Syngas Production via Supercritical Gasification of Leachate: A Review

Leachate is characterized as heterogeneous, recalcitrant wastewater, and potentially harmful pollutant to the environment and human health. It is encountered in landfills municipal disposal, which contains high concentrations of many organic and inorganic compounds such as Chemical Oxygen Demand (COD), Biochemical Oxygen Demand (BOD), Total Organic Carbon (TOC), and Total Nitrogen (TN). This report provides a comprehensive research review of syngas production characteristics via supercritical gasification (SCG) technology as a treatment before leachate is released to final waste disposal. This technology is worked by gasifying the leachate under supercritical water condition (500°C, 23 MPa) followed by syngas production such as H2, CO, CO2, CH4. First, we compare the essential characteristic of leachate by addressing the value of COD, TOC, pH, TN to understand effect contaminants that will be harmful. Second, the effect of gasification techniques are evaluated to syngas production and carbon gasification ratio. Finally, the landfill leachate treatment using supercritical gasification indicates that this method plays a vital role in treating leachate with syngas production that hydrogen is produced as abundant gas compares to the other. The result also summarizes future development that supercritical gasification technology is feasible to reduce leachate pollutants; therefore, it has the possibility to release into surface water.