The Role of Alkaline/alkaline Earth Metal Oxides in CO2 Capture: A Concise Review
Emmanuel Victor *
Chemical Engineering Department, Federal University of Technology, Owerri, Nigeria.
Umenweke Great C
University of Kentucky Center for Applied Energy Research, Lexington, KY 40511, USA and Department of Chemistry, University of Kentucky, Lexington, KY 40506, USA.
Ngozichukwu B
Chemical Engineering Department, Texas A&M University, College Station, USA.
*Author to whom correspondence should be addressed.
Abstract
Reducing the concentration of CO2 from the atmosphere has attracted a lot of attention given the rapid level of industrialization in the world. Process Industries are one of the major contributors to this pollution in terms of the incessant release of CO2 from flue gas streams. In recent times metal oxides have received a lot of attention as potential adsorbents for solving this problem.They find application in post-, pre-, and oxy-combustion conditions. Their basic sites plus a lower charge to radius ratio increase their ionic nature and site basicity and facilitate the capture of this pernicious gas from flue gas streams by reacting to form carbonates, which when heated liberates an almost pure stream of CO2 which can be sequestered, thereby, aiding the release of environmentally benign flue gas streams to the atmosphere. This work takes a concise review of these metal oxides that have been widely studied.
Keywords: CO2, capture technology, carbonation, capture capacity, thermal stability, regeneration heat, structural properties.