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.