Saturday, September 10, 2016

US Nitrogen Says Equipment Failures Caused Excess Emissions

By Walter F. Roche Jr.

Officials of US Nitrogen say a valve stuck in an open position led to two incidents of excess emissions during the recent attempted startup of a nitric acid plant on its 500 acre Greene County site.
In a four-page letter to Tennessee environmental officials US Nitrogen Plant Manager Andrew Velo said the company also "experienced several nitric acid plant process and equipment issues" one of which necessitated "a full rebuild of a portion of the plant's compressor train."
The details were included in a letter in which Velo is requesting waivers and extensions of existing deadlines for completing testing and mandatory reporting requirements.
Citing the equipment problems, Velo said it would be impossible for the company to collect the required monitoring data by the existing deadlines.
He also disclosed that after the failed startup on Aug. 23, a second attempted start up on Aug. 29 was aborted after only 20 minutes "because an additional issue with an instrument was identified."
As for the Aug. 23 incidents, Velo wrote, "Analysis of the process issues ... pointed to a valve that was not operating correctly. The valve was sticking open, causing the plant to not build pressure in the system as intended."
The Aug. 23 incidents produced an orange cloud that hung over the 500 acre site. Velo subsequently reported that the emissions consisted of nitric oxide and nitrogen dioxide, "both are extremely hazardous substances."
The plant was restarted yet again on Aug. 31 Velo reported.
"This start up went well, as the plant started up correctly with the pressure in the plant as expected," he added.
But Velo said even with the repairs, other issues, including limited on-site storage, made it impossible for the company to run the nitric acid plant for 30 consecutive days and record required data.
He said that as a result the 30 consecutive day test period would have to be delayed until Oct. 1 and perhaps even Nov. 1.
Currently, Velo wrote, US Nitrogen faces an Oct. 26 deadline to submit the results of the 30 consecutive day test.
"It is physically impossible to complete and report the results" by that deadline, the letter states.
Other issues causing delays cited by Velo include problems in the ammonia production process including mechanical problems.
"The delay in onsite ammonia production has greatly limited nitric acid plant operation since its certified start up," Velo wrote.
 The company is seeking a 180 day delay in the deadline for reporting monitoring results from 30 consecutive days of operation of the nitric acid plant along with extensions in two other related reporting and testing requirements.

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