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

Abstract

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 °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.

Development of nickel based catalysts for the transformation of natural triglycerides and related compounds into green diesel: a critical review

“…In a third paper [224] published by the same group a new NiWC/Al-SBA-15 catalyst series was studied for the hydrocracking of distillers dried grains with solubles (DDGS) corn oil (Table 6, entry 3).The effect of the Ni/W ratio and the catalyst preparation method on activity, selectivity, and durability of the catalyst for green diesel production was investigated under relatively mild reaction conditions. The metal dispersion on the support and the alloy formation were studied to elucidate their effects on the catalyst performance and provide a better understanding of the hydrocracking process.…”

Biofuels production from hydrothermal decarboxylation of oleic acid and soybean oil over Ni-based transition metal carbides supported on Al-SBA-15

“…The mixture was filtered, dried, and calcined at 550 °C for 4 h. According to our previous work [8], the catalysts NiNb, NiMo, NiW, and NiZr were prepared in the ratio of 6.67 wt% Ni:3.33 wt% M (M = Nb, Mo, W, Zr) by the wet co-impregnation of aqueous solutions of (Ni(NO 3 ) 2 . Carburization was conducted using temperature-programmed reduction (TPR) according to the method of Claridge et al [42].…”

“…The hydrocracking process is the most developed route for removal of oxygen from triglycerides and fatty acids to produce biofuels [5][6][7]. Our previous study [8] has shown that bimetallic carbide catalysts (NiWC/Al-SBA-15) prepared by a Dendrimer-Encapsulated-Nanoparticles (DENP) method with a Ni-W ratio of 2:1 led to a complete conversion of DDGS corn oil (>95% triglycerides) over 16 continuous days with 100% diesel selectivity for 4 days at 400 °C and 4.48 MPa. However, this process requires high pressure of H 2 and has issues related to catalyst deactivation due to the presence of water [9,10].…”

Hydrocracking of DDGS corn oil over transition metal carbides supported on Al-SBA-15: Effect of fractional sum of metal electronegativities

“…According to our previous work [17] Carburization was conducted using temperature-programmed reduction (TPR) according to the method of Claridge et al [22]. Each metal oxide precursor was placed in a quartz tube and subjected to a flow of 20% CH 4 /80% H 2 at 30 cm 3 /min and a heating rate of 10 K/min to 250 °C, followed by 2.0 K/min to 730 °C.…”

“…The conversion of soybean oil reached 100% and the selectivity for green diesel was 97% for the NiMo carbide catalyst over Al-SBA-15 during 7 days at 400 °C and 4.48 MPa. Our earlier study investigated the effect of catalyst preparation method and Ni-W ratio on the carbide form of the NiW/Al-SBA-15 catalyst activity and selectivity [17]. The catalyst prepared by Dendrimer-Encapsulated-Nanoparticles (DENP) method with a Ni-W ratio of 2:1 led to a complete conversion of DDGS corn oil for 16 days and 100% diesel selectivity for 4 days at 400 °C and 4.48 MPa.…”