基于椰壳气化、固体氧化物燃料电池与余热回收的分布式多联产系统4E性能评估：电能、供热、淡水及绿色氢气生产与碳减排

Abstract In this study, a biomass-based multigeneration system, integrating coconut shells feedstock gasification with a solid oxide fuel cell, gas turbine, supercritical Brayton cycle, HDH desalination, and an alkaline electrolyzer for hydrogen production to function in a synchronized manner, has been developed and evaluated. Under the design conditions, the system converts low-heating-value biomass into approximately 492.5 kW of net electrical power and 226 kW of useful thermal energy, achieving net electrical efficiencies of 45.0 % on a biomass basis (57.5 % on a syngas basis) and an overall net energy efficiency of 67.6 %. Exergy analysis shows that 502.5 kW of useful exergy is recovered with an overall net exergy efficiency of 43.1 % (62.5 % on a syngas basis), while total exergy destruction is 369 kW, yielding a high sustainability index of approximately 2.96. The hydrogen production subsystem attains 61.1 % and 59.7 % energy and exergy efficiencies respectively, with oxygen by-product revenues reducing the levelized cost of hydrogen from $1.1981/kg to $0.5981/kg. Techno-economic analysis further reveals that the power production system has an ROI of 3.21 % and a payback period of 9.73 years, which improved dramatically to 56.48 % ROI and 5.68 years when by-product value (heating) is included, with LCOE dropping from $0.3153/kWh to $0.2694/kWh. Finally, exergoeconomic evaluation reveals that the power production subsystem exhibits an overall exergoeconomic factor of approximately 57 % and a relative cost difference of 173 %, identifying the gasifier and heat exchangers as primary targets for optimization due to their significant exergy destruction, while compressors and turbines display high-cost efficiency. In a broader perspective, the integrated system offers highly viable energetic, exergetic, and economic performance, providing a promising framework for sustainable multigeneration applications.