SY/T 6537-2002 Gas and solution analysis methods for natural gas purification plants
Some standard content:
TCS 75.060
Registration No.: 10474—2002
Standard Sharing Network
wbzfyw.com
Petroleum and Natural Gas Industry Standard of the People's Republic of China SY/T 6537—2002
Analysis methods of gas and solution for natural gas treating plant202 — 05 —28 Issued by
National Economic and Trade Commission
2002-08-01 Implementation
Normative references
Preparation of analytical solutions
Determination of hydrogen sulfide content in feed gas and flash gas of gas purification unitDetermination of hydrogen sulfide content in purified gas
Determination of total content of hydrogen sulfide, carbon monoxide, hydrocarbons and permanent gases in acid gas of gas purification unitDetermination of total sulfur content in feed gas, purified gas, acid gas and flash gas of gas purification unitDetermination of hydrogen sulfide and carbon oxide content in gas purification process (gas chromatography)Sulfur collection Determination of the amount of hydrogen sulfide and sulfur dioxide in process gas 10
Determination of sulfur mist content in sulfur recovery tail gas Composition analysis of sulfur recovery process gas (gas chromatography) Determination of water content in sulfur recovery tail gas
Determination of hydrogen sulfide content in desulfurization solution
Determination of carbon dioxide content in desulfurization solution Determination of thiosulfate content in desulfurization solution Composition analysis of desulfurization solution (chemical method)
Composition analysis of desulfurization and dehydration liquid (gas chromatography) 17
Appendix A (Normative Appendix) Simple determination method for hydrogen sulfide content in desulfurization solutionSY/T 6537—2002
SY/T 6537—2002
Appendix A of this standard is a normative appendix:
This standard is proposed and managed by the National Natural Gas Standardization Technical Committee: Drafting unit of this standard: Natural Gas Research Institute of Southwest Oil and Gas Company of PetroChina: Main drafters of this standard: Huang Daihong, Nie Chongbin, Ma Bo, Chang Honggang, Yin Jing1 Scope
Analysis methods of gases and solutions in natural gas purification plantsSY/T6537—2002
This standard specifies the gas purification plant ... This standard is applicable to the determination of hydrogen sulfide, carbon dioxide, sulfur dioxide, sulfur mist, total sulfur, alcohol amine, cyclopentane, triethylene glycol and other components in the gas and liquid of the natural gas purification plant. This standard is applicable to the determination of hydrogen sulfide, carbon dioxide, sulfur dioxide, sulfur mist, total sulfur and other components in the raw gas, purified gas, acid gas, flash gas and sulfur recovery process gas of the gas purification and sulfur recovery unit of the natural gas purification plant, and the determination of hydrogen sulfide, carbon dioxide, thiosulfate, alcohol amine, cyclopentane, triethylene glycol and water and other components in the desulfurization solution. 2 Normative references
The clauses in the following documents become the clauses of this standard through reference in this standard: For dated references, all subsequent amendments (excluding errata) or revisions are not applicable to this standard. However, the parties to the agreement on this standard are encouraged to study whether the latest versions of these documents can be used. For all undated references, the latest versions shall apply to this standard. GB/11060.1—1998 Determination of hydrogen sulfide content in natural gas - Iodometric method GB/T11060.2—1998 Determination of nitrogen sulfide content in natural gas - Methylene dimethod GB/T11061—1997 Determination of total sulfur in natural gas - Oxidative microcoulometry GB/T13609--1999 Guidelines for natural gas sampling SY6277-1997 Regulations on monitoring and personal safety of sulfide atmosphere in sour oil and gas fields SY6278—1997 Safety and enterprise specifications for natural gas purification plants 3 Preparation of analytical solutions
3.1 General provisions
3.1.1 The water used in this standard refers to distilled water or deionized water unless otherwise specified; the reagent refers to analytical grade water unless otherwise specified. 3.1.2 When preparing a 0.02 mol/1. or more dilute standard solution, the standard solution with a higher concentration should be accurately diluted with water that has been boiled for 15 minutes and cooled before use. If necessary, recalibrate. 3.2 Reagents and Materials
3.2.1 Hydrochloric acid.
3.2.2 Sulfuric acid.
3.2.3 Glacial acetic acid.
3.2.4 Potassium hydrogen phthalate.
3.2.5 Sodium hydroxide
3.2.6 Barium hydroxide [Ha(OH)28HO]. 3.2.7 Potassium dichromate: reference reagent.
3.2.8 Potassium iodide,
3.2.9 Sodium thiosulfate Na2503.5HO1. 3.2.10 Iodine
Anhydrous sodium carbonate: Standard reagent
Anhydrous sodium carbonate,
3.2.13 Zinc acetate [Zn(CH.COXO)2-2H20] SY/T 6537—2002
Ammonium sulfate [(NHMO4H2O]
Copper sulfate (CuSO+5H0): Chemical-pure
Sulfuric acid:
Nickel sulfate (NiS04-7H20):
Barium chloride (BaCl-2HO).
