Hydrothermal conversion of lignin to substituted phenols and aromatic ethers

• Published in: Bioresource technology Vol. 165; pp. 319 - 322
• Main Authors: Singh, Rawel, Prakash, Aditya, Dhiman, Shashi Kumar, Balagurumurthy, Bhavya, Arora, Ajay K., Puri, S.K., Bhaskar, Thallada
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Kidlington Elsevier Ltd 01.08.2014; Elsevier
• Subjects: Bio-oil; Biological and medical sciences; Carbon; Conversion; Ethanol - chemistry; Ethers; Ethers - chemistry; Ethyl alcohol; Fundamental and applied biological sciences. Psychology; Hydrocarbons, Aromatic - chemistry; Hydrothermal liquefaction; Lignin; Lignin - analysis; Lignin - chemistry; Liquefaction; Liquids; Methyl alcohol; Phenols; Phenols - chemistry; Spectroscopy, Fourier Transform Infrared; Substituted phenols; Temperature; Thermo-chemical conversion; Time Factors; Water - chemistry; X-Ray Diffraction; Lignin; Thermo-chemical conversion; Substituted phenols; Hydrothermal liquefaction; Bio-oil; Thermochemical treatment; Oil; Hydrothermal treatment; Ether; Liquefaction; Phenols; Biomass
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2014.02.076

•Hydrothermal liquefaction of lignin was performed using ethanol & methanol.•Maximum liquid yield (85%) was observed at low reaction temperature of 200°C.•The major liquid products are substituted phenols and aromatic ethers.•The maximum organic carbon conversion was found to be 72%. Hydrothermal liquefaction of lignin was performed using methanol and ethanol at various temperatures (200, 250 and 280°C) and residence times of 15, 30 and 45min. Maximum liquid product yield (85%) was observed at 200°C and 15min residence time using methanol. Increase in temperature was seen to decrease the liquid products yield. With increase in residence time, liquid yields first increased and then decreased. FTIR and 1H NMR showed the presence of substituted phenols and aromatic ethers in liquid products and breakage of β-O-4 or/and α-O-4 ether bonds present in lignin during hydrothermal liquefaction was confirmed through FTIR of bio-residue. In comparison to the existing literature information, higher lignin conversion to liquid products and maximum carbon conversion (72%) was achieved in this study.