Recovery and refining method of solvent and monomer in industrial production of rare earth isoprene rubber

Abstract

The invention relates to a method for recovering solvents and monomers in the industrial production of rare earth isoprene rubber; the extraction position of the side line of the solvent recovery tower is close to 60 to 70 theoretical trays at the top of the tower; The alkane solvent is pumped into the storage tank as a solvent for the production of isoprene rubber, and part of the isoprene is refluxed to the top of the separator; the side line extraction position of the isoprene refining tower is near the top of the tower with 70 to 90 theoretical plates; Gas-phase isoprene is extracted from the side line of the isoprene refining tower; the metering tank of the side line extraction pumps part of the isoprene into the adsorption tower to obtain polymer-grade isoprene monomer, and part of the isoprene is refluxed to The top of the separator; this method only completes solvent recovery and refining through two rectification towers with side draws, recycling of unreacted monomers and refining of fresh monomers, reducing equipment investment and energy consumption, and realizing The hexane solvent is fully and continuously recycled and the isoprene is partially recycled.

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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