Preparation method for methyl methacrylate deacidification adsorbent

Abstract

A preparation method for methyl methacrylate deacidification adsorbent, comprising the following steps: (1) mixing 5A molecular sieve powder and natural clay, adding calcium nitrate aqueous solution, rolling into balls, drying, roasting, and cooling; 2) Put the product obtained in step (1) into the exchanger, and then exchange it with calcium nitrate aqueous solution. When the calcium content of the inlet and outlet of the calcium nitrate solution is constant, exchange it stably for a certain period of time, then dry, roast, and pack and seal , prepared as methyl methacrylate deacidification adsorbent.

Description

technical field [0001] The present invention relates to a kind of preparation method of the adsorbent used for the deacidification of methyl methacrylate, relates to a kind of low-temperature adsorbent precisely, adopts the mixing method of 5A molecular sieve and natural clay, forms through rolling ball, dry roasting, and then through Calcium nitrate solution is exchanged, dried and roasted. Background technique [0002] In the production of methyl methacrylate (MMA), the alcoholysis of acetone cyanohydrin and methanol is usually used as a catalyst in sulfuric acid to produce methyl methacrylate, and the methyl methacrylate product is obtained through rectification, but in the alcoholysis process , the raw material acetone cyanohydrin contains traces of hydrocyanic acid, hydrocyanic acid is hydrolyzed to produce formic acid; methanol contains traces of formic acid; since the boiling point of formic acid is 100.8°C, the boiling point of methyl methacrylate is 100-101°C, durin...

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Problems solved by technology

[0004] From the perspective of solid adsorbents, one type is capillary solid adsorbents, which are capillary adsorption adsorption, such as silica gel, alumina, activated carbon and molecular sieves. The selectivity of such adsorbents is poor and the effect is not ideal; The other is a solid alkali adsorbent, which uses the alkalinity of the adsorbent and the chemical adsorption principle of formic acid to reduce the acid value in methyl methacrylate.

Among the adsorbents for methyl methacrylate deacidification, one type is 5A molecular sieve, which has suitable pores and alkali center Ca, which overcomes the solid alkali adsorbents loaded with alkali metals (such as K, Na), and K and Na are easy to lose , resulting in excessive K and Na content of methyl methacrylate products, hydrolysis and polymerization of methyl methacrylate, affecting product quality and other issues; one type is 5A molecular sieve and calcium hydroxide wet CaO-Fe2O3-5A molecular sieve solid adsorbent , to avoid strong acidity and product metal exceeding the standard, but the production process is complicated and the cost is high

In the patent CN200610073120.X, oxides or hydroxides of IIA group alkaline earth metals and aluminum oxide are used, and in the presence of glycols and diamine organic dispersants, they are extruded by wet kneading, dried, and roasted at high temperature. Alkaline earth metal oxide-alumina adsorbent, which is especially suitable for the adsorption and deacidification of organic acid esters to prepare high-purity organic acid ester products with low acid value (<20μg / g). The production process is also complicated and the cost high

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