A kind of purification approach of 1,4-dioxane, the actions are as follows:
1) Hydrolysis: put 1,4-dioxane basic material with a content of 98.0% right into the activator, add a solid acidic cation exchange resin with a mass fraction of 0.02% to 0.05% right into the activator, and warmth to 100 to 150 ° C, reflux for 1 to 2 hours, as well as hydrolyze the 2-methyl-1,3- dioxolane impurity in the raw material.
2) Adsorption: Place the hydrolyzed 1,4-dioxane basic material right into the cation exchange resin adsorption column, in which the adsorption column is 1.6 m high as well as 4.2 centimeters in size, and also the height of the cation exchange resin item inside is 4/5 of the column height. Adsorption and purification of some aldehyde impurities in the 1,4-dioxane basic material is carried out via a cation exchange resin adsorption column, and also the filtration circulation rate is 300-500mL/ min;
3) The raw materials adsorbed by cation exchange resin are then adsorbed by an activated carbon filter column. The activated carbon column is 2m high as well as 10cm in diameter, and also the amount of turned on carbon filler inside is 2/3 of the column height. Adsorption as well as impurity removal therapy, the raw material after adsorption treatment enters the home heating tower kettle as well as is heated up to 50-60 ° C, then stops heating and awaits use.
4) Transfer the heated product liquid to two peroxide treatment columns prepared by lithium light weight aluminum hydride in collection for redox response, where the lithium aluminum hydride filled column is 1.2 m high and also 20cm in diameter, as well as includes lithium aluminum hydride filler The dosage is 1/5 of the column elevation. This procedure needs to manage the circulation rate at 500-800mL/ min, with this action to remove the peroxide contaminations existing in the industrial Dioxane Boiling Point items.
5) Drying to get rid of water: the minimized fluid circulations via a 4A molecular sieve drying tower for dehydration.
6) Rectification: Put the dried feed liquid into a rectification pot, as well as include 0.02% to 0.05% calcium hydride dehydrating representative in the kettle for more water removal therapy. Control the heating temperature level of the rectification container to 140-160 ° C, and the top temperature level of the rectification tank to 101-103 ° C; the reflux proportion is 20:1 to accumulate the previous portion, and afterwards transformed to 10:1 to gather the previous portion. When the example absorbance and water content are certified, Collect the ended up product of 1,4-dioxane at a reflux proportion of 5:1 ~ 5, and also stop the heating as well as correction when the continuing to be correction liquid is about 5% to 8%, and also the remaining liquid is the deposit of the kettle, which includes high boiling point Pollutants such as ethylene glycol are eliminated near the bottom.
7) Filtering as well as filling with nitrogen: the item is micro-filtered in the pipeline via a microporous filter component of 0.1 to 0.22 microns of PVDF, as well as the automated filling up device realizes automatic filling with nitrogen. The packaging is usually 1L and 4L, and also the acquired product is The chromatographically pure 1,4-dioxane that fulfills the index demands can meet the requirements of consumers for chromatographically pure Dioxane Boiling Point.
A preparation technique of high-purity liquid chromatography pure 1,4-dioxane, the actions are as complies with:
( 1) Raise the raw material 1,4-dioxane with a content of regarding 99.5% to the top of the zeolite adsorption column, the length of the adsorption column is 1.8 m, the internal size is 5.0 cm, and also the NaX zeolite is loaded, as well as the bit size of the NaX zeolite is about 0.15-0.25 mm, the filling up ability is 4/5 of the size of the column, circulation right into the column by gravity, control the flow rate 60mL ～ 100mL/min, make the organic solvent totally contact with the zeolite, and absorb the contaminations therein, as well as eliminate the preliminary effluent (since the zeolite will certainly be taken in at the starting The contaminations in the liquid are brought out), as well as the liquid is spotted.
( 2) Flow the certified effluent into alumina, the bit dimension of alumina is 0.3 mm ~ 0.5 mm, and the adsorption column (the adsorption column coincides as the zeolite adsorption column), as well as the get in touch with in between the alumina adsorption column as well as the organic solvent can totally soak up the A small amount of impurities are divided from them, the circulation rate is 50mL-80mL/ minutes, as well as the absorbance of the fluid is close to the index.
( 3) Dry the effluent of action (2) through a drying out column (the desiccant is anhydrous calcium chloride or 4A molecular screen). The water content of the dried out effluent is 0.05% to 0.07%. Saturated, changed and after that dried out.
( 4) After dr
ng out, the solution is poured into a 100L reactor for rectification, heated up by warmth conduction oil, as well as the temperature of the warmth conduction oil is controlled at 120 ° C to 180 ° C. 100 ℃ ～ 102 ℃; the reflux proportion is adjusted from 1:0.5 ～ 2 to 1:2 ～ 5 (all displayed on the tool control box) as well as lastly a certified high-purity liquid chromatography grade Dioxane Boiling Point item is gotten;
( 5) After passing the test, the finished product is filtered with a 0.45 μm microporous membrane, bottled, as well as kept under nitrogen security.
