Active and passive monitoring of flare combustion efficiency

Active and Passive Monitoring Of Flare Combustion Efficiency Industrial Monitor & Control Corporation IMACC A Story Of Slow Learners HovH^ong It took to get where we are • 1984 - First passive test done at John Zink in Tulsa with extractive monitoring above flare - Sponsored by Office of Research and Development, US EPA RTP, N.C. And then about two decades passed by and We all got a little older HovH^ong It took to get where we are 1984 - First passive test done at John Zink in Tulsa with extractive monitoring above flare - Sponsored by Office of Research and Development, US EPA RTP, N.C. HovH^ong It took to get where we are • 1984 - First passive test done at John Zink in Tulsa with extractive monitoring above flare - Sponsored by Office of Research and Development, US EPA RTP, N.C. HovH^ong It took to get where we are • 1984 - First passive test done at John Zink in Tulsa with extractive monitoring above flare - Sponsored by Office of Research and Development, US EPA RTP, N.C. • 2003 - Controlled non-combustion test done also at John Zink with extractive monitoring in the stack \ - Sponsored by TCEQ, Austin, TX Then a few more years passed And we did not get any younger Hm^Long It took to get where we are 1984 - First passive test done at John Zink in Tulsa with extractive monitoring above flare - Sponsored by Office of Research and Development, US EPA RTP, N.C. 2003 - Controlled non-combustion test done also at John Zink with extractive monitoring in the stack - Sponsored by TCEQ, Austin, TX HovH^ong It took to get where we are • 1984 - First passive test done at John Zink in Tulsa with extractive monitoring above flare - Sponsored by Office of Research and Development, US EPA RTP, N.C. • 2003 - Controlled non-combustion test done also at John Zink with extractive monitoring in the stack \ - Sponsored by TCEQ, Austin, TX • 2009 - Industrial flare tests performed at Marathon, Texas City and Ineos, Addyston, OH • 2010 - Industrial flare tests performed at Marathon, Detroit, MI at Flint Hills Resources, Port Arthur, TX and at Shell Oil, Deer Park, TX. • September 2010 - TCEQ test at John Zink with extractive monitoring of exhaust plume Active Open-Path FTIR Monostatic FTIR Transceiver Monostatic FTIR Transceiver Dominant Compounds For Combustion Efficiency 3000 2500 2000 Wavenumbers (cm-1) 1500 1000 5 Dominant Compounds For Combustion Efficiency -CO 3000 2500 2000 Wavenumbers (cm-1) 1500 1000 500 Dominant Compounds For Combustion Efficiency 2000 Wavenumbers (cm-1) 1500 1000 500 Dominant Compounds For Combustion Efficiency 2000 Wavenumbers (cm-1) 1500 Dominant Compounds For Combustion Efficiency 1.0 CO 0.5- 0.0 0.4 0.2 0.0 __ / V _ /x . 0.2 0 .1 0.0 I 3000 2500 I Us*. I 2000 Wavenumbers (cm-1) 1500 I 1000 JL i i 500 Typical Monostatic Operation iM k tt Passive Open-Path FTIR Passive FTIR Radiometer Passive FTIR Radiometer V 2500 2000 W ave num be rs (cm-1) Passive Open-Path Signatures • Any hot gas emits infrared with exactly the same pattern that it has in absorption • Therefore species in emission spectra can be identified and quantitated in the same manner as they are in absorption spectroscopy However • The strength of emission is proportional to concentration^ as it is in absorption spectra but also to the temperature of\ the gas. Radiance (m w /c m V s tr/cm 1) Gas Emissions As A Function Of Temperature 5000 4000 3000 2000 Wavenumbers (c m 1) 1000 0 Typical Passive Operation iM k tt Hardware - Imacc Passive FTIR Radiometer Hardware - Passive FTIR At Flare Test Basic Elements o f Flare Radiance Measurements The Signal Observed •The FTIR Signal arises from Four elements: Background Radiance -Background Radiance -Flare Radiance -Atmospheric path Radiance and Transmission Flare Radiance Atmospheric Transmission & Radiance The Total FTIR Signal Mp is then: R b * T plume T atm + R p * ^atm + R atm + R ftl Mp = The measured plume radiance Mb = The measured background radiance Mn = The measured cold source background LPbb = The Planck function at temperature of plume Cal = The system calibration