CaO catalyst for multi-route conversion of oakwood biomass to value-added chemicals and fuel precursors in fast pyrolysis

The impact of CaO on oakwood pyrolysis was explored by the Py-GC/MS at 500 °C. Ca(OH) 2 presents on the CaO surface, indicating its partial hydration (noted as CaO OH ). CaO OH promoted the ketonisation of carboxylic acids to aliphatic ketones, furfural to cyclopentanone/2-cyclopentenone, facilitated the elimination of the methoxy-phenolic compounds. The catalyst loading did not show any significant effect on the formation of acetone, while a noticeable reduction in the phenolics was revealed. Increasing catalyst loading almost eliminated CO 2 , acids, furans, aldehydes, ether groups, whilst the fractions of alcohols, esters, sugars, and alkoxybenzene decreased noticeably. The use of partially hydrated CaO OH in the CFP can create conditions where by-products generated during the ketonisation and phenolics upgrading reactions (CO 2 , H 2 O, CO) interact through the adsorption enhance water-gas-shift reaction and through coking reactions with formation of H 2 used for hydrogenation during multistep conversion of furfural to cyclopentanone in a vapour phase.