Respondent is the owner and/or operator of the Facility, which operates a coal gasification manufacturing plant. At this plant, Respondent uses a coal gasification process to produce industrial chemicals from coal. The reaction takes place at high temperatures and pressures in a series of process vessels and piping called process trains. The facility operates two process trains. When one train is taken offline for maintenance, the other is started up. The process involves the formation of hydrogen sulfide, which is a substance produced, processed, and handled by Respondent at the Facility.
Hydrogen Sulfide is regulated as an extremely hazardous substance under Section 112(r)(1) and (3) of the Act.
On October 4, 2017, Respondent’s Facility experienced a series of explosions that originated within the Facility’s coal gasification plant. The explosions caused damage to the Facility and released chemicals. The incident occurred while the Respondent was starting to switch one coal gasifier train to maintenance mode. The Facility’s coal gasification plant has two coal gasification trains. Switching from one train to the other (e.g., for maintenance, such as cleaning) requires complete isolation of the non-operating train prior to flushing the coal slurry lines with wash water.
The explosions resulted from the failure to isolate the process train due to an isolation valve failing to fully close. The failure to fully close the isolation valve allowed water to flow in the direction of the active process train preventing the flow of coal slurry and halting its normal reaction of coal to hydrogen and conversion chemicals. The buildup of hydrogen interacting with excess oxygen resulted in explosions. The explosions caused damage to the Facility and released chemicals.
The Respondent reported that 53 pounds (lbs) of hydrogen sulfide were released from the incident described in Paragraphs 15 and 16. Explosive hydrogen was generated in the incident; however, the Respondent stated that the hydrogen was consumed by the explosions.
Based on information obtained from the Respondent in response to the EPA’s November 26, 2019, information request letter and at, and following, the meetings referenced in Paragraph 19, the EPA determined that: