Aqueous phase reforming of model hydrothermal liquefaction wastewater with Pt/C and Ru/C catalysts

Aqueous Phase Reforming (APR) was conducted at a temperature of 225 °C, a pressure of 450 psi, and with two catalysts: 5 wt% platinum and 5 wt% ruthenium supported on active carbon. Single- and multi-component surrogate feedstocks consisting of acetic acid, acetone, ethanol, glycerol, succinic acid, and N-methylacetamide were tested to compare the two catalysts. Among the catalysts, the ruthenium catalyst consistently outperformed the platinum catalyst, achieving hydrogen yields of 77-100% compared to 44-54% with platinum for multi-component feedstocks. The wastewater resulting from the Hydrothermal Liquefaction (HTL) of Municipal Sewage Sludge (MSS) was tested at 225 and 250 °C, and at 450 and 650 psi. Results demonstrated that while hydrogen can be produced from MSS-HTL wastewater using a ruthenium catalyst supported on carbon, catalyst deactivation was severe. Future work is suggested to investigate methods to prevent catalyst deactivation due to carbonaceous solid deposition.