1. Analytical Solutions by the Sea The 60th Annual Symposium of the Analysis Division Galveston Island Convention Center, Galveston, Texas, USA; 26th – 30th April 2015 MEASURING H 2 S IN CRUDE OIL FOR QUALITY CONTROL & TRANSPORTATION SAFETY Wesley Kimbell Analytical Systems Keco

2. Analytical Solutions by the Sea The 60th Annual Symposium of the Analysis Division Galveston Island Convention Center, Galveston, Texas, USA; 26th – 30th April 2015 Slide 2 Why measure H 2 S in crude oil? SafetyIndustrial Process Control

3. Analytical Solutions by the Sea The 60th Annual Symposium of the Analysis Division Galveston Island Convention Center, Galveston, Texas, USA; 26th – 30th April 2015 Slide 3 Why measure H 2 S in crude oil? Safety Personnel protection Transportation (rail, roads, pipelines) Industrial Process Control

4. Analytical Solutions by the Sea The 60th Annual Symposium of the Analysis Division Galveston Island Convention Center, Galveston, Texas, USA; 26th – 30th April 2015 Slide 4 Why measure H 2 S in crude oil? Safety Personnel protection Transportation Industrial Process Control Meet product specifications Protect process equipment Environmental concern

5. Analytical Solutions by the Sea The 60th Annual Symposium of the Analysis Division Galveston Island Convention Center, Galveston, Texas, USA; 26th – 30th April 2015 Slide 5 Why measure H 2 S in crude oil? Safety Personnel protection 1.H 2 S gas is toxic and deadly 2.Even H 2 S dissolved in crude is deadly

6. Analytical Solutions by the Sea The 60th Annual Symposium of the Analysis Division Galveston Island Convention Center, Galveston, Texas, USA; 26th – 30th April 2015 Slide 6 H 2 S CHARACTERISTICS Gas with rotten egg smell Specific gravity: 1.1895 vs air LEL 4.3%, UEL 46% Highly corrosive Toxic

7. Analytical Solutions by the Sea The 60th Annual Symposium of the Analysis Division Galveston Island Convention Center, Galveston, Texas, USA; 26th – 30th April 2015 Slide 7 Why measure H 2 S in crude oil? Safety Personnel protection 1.H 2 S gas is toxic and deadly 2.Even H 2 S dissolved in crude is deadly Transportation 1.Prevent car derailments 2.Corrosion

8. Analytical Solutions by the Sea The 60th Annual Symposium of the Analysis Division Galveston Island Convention Center, Galveston, Texas, USA; 26th – 30th April 2015 Slide 8 Why measure H 2 S in crude oil? Industrial Process Control 1.Meet product specifications

9. Analytical Solutions by the Sea The 60th Annual Symposium of the Analysis Division Galveston Island Convention Center, Galveston, Texas, USA; 26th – 30th April 2015 Slide 9 Why measure H 2 S in crude oil? Industrial Process Control 1.Off-spec products 2. Protect process equipment

10. Analytical Solutions by the Sea The 60th Annual Symposium of the Analysis Division Galveston Island Convention Center, Galveston, Texas, USA; 26th – 30th April 2015 Slide 10 Why measure H 2 S in crude oil? Industrial Process Control 1.Off-spec products 2.Industrial process control 3.Environmental concern

11. Analytical Solutions by the Sea The 60th Annual Symposium of the Analysis Division Galveston Island Convention Center, Galveston, Texas, USA; 26th – 30th April 2015 Slide 11 How do we measure H2S in crude oil? Direct optical measurement of crude oil is difficult: Crude oil is opaque in nature Complex compositional characteristics

12. Analytical Solutions by the Sea The 60th Annual Symposium of the Analysis Division Galveston Island Convention Center, Galveston, Texas, USA; 26th – 30th April 2015 Slide 12 How do we measure H2S in crude oil? Question: What is the best method to measure H2S in liquid samples like crude oil?

