Ensure that there is free space of at least 3/16 - inch (4.8 mm) around the DOW Diamond. PDH - 1 Flare System
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1



# FLARE SYSTEMS
Multipoint Ground Flares
PDH - 1 Flare Emissions Test Results

TCEQ / EPA February 2014 The Dow Chemical Company

R2 Feb 2014 Approved for External PresentationEnsure that there is free space of at least 3/16 - inch (4.8 mm) around the DOW Diamond. PDH - 1 Flare System
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## Agenda

• Introductions



## • Meeting Purpose

• Permit Background



## • Burner Testing

– Protocol

– Results



## • Path Forward

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## Dow Participants

• Jarod Davis, Regulatory Services Manager

• Cindy Rodriguez, Project Environmental Manager

• Cheryl Steves, Environmental Manager

• Vance Varner, Dow Flare Subject Matter Expert



## • Russell Wozniak, Operations Regulatory Services

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## Meeting Purpose

• Purpose:

– To review previous meeting on the operation of pressure assist flare technology

– To present the results of emissions testing on the flare burners.



## • Outcome: Agreed path forward for approved 

## operation of Multi Point Ground Flares at the Dow Chemical Company in Freeport, TX

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## • Initial Permit Application for Propane Dehydrogenation Plant (PDH

- 1) was submitted to TCEQ on 1/24/12.

• Agreement to initially permit routine (non

- pressure assisted) emissions, and to seek an AMOC authorization for the MSS (pressure

- assisted) 

## emissions

• PDH

- 1 Permit issued 1/11/13 

## Permit Background/Status

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## • Initial Permit Application for Light Hydrocarbon 9 Plant (LHC

- 9) was submitted to TCEQ on 11/29/12.

• Propose similar permitting strategy as PDH

- 1; i.e., initially permit only routine emissions, and seek an AMOC 

## Permit Background/Status

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## • Pressure assisted burners



## • Header operates at a minimum of 15 psig

• Gas exits at sonic velocity

– Sonic velocity ranges from 700 to 1,400 ft/sec for common parafins and olefins



## • High number of burners

– Number of burners based on required capacity

– Imagine a football field of burners 

## MPGF Burner Operation
– Key Concepts

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## Overall View

R2 Feb 2014 8

Burners Fence Main gas manifold

Stage 1

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## Pressure Assisted Burner

R2 Feb 2014 9

• Multiple arms

• Holes for gas

• Cast construction

• Each supplier has a unique design

• Burner shape

• Number of holes

• Size of holes

• Orientation of holes Approved for External PresentationEnsure that there is free space of at least 3/16 - inch (4.8 mm) around the DOW Diamond. PDH - 1 Flare System
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## Staging Concept

25

- June

- 13 10 Stage 3 Stage 2 Stage 1

Stages ... DCS

3 transmitters From KO Drum

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## • Purpose : Show properly designed and operated PA 

## burners will meet or exceed performance of other flare burners, even though the exit velocity will exceed the limits outlined in 40CFR 60.18 and 63.11.



## • Facility : John Zink R&D test facility, Oklahoma.

– Facility is set up for appropriate data collection.

– Multiple other testing projects performed on site.



## • Measurements : Emissions determined utilizing gas collection system and analytical equipment (TRC).



## – Utilized PFTIR for comparison (Clean Air). Emissions Testing Summary

R2 Feb 2014 11 Approved for External PresentationEnsure that there is free space of at least 3/16 - inch (4.8 mm) around the DOW Diamond. PDH - 1 Flare System
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# • One LRGO burner / pressure assist

• One SKEC burner / steam assist (1 st 

# stage)

• Pilot used for ignition, then turned off for testing



# • Gas collection with scoop

– same as used for TCEQ testing in 2010



# • Testing performed in mid

- November (2013) Test Set Up

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## Test Set Up

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### • P1: 100% propylene

• P2: Mixture of propylene and nitrogen

• P3: Mixture of 50% propylene, 50% natural gas, then diluted with nitrogen

• P4: 90% hydrogen / 10% natural gas

• P1

- P3: At high pressure (sonic velocity) and low pressure 

### (de

- staging).

– 3 tests each point, 20 minutes each



### • P2

- P3: Check for minimum heating value that has flame 

### stability, then do emissions test there.

• P4: Test for flame stability only, 5 minutes. 

## Test Gas Mixtures / Testing Parameters

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### • S1: Mixture of propylene and nitrogen, steam on

• S2: Mixture of propylene and nitrogen, steam off

• S3

– S4: Mixture of propylene and nitrogen, steam at minimum

• S5: Mixture of propylene and nitrogen, high steam flow



### • S6: 100% propylene, steam at design rate

• S1 & S2: At high pressure / sonic velocity.

