In-situ hydrogenation of model compounds and raw bio-oil over Ni/CMK-3 catalyst

- The in situ hydrogenation of bio-oil mixed model were investigated over Ni/CMK3 without adding external hydrogen.
- The effect of different hydrogen donors were investigated on the conversion of MCB and raw bio-oil.
- Different solvents, water, dodecane and water & dodecane, were used in the in situ hydrogenation process of MCB.
- After the in situ hydrogenation, the contents of acids and phenols decreased from 31.78% and 20.08% to 12.99% and 10.31%.

Ni/CMK-3 catalyst, the mesoporous carbon material loading Ni activity, was prepared and used in the in-situ hydrogenation of mixed model compounds (including acetone, acetic acid, furfural, o-cresol, ethanediol and water) of bio-oil (MCB) and actual bio-oil in this paper. The effects of hydrogen donors, solvents and the dosages of catalyst were all investigated in the in-situ hydrogenation process. The results showed that the hydrogen donor of methanol, ethanol and formic acid could all provide hydrogen for the in-situ hydrogenation but the product distributions of bio-oils were different after in-situ hydrogenation. Using alcohols as hydrogen donors, esterification reaction happened between the hydrogen donors and acetic acid. The formic acid could promote the phenols conversion but the conversion of acetic acid was restrained. When the radio of water and methanol was 10:3 and 10:5, most of ketones and aldehydes in the raw bio-oil converted to alcohols and the conversion of acids and phenols was beyond 50%. The contents of alcohols and esters in raw bio-oil increased from 18.52% to 51.14% and 48.21%.