Date: October 21, 2011 

To: Docket ID No. EPA-HQ-OAR-2007-0011 

From: Kristin Sroka 

Subject: NSPS Subpart J Review: Meeting Minutes for February 25, 2011, Conference Call 

Between the U.S. EPA and Representatives of Lion Oil and John Zink 

Introduction

On February 25, 2011, representatives of the U.S. Environmental Protection Agency 

(EPA) and their contractor (RTI International) participated in a conference call with 

representatives of Lion Oil Company (Lion Oil) and John Zink Company LLC (John Zink). This 

conference call was a follow-up to the conference call on July 16, 2009. The names and 

affiliations of the participants are included in Attachment 1. Attachments 2 and 3 contain the 

background information provided by the Lion Oil representatives prior to the conference call; 

Attachment 2 is detailed information regarding flare sampling and Attachment 3 shows facility 

flare information from 2005 and 2006. The purpose of the conference call was to discuss the 

requirements for monitoring flares with flare gas recovery systems in NSPS subpart Ja. 

Discussion

The discussion mainly centered around the flaring information provided in Attachment 3. 

The EPA representatives were concerned that the data did not explain whether flaring instances 

were caused by brief events or large events. The Lion Oil representatives noted that, in general, 

anything that lasted over 2 minutes was a large event that exceeded the three compressors, while 

anything less than 2 minutes could be due to either compressor staging or an event. 

The Lion Oil representatives stated that the data show flaring from two flares, one that 

handles low-pressure releases and another that handles high-pressure releases (designed based on 

the pressure at which each unit releases). Each flare has three compressors, and the capacity of 

each compressor is 700 standard cubic feet per minute (scfm). Most of the releases with higher 

concentrations of sulfur dioxide (SO2) were from the low-pressure flare, which tends to receive 

discharges from the units with more sulfur. The discharges to the high-pressure flares are mostly 

hydrogen from hydrotreaters. 

One EPA representative said that when looking at the data from Lion Oil and backcalculating H2S from SO2 for events that lasted 1 minute or less (which, according to Lion Oil, 

could be either staging or capacity exceedances), there were no exceedances of the subpart J H2S 
 

2

concentration limit for fuel gas combustion devices. He could not be certain because the 

company did not provide direct H2S concentration data, but based on the data provided, he did 

not think Lion Oil would have problems meeting subpart J or subpart Ja. The Lion Oil 

representatives agreed that releases from the high-pressure flare are not as much of a concern 

because of the low sulfur content of the discharges from the units. However, a discharge to the 

low-pressure flare can have an H2S content of 5 percent, and a discharge as short as 1 minute at 

that concentration could cause an exceedance of the 3-hour concentration requirement for the 

flare. The EPA representatives noted that they could consider a paradigm in which they would 

use their enforcement discretion in making decisions about whether discharges due to 

compressor staging are actually violations of the H2S concentration requirements in subpart Ja 

(rather than including a specific exception for compressor staging). 

The Lion Oil representatives stated that another problematic issue is a system with small 

capacitance (small diameter and linear header). Lion Oil put their water seal inside the stack. 

The EPA representatives asked the John Zink representative if that configuration is common, as 

well as whether the system would be improved if a larger seal were placed outside the stack. 

The John Zink representatives replied that every application is different. In this case, 

they looked at the system as it was being designed and agreed that a 30-inch seal would provide 

operational flexibility. The decision to retrofit the existing liquid seals was the best option at the 

time. When designing flare gas recovery systems, if the flare does not already have a liquid seal, 

John Zink will design a new one from scratch. If one already exists, John Zink tries to use or 

modify the seal to the best extent possible. 

The John Zink representatives stated that a 30-inch seal was determined to be more than 

adequate for normal operations of the two flares at Lion Oil. They noted that there is no real 

performance difference between 30- and 40-inch seals. The only gain with a deeper seal is a 

slightly larger band for the set point at which the next compressor is set to start up. A 30-inch 

seal is standard and gives a 15-inch buffer (7.5 inches at the top and 7.5 inches at the bottom) to 

keep compressors from going on and off continuously, burning out motors. 

The John Zink representatives noted that the pressure is monitored in the flare header 

itself, preferably between the knockout and the take-off point of the flare gas recovery unit 

(alternatively, sometimes in the take-off point). The pressure monitors in Lion Oil’s system are 

located between the knockout and the take-off point. The John Zink representatives stated that 

the closer the pressure monitor is to the main flare header, the more time there is for the 

compressors to cycle. The EPA representatives asked whether monitoring the pressure before 

the knockout drum would be better since that is even further from the compressors. The John 

Zink representatives responded that some time would be gained, but it is only fractions of a 

second because only a very small amount of compression occurs. 