Potassium hydroxide.
Anhydrous ethanol.
Hydrogen peroxide.
Alkali asbestos: 101～20 , chemically pure.
Aqueous starch,
Methyl red.
Methylene oxide (biochrome)
Methyl orange (indicator)
Methyl yellow (indicator).
Acetal (indicator),
Bromothymol blue.
Glass fiber
Qualitative filter paper: fast, diameter 180mm.
3.3 Instruments
Alkali asbestos tube See Figure 1.
Figure Alkali asbestos tube
3.3.2 Overflow tube See Figure 2.
Figure 2 Overflow tube
3.3 .3 Commonly used instruments in experimental space.
3.4 Solution preparation
3.4.1 General solution
3.4.1.1 Barium hydroxide solution (4g/ml): Weigh 37g of barium hydroxide and 18g of barium nitride, add 5ml of n-butanol and mix well: After placing in a sealed container for 4-5 days, siphon the upper clear liquid and store it in the device shown in Figure 3. The capacity of the pipette in Figure 3 is 50mL2
1 Barium hydroxide solution: 2 Bath liquid storage bottle;
3-Shark tube: 4-Dummy tube: 5-Waste liquid bottle Figure 3 Barium hydroxide solution storage and liquid collection deviceSY/T 6537—2002
3.4.1.2 Iodine stock solution (50g/L): Weigh 50g iodine and 150g potassium iodide, add 1ml hydrochloric acid to 200mL water, dilute to 1L with water, and store in brown reagent bottle. 3.4.1.3 Iodine paint solution (5g/L): Dilute the solution in 3.4.1.2 with water according to +9. 3.4.1.4 Zinc acetate solution (20g/1.): Weigh 24g zinc acetate, dissolve in 500ml water, add 1-5 drops of ice and stir to make the solution clear, dilute to 1L. 3.4.1.5 Zinc acetate solution (10g/.): Weigh 12g zinc acetate, dissolve }500ml. water, add 1-2 drops of glacial acetic acid, add 30ml. ethanol, dilute to 1L
3.4.1.6 Silver sulfate solution (5g/L): weigh 5g of silver sulfate, dissolve in 1L water under heating, transfer to brown reagent bottle 1 for storage. 3.4.1.7 Copper sulfate solution (20g/.): weigh 32g of sulfuric acid, dissolve in appropriate amount of water, add 10ml. sulfuric acid, 30ml. ethanol, mix and add water to dilute to 1L
3.4.1.8 Hydrogen peroxide solution (1+9): measure 100ml. hydrogen peroxide, inject 90(hml. water, add 1ml. n-butanol, mix, valid for 3d.
3.4.1.9 Nickel sulfate solution (10g/L): weigh 18.2g nickel sulfate, dissolve in 1L water. 3.4.1.10 Ammonium vanadate solution (30g/L): weigh 32g ammonium vanadate, dissolve in 1L water, filter and use. 3.4.1.11 Hydrogen hydroxide solution (200g). 3.4.1.12
Hydrochloric acid solution (1+3):
Hydrochloric acid solution (1+11):
3.4.1.14 Sulfuric acid solution (1+17):
Mixed acid solution: take 970mL water. Add 23mL sulfuric acid and 10mL glacial acetic acid, mix, 3.4.1.16 Starch indicator solution (5g/L): weigh 1.0g soluble starch, add 10mL water, stir well, pour into 200mL boiling water and boil for 2min, cool, and use the liquid, valid period: 3.4.1.17 Phenolphthalein indicator solution (10g/1.): weigh 1.0g phenolic acid, dissolve in 100rm. ethanol 3 Methyl orange indicator solution (1g/L): weigh waist n.1g methyl orange, floating in lo0tnil carrier 3.4.1.18
3.4.1.19 Methyl red: - methyl blue mixed indicator solution (1g/1. ~ 0.5g/.): Weigh (.2g) methyl red, dissolve in 200mL ethanol under heating (water bath), add 0.1g methylene blue, stir to dissolve 3.4.1.20 Bromophenol blue indicator solution (1g/1.): Weigh 0.1g bromophenol blue, dissolve in 100tr1.50% ethanol: 3
SY/r 6537—2002
3.4.1.21 Methyl yellow standard solution (1g/L): weigh 0.1g of methyl yellow and dissolve it in a mixture of 90ml of ethanol and 10mL of water. 3.4.2 Standard solution
3.4.2.1 Decarbonated water: measure 3L~5L of water, heat and boil it in a beaker for 15min, cool it to 50℃~60℃, and store it in a bottle with an alkali solution. Use in the lower bottle of the brown tube, and replace the alkaline asbestos tube every six months. 3.4.2.2 Sodium carbonate standard solution 1c (1/2>aC0) -1. (0ml/L]: Weigh 52.995g 10.005g of sodium carbonate (3.2.11) dried at 270℃~300℃ for 1h, add water to dissolve, transfer to a 1000ml volumetric flask, dilute to the scale, shake the spoon: 3.4.2.3 Hydrochloric acid standard solution c(I[C])-1mol/L: Preparation: Measure 100mL of hydrochloric acid, inject into 1100mL of water, and spread evenly. Calibration: Use a pipette to take 20mL of sodium carbonate standard solution (3.4.2.2), add 40mL of water and 2~3 drops of orange indicator solution (3.4.1.18), and titrate with the prepared hydrochloric acid solution until the solution turns from yellow to red, boil for 2min-3min, cool, and continue to titrate until it turns orange-red.
