There is a great deal of social angst about the future of our energy supplies and the impact of energy use on climate change. Yet, daily we discard vast amounts of energy in the form of wet wastes whose carbon content is eventually evolved to the environment. Anaerobic digestion, where wastes are consumed by bacteria in the absence of oxygen, is increasingly being used to convert the wastes into a stream of methane (i.e. natural gas). Unfortunately, the process also produces large quantities of CO2 which itself contributes to global warming and so subtracts from the environmental advantages of digestion. This project is looking at ways in which a portion of the methane can be used to convert the CO2 into fuel. The fuel that would be produced will be nearly carbon neutral in that it is made from carbon that otherwise would be released to the environment and because it displaces the use of fossil fuels. In order to demonstrate that there really are net energy benefits from taking this approach we will use whole process studies to track mass and energy flows. Moreover, we will tap into some of the latest thinking in quantitative sustainability analysis and consider simultaneously the environmental, economic and social impact of what we propose. We believe that social acceptability is a key criterion for introducing technology of this sort and we will be consulting stakeholders and incorporating their views into our analyses. We see a future in which CO2 will be sustainably captured and converted into valuable materials - Carbon Capture and Utilisation (CCU). Our work will ensure a comprehensive and coordinated approach to the environmental case for CCU.
Not only is development of novel and necessarily complex processes required but also there will need to be real chemical engineering advances in terms of unit operations, materials and reaction routes. We have assembled a top level team of chemical engineers, physical chemists, theoretical chemists, environmental analysts and materials scientists to tackle this problem They will work on novel ways of separating the CO2 from the methane using a recently developed class of solvent materials, Ionic Liquids, that do not evaporate and which do not therefore create atmospheric emissions. These will be used in conjunction with a recent invention, the microbubble contactor, which promises drastically to cut the energy costs of the separation. The theoretical and physical chemists will look at novel approaches to catalysis which will let the reactions occur at under "green" conditions of temperature and pressure and the chemical engineers will look at novel reactors including high temperature gas electrolysis and corona assisted CO2 reduction.

Potential Impact:
Using the RCUK Typology, we see this project as having impact in five fields:
- Environmental sustainability, protection and impact
- Commercialisation and Exploitation
- Improving social welfare, social cohesion and/or national security
- Evidence based policy making and influencing public policies
- Increasing public engagement with research and related societal issues.
In fact, the social, environmental and economic importance of significant scale production of a sustainable, high energy density, economically viable, hydrocarbon fuel, derived from CO2, would be difficult to overestimate. However, the chemistry is thermodynamically adverse and feasible process routes to this objective have yet to be proven. This project will take a comprehensive and coordinated approach, pushing forward towards this far reaching objective. It will do so in a way which is both general, by working on novel ideas which are applicable across a broad range of applications of whatever scale, and specific by looking at a particular example of a local scale water industry process which provides a particularly fecund test bed for the ideas that we are developing. The beneficiaries from this work will therefore be:

Society because of:

The impact on Carbon emissions, sustainability and the environment
The lowered disruption to economic infrastructure required to achieve that environmental improvement
The opportunities for improved security of energy supply
The potential for stable and predictable energy prices
The availability of a broader range of validated energy options involving Carbon utilisation, leading to improved public engagement, a more informed public debate and better evidence based policy making

The UK Economy generally and in particular:

The water industry because of our detailed focus on the important area of water industry activity leading to validated processes for sustainable production of fuels from waste. During the project we will generate detailed information about a wide range of process options of direct relevance to the water industry. These will be of significant and immediate benefit as they fit directly in to the Industry's own development plans for the next decade. This is part of an important national trend injecting more process engineering into water treatment and engendering a greater concentration on process efficiency.

Wider industry wherever there are large scale CO2 emissions (steel, cement, oil, gas etc) or an interest in selling solutions to carbon emissions problems (see letter of support from Tata Steel). This will generate impact over the longer term because we will lead the way in developing new and validated methodologies for assessing sustainability and process efficiency in the context of applying leading edge technology.