Thermochemical liquefaction of Brassica napus straw: Effect of liquefaction parameters on biocrude

Abstract

Rape straw ( Brassica napus ) was used to prepare high-quality biocrude (ORS) through thermochemical liquefaction . The effects of liquefaction temperature, solid-liquid ratio (R 1 ), and solvent filling ratio (R 2 ) on the yield of ORS prepared from rape straw were studied. The yield of ORS reached the maximum value (22.11 %) at 340 °C, with R 1 10 % and R 2 20 %. GC-MS analysis indicated that at low liquefaction temperatures (≤300 °C) the compounds in ORS were mainly esters, whereas at higher temperatures they were mainly phenolic compounds . Analysis based on the boiling points indicated the presence of mainly C 8 , C 9 , and C 20 compounds. Elemental analysis and measurement of the higher heating value (HHV) showed that the HHV of ORS at 340 °C was 41.36 MJ/kg. The process described in this work not only effectively disposes of rape straw, but also converts it into a potential renewable transportation energy alternative. • Biocrude was prepared by liquefaction of rape straw. • The yield of biocrude reached the maximum value (22.11 %) at 340 °C (R 1 :10 %, R 2 :20 %). • The main compounds of biocrude produced at lower temperature (≤300 °C) were esters. • The carbon number of biocrude compounds mainly distributed in C 8 , C 9 and C 20 . • The higher heating value of biocrude at 340 °C reached 41.36 MJ/kg.