Process intensification of CO2 capture by low-aqueous solvent

Low-energy solvent-based CO2 absorption processes have drawn attention as a next-generation post-combustion CO2 capture technology to reduce CO2 emissions from fossil fuel- or biomass-fired power generation and industrial flue gas streams. A low-aqueous (or water-lean) solvent process may substantially reduce the thermal energy consumption for solvent regeneration. Low-aqueous solvent-based processes are thermally sensitive, requiring a delicate temperature control within the absorber because of the fast exothermic amine-CO2 reaction and low heat capacity organic diluent. This reaction may result in heat accumulation in a packed absorption column and undesirable CO2 desorption occurring as the solvent moves through the column, reducing the solvent's CO2 capture efficiency if its temperature is not controlled. Using a 3D printed intensified packing device, enhanced heat and mass transfer were demonstrated in an amine-CO2 scrubbing process using low-aqueous solvent. The multifunctional intensified device facilitates contact of the reactive solvent and gas phases in a single stage and heat removal by a cooling fluid flowing through channels in the interior of the corrugated plates of the device. These functionalities led to effective thermal management along the column via intrastage cooling and significant improvement in CO2 uptake under a wide range of operating conditions. Intrastage cooling effectively reduced the solvent average temperature along the column by similar to 10 degrees C and, as a result, the solvent's capture efficiency improved by up to 25%.

Automated summary

This study investigates a novel intensified packing device for amine-CO2 scrubbing using low-aqueous solvent, which enhances heat and mass transfer efficiency to reduce the thermal energy consumption for solvent regeneration and improve CO2 capture efficiency under a wide range of operating conditions. The multifunctional intensified device facilitates contact between reactive solvent and gas phases in a single stage, while also allowing heat removal through a cooling fluid, leading to effective thermal management and significant improvement in CO2 uptake.