Review of recent trends and various techniques for CO2 capture: Special emphasis on biphasic amine solvents

In the present scenario, the hazardous impacts of greenhouse gases can be restricted by adopting carbon capture and storage (CCS) technology that captures most of the CO2 emitted by numerous industries, human activities, and mostly from thermal power plants. This paper reviewed the main CO2 capturing technologies, i.e., pre-combustion, post-combustion, and oxy-combustion, along with their different operating conditions, performances, and comparisons. Some industrial processes used to capture CO2 by physical solvents are presented with their properties and working conditions. Methodologies like absorption, adsorption, membrane technology, cryogenic separation, and microalgae process are presented. Single alkanolamine-based solvents have limited CO2 loading and high regeneration energy demand, attracting researchers to work on their various amine blends. In today’s scenario, biphasic solvents play a vital role in the field of CO2 capture. Some amine solvent blends show biphasic behavior, leading to faster reaction, higher absorption capacity, and lower regeneration energy. The solvent screening for the biphasic solvent is very rigorous and still challenging. In this work, various blends selected by the researchers with the potential for phase-splitting behavior are reviewed, and the best among them is reported.