Catalytic hydrothermal liquefaction of water hyacinth

Thermal and catalytic hydrothermal liquefaction of water hyacinth was performed at temperatures from 250 to 300 degrees C under various water hyacinth: H2O ratio of 1: 3, 1: 6 and 1: 12. Reactions were also carried out under various residence times (15-60 min) as well as catalytic conditions (KOH and K2CO3). The use of alkaline catalysts significantly increased the bio-oil yield. Maximum bio-oil yield (23 wt%) comprising of bio-oil1 and bio-oil2 as well as conversion (89%) were observed with 1 N KOH solution. H-1 NMR and C-13 NMR data showed that both bio-oil1 and bio-oil2 have high aliphatic carbon content. FTIR of bio-residue indicated that the usage of alkaline catalyst resulted in bio-residue samples with lesser oxygen functionality indicating that catalyst has a marked effect on nature of the bio-residue and helps to decompose biomass to a greater extent compared to thermal case. (C) 2014 Elsevier Ltd. All rights reserved.