Conversion of Triglycerides to Hydrocarbons Over Supported Metal Catalysts

Abstract

The deoxygenation of triglycerides (tristearin, triolein and soybean oil) under nitrogen atmosphere was investigated over 20 wt% Ni/C, 5 wt% Pd/C and 1 wt% Pt/C catalysts. Use of the Ni catalyst resulted in near quantitative conversion of the triglyceride in each case, high yields of linear C5 to C17 alkanes and alkenes being obtained. Oxygen was rejected as CO and CO 2 , while small amounts of light alkanes (C1-C4) and H 2 were also formed. 13 C NMR spectroscopic analysis of the liquid product from soybean oil deoxygenation at intermediate reaction times suggested that one pathway for triglyceride deoxygenation involves liberation of fatty acids via C-O bond scission and concomitant H transfer, followed by elimination of CO 2 from the acids in a later step. Compared to Ni, catalysts containing Pd or Pt supported on activated carbon showed lower activity for both triglyceride deoxygenation and for cracking of the fatty acid chains.

Processing of Soybean Oil into Fuels

“…Lighter alkanes, CO 2 , and CO come from the glycerol backbone. These studies demonstrate alkane production in the gasoline and diesel fraction range, with yields as high as 54% at 92% conversion for soybean oil (Morgan, Grubb et al 2010). A drawback to using catalyzed heterogeneous pyrolysis has been coking of the catalyst, requiring frequent cycles of oxidative regeneration (Milne, Evans et al 1990).…”

Catalytic Hydrodeoxygenation of Fatty Acids for Biodiesel Production

“…The experimental results showed that Pd/SiO2 catalyst gave a much higher yield in decarboxylating heptanoic and octanoic acid (98 % and 97 %, respectively) than that achieved over the Ni/Al2O3 catalyst (26 % and 64 %, respectively). Production of straight-chain olefins from saturated fatty acids and fatty acid esters over a nickel based catalyst promoted with either tin, germanium, or lead was a subject of a patent [7].…”

“…The hydrodeoxygenation catalysts are often platinum group metals supported on inorganic carriers or carbon (Pt/C, Pt/Al2O3, Pd/C) [5][6][7][8]. The industrial catalysts are CoMo/Al2O3 and NiMo/Al2O3) [9], Zeolites [10,11] and composite catalysts Ni-Cu/CeO2-ZrO2 were also explored [12].…”

Catalytic Activity of a Bifunctional Catalyst for Hydrotreatment of Jatropha curcas L. Seed Oil

“…The hydrocracking process involves the saturation and breakage of C-C bonds to produce high-grade gasoline and diesel fuels [7]. A novel alternative for the production of biofuels is catalytic hydrotreatment and hydrocracking of vegetable oils [8].…”