Hydrothermal Liquefaction of Water Hyacinth: Product Distribution and Identification

The utilization of water hyacinth has attracted great attention for its invasive problem. The hydrothermal liquefaction of water hyacinth was conducted at moderate temperatures (240–340°C). Distribution and identification of the products were investigated by using gas chromatography-mass spectrometry and elemental analysis. The results showed that the yield of total oil increased with the increasing temperature, peaked at 320°C, then decreased afterwards. The decomposition of water hyacinth to form small molecular compounds was the dominated process at lower temperatures, while more secondary polymerization reactions happened at temperatures over 280°C. Compositions of oil products were very complex and varied with temperature. Higher temperatures are a benefit for production of high value-added chemicals, such as phenols and cyclopentenes in water soluble oil. This could be the evidence to refine biofuel or biochemicals from water hyacinth by hydrothermal liquefaction.