Gas chromatographic determination of sulfur-containing compounds in hydrocarbon products and device to this end

FIELD: physics.

SUBSTANCE: proposed method comprises forcing analysed product into chromatograph first circuit to define carbon sulphide at its concentration exceeding 0.1 wt % and, at a time, into second circuit at carbon sulphide concentration lower than 0.1 wt %. First circuit comprises piston-type metering valve and packed columns arranged in heated temperature-controlled cabinet and filled with polymer adsorbent, 0.1-1.5 m-long precolumn and 0.5-5 m-long main column, and heat conductivity detector. Second circuit comprises piston-type metering valve, packed capillary columns arranged in heated temperature-controlled cabinet and filled with polymer adsorbent, 0.1-1.5 m-long precolumn and 15-50 m-long main column with their ID making 0.23-0.32 mm, and sulfur-selective detector. Metering valves are arranged sequentially in both circuits along sample feed direction.

EFFECT: shorter easier process.

5 cl, 1 dwg, 2 tbl, 1 ex

 

The invention relates to gas chromatography and can be used for determination of sulfur compounds in hydrocarbon raw materials and products.

The closest technical solution of the present invention, in terms of method, is a method of gas chromatographic determination of sulfur-containing compounds in the hydrocarbon products in which these connections are determined after the surgery, the degassing of the sample, separately, as in the received gas degassing and degassed condensate (Saaristokanava, Aescribed, IAUDIO, Healthview, Usershave, the Determination of individual sulfur-containing compounds in unstable gas condensate methods gas chromatography. Gas industry, 2007, No. 6, p.70-73) [1]. Determination of sulfur compounds in degassed condensate and gas degassing, in the case of hydrogen sulfide concentration below 0.1 wt. -%, carried out using two capillary chromatographic columns, and the detection is carried out using a flame photometric detector. In the analysis of gas degassing containing hydrogen sulfide at a concentration above 0,1% weight., for separation of the sample components using the Packed column with a polymeric adsorbent, and for detection of the detector of Teplopribor the property.

The concentration of sulfur-containing compounds is determined by the method of absolute calibration.

The disadvantage of this technical solution is that the procedure for determination of sulfur compounds in the samples is very long (5-8 h) and time-consuming due to the need for the degassing operation, carrying out two independent analyses and subsequent information obtained results to determine concentrations of components in the original sample.

The closest technical solution of the present invention, in the side of the device, is a device for gas chromatographic analysis of sulfur-containing liquid hydrocarbon products (J.Luong, R.Gras, R.Tymko, Innovations in High-Pressure Liquid Injection Technique for Gas Chromatography: Pressurized Liquid Injection System, J. Chromatogr. Sci., 2003, v.41, №6, 550-559) [2]. The device includes a dispenser for direct input samples under pressure into the chromatograph, equipped with an evaporator, a flow divider, a capillary column CP-Sil 5CB (length 50 m, inner diameter 0.32 mm) and ceaselessly chemoluminescence detector. This device was used for determination of impurities of a number of sulfur-containing compounds in liquefied gases (ethane, propylene, propane, butane and butadiene).

The disadvantages of the known technical solution is that it is not possible to determine in samples of the sulfide, especially PR is its high concentrations as well as a number of other sulfur-containing compounds, among which carbon oxysulphide, methyl mercaptan and ethyl mercaptan contained in such hydrocarbon products, such as unstable gas condensate and liquefied petroleum gas.

The technical result, which directed the proposed group of inventions is to eliminate these disadvantages. In particular, decreases run time quantitative determination of sulfur compounds (hydrogen sulfide in a concentration range of 0.0001 to 40 wt. -%, individual mercaptans CH3S-C4H9SH, carbon oxysulphide, carbon disulfide, dimethyl sulfide, dimethyl disulfide, diethylsulfide, diatinguished, tetrahydrothiophene and other derivatives of thiophene in the concentration range of each compound is 0.0001 to 0.7% of the mass.) the hydrocarbon products, including gas condensate is unstable and liquefied hydrocarbon gases, their own vapor pressures under normal conditions exceeds 0.1 MPa (1 ATM), and also decreases the complexity of the definition.