13. Analytical Solutions by the Sea The 60th Annual Symposium of the Analysis Division Galveston Island Convention Center, Galveston, Texas, USA; 26th – 30th April 2015 Slide 13 How do we measure H2S in crude oil? Answer: Measure the headspace Upon saturation, the headspace concentration and the liquid sample concentration are proportional

14. Analytical Solutions by the Sea The 60th Annual Symposium of the Analysis Division Galveston Island Convention Center, Galveston, Texas, USA; 26th – 30th April 2015 Slide 14 How do we measure H2S in crude oil? Henry’s Law: "At a constant temperature, the amount of a given gas that dissolves in a given type and volume of liquid is directly proportional to the partial pressure of that gas in equilibrium with that liquid."

15. Analytical Solutions by the Sea The 60th Annual Symposium of the Analysis Division Galveston Island Convention Center, Galveston, Texas, USA; 26th – 30th April 2015 Slide 15 Methods of sampling Headspace concentration function of: 1.Saturation time/volume 2.Temperature 3.Vapor pressure of analyte 4.Concentration of analyte

16. Analytical Solutions by the Sea The 60th Annual Symposium of the Analysis Division Galveston Island Convention Center, Galveston, Texas, USA; 26th – 30th April 2015 Slide 16 Methods of sampling

17. Analytical Solutions by the Sea The 60th Annual Symposium of the Analysis Division Galveston Island Convention Center, Galveston, Texas, USA; 26th – 30th April 2015 Slide 17 Methods of sampling Headspace Crude Oil H2SH2S H2SH2S H2SH2S H2SH2S H2SH2S H2SH2S H2SH2S H2SH2S H2SH2S H2SH2S H2SH2S H2SH2S H2SH2S Proportional concentration H2SH2S

18. Analytical Solutions by the Sea The 60th Annual Symposium of the Analysis Division Galveston Island Convention Center, Galveston, Texas, USA; 26th – 30th April 2015 Slide 18 Methods of sampling Goal: Extract the ‘headspace’ vapor of the liquid sample for analysis in the gas phase Two methods: ‘Headspace’ stripping column Sample Transfer Stripper™ with ASI Membrane Technologies (proprietary)

19. Analytical Solutions by the Sea The 60th Annual Symposium of the Analysis Division Galveston Island Convention Center, Galveston, Texas, USA; 26th – 30th April 2015 Slide 19 Methods of sampling Carrier / Stripping Gas In Crude Oil In Crude Oil to Drain Stripped H2S to Detector ~ 3 to 4 feet Stripping Column Headspace stripping column

20. Analytical Solutions by the Sea The 60th Annual Symposium of the Analysis Division Galveston Island Convention Center, Galveston, Texas, USA; 26th – 30th April 2015 Slide 20 Methods of sampling Carrier / Stripping Gas In Crude Oil In Crude Oil to Drain Stripped H2S to Detector ~ 3-4 feet Stripping Column Headspace stripping column Drawbacks Suffers from liquid “carry-over” Cleaning requirements Many moving parts = more maintenance

21. Analytical Solutions by the Sea The 60th Annual Symposium of the Analysis Division Galveston Island Convention Center, Galveston, Texas, USA; 26th – 30th April 2015 Slide 21 Methods of sampling Membrane technology (proprietary) Sample Transfer Stripper™ with ASI Membrane Technologies by

22. Analytical Solutions by the Sea The 60th Annual Symposium of the Analysis Division Galveston Island Convention Center, Galveston, Texas, USA; 26th – 30th April 2015 Slide 22 Methods of sampling Membrane technology (proprietary)

23. Analytical Solutions by the Sea The 60th Annual Symposium of the Analysis Division Galveston Island Convention Center, Galveston, Texas, USA; 26th – 30th April 2015 Slide 23 Methods of sampling Membrane technology (proprietary) ASI Membrane Technology Headspace Crude Oil H2SH2S H2SH2S H2SH2S H2SH2S H2SH2S H2SH2S H2SH2S H2SH2S H2SH2S H2SH2S H2SH2S H2SH2S H2SH2S

