AERflare RolloutFlare Air Dispersion Modelling

Spreadsheet

Brian Zelt, Ph.D., P.Eng., Zelt PSIand Mike Zelensky. M.Sc., P.Eng., AER

12014-01-15

15 Jan 2014PTAC – Alberta Upstream Petroleum Research Fund

&Alberta Energy Regulator

Acknowledgements• Funding for updates and components of the

AERflare and ABflare tool:– PTAC-Alberta Upstream Petroleum Research Fund (AUPRF)

– Alberta Energy Regulator

– Suncor

• AERflare tool (formerly ERCBflare)– Developed by M.Zelensky & Zelt PSI

• AERincin tool (formerly ERCBincin)– Developed by M.Zelensky & Zelt PSI

• ABflare tool– Developed by Zelt PSI, M.Zelensky and Exponent

22014-01-15

AER D060 – Rollout• AER D060 will be released soon

– Download atWWW.aer.ca/rules-and-regulations/directives/directive-060

– Effective 60 days after release

• AERflare Training – To address concerns about the

changes in technical expertise,training courses will be offered

• AERflare Bug fix releases– As more people begin using the tools, bug reports will

be inevitable, and updates will be posted as required32014-01-15

User Guidance Docs• AER D060: Upstream Petroleum Industry Flaring, Incinerating, and

Venting (release has been delayed)

• AESRD Non-Routine Flaring Management: Modelling Guidance (watch website for final version)(Draft http://environment.gov.ab.ca/info/library/8848.pdf)

• CAPP Sour Non-routine Flaring Framework (available)http://membernet.capp.ca/raw.asp?x=1&dt=PDF&dn=237189

• AERflare tool and User Guide (waiting for approval to post)

• ABflare tool and User Guide (waiting for approval to post)

• Classroom Training …

2014-01-15 4

ERCBflare Technical Changes

• Conversion efficiency calculations tweaks

• Hour-by-Hour assessment

• Optional Risk Based Criteria

• Blowdown calculations

• AERSCREEN & AERMOD

• AERSURFACE & AERMET

• Consistency between screening to refined analysis for non-routine and routine flaring assessments

2014-01-15 5

AERflare Screening Tool v2.0• Updated the source model consistent with ABflare

and other requested features (lift gas, steam/air assist)

• AERMOD screening using AERSCREEN methods:– Matrix like meteorology

(i.e., not real nor site specific)

– Land use based upon simplified 8-catagories for AB then increased to BC and SK

– User required to manually input worst case terrain

2014-01-15 6

AERflare… v2.01

• More automation and less user manual input

• Automated terrain processing– For worst case terrain

– For receptor grid creation for site specific

• Automated land-use processing– Creates a site specific meteorological data file

• Refined modelling using full AERMOD setup

• Model routine and non-routine, continuous or blowdown flaring

2014-01-15 7

AERflare… v2.01

• Post-processing of external data

• Batch processing for advanced users

• Advanced switch settings

• Graphics for error checking and assessment

• D060 check list for approval requirements

• Matrix style summary for monitoring planning

2014-01-15 8

2014-01-15 9

MAXIMUM CONCENTRATION

REFINED

SCREENINGAE

Rfla

reAB

flare REFINED

Source Description and Location

RISK BASED CONCENTRATION

RISK BASED CONCENTRATION

RISK BASED CONCENTRATION

Add Site Specific Meteorology

Add Site Specific Terrain

Added sophistication- terrain processing- puff tracking- detailed blowdown- hour-by-hour and daily

AERSCREEN

AERMOD

CALPUFF

AERSCREEN Modelling

• AERSCREEN replaces SCREEN3 for AERflare modelling

• Requires meteorology and surface characterization• AERSCREEN is a specific mode of operation of

AERMOD– All winds blow in direction of every receptor– Meteorology is a µ-meteorological matrix with variation

in:• Heating; Temperature; u*, w*; Monin-Ubukhov length• User selection of Bowen Ratio, surface roughness, temperature

range, Albedo

– AERflare performs lookup of meteorology conditions related to maximums

102014-01-15

Important Pages

1. iSTART : setup

2. iNOTES : keep track

3. iFACILITY : where is the flare?

4. iFLARING : what is flaring?

5. iTERRAIN : modelling domain

6. oSUMMARY : results of assessment

2014-01-15 11

ABOUT

2014-01-15 12

iSTART - AERflare Geek Backdoors

• Several backdoor options are made available for recreational use

• Flags for non-default settings

132014-01-15

oSUMMARY - D060 References

oSummary Page

• Table of D060 dependencies and limits

• D060 Figure 4 – Approval required check

• Updated the modelling output section

• Explicit D060 conditions on flaring or modelling with pass/see requirements

142014-01-15

iNOTES - ** IMPORTANT **

1. Describe the flaring event

2. Frequency of flaring

3. Flaring reduction

4. Assumptions

5. Space for other notes about what you did to complete the flaring assessment…

2014-01-15 15

iFACILITY

2014-01-15 16

• LOCATION, LOCATION, LOCATION !!!

