Online analysis pretreatment device for trace hydrogen isotopes in natural gas

Abstract

The invention discloses an online analysis pretreatment device for trace hydrogen isotopes in natural gas. The device comprises a sample chamber, a six-way valve, an absorption cold trap, a preenrichment cold trap and an enrichment cold trap, wherein the sample chamber is connected with the absorption cold trap, the absorption cold trap is connected with the six-way valve, two ends of the preenrichment cold trap are respectively connected with the six-way valve, one end of the enrichment cold trap is connected with the six-way valve, and the other end of the enrichment cold trap is connected with a chromatographic column, and the six-way valve is respectively connected with a helium pressure regulating valve B and a gas circuit release valve D; an inlet and an outlet of the sample chamber are respectively provided with a gas circuit release valve; and a gas circuit release valve is arranged between the absorption cold trap and the six-way valve. The device disclosed by the invention can be used for realizing the online enrichment of a trace hydrogen component in a natural gas sample, separating the trace hydrogen component from other gas components so as to detect the hydrogen isotopes.

Description

technical field [0001] The invention relates to the field of analytical chemistry, in particular to a pretreatment device for on-line analysis of micro-trace hydrogen isotopes in natural gas. Background technique [0002] In terms of natural gas isotope analysis technology, many advanced laboratories at home and abroad have concentrated their technical strength on hydrocarbon gas isotope testing for natural gas tracer research. It is mainly to connect the isotope mass spectrometer and chromatograph through the high-temperature combustion interface or high-temperature cracking interface to analyze CH in natural gas. 4 The carbon and hydrogen isotopic composition of hydrocarbon gases. And for trace amounts of non-hydrocarbon gas H in gas reservoirs 2 less involved, and the trace gas component H in the gas reservoir 2 As an important part of the gas reservoir, it must record the relevant geological information in the process of natural gas accumulation. However, it is restr...

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Problems solved by technology

[0007] The main problem that prior art exists is: (1) existing H 2 The enrichment device pre-processes the samples to be tested offline, and the process is labor-intensive and time-consuming; at the same time, the pre-treatment process is out of touch with the isotope analysis process, which causes inconvenience to the test work

(2) The traditional chromatographic split injection mode will cause isotopic fractionation of H2, and at the same time cannot meet the analysis of natural gas samples with low hydrogen concentration

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