This relates to the nitric acid plant, taken from Y-S AQMD Breakdown Reports.

From Jan 2007 through Feb 2010

List excludes CEMS breakdowns. Relates to Nitric Acid Plant operations only

Correspondence 

log ENV: Start End Duration

07-012 2/6/2007 13:47 2/6/2007 15:15 Intermittent

07-013

07-054 8/3/2007 5:45 8/3/2007 6:07 00:22 None estimated, Plant shut down to fix the problem. 

08-016 1/26/2008 15:23 1/26/2008 15:26 00:03 None estimated, Plant shut down to fix the problem.

08-017 2/5/2008 10:35 2/5/2008 10:40 00:05 None estimated, Plant shut down to fix the problem.

08-033 4/3/2008 8:00 4/3/2008 8:03 00:03

08-034 4/7/2008 12:15 4/7/2008 12:20 00:05

08-035

08-038 4/15/2008 14:42 4/15/2008 15:00 00:18

08-086 9/11/2008 7:25 9/11/2008 7:40 00:15

08-098 10/9/2008 2:02 10/9/2008 2:30 00:28

08-117 12/18/2008 10:25 12/18/2008 10:27 00:02

08-119 12/20/2008 11:50 12/20/2008 11:55 00:05

09-031 4/7/2009 6:37 4/7/2009 6:49 00:12

09-032 4/9/2009 7:33 4/9/2009 7:40 00:07

09-033 5/2/2009 6:15 5/2/2009 6:20 00:05

09-042 5/26/2009 10:17 5/26/2009 10:20 00:03

09-048

09-082 9/30/2009 12:37 9/30/2009 12:39 00:02

09-104 11/25/2009 7:55 11/25/2009 8:05 00:10

10-001 1/3/2010 8:07 1/3/2010 8:12 00:05 Plant Trip, power trip 

Agrium US Inc

Sacramento Nitrogen Operations

Malfunctions Summary

Short Description

Ammonia release from E-601 PSV & 

Plant Trip

Update to above

NG Compressor to Decomposer trip

Plant Trip, power trip 

Visible Plume Plant trip

Plant Trip, power trip

Plant Trip, power trip

Plant Trip, power trip

Clearing Compressor Train after plant 

was tripped for converter inlet overheating 

Power Trip CEMS stopped logging 

Plant Trip, high mix gas temp 

Plant trip, fuse blown 

Plant trip, instrument failure

NG Compressor to Decomposer trip

Plant Trip, unknown cause

Update to above

NG Compressor to Decomposer trip

correction to above

NG Compressor to Decomposer trip

Natural Gas Compressor failure

No change to NOx information

None estimated. Plant brought back under control. 

None estimated. Plant secured. 

None estimated. Plant secured. 

None estimated. Plant secured. 

None estimated. Plant secured. 

None estimated. Plant secured. 

None estimated for NOx.

None estimated. Plant secured. 

No excess emissions anticipated. 

Plant shut down & secured. Plant had been running 

in steady state and at reduced rates at the time of the 

trip.

No excess emissions anticipated. 

Plant shut down & secured. Plant had been running 

in steady state and at reduced rates at the time of the 

trip.

None estimated. Plant brought back under control.

None estimated. Plant secured. 

None estimated. Plant secured. 

The compressor was re-started and the decomposer 

brought back to stable temperatures. 

Operators secured the Plant and stopped the plume. 

Operators secured the Plant and stopped the plume. 

Operators secured the Plant and stopped the plume. 

Operators secured the Plant and stopped the plume. 

Operators secured the Plant and stopped the plume. 

Steam feed valve taken of automatic and remotely 

manually closed. Plant secured. 

Nitric Acid Plant tripped out due to a PG&E power failure. This resulted 

in a light visible plume of approximately 10minutes duration. 

Nitric Acid Plant tripped out due to a PG&E power failure. This resulted 

in a visible plume of approximately 5 minutes duration. 

The compressor was re-started and the decomposer 

brought back to stable temperatures. 

