Catalytic Deoxygenation of Stearic Acid and Palmitic Acid in Semibatch Mode

Abstract

The deoxygenation experiments of different reactants, i.e., pure palmitic acid, stearic acid, and a technical grade stearic acid containing a mixture of 59% of palmitic and 40% of stearic acid were successfully performed over 4 wt% Pd/C mesoporous catalyst at 300°C under 17 bar of 5% H 2 in argon. The main product in catalytic deoxygenation of saturated fatty acids, C16 and C18, were aliphatic chain length hydrocarbons containing one less carbon than the corresponding acid. Additionally it was found that the deoxygenation rates of different reactant were independent on carbon chain length of its fatty acids.

A Brief Literature Overview of Various Routes to Biorenewable Fuels from Lipids for the National Alliance for Advanced Biofuels and Bio-products (NAABB) Consortium

“…71,[74][75][76][77][78][79][80][81][82][83][84] As evidenced by some reports, improvement in Pd-based catalysts in continuous operation may be necessary because some reports suggest they are hindered by rapid deactivation. Maki-Arvela et al 74 reported that the deactivation of a Pd catalyst while decarboxylating lauric acid may have been due to poisoning by the product gases (CO and CO 2 ) and/or coking.…”

Flash Pyrolysis of Oleic Acid as a Model Compound Adsorbed on Supported Nickel Catalysts for Biofuel Production

“…Together with the cracking of saturated fatty acids, like stearic and palmitic acids formed during the hydrocracking of triglycerides, the use of oleic acid as a model molecule has been used to simulate what can occur in the absence of added hydrogen. [21][22][23][24][25][26][27][28][29] A recent study on the pyrolysis of oleic acid in an autogeneous atmosphere, between 350 and 450 °C, confirmed that both decarboxylation and decarbonylation took place in the reactor, but also revealed internal cracking at the allylic C position, leading to a predominance of C6-C10 hydrocarbons in the liquid products and the formation of C9 and C10 fatty acids. 30 The amount of fatty acids decreased when the temperature of pyrolysis was increased, whereas the amount of mono-and poly-aromatic compounds increased.…”

Hydrothermal Decarboxylation and Hydrogenation of Fatty Acids over Pt/C

“…[1,2] These efforts typically involve conventional hydrotreatment catalysts (e.g., CoMo/Al 2 O 3 NiMo/Al 2 O 3 ) and reaction conditions. A high H 2 partial pressure is required to remove the oxygen atoms in the fatty acids as H 2 O molecules.…”