Comparative studies of heat duty and total equivalent work of a new heat pump distillation with split flow process, conventional split flow process, and conventional baseline process for CO2 capture using monoethanolamine

Abstract

Two absorption/stripping process configurations, namely a new heat pump distillation with split flow process (HPDSFP) and split flow process with an overhead heat exchanger, were evaluated to minimize the energy consumption of CO2 capture from a 300MW power plant flue gas using 30wt% aqueous monoethanolamine (MEA). Their performances were compared with that of the baseline MEA process. All the processes were simulated using ProMax3.2 program. A rigorous model built on SWEET kinetics of ProMax was used to simulate the exothermic, reversible chemical reactions in MEA-CO2 system in the absorption/regeneration process. Sensitivity analyses were performed to evaluate the effects of key parameters (e.g. solvent circulation rate and lean CO2 loading) on energy requirement. Comparison of the HPDSFP, the split feed process with an overhead heat exchanger and the baseline process was conducted in terms of total equivalent work. In this work, the minimal total equivalent works of HPDSFP, the split flow process and baseline process were 0.37, 0.50 and 0.56GJ/tCO2, respectively. The simulation results showed that the new process configuration HPDSFP and split flow process with an overhead heat exchanger resulted in large improvements with reductions of total equivalent work by 10.7% and 33.9%, respectively.