The concentration of hydrochloric acid solution (mol/L) is calculated according to formula (1): V
Where:
ci—concentration of sodium carbonate standard solution, mol/L; V1——volume of sodium carbonate standard solution, ml; V—volume of hydrochloric acid solution consumed in titration, mL()
3.4.2.4 Benzene-potassium hydrogen formate standard solution Standard solution [c(CHCC2HCOK)-0.05000ml/1.: Weigh 10.211g→0.002g of potassium hydrogen benzoate (3.2.4) dried at 105℃--110℃ for 1h, put it into a 1000ml volumetric flask, dissolve it with freshly boiled and cooled water, and dilute to the scale. Note: The validity period of the solution is 7d in summer. If the ambient temperature drops, the usage period can be extended. When suspended matter appears in the solution, adults should prepare it.
3.4.2.5 Potassium dichromate standard solution [r(1/6KzCrzQ)-0.1000mml/L]: Weigh 4.903g (accurate to 0.0001g) of potassium dichromate (3.2.7) dried to constant weight at T150 in a beaker, add water to dissolve it, transfer it to a 1000mL volumetric flask, add water to dilute to the scale, and shake.
3.4.2.6 Sodium thiosulfate standard stock solution [c(Naz0)-0,1nmol/1.] Preparation: Weigh 2hg sodium thiosulfate and 1g anhydrous sodium carbonate, dissolve in 1L water. Boil slowly for 10min, cool, store in a brown reagent bottle, and calibrate and use after 14d. Calibration: Use a pipette to measure 20mL potassium chromite standard solution (3.4.2.5) in a 250mL iodine volumetric flask, add 2g potassium iodide and 20mL hydrochloric acid solution (3.4.1.12), immediately cover the bottle stopper, shake gently, place it in a room for 10min, add 150ml. water, titrate with sodium thiosulfate solution, add 2mL3mlL starch indicator solution when near the end point, continue titrating until the solution changes from blue to bright green, and do a blank test at the same time.
The concentration c (mol/) of the sodium thiosulfate solution is calculated according to formula (2): Vi
C-(V,Va)
Wu Zhong:
G.…—concentration of dichromic acid standard solution, mKolI.; Vt——amount of potassium dichromate standard solution, mL; V2——consumption of sodium thiosulfate solution during test solution titration, mL; Vo-consumption of sodium thiosulfate solution during blank titration, mL The concentration difference of the sodium thiosulfate solution obtained twice should not exceed 0.00021 μl/L(2)
3.4.2.7 Sodium hydroxide standard solution [c(NaOH)-0.2 μl/: Preparation: Weigh 100 g of sodium hydroxide and dissolve it in 100 ml of 4 μl/L. 6537-2002
water, after cooling, transfer the solution into a 25[tm. poly7ene bottle, densely place more than 10g, make the liquid clear: use a pipette to absorb 32mL of clear liquid, inject into 31. freshly boiled 15min and cooled to 60 water, mix and transfer to the package shown in Figure 4 for storage and use. 1 Alkaline cotton; 2 Dissolved sludge storage bottle: 3, spring clip: - a drop is a tube Figure 4 Sodium hydroxide standard solution titration device
Calibration: Weigh 1.2g (accurate to 0.0001g) of benzene: potassium formate (3.2.4) dried at 105℃~110℃, dissolve in water, heat to boiling, add 2 drops of aliquots, and titrate with the prepared sodium hydroxide solution until the test solution is pink and the same color as the standard. Take another 80ml of water and perform the empty mouth test according to the same steps: The concentration of the sodium hydroxide standard solution (mkl/L) is calculated according to formula (3): = (vi- v) x 204.2× 10
Wherein:
Mass of potassium hydrogen phthalate, K:
Consumption of sodium hydride solution during titration with test solution, mL:V
V——Consumption of sodium hydrocyanide solution during titration with air: mL:204.2——Molar mass of cyanoacetic acid cake, g/txl(3)
The standard color is prepared as follows: Take 65ml sodium cyanide solution (containing 19.072NaH·HO) and 3.50ml hydrochloric acid solution (3.4.2.3) with a pipette, add 2 drops of phenol and then indicate, mix, the solution I should be about 8.54. Determination of hydrogen sulfide content in feed gas and flash gas of gas purification device according to GH/1 11061.1-[998 5. Determination of hydrogen sulfide content in purified gas
5.1 Arbitration analysis method for hydrogen sulfide content - methylene blue method Determination shall be carried out in accordance with GB/T11060.2-1998: 5.2 Control analysis method for hydrogen sulfide content - molybdenum blue method 5.2.1 Scope of application
This method is applicable to the control analysis of oxygen sulfide content in natural gas, and the measurement range is 0m%-251%/m 5.2.2 Summary of the method
Use ammonium nitrate solution to absorb hydrogen sulfide in the gas to form molybdenum blue, measure the absorbance of the blue solution, and calculate the content of hydrogen sulfide in the gas.
