Post combustion CO_2 capture by carbon fibre monolithic adsorbents

摘要

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.rnThis 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.rnFinally, 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.