Process configuration studies of the amine capture process for coal-fired power plants

• Ten amine processes were evaluated on the same flue gas and capture rate.
• Novel design concepts of amine process were proposed for greater energy saving.
• Energy penalty incurred by process integration for carbon capture was estimated.
• A 0.9% gain of net power efficiency is achievable with a novel amine process.
• The required steam extraction can be reduced with a novel amine process by 37%.

This study reports the detailed evaluation of ten different configurations of amine capture processes using 30 wt% aqueous monoethanolamine (MEA) solvent to capture 90% CO2 from an exemplary sub-critical PC-fired boiler power plant. The process configurations are compared with respect to total energy consumption, including thermal and electrical energy used. The comparison includes known configurations available in the literature and in patents. Additional configurations which lead to improved amine capture processes are presented, which result in further reduction in the reboiler heat duty. The use of detailed process flowsheet simulations enables the quantification of the effect of using multiple strategies in achieving greater reduction in the energy required for the integrated carbon capture and compression units. The simulations are also constrained to limit temperatures below conditions that lead to amine thermal degradation. Compared to the simple absorber/stripper configuration, which reduced the efficiency of the power plant by 9–12%, the multiple alteration system proposed in this study achieves the same capture rate with a 0.9% gain of net plant efficiency only by an advanced amine process configuration and a reduction in steam consumption of up to 37%.