SY/T 6537—2002
5.2.3 Reagents and materials
5.2.3.1 See 3.2 and 3.4 for reagent purity and solution preparation method. 5.2.3.2 Sodium hydroxide,
5.2.3.3 Hydrochloric acid solution (1+11).
5.2.3.4 Iodine solution (5g/.).
Ammonium molybdate solution (30g/L):
Mixed acid solution.
Ammonium molybdate colorimetric solution: Before use, mix ammonium molybdate solution with mixed acid solution in the ratio of 3+2. 5.2.3.7
5.2.3.8 Sodium thiosulfate standard solution "c (NazS0) -0.02tml/1. 5.2.3.9 Starch indicator solution (5g/.).
5.2.3.10 Hydrogen sulfide: bottled gas or regenerated acid gas from a purification plant (composed of sulfide oxide, carbon oxide and a small amount of hydrocarbon gas). 5,2.3.11
Colorimetric tube rack,
Absorber rack: See Figure 5.
70A50A
Figure 5 Absorber rack
5.2.4 Instrument
5.2.4.1 Absorber: See Figure 6, with No. 3 glass sand core board at the bottom. 5.2.4.2 Wet gas This flowmeter: graduation value 0.011., indication error +1%. 5.2.4.3 Colorimetric tube: capacity 50ml.
5.2.4.4 Spectrophotometer: any type of spectrophotometer that can measure absorbance at a wavelength of 600nm: 5.2.4.5 Common laboratory instruments.
5.2.5 Drawing of standard curve
5.2.5.1 Preparation of sodium sulfide solution
a) Preparation of liquid A (equivalent to 20ng/30ng/L of hydrogen sulfide): In a 500mml conical flask, add 1g of sodium hydroxide, add 400mL of freshly boiled and cooled water, shake to dissolve it, and plug it with a rubber stopper. Use a syringe to inject 8mL of hydrogen sulfide gas. When there is no pure hydrogen sulfide gas, you can inject an appropriate amount of re-acid gas (5.2.3.10): Invert the conical flask several times to allow it to absorb: the effective period of the solution is 2h, the concentration of hydrogen sulfide is measured: in a 250ml iodine flask, add 20mL hydrochloric acid solution (3.4.1.13), then add 10ml of iodine solution and 100ml of liquid A through a pipette in sequence (when adding the middle solution, extend the pipette into the liquid layer), shake and then titrate with sodium thiosulfate standard solution, when it is close to the end point, add 1ml--2ml of starch indicator solution, and continue titrating until the blue color of the solution disappears. Take another 100mL of water as blank and calculate the sulfide oxygen concentration α (n1g/1.) of the test solution according to formula (4): G
Wu Zhong:
Figure 6 Hydrogen sulfide absorber
(Va. - V)e × 17.04 × 10
Vi—When the test solution is titrated, the consumption of sodium thiosulfate standard solution is recorded, ml.: Vu
When the blank is titrated, the consumption of sodium thiosulfate standard solution is recorded, ml.: Concentration of sodium thiosulfate standard solution, mcl/L; 17.04--: M (1/21hS), g/mol
b) Solution B (equivalent to containing 3mg/~-4mg/L of hydrogen sulfide). SY/T 6537—2002
Preparation: Add 1g of sodium hydroxide to a 500ml container, add an appropriate amount of liquid with a pipette and shake. After the sodium hydroxide is dissolved, dilute it with boiled and cooled water to the scale, spread it evenly and calculate the concentration of hydrogen sulfide in liquid B. The validity period of the solution is 2h. 5.2.5.2 Preparation of standard color scale
Take 7 negative tubes, use a pipette to add 0ml: 1ml2ml., 3ml, 4ml5ml., 4ml. of liquid B to tubes 1 to 7 in sequence, and calculate the absolute amount of hydrogen sulfide in each tube. Add 40ml of sawamide colorimetric solution to each tube, immediately cover the tube stopper, invert the colorimetric tube back and forth twice, leave it for 20 minutes, then add sawamide colorimetric solution to the scale, probe evenly. 5.2.5.3 Determination of absorbance
Use 20mm colorimetric III and the solution in tube (empty) as reference, and measure the absorbance at a wavelength of 600 rum on the spectrophotometer: 5.2.5.4 Drawing of standard curve
On the rectangular coordinate paper, use the absolute amount of hydrogen sulfide (μg) as the horizontal axis, and the corresponding absorbance value is Coordinates, draw standard curves: During the use of the curve, it is necessary to repeat the calibration every three months. 5.2.6 Sampling
5.2.6.1 General provisions
