In the past few months, juries have awarded eight injured workers a total of $26.9 million after attorneys “argued that Williams, key management figures and others had known for years that one of two reboilers used in the refinery process was isolated from pressure relief—which meant there was a risk of over-pressurization and explosion,” the Baton Rouge Advocate reported.
A reboiler is a heat exchanger that supplies heat to a distillation column. Last month, the Chemical Safety & Hazard Investigation Board released its investigation findings. Reported Jeff Johnson for C&EN:
The reboiler that failed was one of two in the system that provided heat to the propylene fractionator—a distillation column that separates propylene and propane.
The second reboiler was a backup and had been off-line for 16 months. Plant officials assumed the backup reboiler was clean and available for use. When the operating reboiler appeared to have fouled, plant operators began to shift operations to the idle reboiler.
The plant operators did not know that the standby reboiler contained hydrocarbons and its pressure relief system was not in proper order, CSB found.
As the reboiler’s heat increased, the confined liquid hydrocarbons expanded, resulting in a quick and dramatic pressure rise within the vessel. The shell ruptured, causing a release, an expanding vapor explosion, and a fire.
A series of process safety management program deficiencies over the 12 years before the accident allowed the reboiler to be unprotected from overpressure problems, according to CSB.
The Occupational Safety & Health Administration (OSHA) also investigated the incident. The agency initially cited the company for six safety violations fined the company $99,000, but that was negotiated down to $36,000. The case remains open pending abatement of violations, according to the OSHA inspection database. Another inspection in the fall of 2013 resulted in one citation and a fine of $7,000. That case is closed. OSHA appears not to have inspected the facility since then.
Williams Olefins is a subsidiary of the Williams Cos.