Cooling Water Issues – Cause and Solutions to Microbiologically Induced Corrosion

In the 2007 turnaround at the BASF FINA PETROCHEMICAL L.P. Ethylene Steam Cracker, severe damage was discovered in the cooling tower to process exchangers.  Over 41 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). 

As the result of inspections performed during this scheduled plant outage, the MIC damage mechanism was identified in the cooling water system.  The purpose of this paper is to describe damages found and solution methods implemented.  This experience offers a basis for establishing best practices considering time and service expectations of cooling water systems.