GB/T 43503-2023Natural gas—Determination of oxygen—Electrochemical method (English PDF)

Foreword

This document complies with the provisions of GB/T 1:1-2020 "Standardization Work Guidelines Part 1: Structure and Drafting Rules of Standardization Documents" Drafting:

Please note that some content in this document may be subject to patents: The publisher of this document assumes no responsibility for identifying patents:

This document is proposed and coordinated by the National Natural Gas Standardization Technical Committee (SAC/TC244):

This document was drafted by: Natural Gas Research Institute of China National Petroleum Corporation Southwest Oil and Gas Field Branch, China Testing Technology Research Institute Institute of Chemistry, China Institute of Metrology, Gas Transmission Management Office of PetroChina Southwest Oil and Gas Field Branch, Southwest Petroleum University, China Petroleum & Chemical Corporation Natural Gas Yuji Pipeline Branch:

The main drafters of this document: Wang Weijie, Deng Fanfeng, Zeng Wenping, Zhang Peizhuang, Cai Li, Zhou Li, Wang Yanbing, Pan Yi, Zhan Hui, Li Xiaohong, Zhang Peiying, Feng Bing, Du Shuang, Zhao Yulong:

Determination of oxygen content of natural gas by electrochemical method

1 Scope

This document describes the principles, reagents and materials, instruments, sampling, measurement steps, and data for the determination of oxygen content in natural gas using electrochemical methods:

Data processing, precision and measurement reports:

This document is suitable for online and offline determination of oxygen content in natural gas, with a measurement range of 0:0001%~1:0% (volume fraction):

2 Normative reference documents

GB/T 13609

GB/T 20604

3 Terms and definitions

The terms and definitions defined in GB/T 20604 and the following apply to this document: 3:1 A sensor that uses the measured electrochemical reaction to convert its changes into potential changes, current changes, or conductivity changes:

[Source: GB/T 7665-2005,3:1:26]

4 Principles

Under certain pressure and flow rate conditions, the oxygen molecules in the natural gas sample diffuse to the oxygen electrode of the electrochemical sensor for electrolysis:

chemical reaction, producing an electrical signal proportional to the oxygen content: Telecommunications by comparing the sample to be measured with a standard gas sample of known oxygen content When the signal is output, the oxygen content of the sample to be measured can be obtained: The electrochemical reaction equation for lead as an anode is as follows:

O2 2H2O 4e-->4OH- (cathode reaction) 2Pb 4OH-->2PbO 2H2O 4e- (anodic reaction) 2Pb O2->2PbO (total reaction formula)

5 Reagents and materials

5:1 Oxygen standard material: The oxygen-containing gas standard material in methane should be used:

5:2 Nitrogen: purity (volume fraction) not less than 99:999%:

5:3 Alkali absorption solution: Prepared with chemical reagents that can absorb hydrogen sulfide, such as using industrially pure sodium hydroxide to prepare 10% (mass fraction) Sodium hydroxide solution:

5:4 Sampling materials: Stainless steel cylinders should be used for sampling during offline measurement: