Investigation into simulating Selective Exhaust Gas Recirculation and varying Pressurized Hot Water temperature on the performance of the Pilot-scale Advanced CO2 Capture Plant with 40 wt(%) MEA

Abstract

The concentration of an aqueous solution of amine affects the solvent regeneration energy requirement in the Post-combustion CO2 Capture (PCC) process. Therefore, this study investigates the performance of the impact of Selective Exhaust Gas Recirculation (S-EGR) under the influence of 40 wt(%) MEA i.e. 10 % above the benchmark Monoethanolamine (MEA) concentration and at 90 % CO2 capture efficiency due to its potential to reduce the Normalized Specific Reboiler Duty (N-SRD) of the CO2 capture process. The experimental research work was carried out at the United Kingdom Carbon Capture Storage Research Centre - Pilot-scale Advanced CO2 Capture Technology (UKCCSRC-PACT) National Core Facility, UK. The S-EGR was proposed as a means of CO2 enhancement at the inlet of the absorber column to expedite the driving force of CO2 absorption and consequently reduce the N-SRD. CO2 concentrations from 5.0 to 9.9 vol(%) of CO2 were studied. Also, this experiment studied the influence of the Pressurized Hot Water (PHW) inlet temperature at the reboiler on the performance of the CO2 capture process that includes the CO2 recovery rate, CO2 loadings and N-SRD of the Solvent-based CO2 Capture Plant (SCCP) in order to study the variation of N-SRD with varying reboiler thermal inlet temperature at 9.0 vol(%) CO2.It is found that a pilot-scale CO2 capture process under the influence of simulated S-EGR reduces the N-SRD by 25.1 % under the test condition at 6.6 vol(%) CO2. This test condition was observed to have lower N-SRD as with regards to the other tests with different CO2 concentrations, below and above which the N-SRD begins to lose its value. It was also established that within the boundary of the process conditions used in these tests, the impact of the PHW temperature on the CO2 capture efficiency increases with increasing the PHW temperature, but at the detriment of N-SRD, which begins to increase above 125 °C despite more CO2 being captured.