Effect of temperature on hydrothermal liquefaction of high lipids and carbohydrates content municipal primary sludge

Abstract

The study assessed the valorisation of primary sludge through HTL and the influence of temperature on the product distribution. The experiments were conducted at different temperatures, 30 min reaction time, and 100 rpm stirring rate. The maximum yield of biocrude produced was 39.47% at 270 °C. The best yield of oils was 23.96% at 300 °C. The lowest yield of asphaltenes was 12.50% at 240 °C. HHV for biocrude were always between 39 and 41 MJ/kg, close to petroleum. Best energy recovery for biocrude was 82% at 270 °C.

Keywords

• Municipal primary sludge (PS)
• Hydrothermal liquefaction (HTL)
• Biocrude separation into oils and asphaltenes
• Full characterization of all phases