Optimization of Energy Consumption in a Hydrotreating Process for Green Diesel Production from Palm Oil

Abstract

Green diesel, one of alternative energy products, is a second generation of biofuel, which has a similar molecular structure as petroleum diesel but provides better diesel properties. The green diesel has been produced by a hydrotreating of triglycerides in vegetable oils with hydrogen. The hydrotreating process consists of 3 main reactions: hydrodeoxygenation (HDO), decarbonylation (DCO) and decarboxylation (DCO2), is operated to remove oxygen, carbonmonoxide and water, and carbondioxide respectively. This research has focused on simulation and energy optimization of the hydrotreating process for green diesel production from palm oil. Simulation results show that the green diesel yield, green diesel purity, liquid product distribution, hydrodeoxygenation (HDO) and decarbonylation (DCO)/decarboxylation (DCO2) reactions occurring in the process are in good agreement with experimental data which accuracy of less than 2 %. In the energy optimization with heat exchanger network, the results show that the exchanged heat sequence affects the energy saving due to the allowable minimum temperature difference between exchanged hot and cold streams. Based on the energy optimization, splitting hot stream can decrease the energy consumption by 89.36% when compared with the original process.