Post combustion CO 2 capture by carbon fibre monolithic adsorbents

Abstract

As generation of carbon dioxide (CO 2) greenhouse gas is inherent in the combustion of fossil fuels, effective capture of CO 2 from industrial and commercial operations is viewed as an important strategy which has the potential to achieve a significant reduction in atmospheric CO 2 levels. At present, there are three basic capture methods, i.e. post combustion capture, pre-combustion capture and oxy-fuel combustion. In pre-combustion, the fossil fuel is reacted with air or oxygen and is partially oxidized to form CO and H 2. Then it is reacted with steam to produce a mixture of CO 2 and more H 2. The H 2 can be used as fuel and the carbon dioxide is removed before combustion takes place. Oxy-combustion is when oxygen is used for combustion instead of air, which results in a flue gas that consists mainly of pure CO 2 and is potentially suitable for storage. In post combustion capture, CO 2 is captured from the flue gas obtained after the combustion of fossil fuel. The post combustion capture (PCC) method eliminates the need for substantial modifications to existing combustion processes and facilities; hence, it provides a means for near-term CO 2 capture for new and existing stationary fossil fuel-fired power plants. This paper briefly reviews CO 2 capture methods, classifies existing and emerging post combustion CO 2 capture technologies and compares their features. The paper goes on to investigate relevant studies on carbon fibre composite adsorbents for CO 2 capture, and discusses fabrication parameters of the adsorbents and their CO 2 adsorption performance in detail. The paper then addresses possible future system configurations of this process for commercial applications. Finally, while there are many inherent attractive features of flow-through channelled carbon fibre monolithic adsorbents with very high CO 2 adsorption capabilities, further work is required for them to be fully evaluated for their potential for large scale CO 2 capture from fossil fuel-fired power stations.