Technology for complexing, crystallizing, separating and purifying metacresol

Abstract

The invention provides a technology for complexing, crystallizing, separating and purifying metacresol, belonging to the field of separation and purification in a chemical industry. The technology comprises the steps of dissolving urea in mixed phenol: adding the mixed phenol into a reactor, wherein the mixed phenol comprises 10.907wt% of o-cresol, 34.276wt% of p-cresol, 53.176wt% of m-cresol and 1.641% of dimethyl phenol; adding the urea into the reactor, wherein the mole ratio of the urea to the m-cresol is 1.0-1.8; heating and rising the temperature to be 85-105DEG C in a water bath or an oil bath for 40-80min, so that the urea is completely dissolved in the mixed phenol; cooling, adding normal hexane under the temperature of 60DEG C, and crystallizing for 1-2h under the temperature from -10DEG C to -20DEG C; transporting crystallized serous fluid into a filter to separate solid from liquid; recovering filter liquor in a rectifying way, adding water into crystalline solid, and hydrolyzing during heating at 40DEG C to obtain water phase and organic phase; and recovering the water phase, so that the organic phase is the m-cresol. In the technology, methylbenzene is replaced by normal hexane to be taken as a dissolvent for complexing and crystallizing reaction, so that the technology is higher in the yield of the cresol, the usage amount of the dissolvent can be reduced by one third, and the dissolvent can be covered by less energy consumption.

Description

technical field [0001] The invention belongs to the field of chemical separation and purification, and relates to a process for separating and purifying m-cresol by a complex crystallization method. Background technique [0002] Cresol is an important fine chemical intermediate, including three isomers, namely o-cresol, p-cresol and m-cresol, all of which are relatively tight domestic fine chemical products, especially p- and m-cresol are seriously in short supply in China , a considerable amount is imported every year to meet the domestic market demand. m-cresol is widely used in the fields of pesticides, medicines, spices, dyes, antioxidants, polymerization inhibitors, ultraviolet absorbers, fuel additives, rubber additives, coatings, feed additives and synthetic materials. [0003] It is difficult to separate m-cresol and p-cresol by conventional methods because their boiling points are very close. The separation methods of m-cresol and p-cresol can be generally divided...

AI Technical Summary

Problems solved by technology

None of the above articles mentioned the use of alkanes, especially n-hexane, which is very weak in polarity, as a solvent

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