The in situ hydrogenation of bio-oil was carried out at 220 C
and 3 MPa. After upgrading, the bio-oil was improved not only
on the appearance but also on the compositions significantly.
Ketones/aldehydes and phenols can be converted effectively to
alcohols. In the in situ hydrogenation reaction system, acids could
happen esterification to esters. After in situ hydrogenation, the
contents of ketone/aldehyde and organic acids decreased from
30.36% and 39.89% to 9.32% and 30.25% respectively. The contents
of alcohols and esters increased from 8.89% and 4.9% to 16.33% and
20.53%. During the in situ hydrogenation process, hydrogenation
and esterification were the main reactions in the bio-oil.