Plant Fire a Chemical Chain Reaction

Tuesday, July 10, 2012 @ 03:07 PM gHale

A chemical chain reaction at the Westlake Chemical Corp. complex in Ascension Parish, LA, released enough heat to breach a metal-walled column used to make vinyl chloride monomer, which also touched off a March 22 plant fire, the company said.

That chemical chain reaction was not the result of operator error and could not have been anticipated, therefore the company should not be subject to Louisiana Department of Environmental Quality (DEQ) penalties, said Andrew Kenner, vice president of manufacturing for Houston-based Westlake in a 14-page letter to environmental regulators.

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The initial column conditions setting the stage for the fire-causing chain reaction remain under investigation, including whether key pipeline valves were functioning, Kenner wrote.

The company hired an outside expert to test valves controlling chlorine flow.

The resulting blaze shot a plume of smoke high into the air over Westlake’s Geismar Vinyls Complex on March 22.

The fire forced residents inside for a few hours, closed the Mississippi River and highways for hours to a few days and shut down for a month and a half the complex that makes precursors for common household plastics.

The letter said the release and column fire occurred at 8:03 a.m. March 22, never involved an explosion and was out by 8:20 a.m. The fire involved a far smaller chemical release than initially reported, primarily steam, the letter said. A separate fire continued past 8:20 a.m. in an ethylene line.

Westlake spokesman Dave Hansen said Friday the ethylene fire was out at 9 a.m. March 22.

Initial reports from authorities the day of the fire and later indicated an explosion occurred and the fire lasted longer in the column.

The VCM column, knocked askew in the incident and since replaced, shut down March 19 for routine maintenance before the ill-fated startup sequence.

The March 22 incident, one of two detailed in the letter, prompted two state District Court lawsuits in Ascension Parish filed by residents alleging health and psychological effects from the fire and chemical release.

“Indeed, an incident such as occurred on March 22 has never been reported at any other VCM facility in the history of chemical operations in the United States”
— Andrew Kenner

Investigations by DEQ and the federal Occupational Safety and Health Administration are under way.

State Police also cited the company for not timely notifying a hazardous materials hotline, a State Police report said. Westlake said it notified State Police after several attempts and is working to resolve the matter.

Kenner said in the letter testing by third-party consultants and various agencies shows chemical releases on March 22 and on the second, separate incident on May 9 did not cause any tangible environmental or health concerns.

Four contractors went to the hospital after the May 9 incident, in which a power outage led to a small release of VCM, but the hospital released the contractors to return to their jobs after a few hours without treatment, the letter said.

Kenner wrote there was no way to anticipate the release on May 9 and is asking DEQ for no penalties.

Kenner’s letter asserts the series of events inside the VCM column on March 22, five separate elements in all, have never happened in the 30-year history of that column at the Geismar plant.

“Indeed, an incident such as occurred on March 22 has never been reported at any other VCM facility in the history of chemical operations in the United States,” he wrote.

Kenner sent the May 31 letter to DEQ Assistant Secretary Cheryl Nolan at her request to address the question of her agency’s possible penalties for both incidents.

Jean Kelly, DEQ spokeswoman, said agency officials have reviewed Kenner’s letter and other reports.

“It’s still under investigation, and they don’t talk about it while they are investigating,” she said.

Kenner’s letter said the unexpected levels of chlorine and hydrochloric acid in the VCM column during startup began the chain of events with other chemicals in the column.

Chlorine can react with ethylene dichloride, which is normally in the column at startup, to form hydrochloric acid.

Chlorine and hydrochloric acid reacted with the column wall, catalyzing chemical reactions with column contents and raising temperatures that caused a “tear” in its wall, the letter said.

When the column’s pressurized contents hit the air, the fire started immediately.

Kenner’s letter said valves controlling the flow of chlorine and hydrochloric acid into the column were shut at the time of the fire but added the company is trying to determine if they were functioning properly.

Kenner’s letter said the remedial action includes adding redundant valves and other safety measures to prevent the same kind of chain reaction from happening again.

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