24. Analytical Solutions by the Sea The 60th Annual Symposium of the Analysis Division Galveston Island Convention Center, Galveston, Texas, USA; 26th – 30th April 2015 Slide 24 Methods of sampling Membrane technology (proprietary) Membrane physically blocks mists from headspace vapor Prevents fouling of detector Prevents liquid “carry-over” Radically reduced maintenance Prevents in-gassing / out-gassing of H2S Maintains compositional representation of the headspace vapor

25. Analytical Solutions by the Sea The 60th Annual Symposium of the Analysis Division Galveston Island Convention Center, Galveston, Texas, USA; 26th – 30th April 2015 Slide 25 Methods of sampling | Comparison Sampling Technology: Sample Transfer Stripper™ (STS) with exclusive ASI Membrane Technologies Headspace stripping column Principles incorporated Henry’s Law & proprietary methodsHenry’s Law Maintenance requirements LOW STS Membrane creates ultra-clean sample for detector & physically blocks liquids from passing through to detector. Clean only one to two times per year typical X HIGH Plagued by frequent liquid “carry-overs”. No physical block to prevent liquids from contaminating detector and gas sample lines. User reported constant cleaning & upkeep Moving parts NONE No moving parts X HIGH Complicated system using 85% more parts than STS Membrane Cost of ownership Cost-Effective Minimal maintenance means less cost over time X HIGH Long term expense due to cleaning & maintenance requirements Accuracy HIGH STS creates ultra-clean sample for analysis X LOW System fouls as liquids frequently pass through to detector and gas sample lines requiring frequent cleaning Range PPB, PPM and up to 100% ranges with high precision X Low ppm ranges not reliable Safety SAFE Closed loop system for analysis and cleaning. No H2S exposure to user X CAUTION User potentially exposed to residual H2S when cleaning is required

26. Analytical Solutions by the Sea The 60th Annual Symposium of the Analysis Division Galveston Island Convention Center, Galveston, Texas, USA; 26th – 30th April 2015 Slide 26 Method of Analysis Difficulty of quantifying H2S in crude oil Crude oil is compositionally complex Many components interfere with H2S: Aromatics, SO2, ethyl-mercaptan, methyl-mercaptan and other sulfur compounds Crude composition changes not uncommon Low ppm especially a challenge

27. Analytical Solutions by the Sea The 60th Annual Symposium of the Analysis Division Galveston Island Convention Center, Galveston, Texas, USA; 26th – 30th April 2015 Slide 27 Method of Analysis Colorimetric-Rateometric Tape Detector

28. Analytical Solutions by the Sea The 60th Annual Symposium of the Analysis Division Galveston Island Convention Center, Galveston, Texas, USA; 26th – 30th April 2015 Slide 28 Colorimetric Rateometric Tape Detector Advantages Significant advantages with tape method Only method inherently specific to H 2 S No complicated chemometric modeling needed No need to “trick” system to minimize interferences Measures only H2S, no matter the compositional background Inherently accurate—measure low ppb, ppm to 100% H2S without false positives even in crude oil headspace

29. Analytical Solutions by the Sea The 60th Annual Symposium of the Analysis Division Galveston Island Convention Center, Galveston, Texas, USA; 26th – 30th April 2015 Slide 29 Colorimetric Rateometric Tape Detector Improvements to design Significant technological advancements to Tape Method: Improved tape drive system 75% less parts 3-6 month tape life Reliable and rugged Remote diagnostics & troubleshooting Simplest detection & most straight forward method available

