A review on silica aerogels for CO2 capture applications

Abstract

In recent years, greenhouse gases known as, CH4, N2O, O-3, CFC and especially CO2 are released into the atmosphere through activities such as combustion, industrial emission or anaerobic decomposition and they cause an increase in surface temperature and global climate changes due to their high heat absorption capacities. Both political and scientific studies gained momentum as the countries of the world set the priority for the reduction of CO2 emissions. Developing methods for reducing global carbon emissions; are known as carbon capture and storage are known as (CCS) technologies. They are mainly classified as pre-combustion, post- combustion and oxyfuel combustion processes. Adsorption, physical and/or chemical absorption, membrane and cryogenic process can be considered as the most common CCS technologies. Porous solid sorbents can be also used for the physical adsorption of carbon dioxide from flue gases, as well. However, these processes are also known to have weaknesses in terms of both selectivity and cyclic operation. More recently, modification of mesaporous materials with amine groups have been shown to be efficient solid adsorbents for CO2 capture. With this review, current scientific studies on the recent advances in carbon sorption applications of silica aerogels has been investigated. The review consists of three main sections: preparation and modification of silica aerogels, literature studies on CO2 sorption performances and future perspectives. As a result, it has been concluded that amine-modified silica aerogels are promising materials for the carbon capture for the post combustion processes with their superior properties.