Developing Effective Adsorbent Technology for the Capture of CO2

The earths surface temperature has risen over the last century and appears to be facing a continued rapid warming. It is generally accepted that this increase in surface temperature is, at least in part, from human activities. The burning of fossil fuels, such as coal, oil, and natural gas, which release carbon dioxide (CO2) and other substances known as greenhouse gases into the atmosphere, is thought to be the main cause of this warming. As the atmosphere becomes richer in these gases, it becomes a better insulator, retaining more of the heat provided to the planet by the Sun. With the increasing rate of emission of CO2 into the atmosphere the chance of significant environmental and social damage increases. A rise in sea level over the next century, as a result of the melting of polar ice caps and glaciers, will lead to flooding some coastal regions and even entire islands. The potential consequences of global warming are so great that international cooperation and immediate action is required, such as the Kyoto Protocol, to counteract the problem.The worlds demand and use of energy, such as electricity, will continue to increase steadily over the next 30 years. The majority of which will come from developing countries. With no competitive alternative to fossil fuels currently available they will continue to dominate global energy use, ultimately leading to increased CO2 emissions. Until new, advanced technologies are developed for energy production, carbon capture and storage technologies are required. These will allow fossil fuels to be burned without emitting carbon dioxide into the atmosphere. Carbon capture and storage involves the removal of CO2 from large sources of the gas, such as fossil fuel burning power stations, for storage underground in, for example, depleted oil traps. If CO2 storage in geological formations is going to play a major role it needs to be in place by 2020, with demo plants operating from 2012-2013.The current technology, use of solutions of chemical compounds called amines, has a dominant position in natural gas and refinery gas treatment. However, the technique has a number of shortcomings for treating flue gases. The corrosive nature of the adsorbents, and energy intensive process of recovery of CO2 make the technique very costly and inefficient.To overcome the problems associated with current CO2 capture techniques, this research project involves the creation of a new generation of adsorbents – solids that can ‘soak up’ CO2 – to be used in power plants. Research will take place at Nottingham University, which has the most extensive programme for developing novel adsorbents within Europe. The adsorbents work on the principal that CO2 is a weak acid that can be trapped onto a solid base with the right characteristics and well developed pore-structure. Solid adsorbents will be created using stable polymers, with numerous active sites to soak up CO2. ‘Nanocasting’ a technique that uses various inorganic materials as templates will be used to give the polymer a tailored pore structure, a series of microscopic holes and cavities, to create a large surface area for CO2 capture. The first application of nanocasting for producing CO2 capture adsorbents. By variation of the polymer and template it is proposed that a range of highly stable, efficient adsorbents can be generated. The properties and ability of these novel materials to capture CO2 will be measured in the laboratory and using specially built equipment to simulate the conditions and make up of power station flue gases. Techniques for regeneration will be devised for selectively removing CO2 and other gases. The lifetime of the adsorbents will be measured using multiple adsorption and regeneration cycles. The ultimate goal of the project is to demonstrate the adsorbent materials in real power plant environments. The project will benefit energy producing companies and government bodies interested in the potential of CO2 capture techniques.