Co-liquefaction of faecal sludge and water hyacinth: Exploring the fuel characteristics of biocrude including thermal maturation and petroleum fractionation

Abstract

Today's world is facing a great economic crisis due to the increasing rate of fuel prices as well as irreversible depletion of it has gained major concern regarding future energy security. To mitigate such a problem this study investigated co-liquefaction (co-HTL) of faecal sludge (FS) and water hyacinth (WH) at varying FS to WH ratios (3:1, 1:1, 1:3) for biocrude production. The maximum biocrude yield was 33.47% with a higher heating value (HHV) of 29 MJ kg−1 and an energy recovery (ER) rate of 70.11% for a 1:1 ratio. The comprehensive characteristics of co-HTL biocrude showed 61.84%, 10.16%, 25.23%, 2.37%, 0.39% of C, H, O, N, S, and the highest HHV of 30.88 MJ kg−1 for 1:3 ratio. Co-liquefaction significantly improved the H/C ratio and ER of biocrude. The thermal maturation properties showed biocrudes were mainly immature quality with highly oil-prone which implies predominant hydrocarbon potential. The American Petroleum Institute (API) gravity analysis based on FTIR revealed that biocrudes were heavy type oil due to higher specific gravity (≥1). GC-MS results demonstrated that biocrude contained fatty acids, ester, alcohols, hydrocarbons, phenol, and ketone. The petroleum fractionation of co-HTL (1:1) biocrude showed a tendency to produce kerosene-like fuel. An economic valuation was predicted that through the co-HTL maximum of 6.39 bbls Mt−1 of biocrude could be produced according to the 1:3 mixing ratio of biomass which could revenue $ 683.73. The energy balance analysis suggested that the co-HTL of FS and WH is an energetically viable and economic system.