1) The location of the sampling port should be selected at the gas flow part of the line to ensure the sample's representativeness. b) The pipeline from the gas source to be analyzed to the sampling line should be as clear as possible. The pipeline should be made of materials that are chemically compatible with hydrogen sulfide, such as polyethylene, polytetrafluoroethylene, glass and lead. It is also allowed to use a short hose to connect the sampling components 7
SY/T 6537—2002
c) Before sampling, the gas to be analyzed must fully replace the liquid in the sampling pipeline: During the sampling process, no condensate should appear in the sampling pipeline. d) For gases with ammonia sulfide content lower than 0.5%, the absorption of hydrogen sulfide should be completed at the sampling site. e) For hydrogen sulfide, the safety precautions during sampling shall be implemented in accordance with SY6277-1997 and SY6278-1997. 5.2.6.2 Sampling port||t t||The sampling unit is composed of a probe and a sampling valve. The sampling probe is a stainless steel pipe welded on the gas pipeline and extends into the pipe at one-tenth of the diameter. The sampling valve should be a stainless steel needle valve with a diameter of 3mm-5mm. For other sampling regulations, see GB/T13G09-1999 5.2.6.3 Sample quantity
For the selection of the quantity of each sample, see Table 1.
Table 1 Sample quantity selection table
Pre-set Hydrogen sulfide concentration
10·-25
5,2.7 Analysis steps
5.2.7.1 Absorption
Sample base
The absorption device is shown in Figure 7. Accurately add 50mL of ammonium sulfide colorimetric solution into the absorber, tightly connect the parts in the figure with a short-section rubber hose, open the spiral fire, slowly open the sampling valve, let the gas to be analyzed be properly emptied to replace the dead air in the sampling pipeline, and record the flow rate reading. Adjust the spiral clamp to allow the gas to pass through the absorber at a flow rate of 200ml./min~300nL/nin: When the absorbed liquid shows obvious color and the absorbance is expected to enter the range of 0.1~0.7, close the sampling valve and record the sample volume, flowmeter temperature and atmospheric pressure. Avoid visual exposure during the absorption process: 1-Gas pipeline: 2-Sampling valve: 3-Spiral type; 1 Exhaust pipe: 5 Absorber; 6-Flowmeter Figure 7 Hydrogen sulfide absorption device
5.2.7.2 Absorbance determination
Move the absorber into the room and place it for 20min at room temperature. Inject the absorption liquid into a 20mm colorimetric container and use the ammonium acid colorimetric solution that does not absorb hydrogen sulfide as a reference. Measure the absorbance at a wavelength of 600nm on the spectrophotometer: 5.2.8 Calculation of analysis results
5.2.8.1 The gas sample correction volume V, (L) is calculated according to formula (5): V = x:
Wherein:
V-sampling volume,..
-atmospheric pressure at the time of sampling, kPa
p-temperature: saturated vapor pressure of water at that time, kPa;-flowmeter temperature,
5.2.8.2 Calculation of hydrogen sulfide content in gas sample—
SY/T6537—2002
Use the absorbance value measured in 5.2.7.2 to find out the amount of hydrogen sulfide in the absorption liquid from the calibration curve. The hydrogen sulfide concentration (mg/m3) of the gas sample is calculated according to formula (6):
Where:
The amount of hydrogen sulfide in the absorption liquid, mg/m2;
The calibration volume of the gas sample, 1.
5.2.9 Result report
Take the arithmetic mean of two parallel measurements as the analysis result. When the result is greater than or equal to [/m3, retain 1 significant figure. When it is less than 1ir/m2, retain two significant figures. 5.2.10 Allowable error
The difference between the results of two parallel determinations shall not exceed the values in Table 2. Table 2 Allowable error
Concentration range
nig/ma
1 -- 5
Allowable error (the smaller measured value)
6 Determination of the total content of hydrogen sulfide, carbon dioxide, hydrocarbons and permanent gases in the sour gas of a gas purification unit 6.1 Scope of application
This method is applicable to the determination of the total content of hydrogen sulfide, carbon dioxide, light and permanent gases in the sour gas of a natural gas purification unit. The determination range is 0~100%(9).