The John Zink representatives noted that the system should be set up to avoid a pressure 

drop between the compressors and the flare header. Once in the flare header, the pressure is not 

much different, and slight variations throughout the system could give a false reading. If the 

false reading is too far off, air could be drawn into the flare. 
 

3

The John Zink representatives stated that for a 30-inch seal, 15 inches is a typical set 

point. The John Zink representatives stated that they typically design their systems to turn on the 

second compressor if the pressure reaches 7.5 inches above the set point, or 22.5 inches. Lion 

Oil shortened the band on their system so that the second compressor turns on at 20 inches, to try 

to get better control of events. 

The John Zink representatives stated that the 10-30 second delay in startup of the 

compressor motors is typical of the design because they are large motors. Once they shut down, 

a certain amount of time must pass before they can be restarted. An energy management system 

could be installed so that the second motor runs for a minimum of 15 minutes, but then if the 

event is less than 1 minute, a lot of energy is expended energy just to recycle gas through the 

system, as no gases are being recovered during that time. There is also an issue with spill back 

valve capacity. If all three compressors are running and no gas is being recovered, the pressure 

drops so much that it becomes difficult to operate the system. On the other hand, if the spill back 

valve is designed to handle all three compressors running more often, much of the system control 

is lost, and there is trouble sticking to the pressure set point. 

The John Zink representatives stated that all their systems are custom, but the system at 

Lion Oil could be considered as “standard” as any of their systems today, even though it was 

installed 10 years ago. The John Zink representatives noted that it was one of the first multicompressor systems installed, and they often take prospective clients to see it. They also stated 

that the number of compressors for a system depends on the size of the flare, so there is not 

really a “typical” number of compressors. The John Zink representatives noted that they have 

not heard of many systems flaring between compressor staging like Lion Oil’s system. 

However, they clarified that they do not get a lot of feedback once the systems are in place, so 

while they can understand the conditions under which flaring between compressor staging would 

occur, they do not know for sure how common these types of staging issues are. They did note 

that they have heard of at least one other plant with the same experience as Lion Oil. 
Attachment 1 

Participants in February 25, 2011 Conference Call 

Industry Representatives

Brian Blackwell, John Zink 

Ray Callahan, Ergon 

Scott Fox, John Zink 

Jim Franklin, John Zink 

George Garten, Lion Oil Company 

Chuck Hammock, Lion Oil Company 

U.S. EPA Representatives

Brenda Shine (OAQPS) 

Pat Foley (OECA) 

RTI International (EPA contractor)

Jeff Coburn 

Kristin Sroka 
Lion Oil Company ("Lion Oil") has installed flare gas recovery units ("FGRU's") on

the two flare systems at its refinery in EI Dorado, Arkansas. The FGRU's at Lion

Oil are adequately sized and have not one but two back up compressors in

parallel for each flare. The seal for each flare system consists of a 30 inch water

seal which is located at the base of each flare stack. (See Figure 1A)

The FGRU withdraws gas from the flare header upstream of the liquid seal drum

and recovers gas that would normally be burned in the flare. The recovery

system operates to maintain a slight positive pressure on the flare header

upstream of the liquid seal drum, which ensures that air is not drawn into the flare

system or the FGRU. When gas is relieved to the flare system, the compressors

automatically stage up to handle the increase in volume to the flare system. This

process is not instantaneous and Lion Oil often experiences small flaring

releases, even though the control system is a state-of-art design. There are other

process unit startups, shutdowns and malfunctions that also result in these micro

flaring events.

The above mentioned water seal is monitored on a continuous basis and when

the water seal is broken, which indicates a flaring event is occurring a signal is

sent to the sample collection system to begin the sampling sequence. There is a

delay in the sample collection in order to make sure the horizontal flare line has

been purged, which allows for collection of a representative sample. After

completion of the delay a solenoid opens allowing the flare gas sample pump to

fill the sample canister with a gas sample from the horizontal flare line.

When the water seal is broken, an automatic email is sent to Lab personnel,

Operations personnel and the Environmental department. The lab personnel then

collect and analyze the flare gas sample via GC and provide the results to the

Environmental Department for emissions quantification. The sample gathering

and analysis takes about 1 hour.

The emissions are quantified using the flare gas analysis and the monitored flow

during the flaring event. The flow is measured using a Panametrics measurement

system that corrects for temperature, pressure and also measures molecular

weight.

