Project deliverable Open Access
Antonopoulou, Io; Rova, Ulrika; Christakopoulos, Paul
The goal of BioRECO2VER is to develop and validate the technical feasibility of more energy efficient and sustainable non-photosynthetic biotechnological processes for the capture and conversion of CO2 from industrial point sources into valuable platform chemicals. One of the specific objectives of the project is the development and application of robust enzymes for CO2 capture from industrial point sources and the improvement of a novel concept combining enzymatic absorption with ionic liquid-amine blends. It is aimed to achieve energy and cost reduction compared to the monoethanolamine (MEA)-based state-of-the-art technologies, increased resistance to major impurities and yield a concentrated gas stream of at least 95% CO2.
The objective of D2.4 was to demonstrate the operation of a packed-bed reactor using amine-ionic liquid-immobilized CAs blends for optimal capture of CO2 from off gas. Scaling up of the CO2 capture process using a packed-bed reactor requires the exploitation of the research outcomes of the project regarding CA improvement and the solvent development. The combination of CA with an MDEA-ionic liquid mixture would result in a ternary solvent with exceptional absorption properties compared to standard MDEA solvents and reduced regeneration temperatures compared to MEA-based technologies. Integration of immobilized and/or improved CA proved not to be a viable option for scaling up the CO2 capture. Nevertheless, integration of CA in free form with an amine-ionic liquid mixture for the CO2 capture from off gas using a packed-bed reactor on an automated absorption and stripping pilot plant, resulted in several fold higher absorption rates and CO2 recovery compared to aqueous solution of MDEA. CA-assisted CO2 absorption resulted in higher initial absorption rates, reduced absorption times and overall 25% higher CO2 recovery compared to absorption using only the ionic liquid-amine blend. This would improve the economics of CO2 capture technologies by reducing operation times and energy consumption due to regeneration, yielding a pre-treated concentrated gas stream of at least 92% CO2. The set-up is now ready to perform real off gas pre-treatment for validation testing during the project.