(135a) Ethylene Quench System Fouling

Sasol North America Inc. owns and operates an ethylene unit in Westlake, Louisiana. This is an ethane feed cracker and has a nominal ethylene production capacity of 1 billion pounds per year. In the early nineties a Process Water Stripper (PWS), Dilution Steam Generator (DSG), and a Dispersed Oil Extraction (DOX) unit were added to the quench water system.

Over the years process changes have occurred in operating conditions, equipment, and treatment chemicals. These changes have inadvertently led to emulsion fouling in the quench water system. This fouling led to significant operating problems. One of the root causes was identified as overdosing the emulsion breaker intended to stop the emulsion fouling. The problem: ?Too much of a good thing is bad.?