30. Analytical Solutions by the Sea The 60th Annual Symposium of the Analysis Division Galveston Island Convention Center, Galveston, Texas, USA; 26th – 30th April 2015 Slide 30 Method of analysis | Comparison NOTE: Data based on typical manufacturers published data Measurement Technology Colorimetric-Rateometric Tape Method UV-Absorbance Spectrophotometry TDL Absorbance Spectroscopy Specific to H2S only YES Innately and practically free of cross-interference. No false positives. X NO Problems with mercaptans (including naturally occurring mercaptans), hydrogen, ammonia, etc. giving false positives X NO Problems with moisture and other sulfur components giving false positives Accuracy ± 2% of full scale typical±10% at 0-10ppm FSX ± 4ppmv 0-10ppm FS Sensor Zero Drift NO zero drift (automatic self zero, no zero air required) X YES 5% in 24 hours for low ppm ranges. Requires zero gas. X YES. Normally requires zero gas. Sample pressure requirements Pressure between 5 to 2,000 PSI acceptable Normally requires minimum of ~150 PSI Range PPB, PPM and up to 100% ranges with high accuracy X Low ppm ranges not reliable. PPB range not possible Calibration Stability Long-term even in demanding environments and process changes X Unstable if process changes even slightly. Requires calibrations Maintenance LOW Tape change only 3 to 4 times per year X HIGH Optics / Flow cell require frequent cleaning Mirrors tend to fog or produce haze. Requires cleaning Consumables Tape change every 3 to 6 months. ~$25 per tape reel Zero gas required. Light source and scrubber materials require replacement. Costly. Zero gas required. Scrubber (copper nanoparticle) replaced annually or more. Costly.

31. Analytical Solutions by the Sea The 60th Annual Symposium of the Analysis Division Galveston Island Convention Center, Galveston, Texas, USA; 26th – 30th April 2015 Slide 31 Method of Analysis Colorimetric-Rateometric Tape Analyzer Detection of H 2 S concentrations by the use of H 2 S sensing tape is achieved by exposing the film to an H 2 S sample through an aperture in the sample flow system, called the sample chamber. The reaction of photographic film to the light is analogous to the way that chemically saturated H 2 S sensing tape reacts to hydrogen sulfide

32. Analytical Solutions by the Sea The 60th Annual Symposium of the Analysis Division Galveston Island Convention Center, Galveston, Texas, USA; 26th – 30th April 2015 Slide 32 Method of Analysis Colorimetric-Rateometric Tape Detector The chemical formulation for reaction is as follows: H 2 O Pb(OAc) 2 + H 2 S →→→ PbS + 2HOAc White colored This reaction has three characteristics which allow it to be applied with unique analytical precision: 1.The reactants are colorless (white). 2.The product (PbS) is colored. 3.In more than a century of use, hydrogen sulfide is the only practical reactant found that produces a colored product on lead acetate (Pb(OAc) 2 tape.

33. Analytical Solutions by the Sea The 60th Annual Symposium of the Analysis Division Galveston Island Convention Center, Galveston, Texas, USA; 26th – 30th April 2015 Slide 33 Method of Analysis Colorimetric-Rateometric Tape Detector The rate (r) of this reaction (forming PbS) is as follows: r = k Pb(OAc) 2 x H 2 S Where k, the proportionality factor, is called the rate constant. NOTE: The very large (more than 1000 times) concentration of Pb(OAc) 2 on the H 2 S sensing tape simplifies the reaction as follows: [Pb(OAc) 2 ] 0 = [Pb(OAc) 2 ] 1 – PbS 1 = K 2 (<.1%) Therefore, r n = kk 2 (H 2 S - PbS n ) For simplicity: kk 2 = K r n = K(H 2 S = PbS n )

34. Analytical Solutions by the Sea The 60th Annual Symposium of the Analysis Division Galveston Island Convention Center, Galveston, Texas, USA; 26th – 30th April 2015 Slide 34 Method of Analysis Colorimetric-Rateometric Tape Detector By maintaining a constant H 2 S concentration, with continuous flow of the sample into the sample chamber, the rate of reaction equation is further reduced to: r = KH 2 S Therefore, by maintaining the control conditions of: 1.A large quantity of Pb(OAc) 2 2.Constant H 2 S concentration. 3.Sufficient moisture. The rate of reaction (i.e. the rate of darkening) is linearly proportional H 2 S concentration. Measuring the rate of darkening is therefore directly equivalent to measuring the H 2 S concentration.

35. Analytical Solutions by the Sea The 60th Annual Symposium of the Analysis Division Galveston Island Convention Center, Galveston, Texas, USA; 26th – 30th April 2015 Slide 35 Method of Analysis Colorimetric-Rateometric Tape Detector The rate of reaction (i.e. the rate of darkening) is linearly proportional H 2 S concentration.

