We used to convert bio-oil applying formic acid as both acid catalyst and hydrogen donor (Pd/C was also used in this process). Some acohols in bio-oil can be converted to alkenes and alkanes
Bioparaffins for diesel fuel can be produced by hydrodeoxygenation of triglycerides. This product is not FAME, not an esther. It is better, because the paraffin molecules are as same as the molecules in the fossil diesel. Search on the sciemcedirect for review articles!!!