阅读说明：本技术 一种色谱纯甲醇的纯化方法 (Method for purifying chromatographically pure methanol ) 是由 刘岩 宋金链 于 2019-10-29 设计创作，主要内容包括：本发明涉及一种色谱纯甲醇的纯化方法,包括：(1)将甲醇原料通过活性炭纤维吸附除去部分不饱和烯烃类杂质；(2)加入1号催化剂,向反应釜内充入氮气,置换反应釜内的低沸点醚类和氨类气体；(3)脱醚处理完成后,加入2号催化剂,将甲醇样液中的酯类杂质水解成酸类和醇类杂质；(4将水解蒸出后的甲醇样液打入LS-40大孔树脂吸附柱和硅藻土吸附柱串联的吸附系统进行吸附除杂；之后进行还原、干燥、精馏得到色谱纯甲醇。本发明采取紫外光催化还原技术,利用特殊波长下的紫外线光对还原剂进行辐射,产生亚硫酸根自由基,加强了还原剂的还原性,利用亚硫酸根自由基的强还原性对甲醇样液中的杂质进行还原。加强了还原剂的还原性,提升了还原效率。(The invention relates to a method for purifying chromatographically pure methanol, which comprises the following steps: (1) adsorbing the methanol raw material by activated carbon fiber to remove partial unsaturated olefin impurities; (2) adding a No. 1 catalyst, filling nitrogen into the reaction kettle, and replacing low-boiling-point ether and ammonia gases in the reaction kettle; (3) after the ether removal treatment is finished, adding a No. 2 catalyst, and hydrolyzing ester impurities in the methanol sample liquid into acid and alcohol impurities; (4 the methanol sample liquid after being hydrolyzed and evaporated is injected into an adsorption system formed by connecting an LS-40 macroporous resin adsorption column and a diatomite adsorption column in series to carry out adsorption impurity removal, and then reduction, drying and rectification are carried out to obtain the chromatographic pure methanol.)

1. A method for purifying chromatographically pure methanol, characterized by: the method comprises the following steps:

(1) a first adsorption step: carrying out pre-adsorption treatment on a methanol raw material with the purity of 99.5% by using an activated carbon fiber adsorption device, adsorbing and removing part of unsaturated olefin impurities, and controlling the adsorption flow rate to be 100-800 mL/min;

(2) and (3) ether removal treatment: pumping the adsorbed and filtered methanol sample liquid into a reaction rectifying kettle, adding a No. 1 catalyst, controlling the heating temperature of the rectifying kettle to be 30-45 ℃, reacting for 0.1-0.5 h under the condition of continuous stirring, filling nitrogen into the reaction kettle, and replacing low-boiling-point ether and ammonia gases in the reaction kettle;

(3) hydrolysis: after the ether removal treatment is finished, adding a No. 2 catalyst into a reaction rectifying still, controlling the heating temperature of the rectifying still to be 30-45 ℃, carrying out heating reaction for 0.5-1 h, hydrolyzing ester impurities in the methanol sample liquid into acid and alcohol impurities, simultaneously refluxing and evaporating light components, then continuously heating, controlling the bottom temperature of the rectifying still to be 70-77 ℃, the top temperature of the rectifying still to be 65-67 ℃, and adjusting the reflux ratio to be 2: 1-8 to evaporate the methanol sample liquid;

(4) and (2) an adsorption step II: pumping the methanol sample liquid after being hydrolyzed and evaporated into an adsorption system with LS-40 macroporous resin adsorption columns and diatomite adsorption columns connected in series for adsorption and impurity removal, and controlling the adsorption flow rate to be 300 mL-800 mL/min;

(5) reduction: pumping the sample liquid after adsorption and filtration into an ultraviolet irradiation reaction kettle, adding a reducing agent accounting for 0.05-0.3% of the sample liquid by mass percent, performing irradiation reaction for 0.5-1 h, and reducing and removing aldehyde impurities to obtain a reduced sample liquid;

(6) and (3) drying: pumping the reduction sample solution into a drying column, controlling the adsorption flow rate to be 300-500 mL/min, and reducing the water content to be below 0.05%;

(7) and (3) rectification: putting the dehydrated liquid into a rectifying still, adding an extracting agent accounting for 0.01-0.05% of the sample liquid by mass percent, controlling the heating temperature of the rectifying still to be 100-150 ℃, the bottom temperature of the rectifying still to be 70-77 ℃, the top temperature of the rectifying still to be 65-67 ℃ and the reflux ratio to be 5: 1-5;

(8) filtering, filling nitrogen and filling: and (3) performing microfiltration on the product in a pipeline by using a 0.1-0.22 micron folded filter core made of PVDF, and automatically filling nitrogen and filling to obtain the chromatographic pure methanol.