The technical result of the invention is achieved by that in the method of gas chromatographic determination of sulfur-containing compounds in the hydrocarbon products simultaneously serves analyzed the product under pressure higher than atmospheric, in the first tract chromatographie determination of hydrogen sulfide in concentrations above 0.1% of the mass. and the second tract chromatograph for determination of hydrogen sulfide at concentrations less than 0.1% of the mass. and other sulfur-containing compounds. Next, determine the concentration of sulfur-containing compounds by the method of absolute calibration. Moreover, the analyzed product is fed to the first path, which includes consistently located the valve-piston type dispenser installed in a heated thermostat and filled with a polymer adsorbent Packed column - predalone length of 0.1÷1.5 m and the main column length 0,5÷5 m, and a heat conductivity detector, and a second path comprising sequentially arranged valve-piston type dispenser installed in a heated thermostat capillary column - predalone length of 0.1÷1.5 m and the main column length of 15÷50 m, inner diameter which is 0.23÷0.32 mm, and ceaselessly detector.

The temperature in thermostat capillary columns gradually increase from 60°C to 260°C, and the temperature in thermostat of the Packed column is gradually increased from 100°C to 140°C.

As kerosenetype detector using a flame photometric detector or chemoluminescence detector, or atomic emission detector, or mass-selective detector.

The technical result of the invention is also achieved due to the fact that the chromatograph for gather autographical determination of sulfur compounds in hydrocarbon products includes parallel spaced first tract for the determination of hydrogen sulfide in concentrations above 0.1 wt. -%, contains consistently located is equipped with evaporator, the valve-piston type dispenser that provides dosing analyzed product under pressure higher than atmospheric, set in a heated thermostat and filled with a polymer adsorbent Packed column - predalone length of 0.1÷1.5 m and the main column length 0,5÷5 m, and a heat conductivity detector, and a second path for hydrogen sulfide at concentrations less than 0.1% of the mass. and other sulfur-containing compounds containing consistently located is equipped with evaporator, the valve-piston type dispenser that provides dosing analyzed product under pressure higher than atmospheric, set in a heated thermostat capillary column - predalone length of 0.1÷1.5 m and the main column length of 15÷50 m, inner diameter which is 0.23÷0.32 mm, and ceaselessly detector. The cranes-equipment for the first and second paths are arranged successively in the direction of the line of feed samples, while the chromatograph equipped with an evaporator connected to the input of the capillary predalone, for carrying out calibration of the chromatograph for gas mixtures.

As kerosenetype detector can be used flame photometric detector or chemoluminescence detector, or atomic the emission detector, or mass-selective detector.

The present invention is illustrated in the drawing, which shows a diagram of the chromatograph for gas chromatographic determination of sulfur-containing compounds in the hydrocarbon products, including the supply line of the analyzed product 6, the water supply line for cooling 7, the first tract for the determination of hydrogen sulfide in concentrations above 0.1 wt. -%, containing the valve-piston type dispenser 8, the Packed column - predalone 14 length of 0.1÷1.5 m, the main column 15 length 0,5÷5 m, thermostat Packed columns 13 and a heat conductivity detector 18; a second path for hydrogen sulfide at concentrations less than 0.1% of the mass. and other sulfur-containing compounds containing the valve-piston type dispenser 9 made of quartz glass capillary column - predalone 21 length of 0.1÷1.5 m and the main column 24 length of 15÷50 m, inner diameter which is 0.23÷0.32 mm, thermostat capillary columns 23, ceaselessly detector 30, tee-divider 22. In addition, the chromatograph contains the evaporator 16, the flow switch 5, and the line of the carrier gas supply 17, the electronic controls of the flow of carrier gas 11, 25, 27, 28, electronic pressure regulators gas carrier 12, 26, line air supply 29, a line of hydrogen supply 31, a mechanical pressure regulators 19, 32, pnevmoapparatury is 1, 3, 20, 33, valves purge 2, 4, adjustable choke flow of the analyzed product 10.

