Renewable diesel synthesis by hydro-processing in green solvents

The production of green diesel and jet bio–fuel takes place by hydrodeoxygenation (HDO) through hydrotreatment of natural triglycerides. This demands high pressurized external H2 related to high cost as well as safety and environmental issues. The utilization of green H2 released in situ from green solvents or side HDO products is essential for making the process safer, environmentally friendly and economically beneficial. Recent publications dealing with the utilization of this kind of hydrogen in the HDO of fatty biomass as well as the use of aqueous solutions in the HDO of waste cooking and algae oils containing appreciable amounts of water, are reviewed for the first time. Suggestions for future research in the field are formulated through critical comments at the end of the article.