Method for adding crude anhydride in maleic anhydride production process

Abstract

The invention provides a method for adding crude anhydride in maleic anhydride production process; a refining system used for producing maleic anhydride is a continuous refining system formed by three towers and two kettles including two refining kettles, an azeotropic dehydrating tower, a solvent recovery tower and a refining tower; and the crude anhydride is directly added into the azeotropic dehydrating tower and is added from the middle part of the azeotropic dehydrating tower. The invention also provides the refining system used for the method for adding the crude anhydride in the maleic anhydride production process; the crude anhydride is directly added into the azeotropic dehydrating tower, so that the crude anhydride is completely dehydrated in the adding process, the free acid in the crude anhydride is removed, the refining yield is avoided being influenced, and the economic benefit of enterprises can be more conveniently increased; and the invention leads the refining process of the maleic anhydride to be more convenient, and has the advantages of being simple in structure, convenient to maintain, low in processing cost, high in production efficiency and the like.

Description

technical field [0001] The invention belongs to the technical field of maleic anhydride production, in particular to a method for thickening anhydride in the process of producing maleic anhydride. Background technique [0002] In recent years, the domestic apparent consumption of maleic anhydride has been increasing continuously. Maleic anhydride is a monomer and intermediate with many uses, mainly used in the production of unsaturated polyester resin and 1,4-butanediol, and can also be used to produce Plasticizers, surface coatings, agrochemicals, lubricants, malic and fumaric acids, etc. The methods for producing maleic anhydride include benzene method, n-butane method, carbon tetraolefin method, etc. Among them, the benzene method is widely used as a traditional raw material to produce maleic anhydride, and the refining system in traditional maleic anhydride production uses one tower and one kettle Intermittent production process, complex process, difficult to control th...

AI Technical Summary

Problems solved by technology

The methods for producing maleic anhydride include benzene method, n-butane method, carbon tetraolefin method, etc. Among them, the benzene method is widely used as a traditional raw material to produce maleic anhydride, and the refining system in traditional maleic anhydride production uses one tower and one kettle Intermittent production process, complex process, difficult to control the quality of finished products, which will affect the economic benefits of the enterprise, and produce more waste residue and sewage, which will not only increase environmental pollution, but also greatly shorten the cycle of washing the kettle, which is easy to corrode equipment, increasing the cost of the business

If the continuous refining system with three towers and two kettles is adopted, the continuous refining has the following advantages: the quality of the finished product is stable and the yield is high; the generation of waste residue is reduced; the cleaning period of the kettle is extended to 15-20 days, and the production of wastewater from washing the kettle is reduced, but Once continuous rectification is adopted, if the crude anhydride is directly added to the refining tank, the complete dehydration stage is missing, and the free acid in the crude anhydride is not removed, which will affect the refining yield

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