Abstract:

In order to decrease the content of mercaptans and diolefin in FCC gasoline, an existing 0.2 Mt/a naphtha hydrotreating unit was revamped to a 0.25 Mt/a FCC gasoline pre-hydrotreating unit adopting FCC gasoline pre-hydrotreating technology developed by Petrochemical Research Institute of PetroChina Company. The revamping include decreasing the diameter of naphtha hydrotreating reactor, increasing the stock strainer, coalescence dehydration device and so on .The performance test data show that the mercaptans content in FCC gasoline is reduced to 2.7 μg/g from 26.1 μg/g, the diolefin value is lowered to 0.20 gI/（100 g） from 0.64gI/（100 g） and no octane number loss is observed. Analysis on the process revamping, the performance test results and existing problems could be a reference for the revamping and construction of other similar units.

Key words: thioetherification, selective hydrogenation, prehydrotreating, revamping, operation