Critical material and process issues for CO₂ separation from coal-powered plants

Concentrating CO₂ from the dilute coal combustion or gasification gas stream to a level suitable for sequestration purposes represents a major cost factor to curtail CO₂ emissions by capture and sequestration. This paper provides a short review of CO₂ capture incentives, current separation processes, and research progress of various new technologies. Scientifically, CO₂ can be separated from a gas mixture by all the methods reviewed in this work: distillation, absorption, adsorption, gas/solid reaction, membrane, electrochemical pump, hydrate formation, etc. The challenge lies in practical feasibility and ultimately the cost. Important material issues and their impacts to the process viability will be discussed.