Cooling Water Issues – Follow up Solutions to Microbiologically Induced Corrosion

In the 2007 turnaround at the BASF TOTAL PETROCHEMICALS LLC Ethylene Steam Cracker, severe damage was discovered in the cooling tower water to process exchangers.  Over 40 exchangers had been replaced or required total tube bundle replacement within the first seven years of operation.  Several of the units had been in service for less than five years, and many required immediate replacement.  The damage was determined to be microbiologically induced corrosion (MIC).

Several changes were made as a result of a multi-disciplined member team root cause investigation.  The site has recently performed a turnaround during which follow up inspections were made to evaluate the system changes.  The purpose of this paper is to describe damages found, to review the evaluation of the changes implemented, and share additional recommended actions for improvement. This experience offers a basis for establishing best practices considering time and service expectations of cooling water system exchangers.