Liquefaction of Cornstalk in Sub‐/Supercritical Cyclohexane with Zeolite

Abstract

Liquefaction of cornstalk in sub‐ and supercritical cyclohexane with a zeolite catalyst was performed in a stainless‐steel reactor. The reaction system was divided into four lumps: gas, residue, water‐soluble fraction (WSF), and ethanol‐soluble fraction (ESF). The effects of the cyclohexane‐to‐cornstalk ratio, reaction temperature, reaction time, and zeolite amount on the lump yields were studied. The results show that reaction time and temperature had significant effects on the distribution of the products. The amounts of organic acids, acetic ester and aldehyde in the ESF obtained from cornstalk liquefaction with zeolite were higher than without zeolite. The distributions of the WSF changed with zeolite use. The main secondary reaction pathways of bio‐oil generation are proposed. Part of the unstable WSF was converted into the ESF and gas. The ESF further formed a residue through condensation, cyclization and repolymerization in sub‐/supercritical cyclohexane. GC/MS analysis showed that the WSF and the ESF comprised a mixture of organic compounds, which mainly included organic acids, aldehydes, ketones and phenolic compounds.

Hydrothermal Liquefaction of Cypress: Effect of Water Amount on Structural Characteristics of the Solid Residue

“…As widely confirmed by many researchers [16,17], the competition of two reactions, namely, hydrolysis and polymerization, was mainly present in the hydrothermal liquefaction process. As widely confirmed by many researchers [16,17], the competition of two reactions, namely, hydrolysis and polymerization, was mainly present in the hydrothermal liquefaction process.…”

“…5. The absorption at 1416 cm -1 (benzene ring) represents the lignin, and absorption at 1143 cm -1 corresponds to the b-glycosidic bond vibration in cellulose [17,21]. From the FT-IR spectra, the peak at 1722 cm -1 is attributed to C=O stretching vibration of xylans in hemicelluloses [20].…”

Liquefaction of Oil Shale in Supercritical Ethanol

“…Xu and Donald [6] studied the liquefaction of peat in supercritical ethanol, and the results showed that the oxygen and nitrogen contents were significantly reduced in the liquefied oil. Tao et al [7] investigated the liquefaction behavior of corn stalks in sub-supercritical ethanol. The results demonstrated that when the reaction temperature was 320 °C, the yield of heavy oil was 13.8% and that of the solid residue was 17.8%.…”