Modelling and simulation of hydrotreating of palm oil components to obtain green diesel

This work presents a model for hydrotreating of palm oil components to produce green diesel. The main reactions of triglycerides and fat acids in the presence of a NiMo/γAl₂O₃ catalyst are shown, especially cracking of triglycerides, hydrogenation, decarboxylation, decarbonylation and fat acid reduction. These reactions were modelled using Aspen Plus^® 7.3 software, where an equilibrium reactor was used to predict the reaction behavior. The influence of reactor pressure, temperature and H₂/oil molar ratio was analyzed. The results showed that the optimized conditions are obtained at average pressure from 30 bar to 60 bar, temperature between 300 °C and 400 °C, and H₂/oil molar ratio of 20.1. In the separation system the operating conditions adopted were 40 bar, 200 °C in the first plate and 1.013 bar, 60 °C in the second plate, resulting in green diesel purity of 97%. High levels of n-C₁₈ and n-C₁₆ production were attained, compared with other methods.