Some standard content:
Registration No.: 4080—1999
—1999
HG/T3633-
This standard is formulated based on the actual production and application requirements of pure methane in my country. The main technical contents of the standard include scope of application, requirements, inspection methods, packaging, marking, storage and transportation, etc. Appendix A of this standard is the appendix of the standard.
This standard was proposed by the Technical Supervision Department of the former Ministry of Chemical Industry of the People's Republic of China. This standard is under the jurisdiction of the National Gas Standardization Technical Committee. The drafting units of this standard are: Chengdu Liuling Chemical Plant of Sichuan Petroleum Administration Bureau and Southwest Chemical Research and Design Institute. The main drafters of this standard are: Feng Wanfang, He Daoshan, Lan Xiaoping, Yan Boju. 670
Chemical Industry Standard of the People's Republic of China
Pure methane
Pure methane
HG/T3633—1999
This standard specifies the requirements, inspection methods, packaging, marking, storage, transportation, etc. of pure methane products. It is applicable to methane extracted from natural gas by cryogenic method. It is mainly used for the preparation of standard mixed gas, catalyst evaluation, carburization of metals and alloys, microbial cultivation, refrigerant and chemical raw materials.
Molecular formula: CH4
Relative molecular mass: 16.04 (according to the 1997 international relative atomic mass) 2 Reference standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards will be revised, and the parties using this standard should explore the possibility of using the latest version of the following standards. GB190-1990 Dangerous Goods Packaging Marking
GB5099—1994 Seamless Steel Gas Cylinders
GB7144—1986 Color Marking of Gas Cylinders
GB/T5274-1985 Preparation of Mixed Gas for Gas Analysis and Calibration-Weighing Method GB/T5832.1--1983 Determination of Trace Water in Gas-Electrolytic Method GB/T8981—1988 Determination of Trace Hydrogen in Gas-Gas Chromatography-Preparation of Standard Mixed Gas for Gas Analysis-Static Volumetric Method GB/T 10627-1989
GB/T 14194---1993
Regulations on Filling of Permanent Gas Cylinders
3 Requirements
The technical indicators of pure methane products shall comply with the provisions of Table 1. Table 1
Methane purity, 10- (volume fraction)
Ethane content, 10-6 (volume fraction)
Oxygen (argon) content, 10~6 (volume fraction)Nitrogen content, 10-6 (volume fraction)
Hydrogen content, 10- (volume fraction)
Water content, 10- (volume fraction)
Approved by the State Administration of Petroleum and Chemical Industry on August 12, 1999Superior product
First-class product
Qualified product
Implemented on October 1, 2000
4 Inspection method
4.1 Sampling
HG/T3633—1999
Bottled methane shall be randomly sampled and inspected according to Table 2. When any of the indicators in the inspection results do not meet the requirements of this standard, the same batch of products shall be re-sampled for inspection. If there is still one indicator that does not meet the requirements of this standard, the batch of products shall be unqualified. Table 2 Sampling Table
Product batch/bottle
Sampling quantity/bottle
4.2 Purity
The purity of methane () is expressed in volume fraction and calculated according to formula (1): 16~25
100-(9 +9+9+9+) × 10-4
Where: 9-
Ethane content, 10-6 (volume fraction); Oxygen (argon) content, 10-5 (volume fraction); 9--Nitrogen content, 10-6 volume fraction); 94--Water content, 10-6 (volume fraction); --Hydrogen content, 10-° (volume fraction). 4.3 Determination of oxygen (fluorine), nitrogen and ethane
4.3.1 Method summary
26～50
Use a gas chromatograph with a thermal conductivity detector, use 5A molecular sieve plus activated carbon to separate oxygen (fluorine), nitrogen and methane, and GDX-104 to separate methane and ethane, forming a dual-nature, dual-gas path chromatographic process, inject samples separately on the same chromatograph, and use the comparative method to quantify, so as to determine oxygen (argon), nitrogen and ethane in methane.
4.3.2 Instrument
Use a gas chromatograph with a thermal conductivity detector, the instrument's voltage regulator and measurement bridge are the same as those of a general gas chromatograph, and the recorder range is 0～1 mV. The gas chromatography process is shown in Figure 1. 1--Carrier gas cylinder; 2--High pressure needle valve; 3, 10--Injection valve; 4--Molecular sieve plus activated carbon chromatographic column; 5--Thermal conductivity cell; 6, 7, 8--Float flowmeter; 9--GDX-104 chromatographic column: 11--Adjusting needle valve; 12--High pressure needle pressure reducing valve; 13--Sample gas cylinder Figure 1 Chromatographic flow chart
Gas chromatographs with other detectors (such as nitrogen ionization detector, fluorine ionization detector, etc.) can be used for determination. Two thermal conductivity chromatographs can also be used to measure oxygen (argon), nitrogen and ethane respectively with a single column and single gas path, or a thermal conductivity chromatograph can be used to measure oxygen (argon) and nitrogen; and a hydrogen flame detector chromatograph can be used to measure ethane. Its operation shall be in accordance with the instrument manual, and the detection limit shall comply with the provisions of 4.3.3. 672
4.3.3 Determination conditions
HG/T 3633—1999
Carrier gas: high-purity ammonia or high-purity hydrogen, flow rate 30mL/min～50mL/min. Chromatographic column 1: GDX-104 column, inner diameter 3mm～4mm, length about 0.8m, filled with 0.40mm~0.25mmGDX-104, activated by carrier gas at 160℃～180℃ for 4h～6h. Chromatographic column 2: Molecular sieve plus activated carbon chromatographic column, inner diameter 3mm~~4mm, length about 1m, filled with 0.40mm～~0.25mm5A molecular sieve 0.6m, 0.40mm~~0.25mm activated carbon 0.4m, activated by carrier gas at 200℃~~250℃ for 4h~~6h. Quantitative tube volume: Both gas lines are about 3mL. Chromatographic column and detector temperature: room temperature.