Engineering staff are investigating the improvement 

of the alarm systems to better warn of such a trip.

Operators secured the Plant and stopped the plume.

As the compressor cleared the lines, the NOx 

subsided. No visible emission was evident after 

approximately 1⁄4 hour. 

The Nitric Acid Plant was taken down at 

approximately 07:40 pending return of power and 

proper functioning of the CEMS Data Historian. 

Operators secured the Plant and stopped the plume. 

Secured Plant to stop visible emission. 

Secured Plant to stop visible emission. 

Instrumentation wire came loose causing loss of pressure signal from E601 ammonia heat exchanger. This resulted in a command for the steam 

feed valve to the exchanger to open, causing an increase in heat and 

ammonia pressure. The Pressure Relief Valve PSV 687 at the exchanger 

subsequently opened (chattered). 

The increased pressure of ammonia vapor fed additional ammonia to the 

gauze which ultimately caused the Plant to trip on high temperature with 

a resulting slight visible plume. 

The natural gas compressor supplying the decomposer tripped out 

causing a visible plume from the Plant stack. This caused a visible plume 

of less than 2 minutes duration

Plant tripped causing a visible plume for less than two minutes. This was 

caused by a fuse on the high voltage line failing. The reason for this is 

unknown at the time of this report.

Plant tripped causing a visible plume for between two and five minutes. 

This was caused by an interruption in PG&E supply. 

Nitric Acid Plant tripped out due to a PG&E power failure. This resulted 

in a visible plume of approximately 5 minutes duration. 

Nitric Acid Plant tripped out due instrumentation spike tripping natural 

gas compressor and sending false gauze temperature indication. This 

resulted in a visible plume of approximately 5 minutes duration. 

Nitric Acid Plant tripped because of high mix gas (prior to the gauze) 

temperature. This caused a visible plume. 

Instrumentation failure causing the plant to trip Repair/replace failed instrument

Plant personnel were switching cooling water pumps for planned 

maintenance purposes. The natural gas compressor supplying the 

decomposer tripped out on low cooling water pressure. This caused a 

visible plume of approximately 3 minutes duration. 

Nitric Acid Plant tripped out for unknown reason. This caused a slight 

visible plume of approximately 5 minutes duration. 

Nitric Acid Plant tripped out due to a PG&E power failure. This resulted 

in a visible plume of approximately 2 minutes duration. 

Natural Gas compressor supplying gas to the decomposer tripped out 

four times resulting in three minor visible plumes of short duration. This 

was determined to be caused by a bad trip switch.

Switch has been jumpered out until replaced. 

Compressor running continuously

The cause was found to be related to temperature settings. The main 

process air compressor has two turbines that power it; a steam side and 

decomposer-discharged heat expander side. At the expander inlet, 

temperatures rose to 926degF & to 912degF. It was found that the unit 

was set to trip at 900degF. The trip temperature was adjusted to 

1,000degF. The high temperature alarm set-point was also reduced from 

940degF to 900degF. 

The inlet piping to the Converter was found to be red-hot. Consequently 

the Plant was tripped. In the process of subsequently clearing the lines for 

Maintenance (by rolling the compressor) NOx was released out of the 

stack.

Power to the Administration Building and the Ammonia Storage areas of 

the Plant was interrupted. The Nitric Acid Plant continued to run but 

ammonia supply to the Plant was also interrupted. The Data Historian that 

logs CEMS data also went down (located in the Administration Building). None anticipated. The acid plant was taken down. 

Cause of Breakdown

None estimated, Plant running under reduced rates

Corrective Measures Taken

An electrical failure in a cooling tower pump caused a cascading effect 

resulting in the natural gas compressor supplying gas to the decomposer 

tripping out and would not re-start. This resulted in a visible plume of 

approximately four minutes duration.

Estimated (Excess) Emissions During Breakdown 

Condition

Natural Gas Compressor failed and would not restart. Tripped out the 

plant. Release duration was three minutes. 

Plant is down for planned maintenance outage. GC604 will be examined for failure source and 

Plant was shut down.