Abstract: Investigation on the NH4Cl-NH4HS fouling corrosion of high pressure air cooler (HPAC) in hydrocracking unit of SINOPEC Maoming Company was carried out on a simulation test device using simulated corrosion medium to observe the influences of water injection modes and various corrosion inhibitors on the corrosion of HPAC. The results showed that the inhibition performance of compounded corrosion inhibitor, sodium polysulfide and benzotriazole, was significant; the key points in corrosion protection of HPAC were selecting proper water injection mode and corrosion resistance material; when processing high sulfur and nitrogen feed, the addition of corrosion inhibitor was recommended.

Key words: hydrocracking, air cooler, corrosion, corrosion inhibitor