Thermal Processing of Low-Grade Glycerol to Alcohols for Biodiesel Production, Phase 2

摘要

Conversion of crude glycerol to value added products can broaden its use and ultimately reduce the cost of biodiesel production. During the second year of the project, results from previous experiments were used to comprehensively investigate the thermochemical conversion of glycerol. A surface response experiment was conducted to find out the optimum temperature and reaction time. Statistical results showed that the highest ratio of bio-oil to char could be produced at temperature and reaction time of 320oC and 195 minutes. However, the amount of alcohols produced varied significantly such that no clear correlation between these two parameters with respect to the production of alcohols can be concluded. This variation of data suggests that the process involves a complex set of reactions. Nevertheless, a simple first-order kinetics model was able to describe the conversion of glycerol to the different products. A thorough investigation on the effect of initial pressure and type of reducing agent with an improved feeding system were conducted. Results showed that thermochemical conversion of glycerol occurs at 300oC or higher for 60 min, and that the initial pressure and type of reducing agent does not have a significant effect. The results gathered in the project gave sufficient evidence that the thermochemical of glycerol could produce methanol, ethanol and propanol. However, further studies should be conducted to improve the efficiency of the process. An investigation on applications of metal catalysts and reactive distillation technique is under conduction to further explore the parameters affecting process efficiency and the process optimization.