The objectives of this study were to investigate the most thermodynamically favoured reaction pathway during APR of sorbitol. The thermodynamic analysis of APR of sorbitol was studied using ASPEN Plus V8.0 by applying Gibbs free energy minimization principle, operating at different temperatures (300–800 K), pressure (10–30 bar) and sorbitol concentration (1%, 3%, 5%, 10%, 15% and 20%). The simulation model was validated by comparing the results with the existing work conducted by Serentis and Tsiakaras. The results obtained show that the mol fraction and trend of H2, CO2 and CH4 for both cases are almost similar to the existing work. Therefore the simulation model was validated. Five main reaction pathways of APR of sorbitol were identified and intermediates of each reaction pathway were defined according to their stages and their composition was analyzed. The result obtained show that the decarbonylation reaction (pathway 2) is the most thermodynamically favoured pathway with a total dry basis percentage of 21%.