LA Bucket Brigade : Refinery Accident Database

About the Database

Valero (26003), Norco

Releases in 2012

LDEQ Accident Number Accident Date	Point Source/Release	Cause	Notes
144411 2012-11-05	Point Source(s): Flare 1 and 2 Pollutant(s): Carbon Monoxide - 137 pounds NOx - 25 pounds Particulate Matter - 1 pounds Volatile Organic Compounds (VOCs) - 1 pounds Sulfur Dioxide - 3,142 pounds Hydrogen Sulfide - 8 pounds	Cause of Problem: Equipment Failure The wet gas compressor in the delayed coking unit had malfunctioned.	The maximum hourly permitted emissions for hydrogen sulfide and sulfur dioxide exceeded the maximum hourly permitted emissions. Gas from the coker was combusted in Flare 1 and Flare 2. The resulting combustion byproducts rapidly dispersed. Emissions were minimized by restarting the wet gas compressor. The incident will be communicated to all affected personnel. The XY-53325 A and B solenoids as well as the XY-53325A relay will be replaced during the text outage. Wiring in the compressor control cabinet will be upgraded to separate critical wiring from general purpose wiring.
144357 2012-11-01	Point Source(s): FCCU Pollutant(s): Hydrogen Cyanide - 788,000 pounds	Cause of Problem: Equipment Design Stack testing of the FCCU revealed higher than federally permitted release rates and reportable quantities of hydrogen cyanide gas.	A permit notification will be submitted representing this new data and request an increase in emissions. Testing showed hydrogen cyanide release at 90 lbs/hr. No duration time was given, because emissions are ongoing. Release amount for this database represents one year of HCN emissions and was calculated using the hourly release rate (90 lbs/hr) multiplied by 8,760 hours/year.
143663 2012-10-08	Point Source(s): NIG Pollutant(s): Sulfur Dioxide - 1,718 pounds	Cause of Problem: Equipment Failure The Hydrotreater Hydrocracker (HTHC) unit had malfunctioned resulting in excess SO2 emissions at Flares 1 and 4. A feed pump motor shutdown due to an inboard bearing failure causing all four of the HTHC heaters to trip. When the HTHC heaters tripped, the LCO reactor lost its heat input to the top of the hydrotreating bed. With the loss of the heat input, the quench valve automatically began to close with the change in the bed inlet temperature causing less hydrogen to be fed into the stream creating a change in the hydrogen/oil ratio and ammonia in the vapor phase. In addition, there was tray damage in the LCO reactor causing flow maldistribution which compounded the issue. Thus, the change in composition and flow maldistribution caused increased cracking and significant temperature increase in a subsequent bed. The temperature increase in the subsequent bed activated the high rate depressurization of the HTHC unit.	Gas from the HTHC was combusted in Flare 1 and 4 and the resulting combustion byproducts rapidly dispersed. A quantity of the material was recovered through the fuel gas recovery unit on the flare system. The reportable quantity for SO2 was exceeded as a result of this incident. In addition, the max hourly permitted emissions for SO2 were exceeded at Flares 1 and 4. Operations will implement a guidance document to reduce set points by 15 degrees Fahrenheit on loss of LCO charge heater. Cracking beds operation stability will be improved by limiting the temperature delta. A high priority alarm to the DCS will be added. The logic in the DCS will be revised to eliminate the inlet temperature trips.
142968 2012-09-13	Point Source(s): Wet Gas Compressor Pollutant(s): Carbon Monoxide - 951 pounds NOx - 102 pounds Particulate Matter - 3 pounds Volatile Organic Compounds (VOCs) - 4 pounds Sulfur Dioxide - 12,643 pounds Hydrogen Sulfide - 33 pounds	Cause of Problem: Process Upset The Wet Gas Compressor (WGC) in the delayed coking unit had malfunctioned resulting in excess SO2 emissions at Flares 1 and 2. The WGC malfunction was caused by a loss of power to the Bentley Nevada (B/N) Control Panel. The B/N Panel is powered by two separate supply feeders, each having a breaker. Maintenance personnel who were investigating the WGC malfunction found that both power source breakers to the B/N panel had tripped causing the WGC to lose power, which resulted in flaring. It could not be determined if both breakers tripped at the same time or if one had failed earlier eliminating the redundancy. Maintenance personnel could not find any issues inside the B/N panel so they reset the breakers and restored the power to the panel. The WGC compressor was reset and restarted without further issue. This event is considered reasonably unforeseeable and therefore qualifies as an "upset."	Gas from the coker was combusted in Flare 1 and 2 and the resulting combustion byproducts rapidly dispersed. Emissions were minimized by restarting the wet gas compressor. In the future, the facility will communicate the incident to all affected personnel. They will install a power monitoring system that will trigger an alarm on the Distributed Control System (DCS) if one of the power system fails. They will also install breakers separated by a physical gap on the power supply. Finally, they will review other Bentley Nevada systems in the refinery for similar issues. The reportable quantity for SO2 was exceeded.