• Land-use

• Describe what/why you are flaring … add more information on iNOTES … ** IMPORTANT **

• Date range you plan on flaring for …

• Model for specific date

• Or entire year

How AERSCREEN is implemented

• AERflare uses 8-default meteorology files– Deciduous; Coniferous; Swamp; Grassland; Grassland;

Water; Urban; Desert

– Landcover is prescribed by flare location and lookup

172014-01-15

Refined - Site Specific Meteorology

• Land use created from full detailed Canadian land use shape files

• Uses MM5 data extraction for AERMET and CALMET

• Processing followingAERSURFACE for AERflare

• Processing using CALMET for ABflare

2014-01-15 18

iLOCATION

• Check if you entered the correct coordinates

• Coordinates will determine the land-use and land-use strongly impacts the air dispersion modelling

2014-01-15 19

49

51

53

55

57

59

-140 -135 -130 -125 -120 -115 -110 -105

Latit

ude

Longitude

iFLARING

2014-01-15 20

• Scenario Name• Documentation

• iterations

• Time of Year• Annual

• Month

• Height and diameter • Actual not pseudo

• H2S concentration• Maximum, or

• Licensed

iFLARING

2014-01-15 21

• Assessment Type• From iSTART

• Flaring type• Continuous or Steady

• Transient Blowdown

• Three flaring rates are analyzed

• Max rate

• Mid rate

• Low rateLow Rate = Max Rate/8

iFLARING

• Transient source initial conditions

• Fuel gas

• Lift gas

• Flaring assist– Air Assist

– Steam assist

• Gas composition

2014-01-15 22

oBlowdown

0

100

200

300

400

500

600

700

800

0 60 120

180

240

300

360

420

480

540

600

660

720

780

840

900

960

1020

1080

1140

1200

1260

1320

Flar

ing

Rat

e (e

3m3/

d)

Time (minutes)

TRANSIENT BLOWDOWN MODELLED AS PUFFS

Instantaneous Rate Equal Duration Puffs Equal Mass Puffs

Transient Blowdown of 148.0 e³m³ with an Initial Flow Rate of 655 e³m³/d

Exponential Time Constant, TAU= 313.1 min

97.9% of mass released in 1284.3 min

3 puffs of equal mass

3 puffs of 428 min duration

Transient Source UNITS ENTRY

Expected Maximum Initial Pressure, PRESS0 kPa (gauge) 4200Expected Minimum Initial Gas Temperature, TEMP0 °C 30

Expected Minimum Final Pressure, PRESS1 kPa (gauge) 0Pipeline/Vessel Inside Diameter, VESSELDIA m 0.4364

Pipeline/Vessel Length, VESSELLEN m 25100Minimum Orif ice Diameter, ORIFICE_DIA mm 43

Discharge Coeff icient, DCOEFF -- 0.6

Select the w ay the blow dow n curve is converted from a continuous curve to discrete steps

MDIST-- 2

Raw Gas User Initial maximum flow rate, QMAX10³m³/d

(15°C and 101.325 kPa)

Raw Gas User Total volume w ithin vessels/pipes, QTOTAL10³m³

(15°C and 101.325 kPa)

User selected # of puffs, NPUFFS -- 3User selected puff duration, PUFDUR min

1. Equal Duration

2. Equal Mass

232014-01-15

AERflare default blowdown is three steps

The number of steps in blowdownis not limited in ABflare

iTERRAIN

2014-01-15 24

6112000

6113000

6114000

6115000

6116000

6117000

6118000

475000 476000 477000 478000 479000 480000 481000 482000

Nor

th-S

outh

TM

(m)

East-West TM (m)

DEM TERRAIN VISUAL CHECK(Location of Worst Case Terrain Contours)

Terrain Flare

0

10

20

30

40

50

60

70

80

90

0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000 11000

Hei

ght A

bove

Fla

re B

ase

(m)

Distance from Flare (m)

WORST CASE COMPLEX TERRAIN COMPARED TO COMPLEX TERRAIN CRITERIA

Terrain Rise Above Stack Base Complex Terrain CriteriaFlame (Effective Height) FlareMaximum Elevation

ERCBflare Ver 2.01

AERflare calculates bothparallel and worst case terrain,the complex terrain criteriais no longer used

Worst case terrain points relative to stack location (AERflare)

Worst case terrain compared to complex terrain criteria (AERflare)

AERflare and ABflare Site Specific iUSERTER

2014-01-15 25

Generic receptor grid creation

Example user receptor grid input

oMODELLING

Non-Routine Flaring and Well Tests

Flaring Evaluation Assessment

262014-01-15

oFIGURE1

• oFigure1 shows results for • 3-rates (Qmax, Qmid, Qmin)

• Parallel terrain & elevated terrain predictions

• Terrain elevations

272014-01-15

SO2 and H2S• AERflare and ABflare use a flare conversion

efficiency model• Conversion efficiency is a function of:

– Heating value– Meteorology

• Source parameters are function of efficiency and change hourly with meteorology

• SO2 emissions are worse case 100% conversion– No credit for in-efficiency

• H2S emissions based upon inefficiency– Assumes a fraction of flared gas is stripped away, ∴ H2S stays as H2S

282014-01-15

SO2 and H2S

• SO2 source parameters based upon heat and momentum energy balance

• H2S source parameters based upon momentum of stripped gas and assumed temperature

Hs

Hs’

Ds

Ts

2.5 2

"

Us

SO2 H2S292014-01-15

WIND

Inefficiency results in A (raw gas exitingwarm) and B (raw gas exiting cool)

Wind flowing past the flamestrips raw gases ~ combustionin-efficiency emissions

B

A

B: Remains H2S

A: Converted to SO2

oFIGURE2

• Page for Non-Routine hour-by-hour source

• Emissions Probability for SO2 and H2S

• Conversion Efficiency Probability

Efficiency

Mass Emission Rates

302014-01-15

Questions…

312014-01-15