All connections and components are made protected against corrosive environments.

Each of the two cranes dosing piston type 8 and 9 allows you to enter a fixed amount of the analyzed product under pressure higher than atmospheric (up to 10 MPa) in the evaporation chamber of the corresponding valve, which can be heated up to 350°C. crane-dosing piston type 8 and 9 are equipped with water cooling system (not shown), which prevents any significant heating of the analyzed product during its passage through the valves dispensers 8 and 9.

Supply line of the analyzed product 6 is further provided with two filters (not shown), which are made from resistant to aggressive environment materials. The lack of filters can cause damage to the elements of the device for gas chromatographic determination of sulfur-containing compounds.

When the chromatograph is at the stage of "waiting alert", the valves 2 and 4 are closed. Electronic controllers 11 and 12 regulate the flow of carrier gas through the Packed columns 14 and 15 and through the working chamber of a heat conductivity detector 18. Electronic controllers 25, 26 and 27 control the flow of carrier gas for capillary columns 21 and 24 and tee-divider 22. IU is anceschi the pressure regulator 19 and the pneumatic resistance 20 to regulate the flow of carrier gas through the chamber comparison of a heat conductivity detector 18, and the mechanical pressure regulator 32 with pneumatic resistance 33 and the electronic controller 28 provide power flame photometric detector 30 hydrogen and air, respectively. In line 7 is fed water to a water cooling system (not shown) mounted dispensers piston type 8 and 9. Thermostats 23 and 13 support given temperature columns 21, 24 and 14, 15 respectively.

In addition to the valve-piston type dispenser 9 chromatograph equipped with an evaporator 16 for carrying out calibration of the chromatograph according to the standard sample gas mixtures. For calibration, you must perepodchinenie predalone 21 with the valve-piston type dispenser 9 to the evaporator 16, and to provide switching of the flow of carrier gas from the faucet spout 9 to the evaporator 16 by turning the switch 5 threads.

Analyzed product can be submitted from dvuhventilnyh sampler (not shown)and piston type sampler (not shown). While being under an elevated pressure of the analyzed product is fed into the chromatograph of dvuhventilnyh sampler using a hydraulic press (not shown)and piston type sampler - by displacing the piston with gaseous helium. When applying the analyzed product in the chromatograph pressure in a hydraulic press and pressure is their helium gas must exceed the pressure of the analyzed product at a temperature of 35°C at least 1380 kPa.

Method gas chromatographic determination of sulfur-containing compounds in the hydrocarbon products is as follows.

The sampler (not shown) with the analyzed product is connected to a hydraulic press (not shown) or to a cylinder of compressed helium (not shown), is connected to the supply line of the analyzed product 6, and then open the valve of the sampler. This adjustable choke flow of the analyzed product 10 provides padding and Strait analyzed product lines 6 and filling the chambers of the selection of the analyzed product faucets metering piston type 8 and 9 of the first and second paths. To prevent degassing served in the chromatogram of the analyzed product, as well as the balance of the product in the sampler, the last support of the source pressure using a hydraulic press or compressed helium.

Next, the analyzed product is fed simultaneously in the camera evaporation cranes dosing piston type 8 and 9, heated to 160-200°C to achieve complete evaporation of all components of the analyzed product, not accompanied by their thermal decomposition.

In the first tract evaporated analyzed the product from the chamber to the evaporation of the valve-piston type dispenser 8 is served in the nozzle predalone 14, which occurs prior times the bookmark component. When the designated components from the output nozzle of predalone 14 are received in the main nozzle column 15, open valve 2. This electronic controller 12 continues to support the flow of carrier gas through the main nozzle column 15, which are separated light components of the analyzed product. From the main nozzle column 15 components of the analyzed product is fed to a heat conductivity detector 18. The pressure difference at the ends of the Packed predalone 14 arising from the opening of the valve 2, provides the change in the direction of flow of carrier gas through it. While heavier components of the analyzed product is blown from the nozzle predalone 14 through the valve-piston type dispenser 8, the valve 2 and the pneumatic resistance 1 of the chromatograph. The analysis is performed under isothermal conditions at a temperature of 100-140°C. Simultaneously with the hydrogen sulfide in the first path can be defined in light of individual hydrocarbons, including propane, and methanol, nitrogen and carbon dioxide.

