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ExxonMobil Refinery (2638), Baton Rouge

Releases of Hydrogen Cyanide

LDEQ Accident Number
Accident Date		 Point Source(s) Notes Amount of Release
135706-141385

2011-12-02		Fluid Catalytic Cracking
Cause: Hydrogen Cyanide is being released from the Fluid Catalytic Cracking, but no information was given on the cause of the release (based on first written notification). (There was an initial followup on 8/17/2012 and a final follow up on 1/8/2013 - the following information is from follow up report 8/17/2012): The refinery is reporting a statistically significant increase above the upper bound of the initial reported quantity for hydrogen cyanide (HCN). The increase is based on stack testing on the Fluid Catalytic Cracking Unit Wet Gas Scrubber.

Followup: Yes

Notes: This is a continuous without interruption release of Hydrogen Cyanide from a 250 foot Fluid Catalytic Cracking unit. ExxonMobil reported the initial release based on a change in methodology as a result of the EPA Information Collection Request and subsequent test data becoming publicly available to other facilities. In the Section II Source Information it states that the normal range for HCN has a lower bound of 44.63 lbs/day and an upper bound of 444.3 lbs/day. Per year, the lower bound would result in 16289.95 lbs/year and the upper bound would result in 162169.5 lbs/year of HCN. If ExxonMobil reported the median of these bounds, the reported amount would be 244.47 lbs/day, or 89229.73 lbs/year. The total quantity released over the year reported by ExxonMobil was 22,000 lbs/year. Breaking this down, they are saying that 60.27 lbs/day of HCN was being released, which much closer to their lower bound limit (44.63 lbs/day). In the written notification they state that they have now found that they are releasing a statistically significant increase above their upper bound (444.3 lbs/day), meaning there is a discrepancy between their reported release amounts. In the initial written notification, Exxon reported a release of 82 lbs/day in the upper bound and 25.6 lbs/day in the lower bound. The reportable quantity for a continuous release of Hydrogen Cyanide is 10 lbs/day.		22,000.0 pounds