– 3 tests each point, 20 minutes each



### • S3

– S6: At normal / expected operating pressure. Minimum heating value to maintain stable flame.

– 3 tests each point / 20 minutes each 

## Test Gas Mixtures / Testing Parameters

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## Test Burners

R2 Feb 2014 16 SKEC Burner LRGO Burner Approved for External PresentationEnsure that there is free space of at least 3/16 - inch (4.8 mm) around the DOW Diamond. PDH - 1 Flare System
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## Burner Test

R2 Feb 2014 17 LRGO

– Test P2 Propylene and Nitrogen LRGO

– Test P4 Hydrogen and natural gas Approved for External PresentationEnsure that there is free space of at least 3/16 - inch (4.8 mm) around the DOW Diamond. PDH - 1 Flare System
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## Burner Testing

R2 Feb 2014 18

LRGO

– P1 Propylene Video Monitor in Control Room

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## Results
– LRGO Burner

R2 Feb 2014 19 Approved for External Presentation Report Table JZ
- 2
Report Table JZ
- 4 Combustion Efficiency (%)
- PFTIR 99.8 99.7 99.8 99.8 99.7 99.3Ensure that there is free space of at least 3/16 - inch (4.8 mm) around the DOW Diamond. PDH - 1 Flare System
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## Results
– SKEC Burner

R2 Feb 2014 20 Approved for External Presentation Report Table JZ
- 1 Report Table JZ
- 4 Combustion Efficiency (%) PFTIR 99.2 98.9 98.1 99.1 96.4 99.8Ensure that there is free space of at least 3/16 - inch (4.8 mm) around the DOW Diamond. PDH - 1 Flare System
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• Measurement of combustion efficiency is needed in addition to propylene DRE.

– CO 2 , CO, and THC were measured during each test and combustion efficiency was calculated.

– PFTIR was also used to measure combustion efficiency and to compare against the other measurements.

• Characterization of vent streams

– 1 st stage (SKEC Burner): Nitrogen, methane, hydrogen, ethane, propane with larger amounts of propane and propylene during purges and maintenance flows

– 2 nd stage and above (Pressure Assisted LRGO Burners): Propane and Propylene are the main hydrocarbons flared. Nitrogen, methane, hydrogen, ethane, ethylene may also be present based on the venting scenario 

## EPA Pre - testing Questions

R2 Feb 2014 21 Approved for External PresentationEnsure that there is free space of at least 3/16 - inch (4.8 mm) around the DOW Diamond. PDH - 1 Flare System
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### • 2 nd 

### stage and above Realistic Maximum Flow Case

– PA Flare tip test cases cover a heating value range from 690 to 2,145 Btu/scf. Tests P1H, P2H, P3H cover the highest inlet pressures, thus the highest flows to an individual tip. 

## EPA Pre - testing Questions

R2 Feb 2014 22 Approved for External Presentation Compound Composition Hydrogen 4 wt% (45 mol %) Methane 3 wt% (4 mol %) Ethane 3 wt% (3 mol %) Propylene 27 wt% (15 mol %) Propane 62 wt% (33 mol %) Nitrogen < 1 wt% (< 0.1 mol %) Flow ~ 880,000 lbs/hr Net Heating Value 1,283 Btu/scfEnsure that there is free space of at least 3/16 - inch (4.8 mm) around the DOW Diamond. PDH - 1 Flare System
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### • 2 nd 

### stage and above Hydrogen content



### – Hydrogen content expected to be less than 4 wt% under most scenarios with propylene and propane present.

– One scenario that is not expected to occur often includes a 

### flare header purge and flaring net gas from the process:

• Hydrogen 60 wt% (93 mol %)

• Methane 32 wt% (6 mol %)



### • Ethane 4 wt% (< 0.1 mol %)

• Flow ~ 20,000 lbs/hr

– Test P4 showed a stable flame with mixture of 90% hydrogen and 10% methane. 

## EPA Pre - testing Questions

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### • Instrumentation



### – Both flare systems will be equipped with a vent gas flow meter and an on

- line GC to comply with the Texas HRVOC regulations in the Houston, Galveston, Brazoria area

– GC will be capable of at least one measurement in a 15 minute period for all C1

– C4 compounds, which constitute the vast majority of the hydrocarbons. Any C5+ compounds will be grouped together for inlet gas MW and heating value calculations.

– Instrument calibration and maintenance requirements 

### are detailed in HRVOC regulations to ensure high quality measurements 

## EPA Pre - testing Questions

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• Potential Operating Parameter Limits

– Stage 1 (SKEC tip)

– Plans are to operate these flare tips in accordance with the regulations in 40 CFR 60.18 and 63.11.

