Direct Conversion of Sunflower Shells to Alkanes and Aromatic Compounds

Abstract

Deoxy-liquefaction runs were performed at final temperatures of 350, 400, 450, and 500 °C, with only 10 wt % distilled water as medium. The influence of the final temperature on the properties of biopetroleum obtained from sunflower shell samples (with kernels 5 wt %) via deoxy-liquefaction was examined in relation to the yield and distribution of products (i.e., gas, solid, liquid), especially the compositions of oil products. Furthermore, the liquid oil with a maximum yield and H/C molar ratio of 1.99 and higher heating value (HHV) of 46.9 MJ/kg was obtained at 450 °C. The biopetroleum analyzed by gas chromatography−mass spectrometry (GC−MS) with the National Institute of Standards and Technology (NIST) 98 MS library was mainly composed of benzene derivatives, phenolic derivatives, and alkanes (C7−C19). What is special is that the content of (Z,Z)-9,12-octadecadienoic acid (RT = 21.26 min), which came from the few sunflower kernels decreased from 21.32% at 350 °C to zero at 500 °C. This suggested that deoxy-liquefaction in a closed system could realize not only the deoxygenation of biomass but the deoxygenation of linoleic acid by controlling the final temperature. Moreover, the biopetroleum obtained can be upgraded to transport fuel or separated for chemical products.