6.2 Method Summary
Use potassium hydroxide solution to absorb hydrogen sulfide and carbon dioxide in the acid gas sample, measure the total volume of the residual gas, and obtain the total content of hydrocarbons and permanent gases; use zinc acetate solution to absorb hydrogen sulfide in the dry acid gas sample, and then determine and calculate the hydrogen sulfide content in the acid gas by iodine titration: the carbon dioxide content is calculated by subtraction: 6.3 Determination of the total content of hydrocarbons and permanent gases
6.3.1 Reagents and materials
6.3.1.1 Potassium hydroxide solution (200g/1.). 9Add 40ml of sawamide colorimetric solution to each tube, immediately cover the tube stopper, turn the colorimetric tube back and forth twice, leave it for 20 minutes, add sawamide colorimetric solution to the scale, and probe evenly. 5.2.5.3 Determination of absorbance
Use 20mm colorimetric III, take the solution in tube (empty) as reference, and measure the absorbance at a wavelength of 600rum on the spectrophotometer: 5.2.5.4 Drawing of standard curve
On the rectangular coordinate paper, take the absolute amount of hydrogen sulfide (m) as the horizontal axis, and the corresponding absorbance value is Coordinates, draw standard curves: During the use of the curve, it is necessary to repeat the calibration every three months. 5.2.6 Sampling
5.2.6.1 General provisions
1) The location of the sampling port should be selected at the gas flow part of the line to ensure the sample's representativeness. b) The pipeline from the gas source to be analyzed to the sampling line should be as clear as possible. The pipeline should be made of materials that are chemically compatible with hydrogen sulfide, such as polyethylene, polytetrafluoroethylene, glass and lead. It is also allowed to use a short hose to connect the sampling components 7
SY/T 6537—2002
c) Before sampling, the gas to be analyzed must fully replace the liquid in the sampling pipeline: During the sampling process, no condensate should appear in the sampling pipeline. d) For gases with ammonia sulfide content lower than 0.5%, the absorption of hydrogen sulfide should be completed at the sampling site. e) For hydrogen sulfide, the safety precautions during sampling shall be implemented in accordance with SY6277-1997 and SY6278-1997. 5.2.6.2 Sampling port||t t||The sampling unit is composed of a probe and a sampling valve. The sampling probe is a stainless steel pipe welded on the gas pipeline and extends into the pipe at one-tenth of the diameter. The sampling valve should be a stainless steel needle valve with a diameter of 3mm-5mm. For other sampling regulations, see GB/T13G09-1999 5.2.6.3 Sample quantity
For the selection of the quantity of each sample, see Table 1.
Table 1 Sample quantity selection table
Pre-set Hydrogen sulfide concentration
10·-25
5,2.7 Analysis steps
5.2.7.1 Absorption
Sample base
The absorption device is shown in Figure 7. Accurately add 50mL of ammonium sulfide colorimetric solution into the absorber, tightly connect the parts in the figure with a short-section rubber hose, open the spiral fire, slowly open the sampling valve, let the gas to be analyzed be properly emptied to replace the dead air in the sampling pipeline, and record the flow rate reading. Adjust the spiral clamp to allow the gas to pass through the absorber at a flow rate of 200ml./min~300nL/nin: When the absorbed liquid shows obvious color and the absorbance is expected to enter the range of 0.1~0.7, close the sampling valve and record the sample volume, flowmeter temperature and atmospheric pressure. Avoid visual exposure during the absorption process: 1-Gas pipeline: 2-Sampling valve: 3-Spiral type; 1 Exhaust pipe: 5 Absorber; 6-Flowmeter Figure 7 Hydrogen sulfide absorption device
5.2.7.2 Absorbance determination
Move the absorber into the room and place it for 20min at room temperature. Inject the absorption liquid into a 20mm colorimetric container and use the ammonium acid colorimetric solution that does not absorb hydrogen sulfide as a reference. Measure the absorbance at a wavelength of 600nm on the spectrophotometer: 5.2.8 Calculation of analysis results
5.2.8.1 The gas sample correction volume V, (L) is calculated according to formula (5): V = x:
Wherein:
V-sampling volume,..
-atmospheric pressure at the time of sampling, kPa
p-temperature: saturated vapor pressure of water at that time, kPa;-flowmeter temperature,
5.2.8.2 Calculation of hydrogen sulfide content in gas sample—
SY/T6537—2002
Use the absorbance value measured in 5.2.7.2 to find out the amount of hydrogen sulfide in the absorption liquid from the calibration curve. The hydrogen sulfide concentration (mg/m3) of the gas sample is calculated according to formula (6):
Where:
The amount of hydrogen sulfide in the absorption liquid, mg/m2;
The calibration volume of the gas sample, 1.
5.2.9 Result report
Take the arithmetic mean of two parallel measurements as the analysis result. When the result is greater than or equal to [/m3, retain 1 significant figure. When it is less than 1ir/m2, retain two significant figures. 5.2.10 Allowable error
The difference between the results of two parallel determinations shall not exceed the values in Table 2. Table 2 Allowable error
Concentration range
nig/ma
1 -- 5
Allowable error (the smaller measured value)
6 Determination of the total content of hydrogen sulfide, carbon dioxide, hydrocarbons and permanent gases in the sour gas of a gas purification unit 6.1 Scope of application
This method is applicable to the determination of the total content of hydrogen sulfide, carbon dioxide, light and permanent gases in the sour gas of a natural gas purification unit. The determination range is 0~100%(9).
