Continuous co-processing of HTL bio-oil with renewable feed for drop-in biofuels production for sustainable refinery processes

This study demonstrates the co-hydrodeoxygenation of partially upgraded bio-oil (PUB) obtained from hydro-thermal liquefaction of pinewood, with rapeseed oil (RO) to produce bio-derived drop-in fuel. Enhanced miscibility of PUB in RO showed the high potential of HTL bio-oil for co-processing with different refinery streams in existing refineries. Co-processing experiments were conducted in a continuous unit under different processing conditions and the obtained results were compared with the hydroprocessed oils produced from the pure RO. Temperature and weight hourly space velocity (WHSV) are found to be important parameters to achieve complete deoxygenation and controlling the properties of co-processed bio-oils. Product quality analysis of co-processed bio-oils obtained under optimized conditions showed no oxygen contents and micro carbon residue but high n-paraffins. Furthermore, boiling point distribution of co-processed bio-oils was measured by SimDis, which was found analogous to boiling range of biodiesel. Fuel characteristic properties such as flash point, pour and cloud points of co-processed bio-oils were also measured and found improved compared to the properties of hydroprocessed oil obtained from RO. Therefore, this study demonstrates that HTL bio-oil can be successfully co-processed with renewable feed and petroleum refinery streams in a continuous hydroprocessing unit without any modification to reduce the environmental impacts and overcome the cost, availability and sustainability issues of oleochemical based feedstocks.