Thermodynamic and economic analysis of a novel DME-power polygeneration system based on the integration of biomass gasification and alkaline electrolysis of water for hydrogen production

In order to efficiently utilize biomass resources, reduce dependence on fossil fuels, and produce clean fuels, this study proposed a new type of polygeneration system. The system innovatively couples alkaline electrolyzer hydrogen production and Brayton cycle power generation technology, aiming to optimize syngas composition and efficiently utilize waste heat. The system's reliability was verified through model verification and sensitivity analysis, and the key operating parameters were optimized. Energy and exergy analysis revealed the energy flow and loss of each link in the system, and economic analysis further evaluated the economic feasibility of the system. The results show that the energy and exergy efficiency of the system are 53.70 % and 48.59 %, respectively. The net cash flow is expected to be 50.53 million US dollars, and the payback period is 7.12 years. The system proposed in this study can realize the co-production of dimethyl ether and electricity simultaneously, with high energy utilization efficiency and economic benefits, providing an innovative technical path for efficient biomass conversion and clean energy production.