(771b) Reforming of Model Biodiesel Over Ni-MoO2
Currently, most of the hydrogen is produced by reforming of fossil fuels, which are a non-renewable source of energy and therefore a lot of research is going on in exploring different ways to produce hydrogen from renewable sources. One of the ways is to produce hydrogen from biofuels, which are not only a renewable source but also provide a CO2 neutral cycle, thus addressing the environmental concerns related to burning of fossil fuels. This paper explores the possibility of producing hydrogen via partial oxidation of biodiesel. Biodiesel contains almost no sulfur or aromatics and is an oxygenated fuel. It has a huge potential for hydrogen production via reforming, but there is a lack of studies to explore this field. Most of the catalysts used for reforming are either noble metal catalysts, which are not cost effective or nickel based catalysts, which face the problem of coking. Molybdenum dioxide (MoO2) is a non-noble metal catalyst, which has shown good catalytic activity for the oxidative reforming of various logistic fuels such as isooctane, dodecane and Jet-A fuel. One of reasons for having this high reforming activity for MoO2 is explained in terms of its high lattice oxygen mobility and metallic properties. Its highly mobile lattice oxygen allows its high coke resistance by reacting with the surface carbon, while its metallic property helps to efficiently reform carbon fragments. Therefore an initial activity test at O2/C=0.6 was conducted for reforming of model biodiesel, methyl oleate, over MoO2. MoO2 showed a good catalytic activity for reforming methyl oleate with nearly 100% conversion and average hydrogen yield of 78%. We further added nickel, to MoO2 via wet impregnation method with 10% loading by weight. As mentioned above, nickel is a cheap and cost effective material, which is known for its good catalytic activity for reforming except that it has problem of coking. But since MoO2 has high lattice oxygen mobility, its lattice oxygen could help prevent coking on nickel by scavenging the surface carbon deposited on it. We conducted a 24-hour activity test on the as synthesized Ni-MoO2 catalyst. It showed not only 100% conversion with no deactivation, but also a high hydrogen yield compared to MoO2, averaging around 92% over a period of 24 hours.