Effect of Metal Ratio and Preparation Method on Nickel-Tungsten Carbide Catalyst for Hydrocracking of Distillers Dried Grains with Solubles Corn Oil

The hydrocracking of distillers dried grains with solubles (DDGS) corn oil over bimetallic carbide catalysts was explored for green diesel production. A catalyst composed of nickel tungsten (Ni-W) carbide supported on Al-SBA-15 was designed based on the ability of nickel to adsorb and activate hydrogen and the potential of tungsten for hydrogenation reactions. Four different Ni W ratios (1:9, 1:1, 2:1, and 9:1) were prepared by the impregnation method to study the effect of metal ratio on the catalyst structure, activity, and selectivity. Catalyst activity was evaluated in a fixed bed reactor at 400 degrees C and 650 psi (4.48 MPa) with a hydrogen flow rate of 30 mL min(-1) and DDGS corn oil flow rate of 0.08 mL min(-1). The catalysts showed significant differences in activity and selectivity, with the catalyst having a Ni-W ratio of 9:1 achieving 100% conversion of corn oil and 100% selectivity to diesel for 2 days. Results indicate that by minimizing metal alloy formation and enhancement of the metal dispersion leads to higher activity, selectivity, and durability of the catalysts. A dendrimer-encapsulated nanoparticle (DENP) method was employed to minimize alloy formation and increase the metal dispersion on the support. The catalysts prepared by the DENP method showed activity greater than that of the catalyst prepared by the impregnation method for the hydrocracking of DDGS corn oil.