143284 2012-09-13	Point Source(s): Tail gas incinerator on the 3700 sulfur recovery unit Pollutant(s): Hydrogen Sulfide - 29 pounds	Cause of Problem: Equipment Failure Malfunction of the tail gas incinerator on the 3700 sulfur recovery unit caused the release of 29 pounds of hydrogen sulfide gas.	Initial correspondence between the refinery and Louisiana DEQ indicate an original estimate of a release of 100 pounds of hydrogen sulfide, which was later corrected as 29 pounds of hydrogen sulfide (below the reportable quantity).
142365 2012-08-27	Point Source(s): NIG Pollutant(s): Unknown Substance - BRQ	Cause of Problem: Weather On Monday September 27, 2012 at approximately 08:30 hrs, we made notification. that we will experience a controlled shutdown due to the proximity of Hurricane Isaac. Any emissions associated with this controlled shutdown were within the allowable permit limits.	There is no list of pollutants released/calculations table (there should be even when it is within permit limits). Without this there is no proof that the release was within permit limits. From the EPA Facility Report: Storm water collected within diked areas. Some electrical motors got wet; motors were operationally checked prior to startup. Facility is undergoing startup. There was a power outage due to Hurricane Isaac.
141595 2012-07-27	Point Source(s): wet gas compressor Pollutant(s): Carbon Monoxide - 667 pounds NOx - 62 pounds Particulate Matter - 2 pounds Volatile Organic Compounds (VOCs) - 2 pounds Hydrogen Sulfide - 17 pounds Sulfur Dioxide - 6,024 pounds	Cause of Problem: Equipment Failure The wet gas compressor in the delayed coking unit malfunctioned resulting in excess H2S and SO2 emissions at Flares 1 and 2.	On the day of the incident, the steam control valve that regulated the turbine speed for the Coker WGC to account for increased gas flow rates due to an upstream process upset. When this upset was corrected, the gas flow to the WGC decreased and operators began closing the steam control valve for the steam turbine to reduce the speed of the WGC due to this lower gas flow. However, the steam control valve did not provide adequate response and did not result in a change in turbine speed. The WGC ultimately shutdown when the turbine reached its protective overspeed trip point and stopped all steam flow to the turbine. This happened very quickly and no further adjustments to the steam control valve before the turbine tripped. Emissions were minimized by restarting the wet gas compressor. This incident will be communicated to all affected personnel. The facility will install a control clamp at 80% on the steam control valve output to prevent a delayed control response due a dead band on the valve. A team will also be created from operations, controls, process, and reliability to monitor and record events in the Trilogger and review with the process control design team on a biweekly basis to control performance and tune as necessary. There is a discrepancy regarding the incident date. The subject lists the incident date as 07/27/2012, while the written notification states that it occurred on June 27, 2012.
141519 2012-06-25	Point Source(s): bulk air valve on the 3700 sulfur recovery unit furnace Pollutant(s): Sulfur Dioxide - 304 pounds	Cause of Problem: Equipment Failure SO2 was released due to a malfunction of the bulk air valve on the 3700 sulfur recovery unit furnace.	In a previous report that LABB does not have access to, this release was classified as reportable quantity; however, after further consideration, it was determined that no reportable quantity had been exceeded. 304 pounds of SO2 was released and will be captured in the semiannual deviation report. Discrepancy with the incident date. The subject information states the incident date as 07/25/2012, while the report says June 25,2012. The report does not state whether the previous notification was verbal or written. If it was verbal, and this incident occurred on June 25, the report would have been made more than 7 days after the incident occurred.
140457 2012-06-13	Point Source(s): wet gas compressor Pollutant(s): Carbon Monoxide - 60 pounds NOx - 11 pounds Volatile Organic Compounds (VOCs) - 23 pounds Sulfur Dioxide - 1,037 pounds Hydrogen Sulfide - 3 pounds Particulate Matter - BRQ	Cause of Problem: Equipment Failure The Wet Gas Compressor malfunctioned when operators were warming Coke Drum D. Shortly after switching to Coke Drum D, pressure on the unit spiked and the Fractionator overhead became overloaded. The temperature increased 20 degrees and caused the Interstage drum to become overwhelmed with condensing liquid. The compressor tripped on high interstage level resulting in flaring.	As a result of this incident, the maximum hourly combined permitted emissions for H2S and SO2 were exceeded as well as the reportable quantity. Emissions were minimized by restarting the wet gas compressor. The facility will now hold an operations stand down with each shift to review the incident and stress the importance of following all standard operating procedures. The facility is also adding a line to the console check sheet to verify that the tap water is blocked in before warming up drums prior to switching drums.
