A kind of purification method of chromatographically pure methanol

Abstract

The present application relates to the technical field of methanol purification, and specifically discloses a method for purifying methanol by gradient chromatography. The purification method is as follows: the industrial methanol is sequentially subjected to oxidation neutralization reaction, adsorption column removal treatment and rectification treatment to finally obtain chromatographically pure methanol, wherein the oxidation neutralization reaction comprises the following steps: S1. Methanol is evenly mixed, so that the pH value of the industrial methanol is 9-12; S2, the industrial methanol and the oxidant in a liquid state are added into the oxidation neutralization column from the upper end of the oxidation neutralization column, and the The industrial methanol and the oxidant flow through the filler in the oxidation neutralization column, the flow rate of the industrial methanol is 0.2-2L / min, and the flow rate of the oxidant is 0.05-10ml / min; the adsorption column is treated for impurity removal. Including: passing the solution flowing out of the oxidation neutralization column through 4Å molecular sieve, activated carbon fiber, ZSM-5 molecular sieve and 5Å molecular sieve in sequence to remove impurities. This application can reduce the absorbance of chromatographically pure methanol at 220-280nm.

Description

technical field [0001] The present application relates to the technical field of methanol purification, more specifically, it relates to a method for purifying chromatographically pure methanol. Background technique [0002] With the wide application of liquid chromatography, chromatographically pure methanol as a liquid chromatography mobile phase has more and more uses and more and more demand. Chromatographically pure methanol is used as the solvent of the mobile phase. The smaller the absorbance, the better the separation effect of organics in the sample. Therefore, the quality requirements of chromatographically pure methanol are becoming more and more strict, and the supply of high-standard chromatographically pure methanol products is in short supply. Among them, the graded chromatographic pure methanol is mainly imported from abroad. Among them, the absorbance of the foreign chromatographic pure methanol at the wavelength of 205-400nm is small, 0.26-0.06 in the range...

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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