The flare gas sample collection system consists of a sample pump, heated

sample line, in-line filter, solenoids and sample canister. The sample system

currently utilized was designed in house at a cost of approximately $5000-10,000

(See Figure 1B). A similar type system has been developed by Texas Sampling

(www.TexasSampling.com) at an approximate cost of $26,000-$30,000. (See

Figure 1C)

 Attachment 2 

Lion Oil Flare Gas Sampling Information



2005 2006

Duration Ibs S02 sef Duration Ibs S02 sef 500 Lb Case [Bold] 4 min 0.496 293.8 20mln I 1.631.01 197.779.0 > 500 of total % %<500Ibs 1 min 0.453 268.9 2 min 3.975 288.5 0.00855 0.85 99.1 2005 2 min 0.074 441.2 2 min 0.127 46.8 0.05600 5.60 94.4 2006 2 min 0.056 333.3 12 min 16.545 5.4831 96.8 Avg 4 min 1453 8,618.7 6min 2.596 2,405.5 2 min 0.090 530.8 8min 61.340 80.690.1 100 Lb Case [Italicized] 1 min 0.697 85.6 17 min 252.625 264,289.4 > 100 of total % %<100Ibs 1 min 0.254 150.6 3 min 0,461 582.2 0.12821 12.8 87.2 2005 2 min 0.170 72.5 27 min 9.783 3,946.4 0.09600 9.6 904 2006

12 min 3.151 1,909.5

6 min

I 1.170.818I 593,383.5 88.8 Avg

3 min 22.771 665.5

1 min 0.051 35.3

5 min 0.678 659.4 63 min

I 3.500.945I 25,148.1

3 min 0.099 585.0

1 min 0.115 42.5 Minutes

2 min 0.028 166.4 10 min 4.399 864.2 Mins of flaring

%

% uptime

14 min 8.291 2.092.8

5 min 1,385 748.8 2541 048 99.5 2005

3 min 0.044 259.4

2 min 0.307 162.6 1562 0.30 99.7 2006

1 min 0.040 44.8 4min 5.438 724.3 99.6 Avg

46 min

1297.2751 32,282.8 4min 0.858 978.0

2 min 1.938 1,149.4

7 min 1.182 1.347.6

1 min 1.338 793.7

1 min 0.063 91.4

37 min 8.660 8,365.9

4 min 0.051 300.6

3 min 2.420 287.0 5min 0.041 242.4

2 Hr41 mi1 375.330

1'08 ,537.0 6min 0.469 569.3

3 min 7.913 770.5 2min 0.002 18.2 1 min 0.057 16.2 1 min 0.085 70.1 5 min 0.141 833.3 14 min 8.590 1.732.5

I HR 55 mil 239,972I 33,358.6 18 min 16.898

7 min 1.889 1,166.7 18min 402.207 10.625.4

29 min 1.462 8,668.2 24 min 1.595 1.183.6 1 min 0019 22.9 21 min 390.973 9,994.9

10 min 85.184 4,230.4

1 min 0.589 0.2

4 min 3.369 1,997.7

3 min 0.473 5722

18 min 11.275 5,916.5 12 min 154,632 17,531,9 2 min 0.351 184.3 43 min 5.300 31.429.8 4 min 0.366 2,173.2 4 min 42.425 179.689.1 5 min 30.181 1,737.5 1 min 0.051 18,5

6min 0.203 1,204.3 46 min 521.730 155,462.0 2 min 0070 412.8 9min 1.322 7,840.6 7 min 15.272 1,580.4 2min 0.017 99.5 8 min 12.947 '1,119.1 9min 5.511 3.268.1