6.2 Method Summary
Use potassium hydroxide solution to absorb hydrogen sulfide and carbon dioxide in the acid gas sample, measure the total volume of the residual gas, and obtain the total content of hydrocarbons and permanent gases; use zinc acetate solution to absorb hydrogen sulfide in the dry acid gas sample, and then determine and calculate the hydrogen sulfide content in the acid gas by iodine titration: the carbon dioxide content is calculated by subtraction: 6.3 Determination of the total content of hydrocarbons and permanent gases
6.3.1 Reagents and materials
6.3.1.1 Potassium hydroxide solution (200g/1.). 9Add 40ml of sawamide colorimetric solution to each tube, immediately cover the tube stopper, turn the colorimetric tube back and forth twice, leave it for 20 minutes, add sawamide colorimetric solution to the scale, and probe evenly. 5.2.5.3 Determination of absorbance
Use 20mm colorimetric III, take the solution in tube (empty) as reference, and measure the absorbance at a wavelength of 600rum on the spectrophotometer: 5.2.5.4 Drawing of standard curve
On the rectangular coordinate paper, take the absolute amount of hydrogen sulfide (m) as the horizontal axis, and the corresponding absorbance value is Coordinates, draw standard curves: During the use of the curve, it is necessary to repeat the calibration every three months. 5.2.6 Sampling
5.2.6.1 General provisions
1) The location of the sampling port should be selected at the gas flow part of the line to ensure the sample's representativeness. b) The pipeline from the gas source to be analyzed to the sampling line should be as clear as possible. The pipeline should be made of materials that are chemically compatible with hydrogen sulfide, such as polyethylene, polytetrafluoroethylene, glass and lead. It is also allowed to use a short hose to connect the sampling components 7
SY/T 6537—2002
c) Before sampling, the gas to be analyzed must fully replace the liquid in the sampling pipeline: During the sampling process, no condensate should appear in the sampling pipeline. d) For gases with ammonia sulfide content lower than 0.5%, the absorption of hydrogen sulfide should be completed at the sampling site. e) For hydrogen sulfide, the safety precautions during sampling shall be implemented in accordance with SY6277-1997 and SY6278-1997. 5.2.6.2 Sampling port||t t||The sampling unit is composed of a probe and a sampling valve. The sampling probe is a stainless steel pipe welded on the gas pipeline and extends into the pipe at one-tenth of the diameter. The sampling valve should be a stainless steel needle valve with a diameter of 3mm-5mm. For other sampling regulations, see GB/T13G09-1999 5.2.6.3 Sample quantity wwW.bzxz.Net
For the selection of the quantity of each sample, see Table 1.
Table 1 Sample quantity selection table
Pre-set Hydrogen sulfide concentration
10·-25
5,2.7 Analysis steps
5.2.7.1 Absorption
Sample base
The absorption device is shown in Figure 7. Accurately add 50mL of ammonium sulfide colorimetric solution into the absorber, tightly connect the parts in the figure with a short-section rubber hose, open the spiral fire, slowly open the sampling valve, let the gas to be analyzed be properly emptied to replace the dead air in the sampling pipeline, and record the flow rate reading. Adjust the spiral clamp to allow the gas to pass through the absorber at a flow rate of 200ml./min~300nL/nin: When the absorbed liquid shows obvious color and the absorbance is expected to enter the range of 0.1~0.7, close the sampling valve and record the sample volume, flowmeter temperature and atmospheric pressure. Avoid visual exposure during the absorption process: 1-Gas pipeline: 2-Sampling valve: 3-Spiral type; 1 Exhaust pipe: 5 Absorber; 6-Flowmeter Figure 7 Hydrogen sulfide absorption device
5.2.7.2 Absorbance determination
Move the absorber into the room and place it for 20min at room temperature. Inject the absorption liquid into a 20mm colorimetric container and use the ammonium acid colorimetric solution that does not absorb hydrogen sulfide as a reference. Measure the absorbance at a wavelength of 600nm on the spectrophotometer: 5.2.8 Calculation of analysis results
5.2.8.1 The gas sample correction volume V, (L) is calculated according to formula (5): V = x:
Wherein:
V-sampling volume,..
-atmospheric pressure at the time of sampling, kPa
p-temperature: saturated vapor pressure of water at that time, kPa;-flowmeter temperature,
5.2.8.2 Calculation of hydrogen sulfide content in gas sample—
SY/T6537—2002
Use the absorbance value measured in 5.2.7.2 to find out the amount of hydrogen sulfide in the absorption liquid from the calibration curve. The hydrogen sulfide concentration (mg/m3) of the gas sample is calculated according to formula (6):
Where:
The amount of hydrogen sulfide in the absorption liquid, mg/m2;
The calibration volume of the gas sample, 1.