In the second tract evaporated analyzed the product from the chamber to the evaporation of the valve-piston type dispenser 9 is applied to the capillary predalone 21, in which there is a partial separation of the components. When the designated components from the output of the capillary predalone 21 is transmitted through the tee-divider 22 key concept in the capillary column 24, open the valve 4. This electronic control unit 25 continues to support the flow of carrier gas through the main capillary column 24, in which there is a separation of the components of the analyzed product. The temperature in thermostat capillary column 23 is gradually increased from 60°C to 260°C. From the main capillary column 24 components of the analyzed product serves on ceaselessly detector 30. As kerosenetype detector 30 may be used, for example, a flame photometric detector or chemoluminescence detector, or atomic emission detector, or mass-selective detector. The pressure difference at the ends of the capillary predalone 21 arising from the opening of the valve 4, provides the change in the direction of flow of carrier gas through it. While heavier components of the analyzed product are blown with capillary predalone 21 through the valve-piston type dispenser 9, the valve 4 and the pneumatic resistance 3 from the chromatograph. Time reverse purge capillary predalone 21 may be 4-8 minutes

The concentration of sulfur-containing compounds in the analyzed product is calculated by the method of absolute calibration, which is carried out using gas or liquid standard samples containing known amounts determined sulfur-containing compounds. In the calibration of the liquid is left to the sample injected and analyzed by the above procedure.

For calibration of standard samples of gas mixtures must perepodchinenie predalone 21 with the valve-piston type dispenser 9 to the evaporator 16, and to provide switching of the flow of carrier gas from the faucet spout 9 to the evaporator 16 by turning the switch 5 threads.

To calculate the concentration of sulfur-containing compounds, which is not present in the standard sample, use of the calibration dependence for the nearest in composition (the ratio of carbon:sulfur) or position on the chromatogram of sulfur-containing compounds.

The implementation of this method is illustrated by the following example.

The analysis of the sample gas condensate unstable Orenburg gas condensate field was performed under the conditions shown in table 1. The analyzed sample was applied simultaneously in the first and second paths proposed chromatograph under pressure higher than atmospheric. The same sample was analyzed according to the method known from prototype [1]. The data obtained are shown in table 2.

As can be seen from the above results, the data on the concentrations of sulfur-containing compounds close to each other, the time spent performing the quantitative determination of sulfur compounds in the hydrocarbon product is 80 minutes, and in EMEA, spent retrieving the data according to the method known from prototype [1] - 7 o'clock From the above example it follows that the inventive method allows to reduce the run time quantitative determination of sulfur compounds in hydrocarbon products.

Method gas chromatographic determination of sulfur-containing compounds in the hydrocarbon products and a device for its implementation.

Table 1
The first tractValue
Length Packed predalone, m0,5
The diameter of the nozzle predalone (internal)mm2
The length of the main nozzle column, m2
The diameter of the main nozzle column (internal)mm2
The detector temperature, °C200
The temperature of thermostat Packed columns, °C120
The temperature of the evaporation chamber of the valve-piston type dispenser, °C 200
Volume of sample, mm31,0
The second tract
The length of the capillary predalone, m0,5
The diameter of the capillary predalone (internal)mm0,32
The length of the main capillary column, m30
The diameter of the main capillary column (internal)mm0,32
The initial temperature of thermostat capillary columns (isotherm 1), °C. time, min)60(2)
The heating rate of thermostat capillary columns, °C/min20
Intermediate temperature thermostat capillary columns (isotherm 2), °C. time, min)235 (10)
The heating rate of thermostat capillary columns, °C/min1
The final temperature of thermostat capillary columns, °C240
The temperature of the vapor is Inoi camera crane-dosing piston type, °C180
The temperature of the flame photometric detector, °C250
Time reverse purge capillary predalone, min6
The volume of injected sample, mm30,3
The division of the stream1:20

Method gas chromatographic determination of sulfur-containing compounds in the hydrocarbon products and a device for its implementation.

