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CN-122006638-A - Reaction device for preparing n-butyllithium

CN122006638ACN 122006638 ACN122006638 ACN 122006638ACN-122006638-A

Abstract

The invention relates to the technical field of chemical equipment, in particular to a reaction device for preparing n-butyl lithium. Aims at solving the problems of layering, insufficient contact and easy runaway of strong stirring of reactants due to density difference. The device comprises a reaction kettle, wherein an inclined blade turbine paddle stirrer in the kettle runs at a low speed to construct a light phase region for dispersing metal lithium particles, halobutane is settled into a heavy phase region, and a pretreatment device is arranged at the feed end to assist in initial dispersion of materials. The reaction kettle is matched with a light phase and heavy phase circulation path, light phase materials are sent to the bottom of the kettle, heavy phase materials are sent to the top of the kettle, and two-phase countercurrent mixing is realized, so that mass transfer is enhanced. The device avoids excessive refinement and local overheating of particles, improves the reaction efficiency and the conversion rate, and is suitable for n-butyl lithium production.

Inventors

  • WANG LI
  • HE HONGBIN
  • ZHANG LIANG
  • ZHANG KAILUN

Assignees

  • 江苏新瑞药业有限公司

Dates

Publication Date
20260512
Application Date
20260408

Claims (8)

  1. 1. The utility model provides a reaction unit for preparing n-butyl lithium, includes reation kettle (1), be provided with agitator (15), its characterized in that in reation kettle (1): The stirrer (15) is a helical blade turbine blade and is configured to run at a low speed for constructing and maintaining a light phase zone (16) formed by dispersed metallic lithium particles at the upper part in the reaction kettle (1); a heavy phase region (17) is formed in the reaction kettle (1) by adding halobutane with the density higher than that of the solvent and naturally settling the halobutane; the reaction kettle (1) is provided with a light phase circulation path (3) and a heavy phase circulation path (2), wherein: the light phase circulation path (3) is used for conveying materials in the light phase region (16) to the bottom of the reaction kettle (1); the heavy phase circulation path (2) is used for conveying the materials in the heavy phase region (17) to the top of the reaction kettle (1); the light phase circulation path (3) comprises a light phase circulation pump (31) and a light phase substance distributor (32) arranged at the bottom of the heavy phase region (17); the heavy phase circulation path (2) comprises a heavy phase circulation pump (21) and a heavy phase substance distributor (22) arranged at the upper part of the light phase region (16); The light-phase circulating pump (31) is a positive displacement diaphragm pump; the heavy phase circulating pump (21) is a magnetic drive pump.
  2. 2. The reaction apparatus for producing n-butyllithium according to claim 1, wherein the low-speed operation speed of the stirrer (15) is in the range of 30 to 80rpm.
  3. 3. The reaction device for preparing n-butyllithium according to claim 1, wherein the light phase material distributor (32) is provided with a flow restriction orifice (33) directed downward; The heavy phase material distributor (22) is provided with nozzles (23) for dispersing the liquid into droplets.
  4. 4. The reaction device for preparing n-butyllithium according to claim 1, wherein the top of the reaction kettle (1) is provided with a metal lithium feed inlet (11), a halogenated butane feed inlet (12) and a solvent feed inlet (13), respectively.
  5. 5. The reaction apparatus for producing n-butyllithium according to claim 4, wherein said halobutane feed port (12) is connected to a heavy phase distributor (22).
  6. 6. The reaction device for preparing n-butyllithium according to claim 1, wherein the inlet of the heavy phase circulation path (2) is provided with a first concentration sensor for monitoring the concentration of halobutane, and the inlet of the light phase circulation path (3) is provided with a second concentration sensor for monitoring the concentration of metallic lithium particles, wherein: The first and second concentration sensors are signally connected to a central control unit configured to regulate the operation of the heavy phase circulation pump (21) and the light phase circulation pump (31), respectively, in dependence on the first and second concentration sensor feedback signals.
  7. 7. The reaction device for preparing n-butyllithium according to claim 1, wherein the side wall of the reaction vessel (1) is provided with a discharge port (18) for discharging the n-butyllithium product solution, which is located higher than the heavy phase region (17) and lower than the light phase region (16).
  8. 8. The reaction device for preparing n-butyllithium according to claim 1, wherein the bottom of the reaction vessel (1) is provided with a slag discharge port (19) for discharging solid lithium halide by-products.

