DESIGN AND SIMULATION OF COMBINED BIODIESEL PRODUCTION, GLYCEROL REFROMING AND GREEN DIESEL PRODUCTION

Abstract

Biodiesel, an alternative renewable and biodegradable fuel, has been attractive to substitute petroleum diesel, the large amounts of glycerol as a byproduct will be a problem because of the limitation of glycerol applications. Recently, hydrogen production using glycerol as a main reactant has been attractive, because it can use for several processes. For biodiesel production, oil with high free fatty acids (FFAs) content is unsuitable feedstock due to this make the biodiesel process more complicated and using more equipment than virgin oil. In contrast, if FFAs is utilized in hydrotreating process with low amount of hydrogen as one of reactant. Moreover, a novel process by combination of three alternative fuels involving three processes of biodiesel production, hydrogen production via glycerol reforming and hydrotreating of free fatty acid might show the beneficially overall process and produces a variously alternative fuel. This research studied the simulation of combination process for production of biodiesel, hydrogen and green diesel using soybean oil and stearic acid as raw materials. Firstly, the individual process including of biodiesel production, glycerol steam reforming, and green diesel production was investigated to choose the suitable process for combination as base case. After that, this base case was improved by: (1) glycerol purification column can be neglected from the process. This is leading to produce more hydrogen and green diesel than that of the base case because of methanol reforming; (2) hot unconverted oil was recycle to mix with fresh oil which it can reduce the total energy consumption from 14.02 to 13.85 MW. Moreover, high purity of condensed water can be directly used as the steam. (3) furnace combustor was installed to produce heat from fuel gas which this gas produces large amount of energy and return to the process. Pinch analysis showed that the proposed process offers energy saving of 47.24% comparing to the base case. Furthermore, the proposed process can also decrease the total energy consumption to 31.41% comparing to the conventional biodiesel production, glycerol steam reforming and hydrotreating at the same operating condition. It was found that the main energy consumption from the proposed process was obtained from the FAMEs purification and methanol recovery columns. This proposed process showed the efficiency for producing three alternative energy for humanity.