Hydrolytic depolymerization of hydrolysis lignin: Effects of catalysts and solvents.
Hydrolytic depolymerization of hydrolysis lignin (HL) in water and water-ethanol co-solvent was investigated at 250°C for 1h with 20% (w/v) HL substrate concentration with or without catalyst (H2SO4 or NaOH). The obtained depolymerized HLs (DHLs) were characterized with GPC-UV, FTIR, GC-MS, (1)H NMR and elemental analyzer. In view of the utilization of depolymerized HL (DHL) for the preparation of rigid polyurethane foams/resins un-catalyzed depolymerization of HL employing water-ethanol mixture appeared to be a viable route with high yield of DHL ∼70.5wt.% (SR yield of ∼9.8wt.%) and with Mw as low as ∼1000g/mole with suitable aliphatic (227.1mgKOH/g) and phenolic (215mgKOH/g) hydroxyl numbers. The overall % carbon recovery under the selected best route was ∼87%. Acid catalyzed depolymerization of HL in water and water-ethanol mixture lead to slightly increased Mw. Alkaline hydrolysis helped in reducing Mw in water and opposite trend was observed in water-ethanol mixture.
Institute for Chemicals and Fuels from Alternative Resources (ICFAR), Department of Chemical and Biochemical Engineering, Western University, London, Ontario N6GA5B9, Canada.
Nubla
N
Mahmood
Institute for Chemicals and Fuels from Alternative Resources (ICFAR), Department of Chemical and Biochemical Engineering, Western University, London, Ontario N6GA5B9, Canada.
Zhongshun
Z
Yuan
FPInnovations 570, Boul. Saint-Jean, Pointe-Claire (QC) H9R 3J9, Canada.
John
J
Schmidt
Institute for Chemicals and Fuels from Alternative Resources (ICFAR), Department of Chemical and Biochemical Engineering, Western University, London, Ontario N6GA5B9, Canada. Electronic address: cxu6@uwo.ca.
Chunbao Charles
CC
Xu
D002384:Catalysis; D005740:Gases / Q000138:chemical synthesis; D006868:Hydrolysis; D008031:Lignin / Q000737:chemistry* / Q000302:isolation & purification; D011108:Polymers / Q000737:chemistry; D011140:Polyurethanes / Q000138:chemical synthesis*; D012997:Solvents / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
D005740:Gases; D011108:Polymers; D011140:Polyurethanes; D012997:Solvents; D014867:Water; D008031:Lignin
Acid/base; Depolymerization; Hydrolysis lignin; Water; Water–ethanol mixture