Description

Reaction device for preparing n-butyllithium Technical Field The invention relates to the technical field of chemical equipment, in particular to a reaction device for preparing n-butyl lithium. Background The traditional production process of n-butyllithium adopts metallic lithium sand as raw material, and has the problems of long flow, high energy consumption, poor safety and the like. The improved direct process adopts direct reaction without white oil metallic lithium particles, but the process is simplified, but the problem of serious reverse layering can occur in a general reaction kettle, namely, metallic lithium particles (with the density of about 0.534g/cm 3) are taken as a light solid phase and can float to the liquid level for enrichment in normal hexane or cyclohexane solvent (with the density of about 0.66-0.78g/cm 3), and halogenated butane (with the density of about 1.28g/cm 3) taken as a heavy liquid phase can sink and be gathered at the bottom of the kettle. Such delamination results in inadequate contact of the reactants and inefficiency of the reaction. In the face of the layering problem, the stirring power can be enhanced, a high-power and high-rotation-speed stirrer is adopted to forcedly break up a layered macroscopic static pattern, but the lithium particles are crushed to be finer by the strong shearing action of the stirrer, and the rapidly increased specific surface area can cause the reaction rate to exceed the system heat dissipation capacity in an instant, so that the local temperature flying and uncontrolled decomposition are initiated. Disclosure of Invention The invention aims to provide a reaction device for preparing n-butyllithium, which aims to solve the problems that the contact is insufficient and the reaction efficiency is low due to the reverse layering of metal lithium particles and halogenated butane in a general reaction kettle due to the density difference, and the metal lithium particles are easy to excessively refine and cause local temperature runaway decomposition due to the strong stirring and layering breaking. In order to achieve the above object, there is provided a reaction apparatus for preparing n-butyllithium, comprising a reaction vessel in which a stirrer is provided, the stirrer being a helical blade turbine blade configured to run at a low speed for constructing and maintaining a light phase region composed of dispersed metallic lithium particles at an upper portion in the reaction vessel; the heavy phase area is formed by adding halobutane with density larger than that of the solvent into the reaction kettle and naturally settling the halobutane; The reaction kettle is provided with a light phase circulation path and a heavy phase circulation path, wherein: the light phase circulation path is used for conveying materials in the light phase region to the bottom of the reaction kettle; The heavy phase circulation path is used for conveying the materials in the heavy phase region to the top of the reaction kettle. According to the technical scheme, the inclined blade turbine paddle type stirrer is adopted and runs at a low speed, so that a stable axial downward flow field is formed in the reaction kettle, the flow field can effectively overcome the natural upward floating trend of metal lithium particles due to small density, the metal lithium particles are uniformly dispersed at the upper part of the reaction kettle to form a stable light phase region, the reactant is fully exposed in space, meanwhile, the severe shearing effect caused by the traditional high-speed stirring is avoided, the risk of out-of-control local reaction possibly caused by sudden increase of specific surface area due to excessive refinement of the metal lithium particles is fundamentally prevented, and the safety guarantee is provided for the high-activity n-butyl lithium synthesis reaction. By setting the light phase circulation path and the heavy phase circulation path respectively, a continuous countercurrent flow contact system is constructed in the reactor by utilizing the density difference of materials, so that the metal lithium particles and the halogenated butane can fully contact at each layer of the reaction space, and the mass transfer efficiency and the reaction rate are improved. On the basis, the light phase circulation path comprises a light phase circulation pump and a light phase substance distributor arranged at the bottom of the heavy phase region; The heavy phase circulation path comprises a heavy phase circulation pump and a heavy phase substance distributor arranged at the upper part of the light phase region. In the technical scheme, the light-phase substance distributor is arranged at the bottom of the reaction kettle, so that the metal lithium particle suspension liquid extracted from the upper light-phase zone can be released from the bottommost layer of the reaction system. When the light phase materials are released from the light phase material