Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
This standard is developed in accordance with the rules given in GB/T 1.1-2009.
This standard replaces GB/T 13610-2014 Analysis of Natural Gas Composition — Gas Chromatography. In addition to editorial changes, the following main technical changes have been made with respect to GB/T 13610-2014:
— The "carbon monoxide" component in the "Scope" is added, the concentration range is "0.01% ~ 1%" (see Clause 1);
— The requirement of standard gas concentration is changed to "for components with mole fraction not more than 5%, compared with the sample, the mole fraction of the corresponding components in the standard gas shall not exceed 10% and not less than 1/2 of the concentration of the corresponding components in the sample. For components with mole fraction greater than 5%, the concentration of the corresponding component in the standard gas shall not be less than 1/2 of the concentration of the component in the sample, nor more than 2 times of the concentration of the component. The minimum concentration of components in standard gas should not be less than 0.1% " (See 4.2, 4.2 of Edition 2014).
— The expression of precision is modified. The boundary point of the concentration range of components is changed from discontinuous to continuous but not crossed. For example, the boundary points "0 ~ 0.09" and "0.1 ~ 0.9" are changed to "x < 0.1" and "0.1 ≤ x < 1.0" (See Clause 8, Clause 8 of Edition 2014).
This standard was proposed by and is under the jurisdiction of China Natural Gas Standardization Technology Committee (SAC/TC 244).
The previous editions of standards replaced by this standard are as follows:
— GB/T 13610-1992, GB/T 13610-2003, and GB/T 13610-2014.
Analysis of natural gas composition — Gas chromatography
Warning — This standard does not address all safety issues related to its application. It is the responsibility of the users to prepare the corresponding safety and health operation rules and define the application scope before using this standard.
1 Scope
This standard specifies the analytical method for determining the chemical composition of natural gas and similar gas mixtures by gas chromatography.
This standard is applicable to the analysis of natural gas component range as shown in Table 1, and also applicable to the determination of one or several components.
Table 1 Component and concentration range of natural gas
Component Concentration range
Mole fraction y/%
Helium 0.01 ~ 10
Hydrogen 0.01 ~ 10
Oxygen 0.01 ~ 20
Nitrogen 0.01 ~ 100
Carbon dioxide 0.01 ~ 100
Methane 0.01 ~ 100
Ethane 0.01 ~ 100
Propane 0.01 ~ 100
Isobutane 0.01 ~ 10
N-butane 0.01 ~ 10
Neopentane 0.01 ~ 2
Isopentane 0.01 ~ 2
N-pentane 0.01 ~ 2
Hexane 0.01 ~ 2
Heptane and heavier components 0.01 ~ 1
Carbon monoxide a 0.01 ~ 1
Hydrogen sulfide 0.3 ~ 30
a Conventional natural gas generally does not contain carbon monoxide components, and carbon monoxide components that may be contained in special samples such as synthetic natural gas may be detected by the method specified in this standard.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated reference, only the edition cited applies. For undated references, the latest edition of the referenced documents (including any amendments) applies.
GB/T 5274.1 Gas analysis — Preparation of calibration gas mixtures — Part 1: Gravimetric method for class I mixtures
GB/T 28766 Natural gas — Performance evaluation for analytical systems
3 Method summary
Representative natural gas samples (hereinafter referred to as gas samples) and standard gas mixtures with known composition (hereinafter referred to as standard gas) are separated by gas chromatography under the same operating conditions. Many heavier components in the gas samples may obtain a group of irregular peaks by changing the direction of the carrier gas flowing through the column at a certain time. This group of heavier components may be C5 and heavier components, C6 and heavier components or C7 and heavier components. According to the composition value of the standard gas, the corresponding composition of the gas sample may be calculated by comparing the peak height, peak area or both.
See Annex A for supplementary analytical methods of heavier components of natural gas.
4 Reagents and materials
4.1 Carrier gas
4.1.1 Helium or hydrogen
The purity of hydrogen or helium shall not be less than 99.99%.
4.1.2 Nitrogen or argon
The purity of nitrogen or argon shall not be less than 99.99%.
4.2 Standard gas
The standard gas needed for analysis may adopt national secondary reference materials or be prepared according to GB/T 5274.1.
Diluted dry air is a suitable reference material in the analysis of oxygen and nitrogen components.
All components of standard gas shall be in homogeneous gas state. For components with mole fraction not more than 5%, compared with the sample, the mole fraction of the corresponding components in the standard gas shall not be more than 10% and not less than 1/2 of the concentration of the corresponding components in the sample. For components with mole fraction greater than 5%, the concentration of the corresponding component in the standard gas shall not be less than 1/2 of the concentration of the component in the sample, nor more than 2 times of the concentration of the component. The minimum concentration of components in standard gas should not be less than 0.1%.