36. Analytical Solutions by the Sea The 60th Annual Symposium of the Analysis Division Galveston Island Convention Center, Galveston, Texas, USA; 26th – 30th April 2015 Slide 36 Method of Analysis Colorimetric-Rateometric Tape Detector In actual practice, the rate of darkening is determined by measuring the change in darkness from second to second.

37. Analytical Solutions by the Sea The 60th Annual Symposium of the Analysis Division Galveston Island Convention Center, Galveston, Texas, USA; 26th – 30th April 2015 Slide 37 Method of Analysis Colorimetric-Rateometric Tape Detector tape darkness Y 80 PPM 40 PPM X time b 0 0 The general equation for the lines of the graph above is: y = ax + b b is the zero drift or offset term in conventional equipment that is often adjusted to zero (zero drift)

38. Analytical Solutions by the Sea The 60th Annual Symposium of the Analysis Division Galveston Island Convention Center, Galveston, Texas, USA; 26th – 30th April 2015 Slide 38 Method of Analysis Colorimetric-Rateometric Tape Detector tape darkness Y 80 PPM 40 PPM X time b 0 0

39. Analytical Solutions by the Sea The 60th Annual Symposium of the Analysis Division Galveston Island Convention Center, Galveston, Texas, USA; 26th – 30th April 2015 Slide 39 Case Study Measuring H2S for quality control Location: In-plant study in Middle East Participants: ASI Personnel, Customer Plant Manager, Customer Lab Manager Activity: Startup/commissioning and accuracy test

40. Analytical Solutions by the Sea The 60th Annual Symposium of the Analysis Division Galveston Island Convention Center, Galveston, Texas, USA; 26th – 30th April 2015 Slide 40 Case Study Measuring H2S for quality control Equipment: Model 205 H 2 S in Crude Oil Analyzer Sample Transfer Stripper™ with ASI Membrane Technologies (proprietary) Colorimetric-Rateometric Tape Detector Measuring Range: 0 to 80 ppm by wt.

41. Analytical Solutions by the Sea The 60th Annual Symposium of the Analysis Division Galveston Island Convention Center, Galveston, Texas, USA; 26th – 30th April 2015 Slide 41 Case Study Verification of Calibration Method Volumetric Blending Process The calibration procedure calls for a known concentration of H2S, which is injected into the crude sample in a container. This will cause the concentration of H2S in the sample to read proportionally more based on the concentration of H2S injected.

42. Analytical Solutions by the Sea The 60th Annual Symposium of the Analysis Division Galveston Island Convention Center, Galveston, Texas, USA; 26th – 30th April 2015 Slide 42 Case Study Results The model 205 H2S in Crude Oil Analyzer measured continuously while two field samples were taken by lab personnel which were tested in the laboratory. The cross reference of the readings of the analyzer and the lab results can be seen below: SAMPLE #/ TIMEMODEL 205LAB Sample 1: 12:005.201 ppm/w4 ppm/w Sample 2: 15:0015.02 ppm/w14 ppm/w ASI Prepared Standard 10 ppmw 10.07 ppm/w14 ppm/w

43. Analytical Solutions by the Sea The 60th Annual Symposium of the Analysis Division Galveston Island Convention Center, Galveston, Texas, USA; 26th – 30th April 2015 Slide 43 Case Study Conclusion The Model 205 H 2 S in Crude Oil Analyzer utilizing the membrane Sample Transfer Stripper™ and colorimetric-rateometric tape method of detection was tested by the plant laboratory specialists and found to be accurate. The Volumetric Blending method of calibration was also verified for accuracy. Both the plant engineers and Process Analyzer Engineer specialists along with ASI engineers were very pleased with the testing method and the accuracy of the model 205 H2S in Crude Oil Analyzer. The Sample Transfer Stripper combined with Tape detector results in an accurate and stable analyzer to measure H2S in crude oil: The analyzer maintains calibration long term (no chemometric modeling required) Field calibrations not required Zero gas not required Membrane stripper eliminates liquid carry over and cleanup Advancements in tape technology results in low maintenance Tape change required only 2-4 times annually