Hydroprocessing of synthetic kerosene over a non‐sulphided Ni/ <scp> Al ₂ O ₃ </scp> catalyst: Impact of alcohols and ketones on alkene conversion

Abstract Synthetic jet fuel containing non‐petroleum‐derived kerosene can be produced from synthetic kerosene obtained through processes that include a hydroprocessing step. The potential use of non‐sulphided (reduced) nickel supported on alumina (Ni/Al 2 O 3 ) was evaluated as an alternative to sulphided catalysts to saturate alkenes in sulphur‐free synthetic kerosene during hydrotreating operations. Performance of a 5 wt.% Ni/Al 2 O 3 catalyst for hydrotreating a model feed comprising n ‐decane, 1‐dodecene, and cumenes was evaluated at 50°C–220°C, 2 MPa, weight hourly space velocity of 1.75 h −1 , and a normal volumetric H 2 ‐to‐feed ratio of 500 m 3 /m 3 . At 50°C–110°C, alkene conversion was incomplete. Initial selectivity of alkene conversion was 20%–40% toward double bond isomerization (catalyzed by Ni) and about 60%–80% toward hydrogenation to alkanes. Aromatic saturation under these conditions was &lt;4%. At 220°C, alkene saturation was nearly complete, and aromatic saturation was 40%–50%. A kerosene hydrotreater with steam heating, as opposed to furnace heating, could therefore be considered when using non‐sulphided Ni/Al 2 O 3 . Additionally, the impact of co‐feeding 1‐octene with oxygenates was determined. At 100°C, the presence of either alcohol or ketone co‐feed suppressed alkene conversion and shifted the selectivity toward double bond isomerization. These effects persisted after the oxygenate co‐feed was discontinued. At 220°C, co‐feeding alcohol led to near‐complete alkene conversion, but suppressed aromatic conversion, while oxygenate conversion remained incomplete. The threshold oxygenate tolerance of the catalyst was not established. In conclusion, the non‐sulphided Ni/Al 2 O 3 could be used for hydrotreating sulphur‐free synthetic kerosene to saturate alkenes; however, its performance is adversely affected when the feed contains oxygenates at percentage levels.