A Successful Program in Process Water Corrosion Control

Controlling corrosion in a Process Water System is key for reliable operation of an Olefins Plant. This paper discusses a Multidisciplinary Root Cause Analysis conducted at the Braskem Olefins plant at the Camacari Site together with SUEZ Water Technologies (responsible for the chemical treatment in this section of the plant). The resulting actions significantly reduced the corrosion rate and improved control of process water quality to avoid reoccurrence of past failures that caused emergency shutdowns.

This Process Water System is susceptible to corrosion by many mechanisms, including acid and/or caustic corrosion, pitting, flow accelerated corrosion (FAC), corrosion under deposit etc. This paper will describe the process conditions and water chemistry conducive to corrosion, the strategy adopted, and the results achieved. This strategy was based on the selection of neutralizers, adjustment of pH range, adoption of a chemical responsible to generate an anti-corrosive film inside the pipe and equipment and use of a chemical treatment in the blow down of this system, in order to achieve the required specification by the liquid effluent treatment unit.