5 Instruments and apparatus
5.1 Detector
Choose a thermal conductivity detector, or a detector that is equivalent in terms of sensitivity and stability. It is required that 0.25 mL of gas sample with 1% mole fraction of n-butane shall be injected, and at least 0.5 mV signal shall be generated.
5.2 Sample injection system
Materials that are inert and non-absorbent to the components in the gas samples shall be adopted, and stainless steel shall be preferred.
The sample injection system shall be equipped with an injection valve with a quantitative tube with a volume of 0.25 mL ~ 2 mL and an inner diameter of 2 mm. If the inner diameter is less than 2 mm, the quantitative tube shall be equipped with a heater.
For injection under vacuum, the pipeline arrangement shown in Figure 1 may be selected.
Figure 1 Pipeline arrangement used for injection under vacuum
5.3 Control of column temperature
When operating at constant temperature, the column temperature remains constant, and its variation shall be within 0.3°C. During temperature programming mode, the column temperature shall not exceed the recommended temperature limit of the filler in the column.
5.4 Temperature control of detector
In the whole process of analysis, the detector temperature shall be equal to or higher than the highest column temperature, and keep constant, and its variation shall be within 0.3°C.
5.5 Control of carrier gas
In the whole process of analysis, the flow rate of carrier gas remains constant, and its variation shall be within 1%.
5.6 Chromatographic column
5.6.1 General requirements
The material of the chromatographic column shall be inert and non-adsorbent to the components in the gas sample, and stainless steel tubes shall be preferred. The separation of the components being tested by the column filler shall be able to meet the specified requirements. See Annex B for the arrangement of chromatographic diagram.
5.6.2 Adsorption column
Oxygen, nitrogen, methane and carbon monoxide can be completely separated, and the separation R shall be greater than or equal to 1.5, which is calculated according to Equation (1). Figures 2 and 3 are a typical chromatogram obtained by using an adsorption column.
Foreword i
1 Scope
2 Normative references
3 Method summary
4 Reagents and materials
5 Instruments and apparatus
6 Operation steps
7 Calculation
8 Precision
Annex A (Normative) Supplementary methods
Annex B (Informative) Arrangement of chromatographic column
Annex C (Normative) Preparation of desiccator and removal of hydrogen sulfide
Annex D (Informative) Common errors and precautions
Annex E (Informative) Calculation examples
Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
This standard is developed in accordance with the rules given in GB/T 1.1-2009.
This standard replaces GB/T 13610-2014 Analysis of Natural Gas Composition — Gas Chromatography. In addition to editorial changes, the following main technical changes have been made with respect to GB/T 13610-2014:
— The "carbon monoxide" component in the "Scope" is added, the concentration range is "0.01% ~ 1%" (see Clause 1);
— The requirement of standard gas concentration is changed to "for components with mole fraction not more than 5%, compared with the sample, the mole fraction of the corresponding components in the standard gas shall not exceed 10% and not less than 1/2 of the concentration of the corresponding components in the sample. For components with mole fraction greater than 5%, the concentration of the corresponding component in the standard gas shall not be less than 1/2 of the concentration of the component in the sample, nor more than 2 times of the concentration of the component. The minimum concentration of components in standard gas should not be less than 0.1% " (See 4.2, 4.2 of Edition 2014).
— The expression of precision is modified. The boundary point of the concentration range of components is changed from discontinuous to continuous but not crossed. For example, the boundary points "0 ~ 0.09" and "0.1 ~ 0.9" are changed to "x < 0.1" and "0.1 ≤ x < 1.0" (See Clause 8, Clause 8 of Edition 2014).
This standard was proposed by and is under the jurisdiction of China Natural Gas Standardization Technology Committee (SAC/TC 244).
The previous editions of standards replaced by this standard are as follows:
— GB/T 13610-1992, GB/T 13610-2003, and GB/T 13610-2014.
Analysis of natural gas composition — Gas chromatography
Warning — This standard does not address all safety issues related to its application. It is the responsibility of the users to prepare the corresponding safety and health operation rules and define the application scope before using this standard.
1 Scope
This standard specifies the analytical method for determining the chemical composition of natural gas and similar gas mixtures by gas chromatography.
This standard is applicable to the analysis of natural gas component range as shown in Table 1, and also applicable to the determination of one or several components.
