Analysis of integration of MEA-based CO2 capture and solar energy system for coal-based power plants based on thermo-economic structural theory

Abstract

Installing CO2 capture plants in coal-fired power stations will reduce greenhouse gas emissions and help mitigate climate change. However, the deployment of this technology faces many obstacles-in particular, high energy consumption. Aiming to address this challenge, we investigated the integration of a solar energy system in a 1000 MW coal-fired power plant equipped with monoethanolamine (MEA)-based CO2 capture (termed PG-CC) by comparing the thermo-economic performance of two integrated systems with that of PG-CC. In the first system, solar-aided coal-fired power generation equipped with MEA-based CO2 capture (SA-PG-CC), solar thermal was used to heat the high-pressure feed water in the power plant, while the reboiler duty of the capture plant's stripper was provided by extracted low-pressure steam from the power plant. The second system integrated the power plant with solar-aided MEA-based CO2 capture (SA-CC-PG), using solar thermal to heat the stripper's reboiler. Both systems were simulated in EBSILON Professional and Aspen Plus and analysed using thermo-economics theory. We then evaluated each system's thermodynamic and economic performance in terms of power generation and CO2 capture. Compared with PG-CC, the thermo-economic cost of electricity increased by 12.71% in SA-PG-CC and decreased by 9.77% in SA-CC-PG. The unit thermo-economic cost of CO2 was similar in both the PG-CC and SA-PG-CC systems, but significantly greater in SA-CC-PG. Overall, SA-PG-CC produced less power but used energy more effectively than SA-CC-PG. From a thermo-economic point of view, SA-PG-CC is therefore a better choice than SA-CC-PG.