Catalytic Co-Processing of delayed coker light naphtha with other refinery gasoline streams

Abstract

Upgrading of delayed coker light naphtha is very difficult due to its high diolefin and silicon content. Mixtures of light straight run naphtha and delayed coker light naphtha fractions were hydrotreated in two stages over NiMo/Al₂O_<3> and CoMo/Al₂O_<3> catalysts (diolefin saturation followed by hydrodesulphurization ). The results showed that naphtha fractions free of diolefins, olefins, sulphur and silicon can be produced with the two stage hydrogenation. These are excellent feeds for naphtha isomerization. One-stage selective hydrodesulphurization tests were also conducted with blends of coker naphtha (up to 5 vol%) and fluid catalytic crackers gasoline over CoMo/Al₂O_<3>. Diolefin-free products of < 10 mg/kg sulphur could be produced with a research octane number loss of max. 3.