Table 2
Sulfur-containing compoundThe concentration in the sample gas condensate is unstable, (X±σr), % of the mass.
ExampleThe closest analogue [1]
H2S1,51±0,061,59±0,31
COS0,020±0,0020,020±0,007
CS20,014±0,00030,0007±0,0003
CH3S0,11±0,010,075±0,021
C2H5SH0,33±0,020,33±0,11
dimethyldisulfide0,030±0,0030,022±0,007
i-C3H7SH0,22±0,010,27±0,07
With3H7S0,103±0,0060,09±0,02
2-methyl-2-propylmercaptan0,019±0,0020,022±0,007
2-methyl-1-propylmercaptan0,005±0,0010,010±0,004
1-methyl-1-propylmercaptan0,27±0,020,28±0,08
C4H9SHto 0.060±0,0090,052±0,015
dimethyldisulfide0,007±0,0010,007±0,003
diethylsulfide0,023±0,0020,021±0,007
2-those who thiophene 0,113±0,0070,11±0,03
2.5-dimethylthiophene0,028±0,0030,013±0,005
the tetrahydrothiophene0,008±0,0010,006±0,004

1. Method gas chromatographic determination of sulfur-containing compounds in the hydrocarbon products, which consists in the simultaneous submission of the analyzed product under pressure higher than atmospheric, in the first tract chromatograph for determination of hydrogen sulfide at concentrations of more than 0.1 wt.% and the second tract chromatograph for determination of hydrogen sulfide at concentrations less than 0.1 wt.% and other sulfur-containing compounds, and then determining the concentration of sulfur-containing compounds by the method of absolute calibration, and analyzed the product fed to the first path, which includes consistently located the valve-piston type dispenser installed in a heated thermostat and filled with a polymer adsorbent Packed column - predalone length of 0.1÷1.5 m and the main column length 0,5÷5 m, and a heat conductivity detector, and a second path comprising sequentially arranged valve-piston type dispenser installed in a heated components is the capillary column - predalone length of 0.1÷1.5 m and the main column length of 15÷50 m, inner diameter which is 0.23÷0.32 mm, and ceaselessly detector.

2. The method according to claim 1, characterized in that the temperature in thermostat capillary columns gradually increase from 60°C to 260°C, and the temperature in thermostat of the Packed column is gradually increased from 100°C to 140°C.

3. The method according to claim 1 or 2, characterized in that as kerosenetype detector using a flame photometric detector, or chemoluminescence detector, or atomic emission detector, or mass-selective detector.

4. The chromatograph for gas chromatographic determination of sulfur-containing compounds in the hydrocarbon products, comprising parallel spaced first tract for the determination of hydrogen sulfide at concentrations of more than 0.1 wt.%, contains consistently located is equipped with evaporator, the valve-piston type dispenser that provides dosing analyzed product under pressure higher than atmospheric, set in a heated thermostat and filled with a polymer adsorbent Packed column - predalone length of 0.1÷1.5 m and the main column length 0,5÷5 m, and a heat conductivity detector, and a second path for hydrogen sulfide at concentrations less than 0.1 wt.% and other sulfur-containing co is dinani, contains consistently located is equipped with evaporator, the valve-piston type dispenser that provides dosing analyzed product under pressure higher than atmospheric, set in a heated thermostat capillary column - predalone length of 0.1÷1.5 m and the main column length of 15÷50 m, inner diameter which is 0.23÷0.32 mm, and ceaselessly detector, and cranes-equipment for the first and second paths are arranged successively in the direction of the line of feed samples, while the chromatograph equipped with an evaporator connected to the input of the capillary predalone, for carrying out calibration of the chromatograph for gas mixtures.

5. Chromatograph according to claim 4, characterized in that as kerosenetype detector using a flame photometric detector, or chemoluminescence detector, or atomic emission detector, or mass-selective detector.