140445 2012-06-12	Point Source(s): 3700 SRU TGTU inline mixer Pollutant(s): Sulfur Dioxide - 450 pounds	Cause of Problem: Equipment Failure A malfunction of the 3700 sulfur recovery unit (SRU) tail gas treater unit (TGTU) inline mixer occurred resulting in excess sulfur dioxide emissions.	Excess sulfur dioxide emissions resulting from the 3700 SRU TGTU inline mixer malfunction were emitted through the 3700 TOX stact to the environment and rapidly dispersed. The 3700 SRU TGTU inline mixer was restarted. Measures to prevent recurrence will be identified as part of a pending investigation. Initial reports indicated that this release was reportable quantity, but a report sent on June 26th, 2012 indicates that no reportable quantity has been exceeded. Emissions associated with this malfunction event were 450 pounds of SO2 and will be captured in the semiannual deviation report.
140250 2012-06-05	Point Source(s): wet gas compressor Pollutant(s): Carbon Monoxide - 54 pounds Nitrogen Oxide - 10 pounds Volatile Organic Compounds (VOCs) - 20 pounds Sulfur Dioxide - 1,160 pounds Hydrogen Sulfide - 3 pounds	Cause of Problem: Equipment Failure The wet gas compressor in the delayed coking unit malfunctioned resulting in excess H2S and SO2 emissions at Flares 1 and 2.	Gas from the coker was combusted in flare 1 and flare 2 and the resulting combustion byproducts rapidly dispersed. Emissions were minimized by restarting the wet gas compressor. The incident is still under investigation. No procedures or preventative measures have been identified at this time.
140182 2012-06-01	Point Source(s): 3700 TOX thermal oxidizer Pollutant(s): Sulfur Dioxide - 687 pounds	Cause of Problem: Equipment Failure A malfunction of the 3700 thermal oxidizer (TOX)occurred resulting in excess sulfur dioxide emissions.	Excess sulfur dioxide emissions resulting from the TOX malfunction were emitted through the 3700 TOX stack to the environment and rapidly dispersed. The 3700 TOX was restarted. Measures to prevent recurrence will be identified as part of a pending investigation.
140047 2012-05-26	Point Source(s): wet gas compressor Pollutant(s): Sulfur Dioxide - 1,214 pounds Hydrogen Sulfide - 3 pounds Carbon Monoxide - 65 pounds NOx - 12 pounds Particulate Matter - BRQ Volatile Organic Compounds (VOCs) - 25 pounds	Cause of Problem: Under Investigation The wet gas compressor in the delayed coking unit had malfunctioned resulting in excess SO2 emissions at flares 1 and 2.	Gas from coker was combusted in Flare 1 and Flare 2 and the resulting combustion byproducts rapidly dispersed. Emissions were minimized by restarting the wet gas compressor. This incident is still under investigation. No procedures or preventative measures have been identified at this time. A "30 day follow up report" was submitted on February 28, 2013 citing that the root cause failure analysis report had been submitted for the incident. The document only lists 3 actions Valero plans on taking: "1. We will communicate this incident to all affected personnel. 2. Operations will implement a guidance document to reduce set points by 15 degrees Fahrenheit on loss of LCO charge heater. 3. Improve cracking beds operation stability by limiting the temperature delta. Add a high priority alarm to the DCS." The February 28th letter does not provide the root cause of the accident.
139226 2012-04-30	Point Source(s): Wet gas compressor Pollutant(s): Carbon Monoxide - 56 pounds NOx - 10 pounds Volatile Organic Compounds (VOCs) - 21 pounds Sulfur Dioxide - 768 pounds Hydrogen Sulfide - 2 pounds	Cause of Problem: Equipment Failure The Wet Gas Compressor in the delayed coking unit at Valero St. Charles Refinery malfunctioned resulting in excess SO2 emissions at flares 1 and 2.	Refinery fuel gas was combusted in Flare 1 and Flare 2 and the resulting combustion byproducts rapidly dispersed. Emissions were minimized by restarting the wet gas compressor. This incident is still under investigation. No procedures or preventative measures have been identified at this time.
138677 2012-04-08	Point Source(s): No information given Pollutant(s): Sulfur Dioxide - 320 pounds Hydrogen Sulfide - 25 pounds	Cause of Problem: Under Investigation The 1600 Sulfur Recovery Unit (16 SRU) tripped and went offline for about 2.5 hours. It is suspected that SO2 and H2S levels were elevated at the associated thermal oxidizer (1600 TOX-EQT241). The exact cause is under investigation.	These emissions will be reported in the Refineries Title V permit compliance reports. In the first written follow up report, it is suspected that the rate and reportable quantities of SO2 and H2S were exceeded. The SO2 concentration limit may have also been exceeded. The opacity standard may have been exceeded for 2 hours and 34 minutes. In the follow up report sent May 3, 2012, the values were calculated as below reportable quantity.
137347 2012-02-20	Point Source(s): FLARE: Unspecified flare coming from PSVs on compressors K-14-02A and K-14-02B Pollutant(s): Sulfur Dioxide - BRQ Propylene - BRQ	Cause of Problem: Equipment Failure Hydrocarbon flaring was coming from PSVs located on compressors K-14-02A and K-14-02B in the Alkylation unit.	Fenceline monitoring was conducted to determine impacts to surrounding areas. The results of monitoring are contained in an attachment to the file. The attachment shows no impact.