The catalytic hydroconversion of vegetable oil (CHVO) process associate vegetable oil triglyceride transformation to linear-chain alkanes, via hydrodeoxygenation reactions (HDO) to generate multiple hydrocarbon compounds similar to heavy vacuum oil. The CHVO process was applied to Jatropha curcas seed oil, on commercial hydrodesulfurization (HDS) Ni-Mo/Al2O3 catalyst under HDS operation conditions. Jatropha curcas seed oil triglycerides conversion were observe by Fourier Transform Infrared Spectroscopy (FTIR) and validated by Gas Chromatography (CG/MSD). The process occurs through three reaction pathways including: decarbonylation, decarboxylation and hydrodeoxygenation where the carboxyl group is removed from the fatty acids to produce alkanes similar to fossil fuels. Infrared spectroscopy in CHVO process showed to be a useful method to evaluate the catalytic activity by monitoring specific frequencies intensities of C=O and C-O bonds in carboxylic group. The intensity reduction of these bonds to linear hydrocarbons it associated as a way to quantify for CHVO process.