will develop a strong network of peers who they can draw on in their professional careers. We will continue to offer our training to other Research Council PhD students and cross-fertilise our training with that offered under other CDT programmes, and similar initiatives where that develops mutual benefit. We will further enhance this offering by encouraging industrialists to undertake some of our training as Professional Development ensuring a broadening of the training cohort beyond academe. Students will be very employable due to their knowledge, skills and broad industrial understanding.
2. Industrial partners - Companies identify research priorities that underpin their long-term business goals and can access state of the art facilities within the HEIs involved to support that research. They do not need to pre-define the scope of their work at the outset, so that the Centre can remain responsive to their developing research needs. They may develop new products, services or models and have access to a potential employee cohort, with an advanced skill base. We have already established a track record in our predecessor CDTs, with graduates now acting as research managers and project supervisors within industry
3. Academic partners - accelerating research within the Energy research community in each HEI. We will develop the next generation of researchers and research leaders with a broader perspective than traditional PhD research and create a bedrock of research expertise within each HEI, developing supervisory skills across a broad range of topics and faculties and supporting HEIs' goals of high quality publications leading to research impacts and an informed group of educators within each HEI. .
4. Government and regulators - we will liaise with national and regional regulators and policy makers. We will conduct research directly aligned with the Government's Clean Growth Strategy, Mission Innovation and with the Industrial Strategy Challenge Fund's theme Prosper from the Energy Revolution, to help meet emission, energy security and affordability targets and we will seek to inform developing energy policy through new findings and impartial scientific advice. We will help to provide the skills base and future innovators to enable growth in the decarbonised energy sector.
5. Wider society and the publics - developing technologies to reduce carbon emissions and reduce the cost of a transition to a low carbon economy. Need to ascertain the publics' views on the proposed new technologies to ensure we are aligned with their views and that there will be general acceptance of the new technologies. Public engagement will be a two-way conversation where researchers will listen to the views of different publics, acknowledging that there are many publics and not just one uniform group. We will actively engage with public from including schools, our local communities and the 'interested' public, seeking to be honest providers of unbiased technical information in a way that is correct yet accessible.