Abstract

A review of recent patents on naphthenic acid corrosion (NAC) control strategies in refineries from 2000 to 2011 is presented in this paper. The patents mainly concentrate on corrosion inhibitors and removal of naphthenic acids. The corrosion inhibitor consists of phosphorous inhibitors and non-phosphorous inhibitors; the removal of naphthenic acids includes solvent extraction, chemical conversion, thermal treatment, and hydroprocessing. Advantages and disadvantages of various NAC control strategies are outlined. In addition, a further development of NAC control strategies is prospected.

Keywords: Naphthenic acid corrosion, corrosion inhibitors, removal, thermal treatment