Solid Sorbents for the Reversible Capture of Carbon Dioxide

Publisher Summary The use of fossil fuels at a global level causes a CO 2 yearly emission in the atmosphere of about 25 Gt. Fossil fuels provide for 85% of the world's energy needs, and no alternative energetic sources have the potential for a notable substitute in the foreseeable future. Among the different options under examination, the one considering capture and sequestration of CO 2 originated by point sources, like power plants and refineries, is gaining increasing interest. Such an approach could allow for the pursuance of fossil fuel utilization without the feared drawback of dramatic climatic changes. Key issue in this approach is the identification of a new efficient and convenient technology for the capture of CO 2 . Technologies available today, based on liquid amine solutions and finalized to the enhanced oil recovery (EOR), are considered far too expensive for large scale applications, such as in power plants. Solid sorbents, as compared to the liquid counterparts, have the potential advantages of a more efficient absorption capacity (high surface compounds allow for a high capture density), a lower energetic need in the desorption step (amine-CO 2 reaction compounds are surface distributed, with easy reach by fluids and heat), and a reduced environmental impact (no loss of amine to the atmosphere during the stripping step). The strategy for designing new sorbents consisted in screening different porous solids impregnated with diethanolamine (DEA), followed by screening the selected support impregnated with a variety of different types of amines.