Water separation industrialization method and device for vinylpyridine compound

Abstract

The invention discloses a water separation industrialization method and device for a vinylpyridine compound. The method comprises the following steps: S1, extracting a vinylpyridine compound crude product without water separation by adopting an extracting agent, and carrying out centrifugal separation so as to obtain a mixed organic phase containing the vinylpyridine compound, the extracting agentand trace water, and a water phase; S2, rectifying the mixed organic phase obtained in the step S1, collecting mixed gas containing the extracting agent and trace water from a tower top, and collecting a water-separated vinylpyridine compound from a tower bottom; and S3, condensing the mixed gas obtained in the step S2 into a liquid, and carrying out layering so as to obtain an extracting agent phase and a water phase. The method provided by the invention has the advantages of less product polymerization, high yield, low energy consumption, low wastewater residue, high biodegradability and the like in the production process, and greatly reduces the manufacturing cost. On the basis of the method, the invention also provides a water separation industrialization device. The water separationindustrialization device can be completely applicable to the water separation industrialization method for the vinylpyridine compound provided by the invention.

Description

technical field [0001] The invention belongs to the technical field of chemical production, and in particular relates to an industrial method and device for water separation of vinylpyridine compounds. Background technique [0002] 2-Vinylpyridine (2-vp) is an important pyridine derivative, slightly soluble in water, easily soluble in ethanol, ether and chloroform, soluble in benzene, acetone, etc., and prone to polymerization when heated. [0003] At present, a main synthesis method is as follows: 2-picoline and formaldehyde are used as raw materials, synthesized by a gas-phase one-step method or a liquid-phase two-step method, using a gas-phase one-step synthesis technology, the reaction temperature is relatively high, and the reaction pressure is large. The reaction tube is pipeline type, which is easy to block, and the equipment needs to be pressure-resistant and anti-corrosion. The requirements are high, and the product yield can only reach 60%. The liquid-phase two-st...

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Problems solved by technology

The main disadvantage of this method is that the amount of sodium hydroxide used in the water separation process is large, the 2-vp content in the wastewater after water separation is high, and it is difficult to biochemically degrade. The water content of the 2-vp and water azeotropic components produced at the top of the section tower is 75%, and the 2-vp content is 25%. It is necessary to return to the previous process to continue adding alkali to divide the water. Increase the liquid holding capacity and residence time of 2-vp in the system, increasing the risk of 2-vp polymerization

Another method is heating and water separation method: when the 2-vp and water mixture is at about 55°C, the water contains the least 2-vp, only 1.5-2%. The method of layering can separate about 10% of the waste water, and then continue to remove the remaining water through azeotropic distillation, and then return the azeotropic part to the layered tank at 55°C to stand for water separation. This is the first method Compared with the first one, the improved version saves the pollution of alkali, but fundamentally does not solve the difficulty that the content of 2-vp in wastewater is too high to be biochemically treated. At the same time, 2-vp needs to be stored at low temperature, and it is obvious to increase the polymerization by heating method It is a relatively green process of sacrificing the yield, and, these two methods 2-vp azeotrope at the top of the column during rectification, the water content in the azeotropic component is 75%, the 2-vp content is 25%, and the temperature rises When layering, the residence time should be kept more than half an hour, the residence time is long, and the temperature is high and easy to polymerize, so a high-yield and green cleaning process that can comprehensively solve the above problems is urgently needed

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