It is now a widely accepted fact that carbon emissions from fossil fuel combustion and change in land use are forcing a rapid increase in atmospheric CO2 levels, with consequent enhancement of the greenhouse gas (GHG) effect leading to climate change. The UK has set a target of reducing the net CO₂ emission by 80% by 2050 (compared to a 1990 baseline). In order to achieve this target, multiple measures must be implemented. The development of a simple air capture technology to remove CO₂ from the atmosphere would go far to achieving these goals and provide an option for accelerating the correction and possibly reversing the trend in atmospheric CO₂ concentrations. Much effort is being expended on capturing CO₂ from fossil fuel plants, however, 50% of the emission comes from small distributed sources and transport. Considerable progress could be made if it was possible to develop a small-scale low maintenance device for local CHP (Combined Heat and Power) plants or domestic use. One of the major challenges in developing such a technology lies in the choice and development of a material that can efficiently absorb but also easily and with low energy cost desorb and concentrate the captured CO2 for further large scale storage or use in chemical synthesis approaches that are currently being developed.

This project consists of a number of interdisciplinary and speculative research activities that collectively are focused on the goal of determining the feasibility of developing a small scale carbon capture system (CCS) based on the adsorption properties of chemically functionalised carbon nanotubes (CNT).

Carbon nanotubes (CNT) are cylinders of pure carbon with diameters on the order of some nm and lengths that can range from 100nm to mm. They exist both as single-walled CNT where the wall of the cylinder is 1 atom thick and as multi-walled nanotubes where a number of cylinders are nested inside each other. The bulk material is extremely lightweight and highly porous and due to its high surface area is very suitable for gas storage applications. CNT also possess a high thermal and electrical conductivity and exhibit a rich chemistry. These properties all make them very promising materials for efficiently and selectively adsorbing and desorbing CO₂. The worldwide production of CNT has increased dramatically in the past couple of years and the price is falling rapidly, making the large scale application of bulk quantities of CNT feasible. The activities to be addressed include the synthesis and characterisation (including toxicological studies) of new CNT material with a high selectivity and affinity for CO₂ adsorption as well as potential for the development of selective gas sensors, the modelling and design of a small scale CCS taking into account extensive feedback from public consultation and a life cycle analysis to determine the economic and environmental feasibility of the development of such a system. Each activity in itself has the potential to produce ground-breaking developments and high impact results while the results of the combined suite of activities will provide a firm foundation for taking these ideas forward at a later stage to develop a prototype carbon capture system.

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