(35e) Improved Intra-Column Heat Removal from a CO2-Capture Solvent System Via Modification of Additively Manufactured Intensified Packing Devices

Solvent-based CO₂ absorption is technologically the most matured CO₂ capture pathway, but still suffers from: (a) high regeneration energy demand, and (b) mid-column temperature rise brought about by reactive heat which lowers absorption efficiency. While scientists are developing non-aqueous and low-aqueous solvents for decreasing the regeneration heat, the mid-column temperature rise is typically dealt with by an external inter-stage heat-exchanger that cools the solvent; this approach increases the overall process footprint, capital, and operating costs. The current study explores a process intensification approach by incorporating inside the column an additively manufactured (3D-printed) intensified packing device that consists of corrugated plates and internal channels; the corrugated plates provide surface area for mass transfer between gas and liquid, while cooling fluid inside the internal channels removes heat from the exothermic reactive system. Two different intensified devices with specific surface areas of 250 m²/m³ and 350 m²/m³ were designed, manufactured, and tested by positioning, them one at a time, inside a 2.06-m long and 0.2-m diameter column packed with commercial Mellapak 250Y packing. The device with higher specific surface area showed up to 50% better cooling performance. A steady-state heat-transfer model provides good agreement with the experimentally obtained column temperature and intra-stage heat removal data. An earlier version of such intensified devices had shown a 10°C-decrease in the average solvent temperature along the column and increased the CO₂ capture efficiency by up to 25%. The improved designs of the current intensified devices are expected to produce better intra-stage solvent cooling and CO₂ capture efficiency improvement.