ef5b00308_si_001.pdf (49.32 kB)
Rapid Hydrothermal Deoxygenation of Oleic Acid over Activated Carbon in a Continuous Flow Process
journal contribution
posted on 2015-12-17, 08:16 authored by Sergiy Popov, Sandeep KumarIn
this study, a novel approach to converting fatty acids into n-alkanes was investigated. Fuel range hydrocarbons were
obtained in a continuous flow process from oleic acid using near-
and supercritical water as the reaction medium, granulated activated
carbon as a catalyst, and 1% v/v formic acid as an in situ source
of hydrogen. Experiments were conducted in a packed tubular reactor
with the weight hourly space velocity of 4 h–1 at temperatures from 350 to 400 °C and pressure 3500 psi (24.1
MPa). The oil to water to formic acid ratio was 1:5:0.05 by volume.
The main reaction pathways were hydrogenation of oleic acid and decarboxylation/decarbonylation
of the resulting stearic acid to form heptadecane. The yield of heptadecane
of above 70% with a selectivity 80% was observed between 370 and 380
°C. The results of the study show that efficient hydrothermal
deoxygenation of fatty acids can be achieved with activated carbon
as a catalyst and formic acid as an in situ source of hydrogen within
minutes. Kinetics study showed that the rates of oleic acid conversion
displayed Arrhenius behavior with an activation energy of 120 kJ/mol.