2. A method of purifying chromatographically pure methanol according to claim 1, characterized in that: the activated carbon fiber device is composed of 3 groups of activated carbon fiber adsorption devices, each group of the devices is composed of 3 activated carbon fiber columns, the height of each adsorption column is 1.0m, the diameter of each adsorption column is 10cm, 9 activated carbon fiber adsorption columns are formed in a series connection mode, the activated carbon fibers are prepared by chemical activation of phosphoric acid, the activated carbon fibers are soaked in 1-5 mol/L phosphoric acid for 3-5 h, taken out and dried at 150 ℃, cooled and soaked in distilled water for 5-8 h, fully washed to be neutral, and then dried in an oven at 120 ℃.

3. A method of purifying chromatographically pure methanol according to claim 1, characterized in that: the No. 1 catalyst is an IM-5 type molecular sieve, the adding amount of the No. 1 catalyst is 0.05-0.3 percent of the mass ratio of the methanol sample liquid, and the No. 2 catalyst is 732 type acidic cation exchange resin, and the adding amount of the No. 2 catalyst is 0.1-0.5 percent of the mass ratio of the methanol sample liquid.

4. A method of purifying chromatographically pure methanol according to claim 1, characterized in that: the LS-40 macroporous resin adsorption column can remove amine impurities and alkaline impurities in a methanol sample liquid, the resin is soaked in 15% -30% sulfuric acid for 3-5 h, and the resin is taken out and dried in an oven at 150 ℃ for use.

5. A method of purifying chromatographically pure methanol according to claim 1, characterized in that: the diatomite adsorption column is a product obtained by modifying diatomite with hexadecyl trimethyl ammonium bromide, the height of the adsorption column is 1.6m, the diameter of the adsorption column is 10cm, and an adsorption material accounts for 1/2 of the adsorption column.

6. A method of purifying chromatographically pure methanol according to claim 1, characterized in that: the height of the drying column is 1.2m, the diameter of the drying column is 8cm, and the drying agent is calcium hydride and accounts for 1/2 of the drying column.

7. A method of purifying chromatographically pure methanol according to claim 1, characterized in that: the extractant is chromatographically pure N, N-dimethylformamide.

Technical Field

The invention belongs to the field of chemical reagents, relates to a purification technology, and particularly relates to a method for purifying chromatographically pure methanol.

Background

At present, with the rapid development of the biomedical, new energy and new material industries, the application of chromatographic instruments is wider and wider, the use amount of chromatographic solvents is increased rapidly, and chromatographic pure methanol is widely applied to a plurality of fields of electronics, pharmacy, biochemical industry, food, fine chemical industry and the like due to low price and strong solubility.

The industrial methanol is one of main downstream products of petrochemical enterprises, and has the characteristics of low price and sufficient raw materials, so that the method for preparing chromatographic methanol by utilizing the industrial methanol has a very high development prospect.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide a method for purifying chromatographically pure methanol, and the methanol prepared by the method can remove the aldehyde ketone, alcohol, ester, ether and unsaturated hydrocarbon impurities which are difficult to remove and have lower content, thereby achieving the indexes and application requirements of the chromatographically pure methanol.

The technical problem to be solved by the invention is realized by adopting the following technical scheme:

a method for purifying chromatographically pure methanol, comprising the method steps of:

(1) a first adsorption step: carrying out pre-adsorption treatment on a methanol raw material with the purity of 99.5% by using an activated carbon fiber adsorption device, adsorbing and removing part of unsaturated olefin impurities, and controlling the adsorption flow rate to be 100-800 mL/min;

(2) and (3) ether removal treatment: pumping the adsorbed and filtered methanol sample liquid into a reaction rectifying kettle, adding a No. 1 catalyst, controlling the heating temperature of the rectifying kettle to be 30-45 ℃, reacting for 0.1-0.5 h under the condition of continuous stirring, filling nitrogen into the reaction kettle, and replacing low-boiling-point ether and ammonia gases in the reaction kettle;

(3) hydrolysis: after the ether removal treatment is finished, adding a No. 2 catalyst into a reaction rectifying still, controlling the heating temperature of the rectifying still to be 30-45 ℃, carrying out heating reaction for 0.5-1 h, hydrolyzing ester impurities in the methanol sample liquid into acid and alcohol impurities, simultaneously refluxing and evaporating light components, then continuously heating, controlling the bottom temperature of the rectifying still to be 70-77 ℃, the top temperature of the rectifying still to be 65-67 ℃, and adjusting the reflux ratio to be 2: 1-8 to evaporate the methanol sample liquid;

(4) and (2) an adsorption step II: pumping the methanol sample liquid after being hydrolyzed and evaporated into an adsorption system with LS-40 macroporous resin adsorption columns and diatomite adsorption columns connected in series for adsorption and impurity removal, and controlling the adsorption flow rate to be 300 mL-800 mL/min;

(5) reduction: pumping the sample liquid after adsorption and filtration into an ultraviolet irradiation reaction kettle, adding a reducing agent accounting for 0.05-0.3% of the sample liquid by mass percent, performing irradiation reaction for 0.5-1 h, and reducing and removing aldehyde impurities to obtain a reduced sample liquid;

