Enrichment and pre-separation system for VOCs in atmosphere

Abstract

The invention discloses an enrichment and pre-separation system for VOCs in atmosphere. The system comprises a sampling device, a water removal device, an enrichment and pre-separation device and a sampling device. The enrichment and pre-separation device comprises a second cold trap, a third cold trap, a fourth cold trap, a second gas flow controller and a third gas flow controller. According tothe enrichment and pre-separation system for VOCs in the atmosphere, VOCs in sample gas can be synchronously adsorbed, concentrated and preliminarily separated, and the adsorption efficiency is high.VOCs subjected to preliminary adsorption and separation are respectively classified and captured through different desorption and capture channels, so that pre-separation of various VOCs is realized.Self-cleaning of the equipment can be achieved, operation is easy, and no extra auxiliary device is needed.

Description

technical field [0001] The invention relates to the technical field of atmospheric environment detection equipment, in particular to a system for enriching and pre-separating VOCs in the atmosphere. Background technique [0002] Volatile organic compounds (VOCs) in my country refer to organic compounds with a saturated vapor pressure greater than 70Pa at normal temperature and a boiling point below 260°C at normal pressure, or all organic compounds with corresponding volatility at a vapor pressure greater than or equal to 10Pa at 20°C. . Usually its main components include hydrocarbons, oxygen hydrocarbons, halogen-containing hydrocarbons, nitrogen and sulfur hydrocarbons, polycyclic aromatic hydrocarbons with low boiling points, etc. VOCs can cause respiratory diseases, can cause acute poisoning under the action of high-concentration pollutants, and undergo photochemical reactions under the action of sunlight to generate secondary pollutants, forming smog pollution. The ch...

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Problems solved by technology

[0003] Under normal circumstances, there are many types of VOCs in the ambient air and the concentration is low. It needs to be enriched and concentrated first to meet the requirements of analytical instruments. However, due to the variety of VOCs and complex characteristics, especially for olefins, which are difficult to capture The enrichment and concentration efficiency is low, and the obtained sample gas is a mixture of various gases. It is difficult to completely separate it only by chromatographic separation technology, and the test range and accuracy of the chromatograph are high.

At present, there is no device on the market that can simultaneously enrich and initially separate the VOCs in the ambient air by using physical methods.

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