The Study Of Measuring Technique For C₆^C₉ Components In Natural Gas

Natural gas is used throughout the world to provide heating and power to homes and industry, and provide fuel to vehicle, as feedstock in industrial processes, and to generate electricity because of high thermal value, safety, large reserves, low pollution.Gas RM can ensure the accuracy and traceability of measurement provide informations for energy measurement, oil and gas exploration, geochemical investigation, hydrocarbon dew point calculation. We prepare C6~C9 gas reference material according to ISO 6142. The research contents are as follows:(1) Purity analysis of parent gases: GC-MSD and GC-FID are used to determinate hydrocarbon impurities, and Karl-Fischer moisture titrator is used to determinate moisture. Purity of parent gases is obtained using deduction method.(2) Establishing laboratory analysis method: compare analysis results from different chromatographic column, and optimize analysis method.(3) Establishing method for the preparation of gas mixtures: injection method is selected through compra injection and micro transfer.(4) Cylinder screening: subpacking experiment is used for examining popular gas cylinders made in China, and result of supacking shows that aluminium alloy gas cylinder after mechanical and chemical polishing has the lowest adsorption effect no more than 1.6%.(5) According to ISO Guide 35 examine gas reference material’s stability as the change of pressure. The result shows that gas reference material has no significant variation as the change of pressure, so the variation is neglected.(6) The concentration of C6~C9 hydrocarbon in gas reference material is 15μmol/mol, the relative expanded uncertainties of concentration are within range from 1.5% to 3.5%.Gas reference material prepared in this research can be used as calibration gas mixtures to measure C6~C9 hydrocarbon in natural gas, and ensure the accuracy and traceability of measurement.