Guaiacol, a model lignin compound, conversion to catechol over SBA-15 and ZSM-5 catalyst in a fixed bed reactor

Biomass conversion to value added chemicals to be used as industrial platform molecules for further synthesis of commodity chemicals has opened new window for scientists. Biomass is a lignocellulosic compound and it requires technological development since biomass is a complex molecule of linear, cyclic and aromatic hydrocarbons. Lignin being aromatic in nature can beneficial for the production of phenolic hydrocarbons. In this work conversion of Guaiacol, a model lignin compound to different aromatic hydrocarbon is performed over pure silica and alumina silica catalysts e.g. SBA-15and ZSM-5 in a fixed bed catalytic reactor. SBA-15 material was synthesized at different aging time leading to improvement in surface area and pore diameter whereas ZSM-5 was pre-treated with H₃PO₄ and KOH to modify their acidic strength. Maximum Guaiacol conversion in absence of catalyst was obtained aa 90.1 % at 550oC, 97.33 % at 550 °c in presence of SBA-15 (C) and 95.33 % in presence of P/ZSM-5, indicating the catalyst helps in enhancing the conversion, however depends on the type of catalysts and its properties like surface area, pore diameter and Lews/Bronsted acid strength. Similarly the selectivity of catechol was observed to be maximum with SBA-15 (C) as compared to other catalyst owing to its high surface area and large pore diameter. The GCMS analysis of the liquid product obtained includes Dimethyl phenol, 2-dimethoxy benzene, 2-ethyl,5-methyl phenol, catechol, Ethynylanisole and O-cresol