 

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Gas analyzer // 2267123

FIELD: investigating or analyzing materials.

SUBSTANCE: gas analyzer comprises chromatographic columns, detectors, unit for preparing air mounted inside the thermostat, unit for control and processing signals, member for sampling, switches of gas flows, pump for pumping gas mixture, and separating passages connected in parallel and provided with the check valve interposed between them. Each of the separating passages is made of absorbing and separating chromatographic columns connected in series, and the pump is connected to the input of the gas line through the electric valve. The gas analyzer can be made of two separating passages and low pressure chromatographic columns.

EFFECT: enhanced quality of analyzing.

2 cl, 1 dwg, 1 ex

FIELD: analytical methods.

SUBSTANCE: to determine methyl alcohol in water, sample to be assayed is preliminarily subjected to distillation with sulfuric acid added in amount required to provide its concentration in mixture to be distilled c(1/2 H2SO4) = 0.002 M, while strippings constitute 6-7% of the volume of sample. Stripped liquid is thrice rinsed with hexane or Nefras at 1:1 hexane (Nefras)-to-strippings ratio. Rinsed material is then introduced into packed column filled with diatomite modified with 1,2,3-tris(β-cyanoethoxy)propane having deposited fixed phase thereon, which phase is prepared by way of consecutively keeping glycerol each time for 4 h at ambient temperature, 100°C, 130°C, 160°C, and 200°C, and then for 8 h at 230°C and for 40 h at 200°C under nitrogen bubbling conditions. Calculation of methanol content is performed taking into consideration calibrating coefficient.

EFFECT: enabled determination of small concentrations of methyl alcohol in water with sufficient selectivity and reliability.

2 cl, 2 tbl, 6 ex

FIELD: analytical chemistry.

SUBSTANCE: invention relates to method for quantitative determination of thiotriazoline and pyracetam in complex drugs by high performance chromatography, wherein silicagel with grafted 3-(chlorodimethyl)-propyl-N-dodecylcarbamate having particle size of 5 mum is used as sorbent; and degassed 0.05 M aqueous solution of potassium dihydrophosphate is used as mobile phase. Mobile phase velocity is 1 ml/min, and column temperature is 30°C. Method of present invention makes it possible to determine content of two abovementioned active ingredients simultaneously.

EFFECT: simplified process of sample preparation.

3 ex, 3 tbl

FIELD: biotechnology, in particular content determination of polymer chitosan molecules, chitosan-chitine polymer molecules and molecules of chitosan-protein complex in finished form of chitosan.

SUBSTANCE: claimed method includes application of high performance chromatography column filled with polyvinylbenzene sorbent with refractometer detector. As eluent and for dissolving of chitosan preparation samples acetic acid aqueous solution is used. Chain-length distribution is determined on the base of first chromatography peak, and polymer molecular content is calculated on the base of area of first, second and third chromatography peaks, divided up to zero line and belonging to polymer chitosan molecules, chitosan-chitine polymer molecules and molecules of chitosan-protein complex, respectively. To calculate chain-length distribution of polymer chitosan molecules separately calibration curve is plotted using dextran polymer standards.

EFFECT: new effective method for determination of polymer chitosan molecules in chitosan preparations.

4 cl, 3 dwg

Express-chromatron // 2300764

FIELD: the invention refers to laboratory chromatographic devices for conducting high-speed chromatographic analysis.

SUBSTANCE: the express-chromatron has an injector, a chromatographic column located in a thermostat, a detector, an amplifier of the signal of the detector, an analog-digital converter, a control system, a pneumatic system. The column is fulfilled either in the shape of a short capillary column or either in the shape of a polycapillary column. The injector is fulfilled with possibility of introduction of the test for the time of 5-50 ms. The detector and the amplifier of its signal are fulfilled with possibility of ensuring constant time of no worse then 10-3 sec. The analog-digital converter is fulfilled with possibility of ensuring speed of no less then 200 measurements in a second.

EFFECT: ensures conducting high-speed chromatographic analysis.

11 cl, 2 dwg

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