function T ■ = Air Transmission Calibration and Validation Mn = The system and atmospheric emissions Cal = The radiant system calibrations Tau = The atmospheric transmission \ x • These are obtained using a collimator telescope \ (identical to that on the PFTIR) and this telescope is fitted with: - An infrared source (atmospheric transmission) - A Black Body Source (system calibration) \ - A liquid nitrogen cold source (system and atmospheric emissions) Calibration Cart for Passive FTIR Calibration Cart for Passive FTIR Calibration Cart for Passive FTIR Black Body Source on PFTIR Collimator Flare Emissions E m itta n ce Wavenumbers (cm-1) S in g le B e a rn -In{int</f 4 * (j'+ j" + 1 )) } Temperature Determination Combustion Efficiency Efficiency of Combustion • The efficiency of combustion is given by: T ?rr _ _____________ CO2_____________ C 02 + CO + HC + Soot • CO is easy to measure directly at -2150 cnH • C02 can be measured at 765 cm-1 or at 2050 chi"1 • If there is sufficient signal at 3000 cm-1 \ - CH4 can be measured directly, and - Total hydrocarbon can be assessed using the C-H stretch region calibrating against a heavy organic. • If there is insufficient Energy at 3000 cm-1 an alternate region must be used to get CH4and THC is in general inaccessable Typical Flare Radiance Relative Response (%) Two-Color Infrared Detector ................J ...... / HgCdTe InSb . A / \ * \ \ 20 / 1 / Y 30 ............. ' 1 / / ........ / 1 \ \ \ f 1 ! ■; 11 - 1-6|.jm 12 = 6- 12[jm InSb ( ( ^ \ 1 ■-- - 1 10 ....... „..i ___ _ 4 \ i l \ , HgCd'fe .... 6 8 10 Wavelength (pm) 15 20 Passive Measurement Calibration &Validation Hot Cell for PFTIR Method Validation Hot Cell for PFTIR Method Validation • In passive mode, we are using a hot gas emission cell to validate the analytical methodology - This cell is placed in the collimator andsheld at elevated temperature (250 C). - Calibrated gas mixtures are run through the cell providing a "gas emission" source. - For flares the cal gas has high level C 02, low level CO, CH4 and possibly a heavy organic - Measuring the gas emissions in the same manner as the plume allows the accuracy and precision of the methodology to be determined. Spike (ppm) PFTIR Hot Cell Validation for CO 0 20000 40000 Quant (ppm) 60000 80000 Spike (ppm) PFTIR Hot Cell Validation for CO 0 200 400 600 Quant (ppm) 800 1000 PFTIR Validation • With the high accuracy possible with the hot cell data one would expect high accuracy in the plume itself. However: - It appears the plume is highly inhomo^eneous even in combustion efficiency -The C 0/C 02ratio varies with position in the plume implying varying efficiency - Low flow flares seem worse because they are very \ broken up, are optically thin and are influenced more \ significantly by the wind IR Image of High Flow Flare IR Image of Low Flow Flare Flare Efficiency 1 <► ■' W v i f f ' n 0 .9 9 5 Efficiency (%) ' 1 \ 1. ► f 0 .9 9 Moderate O v e r ^ - Steaming (1 0 .9 8 5 Heavier Over Steaming A 11j - 0 .9 8 0 .9 7 5 0 .9 7 8:0 0 9 :0 0 10:00 11:00 Time 1 2 :0 0 13:00 Some Comparisons With The TCEQ Program s te p i : T est " P r e p a r a t i o n s te p 2 .: The re s t S te p 3 : E>fltfl A i'U llw s ls f i PFTIR Versus Extractive Measurements as TCEQ 100 95 90 85 80 75 70 65 60 55 50 45 40 35 30 25 i i i i I 20 40 60 80 100 Test Points Ranked by CE -i 120 ❖ PFTIR ■a - E x tractiv e PFTIR vs Extractive Results Test Po in ts R a nke d by CE . irfd tlljt't' PFTIR vs Extractive Variability Analysis Replicate Variation vs Net Heating Value CleanAir Relative Standard Deviation of the Replicates (%) 25% 20 % O 15% O O PFTIR O O Extractive 10% O 5% O (D O O O o • ___________ f t n o O O O • ____ 0% 50 100 150 200 Combustion Zone Net Heating Value (Btu/scf) 250 300 350 Cl PFTIR vs Extractive Variability Analysis Replicate Variation vs Steam to Vent Gas Ratio CleanAir Relative Standard Deviation of the Replicates (%) 25% 20 % O 15% O O 10 % O Extractive 0 5% o 0 0 O o o o 0 0 0% 0 0.2 g 0.4 > R o o 0.6 o o q 0 0.8 1 S/VG (unitless) 1.2 1.4 1.6 O PFTIR 1.8 Comparison of PFTIR and Extractive Monitoring - All Steam