Purification method of chromatographically pure methanol

Abstract

The invention relates to the technical field of methanol purification, and particularly discloses a purification method of gradient grade chromatographically pure methanol. The purification method comprises the following steps of: sequentially carrying out oxidation neutralization reaction, adsorption column impurity removal treatment and rectification treatment on industrial methanol to finally obtain chromatographically pure methanol. The oxidation neutralization reaction comprises the following steps of: S1, uniformly mixing a neutralizer with the industrial methanol to enable the pH valueof the industrial methanol to be 9-12; and S2, adding the industrial methanol and an oxidant in a liquid state into an oxidation neutralization column from the upper end of the oxidation neutralization column, and enabling the industrial methanol and the oxidant to flow through a filler in the oxidation neutralization column, the flow rate of the industrial methanol being 0.2-2 L / min and the flowrate of the oxidant being 0.05-10 ml / min. The adsorption column impurity removal treatment comprises the step of enabling a solution flowing out of the oxidation neutralization column to sequentiallyflow through a 4-angstrom molecular sieve, activated carbon fibers, a ZSM-5 molecular sieve and a 5-angstrom molecular sieve to remove impurities. According to the method, the absorbance of the chromatographically pure methanol at 220-280nm can be reduced.

Description

technical field [0001] The application relates to methanol purification technical field, more specifically, it relates to a kind of purification method of chromatographically pure methanol. Background technique [0002] With the wide application of liquid chromatography, chromatographically pure methanol is used as the mobile phase of liquid chromatography, and its use is more and more extensive, and the demand is also increasing. Chromatographically pure methanol is used as the solvent of the mobile phase. The smaller the absorbance, the better the separation effect of organic matter in the sample. As a result, the quality requirements for chromatographically pure methanol are becoming more and more stringent, making high-standard chromatographically pure methanol products in short supply. Among them, gradient-grade chromatographically pure methanol mainly relies on foreign imports. Among them, the absorbance of foreign chromatographically pure methanol is relatively small ...

AI Technical Summary

Problems solved by technology

Among them, gradient-grade chromatographically pure methanol mainly relies on foreign imports. Among them, the absorbance of foreign chromatographically pure methanol is relatively small at 205-400nm wavelength, 0.26-0.06 in the range of 220-240nm, and 0.06-0.01 in the range of 241-300nm. When it is above 300nm, it does not exceed 0.01. Therefore, the price of foreign gradient-grade chromatographically pure methanol (HPLC) is ten times the price of national standard-grade chromatographically pure methanol, but the difference in manufacturing costs is not obvious, so that chromatographically pure methanol has a large profit margin

[0003] At present, the purification method of chromatographically pure methanol is mainly to oxidize the raw material methanol with potassium permanganate to remove impurities, then add alkaline substances to neutralize it, separate it by extraction, treat it with Al2O3 adsorption, and finally obtain chromatographically pure methanol through rectification. However, through the above purification method, the obtained chromatographically pure methanol has a large difference in the absorbance values ​​obtained in different bands from foreign chromatographically pure methanol

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