(117c) Synthesis Gas Production by Autothermal Reforming of Crude Glycerol using a Dual Layer Monolith Catalyst

Crude glycerol is the principal by-product of biodiesel production via transesterification of triglycerides. For 3.33 kg of biodiesel produced, approximately 0.3 kg of crude glycerol is formed. As the demand and production of biodiesel increase exponentially, the utilization of the crude glycerol by-product will be of commercial significance. The conversion of crude glycerol to synthesis gas and then to methanol represents an important niche for glycerol processing that could relieve small biodiesel producers from high crude glycerol disposal cost while reducing their dependence on methanol from fossil fuels. The composition of crude glycerol varies depending on the feedstock and the biodiesel production process; glycerol content ranged between 38 and 96%, with containing up to 29% ash and 14% methanol. Those impurities may affect the catalyst activity. New results on the autothermal reforming of crude glycerol using the BASF dual layer monolith catalyst are presented and compared with results of pure glycerol. Heat management requires balancing the exothermic partial oxidation and endothermic reforming reactions in the catalytic autothermal reforming system. The composition of synthesis gas obtained was determined as a function of temperature, steam to carbon ratio, oxygen to carbon ratio and gas hourly space velocity. The optimum operating conditions to produce desired conversion of crude glycerol, yields of H2, and H2 /CO ratio with minimal coke formation were also determined. The Aspen simulation software package was used to determine the equilibrium product composition from major compounds for various reaction conditions. A comparison between process simulation results and experimental data was also made.