Establishment of A General Method for Analysis of Process Gas in the Synthesis Natural Gas from Coke Oven Gas by Multi-Dimensional Gas Chromatography

A method of multi-dimensional gas chromatography with four valves and six columns was established for analysis of 18 gases in the process of synthesis of natural gas from coke oven gas. The target components were divided into three channels in this method. Channel 1 was used to analyze hydrogen and oxygen with argon as carrier gas, where hydrogen and oxygen were separated and determined by Porapak Q packed chrometographic column, MolSieve 5A chromatographic column and TCD; channel 2 was used to analyze carbon monoxide, carbon dioxide and nitrogen with hydrogen as carrier gas, where the 3 gases were separated and determined by two Porapak Q packed chrometographic columns, molsieve 5A chromatographic column and TCD; channel 3 was used to analyze methane, ethane, ethylene, propane, propylene, n-butane, butene, n-pentane, pentene, n-hexane, hexene, benzene and toluene with nitrogen as carrier gas, where the 11 gases were separated and determined by HP-AL/KCL capillary chromatographic column and FID, respectively. The results showed that linear relationships between the volume fractions of 18 components and their corresponding peak areas were found in the definite ranges, and values of linear correlation coefficients found were all above 0.999 5. The detection limits (3S/N) were in the range of 1.27×10^-5%-2.00×10^-2%. The standard gases of the 18 components were analyzed, giving values of absolute error in the range of -0.026%-0.019%. The prescribed method was used in analyzing the sample of coke oven gas, and RSDs (n=8) of the determined values were ranged from 0.015% to 2.4%.