Method for absorbing and utilizing phosgene tail gas

A tail gas absorption and phosgene technology, applied in chemical instruments and methods, preparation of organic compounds, carboxylate preparation, etc., can solve the problems of unrealized industrial utilization value, environmental pollution, large liquid alkali, etc., and achieve easy operation, The effect of less investment and low energy consumption
CN102160956BActive Publication Date: 2013-01-02JIANGSU KUAIDA AGROCHEM
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
JIANGSU KUAIDA AGROCHEM
Publication Date
2013-01-02

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Abstract

The invention discloses a method for absorbing and utilizing phosgene tail gas. The method comprises the following steps: the phosgene tail gas generated in a phosgenation process (especially the phosgene tail gas generated in the phosgenation process with content of between 10 and 50 percent (V / V), such as the phosgene tail gas generated in the phosgenation process of diuron, chlortoluron and other products) is directly cooled and absorbed through a halohydrocarbon solvent, phosgene and partial hydrogen chloride in the phosgene tail gas are recovered to obtain a phosgene tail gas solution; the phosgene tail gas solution is used as a phosgene raw material for synthesizing pesticide intermediate or acyl chloride chemical products in the action of a composite catalyst; and the composite catalyst contains at least one pyridine or bipyridyl and Lewis acid salt of at least one rare-earth metal. Compared with other methods, the solvent cooling direct absorption method has the advantages of less investment, low energy consumption, convenience in operation and the like.
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Description

technical field

[0001] The invention relates to a method for absorbing and utilizing phosgene tail gas. Background technique

[0002] Phosgene is an important raw material for chemical production, with a domestic production capacity of 1.5 million tons (the statistical production capacity in 2008 was 1.16 million tons). It is widely used in industrial production such as pesticides, medicines, fuels, and polyurethane. attention. In the chemical production process using phosgene as raw material, phosgene tail gas containing phosgene will be produced. Due to the different requirements of process control in the production process, the content of phosgene tail gas produced is also different, generally between 10% and 50% (V / V). At present, in terms of absorption and utilization of phosgene tail gas in China, except for the production of TDI and MDI polyurethane industries, which have invested heavily in toluene absorption and thermal desorption method to recover phosgene, othe...

Claims

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