Continuous on-line analysis device of benzene, total hydrocarbons, methane and CO in carbon dioxide

Abstract

The invention discloses a continuous on-line analysis device of benzene, total hydrocarbons, methane and CO in carbon dioxide, wherein a gas chromatograph is provided with two hydrogen flame detectors. The continuous on-line analysis device comprises a gas carrying pipe, a first six-way plane valve, a second six-way plane valve, a ten-way plane valve, a first chromatographic column, a second chromatographic column, a third chromatographic column, a fourth chromatographic column, a methanation transforming pipe and the gas chromatograph. The chromatographic columns with different characteristics are combined, one ten-way valve is used for completing sample introduction and back flushing operations, the methane and the carbon monoxide are separated from the carbon dioxide and enter into thenext chromatographic column, and simultaneously, the carbon dioxide is evacuated through back flushing without interfering the measurement of the methane and the carbon monoxide; the two six-way valves are used for respectively completing sample introduction and chromatographic column switching; and meanwhile, the benzene and the total hydrocarbons are measured. In the invention, the gas chromatograph in a laboratory can be used for realizing the functions of continuous on-line analysis, automatic sampling, sample introduction, sample back flushing, chromatographic column switching and the like. Meanwhile, the components of trace benzene, methane, carbon monoxide, total hydrocarbons and the like in the carbon dioxide can be analyzed on line.

Description

technical field [0001] The invention relates to a gas chromatographic analysis device for continuous on-line monitoring of trace amounts of benzene, total hydrocarbons, methane and carbon monoxide in carbon dioxide, in particular to a multi-dimensional gas phase that uses automatic flat valves to complete sample injection and component backflushing Continuous online analysis device for benzene, total hydrocarbons, methane and CO in chromatographic carbon dioxide. technical background [0002] Trace benzene, total hydrocarbons, methane and carbon monoxide in carbon dioxide are the main technical indicators specified in GB 10621-2006 "Food Additive Liquid Carbon Dioxide", and are the main indicators to evaluate whether carbon dioxide meets the technical requirements of food additives. The technical requirements are benzene≤ 0.02×10 -6 ;Total hydrocarbons (calculated as methane)≤50×10 -6 (of which non-methane hydrocarbons do not exceed 20×10 -6 ); carbon monoxide≤10×10 -6 ....

AI Technical Summary

Problems solved by technology

[0008] The analysis of carbon monoxide in carbon dioxide needs to be equipped with a methanation conversion furnace. First, carbon monoxide and carbon dioxide are converted into methane at a temperature of 360-380 ° C using a nickel catalyst in the presence of hydrogen, and then detected by an FID detector. However, due to the separation of the chromatographic column and carbon dioxide concentrations are too high, although methane can be analyzed at the same time, an analysis cycle often takes more than 10 to 20 minutes

However, for the continuous on-line analysis of gas samples, the start signal needs to be manually given before the instrument can start working.

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