Effect of Solvent, Role of Formic Acid and Rh/C Catalyst for the Efficient Liquefaction of Lignin

Babasaheb M. Matsagar, Zheng Yen Wang, Chularat Sakdaronnarong, Season S. Chen, Daniel C.W. Tsang, Kevin C.W. Wu

Research output: Journal article publicationJournal articleAcademic researchpeer-review

22 Citations (Scopus)

Abstract

We demonstrate highly efficient liquefaction of alkali lignin with a very high yield of THF-soluble bio-oil (91.5 wt %) using formic acid (FA) and Rh/C catalyst under relatively mild reaction conditions (250 °C, 6 h) in EtOH−H2O co-solvent system. The monomeric products are identified in which alkyl guaiacols accounts for the main proportion. The role of FA was not only used as a liquid-phase in-situ hydrogen source but also acts as organic acid which can catalyze the hydrolysis reaction of −C−O−C ether bonds of lignin. Moreover, in the present study, the role of Rh/C and FA is demonstrated for the liquefaction of lignin. The replacement of pure H2 gas by the liquid-phase FA (hydrogen source) can effectively prevent the char formation. The utilization of Rh/C catalyst helps for the conversion of alkenyl guaiacols to alkyl guaiacols suggesting the hydrogenation of phenolic monomers and further cleavage by hydrogenation results in the formation of bio-oil with lower molecular weight (Mn=466 g mol−1) as well as lower O/C ratio (0.26).

Original languageEnglish
Pages (from-to)4604-4616
Number of pages13
JournalChemCatChem
Volume11
Issue number18
DOIs
Publication statusPublished - 19 Sep 2019

Keywords

  • Alkali lignin
  • Bio-oil
  • Formic acid
  • Liquefaction
  • Rhodium/Carbon

ASJC Scopus subject areas

  • Catalysis
  • Physical and Theoretical Chemistry
  • Organic Chemistry
  • Inorganic Chemistry

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