Abstract: The 2nd vacuum side cuts are the feedstocks of lube oil, but naphthenic acid in the distillates could cause serious corrosion problems during processing. In this paper, Mg-Al hydrotalcite spherical catalyst made by mechanical rolling process was used to catalytic decompose the naphthenic acid in Zhonghai 2nd vacuum distillate and the effect of reaction conditions on the removal rate of naphthenic acid was investigated. Test results show that Mg-Al hydrotalcite is an effective catalyst for decomposing naphthenic acid, and the Mg-Al hydrotalcite catalyst particles made by mechanical rolling possess excellent anti-press strength and good pore structure. Under the conditions of a reaction temperature of 320℃, a reaction time of 60 min, a reaction pressure of 0.1 MPa and catalyst/oil mass ratio of 0.2, the acid number of treated Zhonghai 2nd vacuum distillate was reduced from 4.32 mgKOH/g to 0.46 mgKOH/g, its corrosion hazard is less. Therefore, materials of equipments and pipeline in processing this distillate do not need to be upgraded.

Key words: distillates, naphthenic acid, catalytic decomposition, deacidification , Mg-Al hydrotalcite