Process modeling and economic assessment of converting municipal solid waste into solid fuel via hydrothermal processing: a case study in Vietnam

As with any developing country, Vietnam has faced numerous challenges in the management and treatment of municipal solid waste (MSW). Vietnam consumed of 65.5 million tons coal in 2020, whilst a large amount of MSW was not able to use for energy production. Therefore, a searching for alternative fuels that could replace fossil fuel and reduce gases emission is an urgent need. In this study, the conversion of MSW into solid fuel was performed using hydrothermal treatment. Our results revealed that MSW treating by hydrothermal method at 220 °C produced solid fuel with calorific value of 4491 kcal/kg. As compared to coals using for thermal power plants, the quality of solid fuel was better. This implies the potential uses of solid fuel, which could be combusted independently or co-combusted with coals at the power sector. The simulation of MSW treatment by hydrothermal process with 240 MT/d was evaluated, two scenarios of treatment plant for solid fuel (HRtS) and electricity production (HRtE) were modeled and analyzed in terms of techno-economic feasibility. HRtS plant would generate 26,667 MT/y of solid fuel and total sale revenue of 2.47 million USD/y. Meanwhile, the HRtE plant would generate 19,880 MWh/y with 3.4 million USD/y.