HZSM5 Assisted Upgradation of Kraft Lignin Derived Bio-oil

Hierarchical and non-hierarchical mono and bimetallic Ni and/or Zn-HZSM5 catalysts were synthesized and compared for upgrading of Kraft lignin derived liquefaction bio-oil in a batch reactor at 300 ℃ for 1h under H2 atmosphere in supercritical ethanol. N2 adsorption-desorption isotherms, FE-SEM, XPS, ICP-OES and XRD techniques were used to characterize the synthesized catalysts. HZSM5 crystalline structure was not significantly influenced by the incorporation of Ni and Zn. GC-MS and elemental analysis were used to analyze the upgraded bio-oils. After bio-oil upgrading, the amounts of 4-ethylguaiacol and 4- propylguaiacol increased considerably because of reduction in the amounts of unsubstituted guaiacol, 4-methylguaiacol, 4- propenylguaiacol and homovanillic acid. Hydrogenation, alkylation and deoxygenation were the prominent reaction mechanisms responsible for bio-oil upgrading. Highest HHVBoie (~29.93 MJ/Kg) was obtained for non-hierarchical 15Ni5Zn-HZSM5 and hierarchical 20Zn-HZSM5 catalysts. Hierarchical and non-hierarchical catalysts favored hydrogenation and deoxygenation, respectively.