5.2.9 Result report
Take the arithmetic mean of two parallel measurements as the analysis result. When the result is greater than or equal to [/m3, retain 1 significant figure. When it is less than 1ir/m2, retain two significant figures. 5.2.10 Allowable error
The difference between the results of two parallel determinations shall not exceed the values in Table 2. Table 2 Allowable error
Concentration range
nig/ma
1 -- 5
Allowable error (the smaller measured value)
6 Determination of the total content of hydrogen sulfide, carbon dioxide, hydrocarbons and permanent gases in the sour gas of a gas purification unit 6.1 Scope of application
This method is applicable to the determination of the total content of hydrogen sulfide, carbon dioxide, light and permanent gases in the sour gas of a natural gas purification unit. The determination range is 0~100%(9).
6.2 Method Summary
Use potassium hydroxide solution to absorb hydrogen sulfide and carbon dioxide in the acid gas sample, measure the total volume of the residual gas, and obtain the total content of hydrocarbons and permanent gases; use zinc acetate solution to absorb hydrogen sulfide in the dry acid gas sample, and then determine and calculate the hydrogen sulfide content in the acid gas by iodine titration: the carbon dioxide content is calculated by subtraction: 6.3 Determination of the total content of hydrocarbons and permanent gases
6.3.1 Reagents and materials
6.3.1.1 Potassium hydroxide solution (200g/1.). 92, the absorbance value measured, from the calibration curve to find out the amount of hydrogen sulfide in the absorption liquid. The hydrogen sulfide concentration of the gas sample (mg/m2) is calculated according to formula (6):
Where:
The amount of hydrogen sulfide in the absorption liquid, 1.
The calibration volume of the gas sample, 1.
5.2.9 Result report
Take the arithmetic mean of two parallel measurements as the analysis result. When the result is greater than or equal to [/m2, retain 1 significant figure, and when it is less than 1ir/m2, retain two significant figures. 5.2.10 Allowable error
The difference between the results of two parallel determinations shall not exceed the values in Table 2. Table 2 Allowable error
Concentration range
nig/ma
1 -- 5
Allowable error (the smaller measured value)
6 Determination of the total content of hydrogen sulfide, carbon dioxide, hydrocarbons and permanent gases in the sour gas of a gas purification unit 6.1 Scope of application
This method is applicable to the determination of the total content of hydrogen sulfide, carbon dioxide, light and permanent gases in the sour gas of a natural gas purification unit. The determination range is 0~100%(9).
6.2 Method Summary
Use potassium hydroxide solution to absorb hydrogen sulfide and carbon dioxide in the acid gas sample, measure the total volume of the residual gas, and obtain the total content of hydrocarbons and permanent gases; use zinc acetate solution to absorb hydrogen sulfide in the dry acid gas sample, and then determine and calculate the hydrogen sulfide content in the acid gas by iodine titration: the carbon dioxide content is calculated by subtraction: 6.3 Determination of the total content of hydrocarbons and permanent gases
6.3.1 Reagents and materials
6.3.1.1 Potassium hydroxide solution (200g/1.). 92, the absorbance value measured, from the calibration curve to find out the amount of hydrogen sulfide in the absorption liquid. The hydrogen sulfide concentration of the gas sample (mg/m2) is calculated according to formula (6):
Where:
The amount of hydrogen sulfide in the absorption liquid, 1.
The calibration volume of the gas sample, 1.
5.2.9 Result report
Take the arithmetic mean of two parallel measurements as the analysis result. When the result is greater than or equal to [/m2, retain 1 significant figure, and when it is less than 1ir/m2, retain two significant figures. 5.2.10 Allowable error
The difference between the results of two parallel determinations shall not exceed the values in Table 2. Table 2 Allowable error
Concentration range
nig/ma
1 -- 5
Allowable error (the smaller measured value)
6 Determination of the total content of hydrogen sulfide, carbon dioxide, hydrocarbons and permanent gases in the sour gas of a gas purification unit 6.1 Scope of application
This method is applicable to the determination of the total content of hydrogen sulfide, carbon dioxide, light and permanent gases in the sour gas of a natural gas purification unit. The determination range is 0~100%(9).
6.2 Method Summary
Use potassium hydroxide solution to absorb hydrogen sulfide and carbon dioxide in the acid gas sample, measure the total volume of the residual gas, and obtain the total content of hydrocarbons and permanent gases; use zinc acetate solution to absorb hydrogen sulfide in the dry acid gas sample, and then determine and calculate the hydrogen sulfide content in the acid gas by iodine titration: the carbon dioxide content is calculated by subtraction: 6.3 Determination of the total content of hydrocarbons and permanent gases
6.3.1 Reagents and materials
6.3.1.1 Potassium hydroxide solution (200g/1.). 9
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.