Biofuel production from catalytic thermochemical conversion of animal manure and biomass

The objective of the research is to identify suitable catalysts to convert animal manure- based and biomass-based synthesis gas (syngas) to liquid biofuels such as mixed alcohols and hydrocarbons. Two pathways of catalytically converting syngas are investigated: (1)a two-step process involving the intermediate methanol and (2) one-step direct conversion process. A mixed stream of calibrated gases resembling the product synthesis gas composition from gasifying animal wastes and/or biomass is used as simulated feed syngas. The temperature controlled batch system consists of a 300 mL high-pressure vessel that can maintain high pressure (2-15 MPa) and mild temperature (100 - 300 °C). A series of batch runs include varying catalyst size, reaction time, temperature and pressure. To date, we have evaluated the efficacy of the Ru and Rh catalysts in synthesizing dimethylether (DME). The results show that under the operating conditions of 150- 200°C and 2 MPa, dimethyl ether (C-O-C bond formation) was the main product formed in preference to ethanol (C-C bond formation). The efficacy of synthesizing mixed alcohols from the simulated synthesis gases having the same composition is now underway. Furthermore,the effects of sulfur on the performance of sulfur resistant catalyst such as MoS₂ will also be investigated.