Hydrogen production from wet MSW entrained flow gasification based on drying and torrefaction pretreatment: Modeling and techno-economic study

Hydrogen production via gasification is an important approach for municipal solid waste (MSW) utilization. Most studies focus on gasification in fluidized beds or fixed beds using Refuse-derived fuel (RDF) prepared from MSW. However, the preparation of RDF requires effective waste classification, and the slow progress of waste sorting in developing countries has led to significant challenges in RDF preparation. This paper proposes a process based on raw wet MSW, involving drying, torrefaction, grinding, entrained-flow gasification, and hydrogen separation, which is more adapted to the current MSW situation in developing countries. Based on the proposed novel process, this study establishes a process simulation model for 500 T/D wet MSW-to-hydrogen conversion, investigating the impact of key operating parameters on hydrogen production. The results demonstrate that hydrogen yield initially increases with the equivalence ratio (ER) but subsequently declines, with the optimal yield occurring at an ER range of 0.3–0.32. Increasing the torrefaction temperature from 220 to 300 °C reduces hydrogen yield by 7.8 %. To further evaluate the process's economic viability and sustainability, a techno-economic analysis was conducted, complemented by extensive sensitivity analysis on economic indicators. The analysis reveals that the total investment is 523 million Renminbi (RMB), with equipment costs accounting for 42 %. Operational and maintenance costs lead to a hydrogen production cost of 15.38 RMB/kg, significantly lower than the current cost of green hydrogen produced via water electrolysis.