Co-hydrotreatment of Pyrolysis Oil with Coconut Oil Towards Jet Fuel-Range Hydrocarbons

Although fast pyrolysis is a relatively mature technology, the upgrading of pyrolysis oil to drop-in transportation fuels remains a major challenge. Catalyst deactivation,  formation of coke, and the removal of methoxyl groups in the form of CH4 are the key limitations identified. Furthermore, the resulting cuts are typically rich in aromatics, while stringent fuel specifications add additional difficulties to pyrolysis oil hydroprocessing. As a result, co-hydrotreatment approaches with lipids and other hydrocarbons have gained attention. However, prior studies have reported limited selectivity toward jet fuel-range hydrocarbons. In this study, co-hydrotreatment of pyrolysis oil (PyOil) with coconut oil (CNO) was investigated as a strategy to maximize jet fuel cut. Co-hydrotreatment results showed that increasing CNO content led to a near-linear increase in upgraded oil yield, substantial reductions in coke, gas, and water formation, and lower hydrogen consumption. With CNO blending, upgraded oils revealed a marked shift in hydrocarbon distribution toward n-paraffinic, jet fuel-range hydrocarbons, accompanied by a significant reduction in oxygenated compounds. Jet fuel-range hydrocarbon selectivity increased from 28% for pure PyOil to over 80% for CNO-rich blends, with jet fuel hydrocarbon yields increasing by up to eightfold relative to pure PyOil. All jet fuel distillation cuts exhibited high calorific value (up to ~48 MJ/kg. Although upgraded oil yield improvements were largely additive, the compositional shifts induced by CNO blending were highly favorable for sustainable aviation fuel production. These results demonstrate that medium-chain fatty acid–rich CNO provides an effective co-feed strategy to enhance the jet-fuel relevance of biomass-derived pyrolysis oils.