Corrosion Control in Petroleum Refineries Processing Western Canadian Crude Oils

Abstract

Abstract Corrosion problems encountered m petroleum refineries processing Western Canadian crude oils, and the methods used to overcome them, are outlined. Hydrogen sulfide and other sulfur compounds, together with hydrochloric acid formed from chlorides in the water associated with the crude oils, are the chief factors in the corrosion of crude distillation units. Preventive measures include desalting, use of alloy materials, neutralization of the hydrochloric acid, and the use of film forming organic inhibitors. Corrosion in catalytic cracking light ends equipment is attributed to nitrogen compounds and cyanides. Water washing to reduce cyanide concentration,, the use of film-forming inhibitors, and the use of corrosion resistant materials are used with success to reduce the severity of the attack. In catalytic reforming units, the problem of high temperature hydrogen sulfide corrosion is overcome by removing the sulfur in a feed preparation unit. Embrittlement of carbon steel by high temperature, high pressure hydrogen is a potential hazard in reforming units, but can be prevented by the use of refractory linings or low alloy steels containing chromium and molybdenum. Under certain conditions, strong acids are formed in these units creating further corrosion problems at temperatures below the dew point. 8.4.3