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Volume 91 Issue 28 | pp. 21-23
Issue Date: July 15, 2013

Williams Investigation Under Way

Plant Safety: Distillation Tower Being Examined
Department: Government & Policy | Collection: Safety
Keywords: CSB, EPA, ammonium nitrate, reactive chemicals, fertilizer, accidents
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DEADLY
The June 13 explosion at the Williams Cos. olefins plant killed two workers.
Credit: CSB
09128-govpol-williams
 
DEADLY
The June 13 explosion at the Williams Cos. olefins plant killed two workers.
Credit: CSB

Two workers died on June 13 from a fire and an explosion at a Williams Cos. olefins plant in Geismar, La., reported Chemical Safety & Hazard Investigation Board (CSB) Chairman Rafael Moure-Eraso, testifying on June 27 at a Senate Environment & Public Works Committee hearing.

The plant produces ethylene and propylene and employs more than 100 workers. At the time of the accident, hundreds of contract workers were also at the facility, which was in the midst of a $400 million plant expansion to increase ethylene capacity by 50%.

At approximately 8:30 AM, the plant experienced a large-scale release of propylene, propane, and other hydrocarbons from several release points, according to CSB’s preliminary investigation. The release resulted in a vapor cloud more than 200 feet high. Within seconds, the cloud ignited, killing two workers and injuring another 105. The fire burned for more than four hours.

The incident involved a large distillation tower that processes hydrocarbons and was in normal operation at the time of the accident. There appeared to be a sudden catastrophic failure involving a heat exchanger and associated piping attached to the tower, CSB found. The heat exchanger’s steel shell ripped open, detaching piping connected to the tower, according to CSB, but the exact sequence and cause of these events have yet to be determined.

CSB investigators arrived at the site two days after the accident and are still there, Moure-Eraso said. They have interviewed more than 28 witnesses. Also various electronic control systems data are being recovered and investigated to determine conditions at the time of the incident, such as material flows, pressures, and temperatures as well as valve position, according to information presented by CSB at the hearing.

A day after the Williams’ accident, another deadly chemical plant accident occurred in Louisiana. This one happened at the CF Industries nitrogen fertilizer plant in Donaldsonville, 10 miles from the Williams facility. One worker died and seven were injured in the early evening of June 14 when a temporary distribution manifold ruptured during off-loading of nitrogen gas.

Like the Williams facility, the CF facility was undergoing an overhaul. The CF explosion took place in an ammonia unit that was shut down for maintenance. CSB is not examining the CF explosion because of resource constraints.

CSB accident reports show that plant transitions—such as shutdowns, expansions, start-ups, and maintenance—are operations that merit safety concerns. The American Chemistry Council, a chemical industry trade association, has noted that some 97 planned expansions with a total investment of $71.7 billion are in the works in the U.S. because of the natural gas and ethane feedstock boom. The U.S. Gulf Coast will see most of the construction activity, and much of it is likely to be done by contract workers who are sometimes unfamiliar with chemical safety procedures.

Lousiana is expected to pick up about half of these projects or some $30 billion in new investments, said Sen. David Vitter (R-La.) speaking at the hearing. “And while we certainly welcome these investments in our state and all the jobs that will come along,” he said, “we must ensure that all these facilities are as safe as possible for the workers and the local communities.”

 
Chemical & Engineering News
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