Catalyst for synthesizing 6-aminocapronitrile, preparation method thereof and method for synthesizing 6-aminocapronitrile by using catalyst

Abstract

The invention provides a preparation method of a catalyst for synthesizing 6-aminocapronitrile from caprolactam. The preparation method comprises the following steps: 1) preparing a mixed aqueous solution of ternary active components of ytterbium nitrate, calcium nitrate and copper nitrate for later use; (2) weighing a ZSM-5 silicon-aluminum molecular sieve, and adding the molecular sieve into the mixed aqueous solution of the ternary active components in the step (1); (3) dipping for 4-10 hours at the temperature of 25-80 DEG C; and 4) evaporating to dryness, drying, forming and roasting to obtain the catalyst. Wherein the mass ratio of the ytterbium nitrate to the calcium nitrate to the copper nitrate is 1: (1-20): (1-20), and the ratio of the total mass of the ytterbium nitrate, the calcium nitrate and the copper nitrate to the mass of the ZSM-5 silicon-aluminum molecular sieve is (0.01-0.4): 1. The catalyst disclosed by the invention is simple in preparation method, stable in quality, high in catalytic efficiency, high in product space-time yield, long in service life, low in requirements on catalyst preparation equipment and easy for industrial production.

Description

technical field [0001] The invention relates to the field of organic synthesis of 6-aminocapronitrile prepared from caprolactam, in particular to a method for preparing a catalyst for synthesizing 6-aminocapronitrile by using ZSM-5 silica-alumina molecular sieve as a carrier to load active components, A catalyst prepared by the method and a method for synthesizing 6-aminocapronitrile using the catalyst. Background technique [0002] Hexamethylenediamine is a key intermediate in the production of polyamides such as nylon 66 and nylon 610, and is also used in the preparation of diisocyanate and as a curing agent for epoxy resin and urea-formaldehyde resin. At present, the main synthetic route is the synthesis of adiponitrile by butadiene-hydrocyanic acid method, and the catalytic reduction of adiponitrile to hexamethylenediamine. In recent years, with the continuous expansion of caprolactam production capacity and the continuous reduction of costs, 6-aminocapronitrile (precur...

AI Technical Summary

Problems solved by technology

Disclosed in CN107739318A is a liquid-phase synthetic process, phosphoric acid or phosphate is a catalyst, batch process, caprolactam conversion rate 55%, 6-aminocapronitrile selectivity 97%, conversion rate is low, catalyst separation and recycling make the process Complicated, low overall performance of the device

In the early years of the gas phase process, the U.S. patent US 2234566 A used silica gel as a catalyst to support copper, and the conversion rate was low, less than 25%, and the selectivity of 6-aminocapronitrile was low, less than 90%. Pay attention, patents such as CN110404582A, CN111992241A, CN111672526A, CN111672494A, CN111659463A and CN111659374A disclose their respective preparation methods of gas-phase catalyst systems. ℃ and the space velocity is low. According to past practical experience, high temperature and low space velocity are often prone to carbon deposition and shorten the service life

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