Recovery and refining method of solvents and monomers in the industrial production of rare earth-isoprene rubber

Abstract

The invention relates to a recovery method of solvents and monomers in the industrial production of rare earth-isoprene rubber. The distance between the top of a solvent recovery tower and a side withdrawing position of the solvent recovery tower is 60 to 70 theoretical plates. Part of the refined hexane solvent, which is withdrawn from the side line, in the gauge tank is pumped into a storage tank and is used as a solvent for production of isoprene rubber, and part of isoprene is refluxed to the top of a separator. The distance between the top of an isoprene refining tower and a side withdrawing position of the isoprene refining tower is 70 to 90 theoretical plates. Gas isoprene is withdrawn from the side line of the isoprene refining tower, part of isoprene is pumped into an adsorption tower by a side line withdrawing gauge tank so as to obtain polymer grade isoprene monomers; and part of isoprene is refluxed to the top of a separator. In the provided method, the solvent is recovered and refined only through two rectifying tower provided with a side withdrawing device, the unreacted monomers are recovered, the fresh monomers are refined, the equipment investment and energy consumption are reduced, the hexane solvent can be used in a circle repeatedly, and part of isoprene can also be used in a circle repeatedly.

Description

Technical field: [0001] The invention relates to a method for recovering and refining solvents and monomers in the industrial production of rare earth isoprene rubber. Background technique [0002] Natural rubber is the most important raw material for tire manufacturing and an important material closely related to the national economy and national security. It is listed as a national strategic resource along with petroleum and iron ore. China's annual rubber consumption exceeds 3.1 million tons, ranking first in the world. However, my country's natural rubber output is only about 600,000 tons, accounting for only 5.4% of the world's total output. The self-sufficiency rate of natural rubber is less than 1 / 3, which is lower than the most basic national security line. supplies. In order to meet domestic development, China will import more than 2 million tons of natural rubber every year, accounting for more than 20% of the world's total natural rubber resources. Excessive dep...

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Problems solved by technology

[0004] At present, there are few patents on the recovery and separation of solvent and unreacted monomer in the production process of isoprene rubber. Arrived a rectifying tower to complete the dehydration, delightening and deweighting of solvent and unreacted monomer, but this method does not separate monomer and solvent completely, also can't overcome the monomer in the rectifying tower in the refining process simultaneously. Self-aggregation in

Patent CN1908040A (a solvent refining process in the production of synthetic rubber) mentions the use of multiple rectification towers instead of a single-column rectification process. By increasing the operating pressure of a single-effect rectification tower, the pressure difference and temperature difference between each , adding the heat of condensation of the vapor-phase solvent at the top of the first-effect rectification tower as the heat source for the reboiler of the second-effect rectification tower. Although this method can save a certain amount of steam consumption and cooling water consumption, in the actual operation process, the latter The operation stability of the first-effect rectification tower is easily affected by the rising vaporization amount of the previous first-effect rectification tower

The patent CN102234356.A (rare earth pentylene rubber production method) involves the process route of solvent recovery and monomer refining. It adopts multi-tower cycle preparation process to solve the problem of monomer and solvent caused by the cross boiling point of various monomers and their impurities. The problem of low purity, in order to repeatedly vaporize and condense a large amount of solvents and monomers between the rectification towers, it needs to consume more steam and cooling water

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