Energy, exergy and economic (3E) analyses of a novel DME-power polygeneration system with CO2 capture based on biomass gasification

With the global energy supply shortage and increasingly severe global environmental problems, lignocellulosic biomass is seen as a potential renewable energy source to replace traditional fossil fuels. Corn stover, an abundant renewable lignocellulosic biomass, has good application potential in biofuel production. This study innovatively proposes a polygeneration system that produces dimethyl ether (DME) and power simultaneously. The system integrates biomass gasification, supercritical CO2 Brayton cycle (S-CO2) power generation, and water gas shift (WGS), effectively converting corn straw into DME while generating electricity. Additionally, the carbon dioxide (CO2) produced in the system is captured using monoethanolamine chemical absorption methods. Perform sensitivity analysis on the system, analyze the impact of multiple factors on the product DME, and optimize various parameters. In addition, the system's energy, exergy, and economic efficiency were calculated, and the system's thermal performance and economic benefits were analyzed. The results show that the system's energy efficiency is 49.54%, and the exergy efficiency is 41.12%. The system has significant economic benefits, with the ability to recover initial investment within 7.12 years and achieve a net present value of approximately $21.30 million over a 20-year lifespan. [Display omitted] •A novel power and DME polygeneration system is proposed.•The system integrates biomass gasification and carbon capture.•Sensitivity analysis is performed to optimize operation parameters.•An energy, exergy, and economic analysis are conducted on the system.•The system has thermal efficiency of 49.54% and exergy efficiency of 41.12%.