Detection limit: less than or equal to 2×10- for oxygen and nitrogen in methane, less than or equal to 5×10-6 for ethane. 4.3.4 Operation steps
4.3.4.1 Instrument startup
Turn on the instrument according to the instrument manual, adjust the operating parameters to the selected values, and wait for the instrument to work stably. 4.3.4.2 Calibration
The standard sample uses methane as the base gas and oxygen, nitrogen, and ethane as the component gas. Its content is similar to that of the sample to be tested and is prepared according to the provisions of GB/T5274 or GB/T10627.
Connect the standard sample cylinder to the instrument through the needle pressure reducing valve and the metal sampling tube, open the standard sample cylinder valve and the pressure reducing valve, and use the pressure increasing/depressurizing method at least three times to fully replace the sampling system before sampling. Determine the retention time and peak height (or peak area) of each component in the standard sample. 4.3.4.3 Determination
Send the sample gas into the instrument in the same way as in 4.3.4.2, measure and record the retention time and chromatographic peak height (or peak area) of each component. 4.3.4.4 CalculationwwW.bzxz.Net
The content of each component to be measured is calculated according to formula (2):
Wherein:—#
The content of the component in the sample gas, 10-6 (volume fraction);:—The content of component i in the standard gas, 10-(volume fraction); H;—-The peak height of component i in the sample gas, mm (or bee area, mm\); Hs—The peak height of component i in the standard gas, mm (or peak area, mm\); i——Represents the components oxygen (fluorine), nitrogen, and ethane. The arithmetic mean of two parallel determinations is the determination result. The relative deviation should not be greater than 10%, otherwise it should be re-determined. 4.4 Determination of moisture content
The determination shall be carried out in accordance with the provisions of GB/T5832.1. 4.5 Determination of hydrogen content
The determination shall be carried out in accordance with the provisions of GB/T8981.
5 Packaging, marking, storage and transportation
5.1 The gas cylinders filled with methane and the paint color markings shall comply with the provisions of GB5099, GB7144 and the "Regulations on Safety Supervision of Gas Cylinders". 5.2 The filling of methane gas cylinders shall comply with the provisions of GB14194. (2)
5.3 The pressure of methane gas in the cylinder shall be (14.0 ± 0.5) MPa (gauge pressure) at 20°C. The pressure of methane gas in the cylinder shall be measured when it is confirmed that the gas temperature is equal to the ambient temperature. The accuracy of the pressure gauge used for measurement shall not be lower than Class 2.5, and the range is 0~25.0 MPa. 5.4 The volume of methane gas in the cylinder is calculated according to formula (3): V = KV, × 10-3
Wherein: -- Volume of methane gas in the cylinder, m\; V, water volume of the cylinder, L;
HG/T3633-1999
K is converted to 20C, 0.For the volume conversion coefficient of methane gas at 1013MPa, see Appendix A (Appendix to the standard). 5.5 The safety mark for the transportation of methane gas cylinders shall comply with the provisions of GB190. 5.6 Methane gas shall have a quality certificate when leaving the factory, and its contents shall include: product name and quality grade, manufacturer name, production date or production batch number, methane gas quantity (m), pressure (MPa), and this standard code. 5.7 Methane is a colorless, tasteless, odorless, non-toxic flammable gas. When the methane content in the air is in the range of 5% to 15%, it will explode violently when exposed to fire. In places where the methane content may increase, ventilation devices should be installed and the methane content should be monitored. Before repairing and processing methane gas devices or containers, methane should be replaced with nitrogen until the methane content is less than 0.5%. 5.8 The residual pressure of methane gas cylinders returned to the manufacturer for filling should not be less than 0.2MPa. Gas cylinders without residual pressure, new gas cylinders, and gas cylinders that have passed the water pressure test must be strictly pre-treated by heating, evacuation, replacement, and filling before filling. 5.9 Before leaving the factory, the threaded connection of the gas cylinder valve, the outlet of the bottle valve, and the interval between the valve stems of the bottle valve should be checked for leakage, and the cylinder width and vibration-proof rubber ring should be put on. The gas cylinder must be prevented from collision when moving. Methane cylinders should be stored in a cool, well-ventilated place, away from fire sources. 674
HG/T 3633-1999
(Appendix to the standard)
Table A1 of conversion coefficient (K) of methane gas volume in cylinders
HG/T 3633-1999
Table A1 (end)
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