Performance improvement for chemical absorption of CO2 by global field synergy optimization

Chemical absorption of CO2 is deemed as an effectively controllable way to accomplish large reduction of greenhouse gas emission. A two dimensional (2-D) model for two-phase flows is established for chemical absorption of CO2 in the packed column. A good agreement has been reached between the simulated temperature and fluid flow profiles and experimental results. The field synergy equations are deduced to optimize the fluid flow, mass transfer, heat transfer and chemical reaction by an established Lagrange function. The synergy angle is an index to express the synergy degree among the physical phenomena. The global field synergy optimized velocity field, temperature distribution and gas concentration variation trend are obtained, contributing to improvement of 9% CO2 removal efficiency. Meanwhile, the entropy generation rate was well applied to quantify the overall improvement from the perspective of exergy. The results indicated that the entropy generation rate induced by mass transfer and reaction composes the most part of the irreversibility. The exergy loss is reduced by 12.8% after global field synergy optimization mainly for the two resistances reduction. The results showed that the field synergy optimization could be an intensification method for CO2 capture, whose improvement effect could be assessed by entropy generation analysis.

► To establish the two-phase flow model for CO2 capture process.
► Based on the field synergy model, to optimize the chemical absorption process.
► To increase capture efficiency and reduce exergy loss for performance improvement.
► To assess the overall field synergy effect based on entropy generation.