(515c) Catalytic Enhancement of the Alkaline Thermal Treatment of Cellulose to H2 in the Presence of Ca(OH)2 and Low-Loading Catalysts

Authors: 
Chen, J. G., Columbia University
Stonor, M., Columbia University
Park, A. H. A., Columbia University

Concerns over climate change have led to the development of renewable technologies that can produce energy without the associated carbon-footprint of fossil fuels. Biomass is a suitable feedstock for energy conversion since it is inherently a carbon neutral feedstock, yet its low energy density and high moisture content exclude its use in conventional power generation facilities. Consequently, a simple conversion technology is investigated that can convert biomass to H2 at moderate temperature and ambient pressure, in a distributed manner. Previous work has shown that NaOH or Ca(OH)2 combined a 10% Ni/ZrO2 catalyst, are effective in converting cellulose to H2, while significantly suppressing CO2 production. Ca(OH)2 is an attractive substitute to NaOH due to its relative abundance as CaO in industrial waste sources (steel-slag) and lower price. Research has focused on utilizing Ca(OH)2 with low-loading Ni, Pt, Pd, Co, Fe, and Cu supported on  α-Al2O3 to enhance H2 production from cellulose. Ni has shown to enhance H2 when in direct contact with the solid reactants (4% to 10% H2 yield), however 40% to 50% of enhancement in yield was due to gas phase reforming. Relatively constant CO and CH4 formation rates have suggested that reactions such as steam reforming and the water-gas shift are not likely mechanisms for H2 production. It is possible that Nienhances H2 production in the gas phase through the reforming of higher molecular weight hydrocarbons to H2 and CO2. In this study the reaction pathways are elucidated in order to provide insight into the alkaline thermal treatment of cellulose in the presence of a Ni catalyst.