Carbon Capture and Utilization Technology without Carbon Dioxide Purification and Pressurization: A Review on Its Necessity and Available Technologies

Carbon capture and utilization (CCU) has attracted increased attention as a means to mitigate and adapt to climate change. CCU technology regards CO2 as a raw material and reduces CO2 emissions. However, purity and pressurization requirements in most CCU technologies are high. Flue gas that is emitted from industries and transportation requires advanced purification and pressurization, which limits the development and decreases the feasibility of CCU application. Hence, a new approach to CCU technology without CO2 purification and pressurization is desirable. This study reviews differences between the CO2 purity and pressure of waste CO2 and feedstock CO2, reviews difficulties of CO2 purification and pressurization in recent developments of CCU, and provides several promising examples of CCU technologies without CO2 pressurization and/or purification. Various promising CCU technologies and their future research prospects are discussed. Mineral carbonation and biological conversion appear to be possible solutions as CCU technologies without CO2 purification and pressurization. For all other CCU approaches, research trials to decrease the required CO2 purity and pressure of the feedstock CO2 will be required.