Investigating Biofuel Production from Microalgae Biomass (Spirulina) using Hydrothermal Liquefaction Process (HTL)

Among different types of biomass, the inherent advantages of microalgae have made them a useful source for biofuel production. The hydrothermal liquefaction process is one of the thermochemical processes that has attracted the attention of researchers due to its advantages such as the production of valuable products and low energy consumption. The aim of this article is to investigate the production of biofuel from spirulina microalgae using the hydrothermal liquefaction process in a subcritical water environment in a laboratory and discontinuous manner. The results of detailed elemental analysis of biofuel showed that the amount of carbon, hydrogen, sulfur and nitrogen of raw biofuel is equal to 68.27, 15.56, 3.08 and 0.38 percent, respectively. In addition, the produced biofuel compounds were analyzed by infrared Fourier transform spectroscopic analysis, the results of which confirm the production of clean fuel compared to fossil fuels.
Gas chromatography-mass spectrometry, Fourier Transform Infrared Spectroscopy and CHN analyzer were used for analyzing the samples. The result showed that the products of hydrothermal process consisted of different range of hydrocarbons almost similar to hydrocarbon chain available in fuel oil (gasoline). Also, carbon, nitrogen and sulfur contents of the oil obtained from hydrothermal liquefaction process, was consistent with those reports provided by other similar studies.This research has proved that hydrothermal liquefaction is a promising process for converting micro algae to bio oil and emphasizing the effect of pretreatment on improving the oil production.