53 min 179.256 24,143.6

2 min

0 1.7

24 min 1.386 9,133.9

1 min 0.001 250.5

12 min 4.703 5,261.6

2 min 0.380 1.1

10 min 17.290 813,1

2 min 0.162 94,9

34 min 1.195 4,016.4

9 min 0.305 3,617.5

2 min 0.002 10.6 24 min 70.328 7.168.7

12 min 78.271 5,298,2

1 min 0.076 29.1

2hr 25 mini 216.814 86,931.5

2 min 0.076 31.8

5 min 56,605 2.624.3 13 min 11.665 4.705.2

20 min

I 254.794 13,568.9

2 min 0.261 127.7

22 min 6,508 2.901.7 19 min 22.648 9.866.2

22 min 3.177 784.8

4 min 0.300 264.5

55 min 52.163 7,176.5

2 min 0.292 250.7

16 min 105.789 26,137.2 5min 5.843 255.3

65min 3.061

2 min 0.065 26,2

8 min

I 266.170I 20,739.9

7 min 8.617 2,903.1

50 min 23.129 13,578.9

3 min 0.842 419.3

6 min 0.025 145.9 16 min 163.086 14,731.6

226 min 104.705 45,449.9 6mln 35,220 9,277.8

137 min 465.510 105,207.7 15 min 16,074 2,564,6

22 min 6.778 4.343.3

8 min 33.109 1,823.1

 Attachment 3 

Lion Oil Flaring Data - 2005 and 2006
612.1

2,468.4

258.8

795.7

25,948.6

2.1

2,531.5

1,424.9

940.4

47.339.3

3.7

3,062.1

5.8

43.4

66.422.2

11,001.1

2,750.0

3,331.3

1,665.5

13.095.5

1,196.4

349.3

19,851.2

1,455.0

1,338.1

2,871.7

20.9

89.1

6,602.8

150.7

17.0

664,039.4

1,290.5

296.7

211.1

54,612.8

78.9

49,456.9

48.0

23,020.6

683.8

11.7

0.0

683.8

4,564.1

2,698.5

176.3

104.4

3.5

21.2

228.3

7.3

1,3

1,635.7

15.0

603.5

113.3

645.3

403.6

867.4

1,148.4

68.824

38.503

3.258

96.958

20.904

0.330

62.268

41.910

49.601

37.487

89.395

41.476

11.339

738.297

0.002

1.188

0.004

0.745

39.941

4.792

4.883

15.309

40.295

6.909

13.366

14.615

0.001

0.387

0.015

0.024

6.508

1.670

3.103

0.003

1 7,213.0871

9.402

2.447

0.032

71.877

0.037

84.386

0.030

80.884

13.953

0.004

0.01

13.953

1.770

0.455

0.006

0.164

0.004

0.021

0.010

0.001

0.0004

0.055

0.005

1.364

0.023

0.098

0.197

2.072

0.213

11 min

19min 6 min

22 min

10 min 4 min

43 min 4 min 4 min

15 min 8 min 7 min 3 min

2 hr43 ml~ 2 min 8 min 2 min 2 min

53 min

22 min

10 min 5 min

16 min 2 min 8 min

66 min 1 min 9 min 2 min 2 min

12 min

6min 2 min 2 min

11 min 6 min 2 min 3 min

1 hr 21min 1 min

44 min 1 min

32 min 4 min 1 min 1 min 5 min

1 hr 36 min

23 min 4 min 2 min 1 min 3 min

10 min 2 min 1 min

20 min 3 min 3 min 8 min 7 min 6 min

32 min 9 min

5 min 19.901 2,164.5

2 hr44 mi~ 287.543 18,570.0

15 min 47.633 3,307.4 4 min 0.022 76.6

20 min 0.040 183.7 2 min 0.051 32.1

7min 18.700 1,820.5

58 min 68.700 27,334.8

28 min 10.000 3,488.3 2 min 0.054 22.6 7 min 0.319 451.9

1 hr 17 mi~ 183.202 66,138.0 6 min 46.924 3,216.7 2 min 0.304 1,638.1 6 min 7.655 590.3 2 min 0.031 183.0 3 min 40.295 1,384.3 1 min 0.111 80.9

17 min 149.887

1 6,435.8

2 min 0.003 151 2 min 1.726 79.9 2 min 0.023 126.5 2 min 0.011 65.8

26 min 78.636 4,342.4 4 hrs 11527.6881 119,395.2 3 min 0.021 75.6

4min 34.623 1,114.0

5min 45.884 6,141.7

60 min

1230.960 1139,292.8

6min 56.110 6,277.6 6 min 7.209 5,277.4 2 min 2.954 144.4 4 min 2.395 1,753.0 2 min 0.126 92.6 9 min 18.063 937.9 2 min 0.019 111.2 5 min 0.027 163.0 5 min 0.065 642.1

34 min 25.774 127,360.5 9 min 0.836 495.5

13 min 2.453 14,544.9

10 min 3.487 20,675,8 1 min 0.029 172.7

21 min 3.348 12,694.8

15 min 10.973 18,590.8 7 min 9.096 1,840.8

34 min 8.691 51,533.5 2 min 2088 154.4 2 min 0.781 1,322.6 5 min 0.229 1,359.8 5 min 8.437 1,558.5

29 min 1.337 8,581.7 3 min 3.362 678.0 4 min 6.504 1,329.9

11 min 12.806 12,093.0 1 min 0.001 !i.631 2 min 0.021 33.500