A Review of Carbon Capture and Valorization Technologies

Global fossil fuel consumption has induced emissions of anthropogenic carbon dioxide (CO2), which has emanated global warming. Significant levels of CO2 are released continually into the atmosphere from the extraction of fossil fuels to their processing and combustion for heat and power generation including the fugitive emissions from industries and unmanaged waste management practices such as open burning of solid wastes. With an increase in the global population and the subsequent rise in energy demands and waste generation, the rate of CO2 release is at a much faster rate than its recycling through photosynthesis or fixation, which increases its net accumulation in the atmosphere. A large amount of CO2 is emitted into the atmosphere from various sources such as the combustion of fossil fuels in power plants, vehicles and manufacturing industries. Thus, carbon capture plays a key role in the race to achieve net zero emissions, paving a path for a decarbonized economy. To reduce the carbon footprints from industrial practices and vehicular emissions and attempt to mitigate the effects of global warming, several CO2 capturing and valorization technologies have become increasingly important. Hence, this article gives a statistical and geographical overview of CO2 and other greenhouse gas emissions based on source and sector. The review also describes different mechanisms involved in the capture and utilization of CO2 such as pre-combustion, post-combustion, oxy-fuels technologies, direct air capture, chemical looping combustion and gasification, ionic liquids, biological CO2 fixation and geological CO2 capture. The article also discusses the utilization of captured CO2 for value-added products such as clean energy, chemicals and materials (carbonates and polycarbonates and supercritical fluids). This article also highlights certain global industries involved in progressing some promising CO2 capture and utilization techniques.