(6) and (3) drying: pumping the reduction sample solution into a drying column, controlling the adsorption flow rate to be 300-500 mL/min, and reducing the water content to be below 0.05%;

(7) and (3) rectification: putting the dehydrated liquid into a rectifying still, adding an extracting agent accounting for 0.01-0.05% of the sample liquid by mass percent, controlling the heating temperature of the rectifying still to be 100-150 ℃, the bottom temperature of the rectifying still to be 70-77 ℃, the top temperature of the rectifying still to be 65-67 ℃ and the reflux ratio to be 5: 1-5;

(8) filtering, filling nitrogen and filling: and (3) performing microfiltration on the product in a pipeline by using a 0.1-0.22 micron folded filter core made of PVDF, and automatically filling nitrogen and filling to obtain the chromatographic pure methanol.

And the activated carbon fiber device is composed of 3 groups of activated carbon fiber adsorption devices, each group of the devices is composed of 3 activated carbon fiber columns, the height of each adsorption column is 1.0m, the diameter of each adsorption column is 10cm, 9 activated carbon fiber adsorption columns are formed in a series connection mode, the activated carbon fibers are prepared by chemically activating phosphoric acid, the activated carbon fibers are soaked in 1-5 mol/L phosphoric acid for 3-5 hours, taken out and dried at 150 ℃, cooled and soaked in distilled water for 5-8 hours, fully washed to be neutral, and then dried in an oven at 120 ℃.

The No. 1 catalyst is an IM-5 type molecular sieve, the adding amount of the No. 1 catalyst is 0.05-0.3% of the mass ratio of the methanol sample liquid, and the No. 2 catalyst is 732 type acidic cation exchange resin, and the adding amount of the No. 2 catalyst is 0.1-0.5% of the mass ratio of the methanol sample liquid.

And the LS-40 macroporous resin adsorption column can remove amine impurities and alkaline impurities in the methanol sample liquid, the resin is soaked for 3-5 hours by 15% -30% sulfuric acid, and the resin is taken out and dried by an oven at 150 ℃ for use.

Furthermore, the diatomite adsorption column is a product obtained by modifying diatomite with hexadecyl trimethyl ammonium bromide, the height of the adsorption column is 1.6m, the diameter of the adsorption column is 10cm, and the adsorption material accounts for 1/2 of the adsorption column.

Furthermore, the height of the drying column is 1.2m, the diameter of the drying column is 8cm, and the drying agent is calcium hydride and occupies 1/2 of the drying column.

Moreover, the extractant is chromatographically pure N, N-dimethylformamide.

The invention has the advantages and positive effects that:

1. the invention takes methanol with the content of 99.5 percent as a raw material, and the methanol produced by the preparation method of multi-stage adsorption, multi-stage reaction, drying and dewatering and extractive distillation meets the index and application requirements of chromatographic pure methanol. Compared with the prior art, the method has the advantages of high product quality, good batch stability, stable operation, high recovery rate of more than 95 percent and suitability for large-scale production.

2. The invention adopts the activated carbon fiber prepared by phosphoric acid activation, and the common activated carbon fiber has the advantages of poor adsorption selectivity to substances, weak adsorption capacity to substances with low boiling point and small relative molecular mass, and small adsorption capacity. The modified activated carbon fiber has the advantages of large specific surface area, developed microporous structure, large adsorption capacity, high adsorption and desorption speed, good adsorption effect, easy regeneration and the like. Compared with the traditional adsorption process, the method greatly improves the effect and efficiency of methanol raw material treatment.

3. According to the invention, the diatomite is modified by cetyl trimethyl ammonium bromide and polyacrylamide, the adsorption capacity of the prepared modified diatomite to acid impurities is obviously increased, the adsorption effect is obviously improved, and the diatomite is made of SiO₂And Al₂O₃The composition can simultaneously remove a small amount of oxidizing impurities.

4. According to the invention, the modified LS-40 macroporous resin is adopted to adsorb impurities of similar types, the aperture of the modified LS-40 macroporous resin is enlarged, the adsorption capacity is enhanced, and the adsorption effect on amine and alkaline impurities is greatly improved due to the modified LS-40 macroporous resin loaded with acidic groups.

5. At present, in the traditional process, strong oxidizing agents such as potassium permanganate and the like are generally adopted to remove aldehyde and olefin impurities, although the impurity removal effect is good, in the impurity removal process, the strong oxidizing agents such as potassium permanganate and the like can react with methanol to generate new impurities, so that the recovery rate of the methanol is reduced. The technology enhances the reducibility of the reducing agent and improves the reduction efficiency.

Detailed Description

The present invention will be further described by the following specific examples, which are illustrative only and not intended to be limiting, and the scope of the present invention is not limited thereby.