Solid fuel production by hydrothermal carbonization of water-like phase of bio-oil

Hydrothermal carbonization was applied in water-like phase of bio-oil for the polymerization and carbonization of sugars and sugar derivatives. The hydrothermal carbonization was carried out in an autoclave from 130 to 230 degrees C, and solid fuels and stable oxygen containing liquid fuels were successfully obtained simultaneously. Results showed that with the temperature increased, polymerization and carbonization between sugars and sugar derivatives were accelerated and concurrent. The increase in final pressure and yields of extraction phase when the temperature was over 190 degrees C was mainly occurred by depolymerization of the polymer. The maximum yield, energy recovery efficiency, and carbon recovery efficiency of solid fuel (hydrochar) were 11.22 wt%, 50.38%, and 18.04%, respectively. The carbon content of hydrochars ranged from 63.87 to 73.95 wt%, and the high heating value (HHV) of hydrochars ranged from 25.51 to 30.48 MJ/kg. Compared with the water-like phase of bio-oil, the carbon content and high heating value of hydrochars were increased 1.58-1.84 times and 4.35-5.29 times, respectively. Combining the FT-IR spectra of hydrochars and ethyl acetate (EA) phase results, phenolic compounds were detected to be incorporated with hydrochars and the incorporation of both phenol, 1,2-Benzenediol was occurred when the temperature increased to 190 degrees C. (C) 2016 Elsevier Ltd. All rights reserved.