Tests P a s s iv e FTIR (CE) CE vs. CZG NHV - All TCEQ Steam CleanAin 100% -r ■■p • • 90% 80% Combustion Efficiency (%) a. - * #l 70% 60% • • ----- 50% 40% 30% 20% TCEQ 20:80 TNG to Propylene (S3,S4,S5,S6) TCEQ 20:80 TNG to Propylene (57,58,59,510,511) 10% TCEQ 100% Propane (S12,S13,S14) 50 100 150 200 250 300 350 400 Combustion Zone Gas Net Heating Value (H2=1212 BTU/scf) (BTU/scf) 450 500 CE vs. CZG NHV - All TCEQ Steam CleanAin 100% 5 < > 90% 8 . « • » io o ° °o °o 0 -------- - • -------- 80% Combustion Efficiency (%) o Oo • 70% • % 60% • • 50% o 40% O o 30% • • TCEQ 20:80 TNG to Propylene (S3,S4,S5,S6) 20% TCEQ 20:80 TNG to Propylene (57,58,59,510,511) o o 10% TCEQ 100% Propane (S12,S13,S14) • TCEQ Extractive 0% -A 50 - l --------A - 100 150 200 250 300 350 400 Combustion Zone Gas Net Heating Value (H2=1212 BTU/scf) (BTU/scf) 450 500 CE vs. CZG NHV Constant VG Flow/Variable Steam Flow (S3, 4, 5, 6) CleanAin 100% 90% Combustion Efficiency (%) 80% 70% --------- 60% 50% 40% 30% S3 - PFTIR, 937 lb /h r, 350 Btu 20% S4 - PFTIR, 2342 lb/h r, 350 Btu 10% S5 - PFTIR, 937 lb /h r, 600 Btu S6 - PFTIR, 2342 lb/h r, 600 Btu • i • 0% 50 100 150 200 250 300 350 400 C o m b u s tio n Z o n e Gas N e t H e a tin g V a lu e (H 2= 1 2 1 2 B T U /scf) (B T U /s c f) 450 500 CE vs. CZG NHV Constant VG Flow/Variable Steam Flow (S3,4, 5, 6) CleanAin 100% o 0 «' 5 < > <-O- 90% 80% Combustion Efficiency (%) o - 70% • 60% 50% •• o 40% o 30% S 3 -PFTIR, 937 lb /h r, 350 Btu 0 5 3 - Extractive, 937 lb/h r, 350 Btu CO 20% S4 - PFTIR, 2342 lb /h r, 350 Btu 0 5 4 - Extractive, 2342 lb /h r, 350 Btu o o S 5- PFTIR, 937 lb/h r, 600 Btu 10% 0 5 5 - Extractive, 937 lb/h r, 600 Btu S6 - PFTIR, 2342 lb/h r, 600 Btu 0% 0 5 6 - Extractive, 2342 lb /h r, 600 Btu - i-----------------# - |- • ---------------1---------------------1--------------------- 1--------------------- r 50 100 150 200 250 300 350 400 C o m b u s tio n Z o n e Gas N e t H e a tin g V a lu e (H 2= 1 2 1 2 B T U /scf) (B T U /sc f) 450 500 CE vs. NHVcz le a n A ir T^EQ Constant Steam Flow/Variable VG Flow (S7, 8, 9 ,1 0 ,1 1 ) 100% c • # 90% • • 80% • • • Combustion Efficiency (%) C • 70% • 60% 50% 40% ♦ S7 - PFTIR, Center=500, Upper=525 30% S8 - PFTIR, Center=0, Upper=500 20% S9 - PFTIR, Center=0, Upper=1025 10% S10 - PFTIR, Center=0, Upper=825 S l l - PFTIR, Center=300, Upper=525 0% I I I 50 100 150 -r« - 200 I I 250 300 ----------------- 1 ---------------------- 1 ---------------------- 1 ---------------------- 1 350 400 450 Combustion Zone Gas Net Heating Value (H2=1212 BTU/scf) (BTU/scf) 500 CE vs. NHVcz le a n A ir T^EQ Constant Steam Flow/Variable VG Flow (S7, 8, 9 ,1 0 ,1 1 ) lU k C J b 100% ^ ° ° 90% 0 8 • o 80% O Combustion Efficiency (%) C o 70% O u . O • o • o 60% 50% 40% ♦ S7 - PFTIR, Center=500, Upper=525 OS7 - Extractive, Center=500, Upper=525 30% S8 - PFTIR, Center=0, Upper=500 o O S 8 - Extractive, Center=0, Upper=500 S9 - PFTIR, Center=0, Upper=1025 20% OS9 - Extractive, Center=0, Upper=1025 S10- PFTIR, Center=0, Upper=825 10% O S IO - Extractive, Center=0, Upper=825 S l l - PFTIR, Center=300, Upper=525 0% I I I I I I 50 100 150 200 250 300 O S 1 1 - Extractive, Center=300, Upper=525 ----------------- ---------------------- ---------------------- ---------------------- 1 1 1 1 350 400 450 500 Combustion Zone Gas Net Heating Value (H2=1212 BTU/scf) (BTU/scf) Active and Passive FTIR Comparisons Tests S3,S4,S5,S6 0% 10% 20% 30% 40% 50% Passive FTIR 60% 70% 80% 90% 100% Where Are We % Hteatafth<Feteii§gy Appears solid: -We can reproduce concentrations from hot cell tests and stack tests accurately -The TCEQ-John Zink test shows theN\<alidity of the approach compared to extractive measurements • EPA - RTP funded generation of high temperature (250 C) reference spectra for: C2H4, C3H6, CH4, CO, C02, H20 spanning a large range of concentrations. Other compounds may still need to be generated. • There is an Imacc/ERG draft "TechnologyReview" document that was submitted to EPA in preparation for an OTM. • An ASTM Committee has been formed to begin work on an ASTM standard for passive FTIR efficiency measurements