Table 1 Component and concentration range of natural gas
Component Concentration range
Mole fraction y/%
Helium 0.01 ~ 10
Hydrogen 0.01 ~ 10
Oxygen 0.01 ~ 20
Nitrogen 0.01 ~ 100
Carbon dioxide 0.01 ~ 100
Methane 0.01 ~ 100
Ethane 0.01 ~ 100
Propane 0.01 ~ 100
Isobutane 0.01 ~ 10
N-butane 0.01 ~ 10
Neopentane 0.01 ~ 2
Isopentane 0.01 ~ 2
N-pentane 0.01 ~ 2
Hexane 0.01 ~ 2
Heptane and heavier components 0.01 ~ 1
Carbon monoxide a 0.01 ~ 1
Hydrogen sulfide 0.3 ~ 30
a Conventional natural gas generally does not contain carbon monoxide components, and carbon monoxide components that may be contained in special samples such as synthetic natural gas may be detected by the method specified in this standard.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated reference, only the edition cited applies. For undated references, the latest edition of the referenced documents (including any amendments) applies.
GB/T 5274.1 Gas analysis — Preparation of calibration gas mixtures — Part 1: Gravimetric method for class I mixtures
GB/T 28766 Natural gas — Performance evaluation for analytical systems
3 Method summary
Representative natural gas samples (hereinafter referred to as gas samples) and standard gas mixtures with known composition (hereinafter referred to as standard gas) are separated by gas chromatography under the same operating conditions. Many heavier components in the gas samples may obtain a group of irregular peaks by changing the direction of the carrier gas flowing through the column at a certain time. This group of heavier components may be C5 and heavier components, C6 and heavier components or C7 and heavier components. According to the composition value of the standard gas, the corresponding composition of the gas sample may be calculated by comparing the peak height, peak area or both.
See Annex A for supplementary analytical methods of heavier components of natural gas.
4 Reagents and materials
4.1 Carrier gas
4.1.1 Helium or hydrogen
The purity of hydrogen or helium shall not be less than 99.99%.
4.1.2 Nitrogen or argon
The purity of nitrogen or argon shall not be less than 99.99%.
4.2 Standard gas
The standard gas needed for analysis may adopt national secondary reference materials or be prepared according to GB/T 5274.1.
Diluted dry air is a suitable reference material in the analysis of oxygen and nitrogen components.
All components of standard gas shall be in homogeneous gas state. For components with mole fraction not more than 5%, compared with the sample, the mole fraction of the corresponding components in the standard gas shall not be more than 10% and not less than 1/2 of the concentration of the corresponding components in the sample. For components with mole fraction greater than 5%, the concentration of the corresponding component in the standard gas shall not be less than 1/2 of the concentration of the component in the sample, nor more than 2 times of the concentration of the component. The minimum concentration of components in standard gas should not be less than 0.1%.
5 Instruments and apparatus
5.1 Detector
Choose a thermal conductivity detector, or a detector that is equivalent in terms of sensitivity and stability. It is required that 0.25 mL of gas sample with 1% mole fraction of n-butane shall be injected, and at least 0.5 mV signal shall be generated.
5.2 Sample injection system
Materials that are inert and non-absorbent to the components in the gas samples shall be adopted, and stainless steel shall be preferred.
The sample injection system shall be equipped with an injection valve with a quantitative tube with a volume of 0.25 mL ~ 2 mL and an inner diameter of 2 mm. If the inner diameter is less than 2 mm, the quantitative tube shall be equipped with a heater.
For injection under vacuum, the pipeline arrangement shown in Figure 1 may be selected.
Figure 1 Pipeline arrangement used for injection under vacuum
5.3 Control of column temperature
When operating at constant temperature, the column temperature remains constant, and its variation shall be within 0.3°C. During temperature programming mode, the column temperature shall not exceed the recommended temperature limit of the filler in the column.
5.4 Temperature control of detector
In the whole process of analysis, the detector temperature shall be equal to or higher than the highest column temperature, and keep constant, and its variation shall be within 0.3°C.
5.5 Control of carrier gas
In the whole process of analysis, the flow rate of carrier gas remains constant, and its variation shall be within 1%.
5.6 Chromatographic column
5.6.1 General requirements
The material of the chromatographic column shall be inert and non-adsorbent to the components in the gas sample, and stainless steel tubes shall be preferred. The separation of the components being tested by the column filler shall be able to meet the specified requirements. See Annex B for the arrangement of chromatographic diagram.
5.6.2 Adsorption column
Oxygen, nitrogen, methane and carbon monoxide can be completely separated, and the separation R shall be greater than or equal to 1.5, which is calculated according to Equation (1). Figures 2 and 3 are a typical chromatogram obtained by using an adsorption column.
Contents of GB/T 13610-2020
Foreword i
1 Scope
2 Normative references
3 Method summary
4 Reagents and materials
5 Instruments and apparatus
6 Operation steps
7 Calculation
8 Precision
Annex A (Normative) Supplementary methods
Annex B (Informative) Arrangement of chromatographic column
Annex C (Normative) Preparation of desiccator and removal of hydrogen sulfide
Annex D (Informative) Common errors and precautions
Annex E (Informative) Calculation examples
