D2.4 - Packed-bed reactor using amine-ionic liquid -immobilized CAs blends for optimal capture of CO2 from off gas

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.