Catalyst stability and deactivation studies for efficient biomass conversion processes
Consumption of fossil fuel reserves and the continuously increasing energy demands are big challenges facing researching now. Against this background, biomass has been considered as the most promising long-term alternatives since its broad availability and low cost. Currently, a large amount of glycerol are produced as a major side-product by biodiesel industry (100kg of glycerol produced per ton of biodiesel each day). However, recent rapid growth of biodiesel manufacture resulting in the glut production of secondary products. Thus, it is necessary to find a utilization for those, notably for glycerol. In this sense, producing hydrogen from biomass derived glycerol is of high interesting.
Aqueous phase reforming (APR) is an attractive and efficient route in producing hydrogen from oxygenated hydrocarbon compounds. Compared to conventional reforming process, it is operating at a relatively mild temperature (150-250°C) and elevated pressure (1.5-6.0 MPa) with a low CO concentration . However, the condition of APR process is still harsh for catalysts. It has been proved that γ-Al2O3, one of the most commonly studied supports in the APR reactions, transforms to crystalline boehmite (AlOOH). This transformation will result in metal sintering, loss of surface area and acid sites, finally dissolve the potential catalytic activity of catalyst . Hence, the hydrothermal stability of these catalysts in high temperature aqueous phase environments should be improved.
In this work, various strategies for stabilizing the catalyst and tests for the new catalyst in the APR of glycerol have been done. The results showed the modification procedures have effectively slow transformation of γ-Al2O3.