Composite carbon supported Ca-V-noble metal catalyst and method for continuously producing 2, 3-dichloropyridine

Abstract

The invention discloses a composite carbon supported Ca-V-noble metal catalyst and a method for continuous production of 2, 3-dichloropyridine. The catalyst takes composite carbon as a carrier to loadCa, V and noble metals, the noble metals mainly comprise palladium, and also comprise one of Pt, Ru, Ir, Au and Rh. According to the invention, the composite carbon supported Ca-V-noble metal catalyst is adopted, 2, 3, 6-trichloropyridine is adopted as the raw material, a solvent and an acid-binding agent are added, a trickle bed is adopted for carrying out dechlorination reaction on a catalyst bed layer to continuously produce 2, 3-dichloropyridine, the catalytic reaction efficiency is relatively high, the energy consumption is low, the catalyst selectivity is good, the raw material conversion rate is greater than 98%, the molar yield of a target product is greater than 97.5%, and after continuous operation for 4000h, the catalyst is stable in performance. According to the method disclosed by the invention, one chlorine is selectively removed, and excessive 2, 3, 6-trichloropyridine is efficiently converted into 2, 3-dichloropyridine, so that the additional value of the product is greatly improved.

Description

technical field [0001] The invention belongs to the technical field of catalytic hydrogenation, and in particular relates to a composite carbon-supported Ca-V-noble metal catalyst and a method for continuously producing 2,3-dichloropyridine by using the catalyst. Background technique [0002] 2,3-Dichloropyridine is a high value-added fine chemical intermediate and one of the key intermediates for the synthesis of chlorine-containing pesticides. There are many synthetic routes for 2,3-dichloropyridine, and various synthetic methods have their own advantages and disadvantages. Among them, the selective dechlorination of 2,3-dichloropyridine to prepare 2,3-dichloropyridine has relative advantages. Strong advantages, the core of this route is the catalyst and the corresponding catalytic reaction process. 2,3,6-Trichloropyridine is a by-product of chlorinated pyridine to produce chloropyridine compounds. Since the chlorination reaction has certain selectivity to this by-product...

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Problems solved by technology

[0004] The purpose of the present invention is to provide a solution for the defects of low efficiency, high three wastes and high catalytic cost of selectively removing one chlorine from 2,3,6-trichloropyridine and converting it into 2,3-dichloropyridine in the prior art. Composite carbon-supported Ca-V-noble metal catalyst and method for efficient continuous production of 2,3-dichloropyridine