Hydrothermal Catalytic Gasification of Municipal Solid Waste

The influence of sodium hydroxide, water density and reaction temperature on the hydrothermal gasification of a compositionally complex municipal solid waste material in the form of refuse derived fuel (RDF) has been studied. RDF and sodium hydroxide corresponding to NaOH/C mass ratios of 0.2 to 1.2 were reacted at 375 °C using initial water densities of 0.04, 0.10, and 0.15 g·cm−3 in a 500 mL stainless steel batch reactor. The effect of reaction temperature was studied between 300 and 375 °C. The reactions produced a hydrogen-rich gaseous product. Other gases included CO, CO2, and small amounts of C1–C4 hydrocarbons. The results showed that hydrogen gas production increased dramatically with increasing NaOH/C mass ratio up to a ratio of 0.8 but decreased slightly when the ratio was increased to 1.2. CO2 and CO concentrations decreased with increasing NaOH/C mass ratio, indicating that NaOH catalyzed the gasification via removal of CO2 as carbonate. Hydrogen production was also enhanced with increasing wa...