– Stage 2 and above (LRGO pressure assisted tips)

–

• Results indicate that a high combustion efficiency and destruction efficiency can be maintained as long as the inlet gas net heating value is > 690 Btu/scf

• Note: LRGO flare tip testing by Marathon indicates that a net heating value of 550 Btu/scf is necessary for mixtures of natural gas and nitrogen.

• Results indicate that high efficiencies can be obtained when hydrogen is flared. Since pure component net heating value for hydrogen is only 266 Btu/scf, will need different limit for the case where high hydrogen content may be encountered. 

## EPA Pre - testing Questions

R2 Feb 2014 25 Approved for External PresentationEnsure that there is free space of at least 3/16 - inch (4.8 mm) around the DOW Diamond. PDH - 1 Flare System
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# Compliance with 40 CFR 60.18 Heating Value & Exit Velocity Requirements

• Routine vents will be routed to the first stage of the MPGF, which will operate similar to a steam assisted flare. This section of the MPGF will comply with 40 CFR 60.18 and 63.11.

• MSS vents will increase the flare header pressure and the remaining stages will become operational. Since these stages operate at sonic exit velocity, the limits on maximum allowable exit velocity in 40 CFR 60.18 and 63.11 cannot be met.



### – Similar pressure assisted flares in our pipeline organization have been recognized as approved alternative flares for the TX HRVOC rules through the Alternative Means of Control (AMOC) process with 

### alternate minimum net heating values. Dow has successfully worked with John Zink / TCEQ / EPA in the past to set AMOC limits.

R2 Feb 2014 26 Approved for External PresentationEnsure that there is free space of at least 3/16 - inch (4.8 mm) around the DOW Diamond. PDH - 1 Flare System
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27 R2 Feb 2014 

## Known Pressure Assisted Flare Testing

• 1982

– Zink testing immediately after EPA

- CMA flare testing

– Same instruments and techniques

• 1985

– Pohl & Soelberg

– EPA 600/2

- 85

- 106

• 2006

– Dow pipeline burners

• 2006

– BP

• 2012

– Marathon

• 2013

– Dow PDH

- 1

• Other testing by suppliers part of burner design / technology development

– Flame length / shape

– Flame stability

– Smokeless operation

– Noise / radiant heat Approved for External PresentationEnsure that there is free space of at least 3/16 - inch (4.8 mm) around the DOW Diamond. PDH - 1 Flare System
– Pressure Assist

• Pressure

- assisted flares perform equivalent to or better than a conventional steam or air

- assisted flare that meets the current regulations in 40 CFR 60.18 and 63.11.

• Test results show both combustion and destruction efficiency > 99 %.

• The exit velocity limits for pressure

- assisted flares should not apply.

• An inlet gas net heating value greater than 300 Btu/ scf may be appropriate to ensure operations with a stable flame

– Dow Testing in 2013 indicates that > 690 Btu/ scf may be appropriate

– Marathon Testing reported in 1Q 2013 indicates that > 550 Btu/ scf may be appropriate.

• Additional provisions are needed to address high hydrogen flaring cases since the net heating value is only 266 Btu/ scf

. 

## Conclusions
– Dow Perspective

R2 Feb 2014 28 Approved for External PresentationEnsure that there is free space of at least 3/16 - inch (4.8 mm) around the DOW Diamond. PDH - 1 Flare System
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## • Submittal of Test Report
– February 2014

• Technical Review of Test Report

- ?

• Approval of Alternative Non

- Opacity Emission 

## Standard ?

• Public Comment Period on Approval ?

• Federal Register Notice permitting the use of the alternative

- October 2014

• Review and approval of TCEQ AMOC - October 

## 2014 Proposed Timeline

R2 Feb 2014 29 Approved for External PresentationEnsure that there is free space of at least 3/16 - inch (4.8 mm) around the DOW Diamond. PDH - 1 Flare System
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## Path Forward

• Present the test results to TCEQ on February 25 th



## • Address any remaining questions and/or provide additional information to assist with the technical 

## review of the test report or the flare system in general

• Engage both regulatory agencies to achieve agreement on future Operating Parameters

R2 Feb 2014 30 ApprEnsure that there is free space of at least 3/16 - inch (4.8 mm) around the DOW Diamond. PDH - 1 Flare System
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# Questions/Discussion

R2 Feb 2014 31 Approved for External PresentationEnsure that there is free space of at least 3/16 - inch (4.8 mm) around the DOW Diamond. PDH - 1 Flare System
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## Staging Curve

R2 Feb 2014 32 Staging pressure set points:

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