A Review: CO2 Utilization

ABSTRACT

Global warming due to the accumulation of atmospheric CO₂ has received widespread attention in recent years. Although various CO₂ capture technologies have been proposed, using the captured CO₂ from power plants is increasingly popular because of concerns with regard to the safety of underground and ocean CO₂ storage. Various techniques related to utilization of CO₂ from the exhausted gas of power plants are discussed in this article. The existing and under-development technologies for CO₂ utilization in the world are briefly reviewed. Two categories, direct utilization of CO₂ and conversion of CO₂ to chemicals and energy products, are used to classify different forms of CO₂ utilization. Regarding the direct utilization of CO₂, in addition to its use in soft drinks, welding, foaming, and propellants, as well as the use of supercritical CO₂ as a solvent, CO₂ capture via photosynthesis to directly fix carbon into microalgae has also attracted the attention of researchers. The conversion of CO₂ into chemicals and energy products via this approach is a promising way to not only reduce the CO₂ emissions, but also generate more economic value. Since CO₂ is just a source of carbon without hydrogen, a clean, sustainable and cheap source of hydrogen should be developed. This article reviews the literature on the production of biofuel from microalgae cultivated using captured CO₂, the conversion of CO₂ with hydrogen to chemicals and energy products, and sustainable and clean sources of hydrogen, in order to demonstrate the potential of CO₂ utilization.