4135 Bluebonnet Dr. Stafford, TX

Photoionization Detectors for Industrial Hygiene in the Oil & Gas Industry Werner Haag, Ph.D. Brent Yaschuk Factory Direct Safety & Environmental, Inc.

PID Standard Features: Measure many organic vapors Measure many organic vapors & some inorganics 10.0 eV, 10.6 eV, & 11.7 eV Lamps 10.0 eV, 10.6 eV, & 11.7 eV Lamps Non-specific: Need to know gas being measured to quantify Non-specific: Need to know gas being measured to quantify Datalogging Datalogging TWA & STEL Recording TWA & STEL Recording Fast response (<3 seconds) Fast response (<3 seconds) Continuous read-out Continuous read-out

PID Chemical Response Compound ClassRelative Sensitivity Aromatics (e.g., Benzene, Pyridine)++++ Alkyl Iodides, Bromides, Chlorides++++, +++, + Double Bonded Compounds+++ Organic Amines+++ Sulfides & Mercaptans+++ Ketones, Ethers & Silicates+++ Alkanes, Esters, Alcohols, Aldehydes++ H 2 S, NH 3 & PH 3 + to ++ H 2, CO, CO 2, O 2, N 2, HCN, SO 2, Acids-

PID Applications: Oil Refineries Hydrocarbons

PID Applications: Oil/Chemical Tankers Diesel Fuel, HCs, Solvents, NH 3, etc. Confined Space Entry

PID Applications: Heat Exchangers Dowtherm: Diphenyl oxide / Biphenyl OSHA PEL for mix = 0.5 ppm

PID Applications: Fugitive Emissions Testing - EPA Method 21

PID Applications: Hazmat Response Various Chemicals

PID Applications: Soil Remediation Screening & Leaking Underground Storage Tanks Various Chemicals

PID Applications: Natural Gas Dehydrator Re-boilers & Compressor Condensate (Benzene)

PID Applications: Fenceline Monitoring

PID Applications: Indoor Air Quality ppb Level TVOC & Locating Odor Sources

PID Applications: Space Shuttle Tanks Hydrazine Fuel Decontamination

Modern PIDs Recent Improvements: Sensitivity to low ppb levels Sensitivity to low ppb levels 450 Chemical Response Factors 450 Chemical Response Factors Improved Linearity: ppb to 10,000 ppm Improved Linearity: ppb to 10,000 ppm Humidity Effects Almost Eliminated Humidity Effects Almost Eliminated Reduced Methane Interference Reduced Methane Interference 30-hour Li-Ion Battery 30-hour Li-Ion Battery

Improvements Accomplished by: Shorter cell path length to improve linearity & reduce interference, requires precise manufacturing & strong lamps Shorter cell path length to improve linearity & reduce interference, requires precise manufacturing & strong lamps “Fence” Electrode removes Leak Current “Fence” Electrode removes Leak Current Proprietary Anti-contamination Technology Proprietary Anti-contamination Technology

Water Vapor Effects 1) Reduced response of Organic Vapors due to competitive light absorption & chemical quenching

Water Vapor Effects 2) “Leak” Current at high humidities when sensor is not ultra-clean “Fence”

FENCE ELECTRODE PREVENTS LEAK CURRENT IN HIGH HUMIDITY

Benzene in Gasoline Typically 0.5-2%: Difficult to measure selectively

Benzene in Fuels Exposure Limits for Various Fuels ChemicalACGIH TWA Benzene0.5 ppm Diesel Fuel12 ppm Jet Fuel30 ppm Gasoline300 ppm

Benzene in Fuels Mixture TWA Calculation TWA total = ______________1 f benzene f gasoline + TWA benz ____________ TWA gas.

Benzene in Gasoline Typically 0.5-2%: Difficult to measure selectively

Benzene in Fuels Exposure Limits for Various Fuels ChemicalACGIH TWA Benzene0.5 ppm Diesel Fuel12 ppm Jet Fuel30 ppm Gasoline300 ppm

Benzene Specific Measurement Methods with DL near 0.5 ppm MethodTimeDLCostOther Tubes10-20 min0.5 ppm¢ Automated Tubes (Draeger CMS) 10 min0.2 ppm¢¢ PID w/Filter Tube1-3 min0.02 ppm$ Portable GC5-10 min0.1 ppm$$Bulky Portable IR<1 min2 ppm$$$Heavy GAC or Gas Bag + Lab Analysis 1 week0.01 ppm$$$$Off-site

Tiger Select PID/Tube can measure Continuous ppb Levels Total Aromatic Compounds (TAC) Benzene Specific readings – Single Point and 15- minute STEL

Total Aromatic Compounds Mode Uses 10.0 eV lamp Applies the Benzene response factor (0.5) Responds predominantly to aromatics Continuous readings with ~5 ppb resolution If a reading over 0.5 ppm is seen, insert a tube and make a Benzene specific measurment ChemicalI. E.R.F. Benzene9.25 eV0.55 Toluene8.82 eV0.54 o-Xylene8.56 eV0.56 n-Hexane10.13 eV- n-Octane9.82 eV13

Benzene Tube Specificity No Effect of: 400 ppm Toluene 200 ppm o-Xylene 300 ppm Octane 25 ppm H 2 S ● 100% Methane

Benzene STEL measurements Continuous benzene readings and/or STEL measurements can be made until the color change proceeds up to the 3/4 length mark indicated on the tube Response will lag actual concentrations by a minute or two

Benzene Standard – Humidity Test (Filter Tube absorbs moisture) Tube #Relative Humidity PID/Tube Response 1Dry5.0 ppm 2Dry4.9 ppm 3100 %5.1 ppm 4100 %4.8 ppm

Benzene in Refinery Samples Sample Lab GC/FID (mole %) PID/Tube (mole %) 87 Octane Gasoline0.86 %0.63 % Reformer Feed1.2 %1.0 % Reformer Product6.3 %7.2 % Benzene Light Ends22 %24 %

Benzene Field Comparison ± Standard Deviation As % of Lab Value ± Standard Deviation SamplePID/Tube Portable GC/FID Draeger CMS Standards 1) 101 ± 16%116 ± 23%120 ± 52% Field Samples 2) 97 ± 29%84 ± 21%103 ± 92% 1) Avg of 24 Standards, including BTEX mixtures 2) Avg of 18 different field measurements

Stafford, Texas Thank you