Method for preparing tetrahydro-2-ethyl anthraquinone from working solution for production of hydrogen peroxide by anthraquinone process

Abstract

The invention relates to a method for preparing tetrahydro-2-ethyl anthraquinone from a working solution for the production of hydrogen peroxide by anthraquinone process, comprising the following steps: taking a certain amount of the working solution for the production of hydrogen peroxide by anthraquinone process to conduct vacuum distillation, removing heavy aromatics and other substances of low boiling point to obtain a dried substances; carrying out oversaturated dissolving on the obtained dried substances with organic solvents, stirring, oscillating, conducting suction filtration, letting trioctyl phosphate and 2-ethyl anthraquinone, etc. in the solvent, drying insoluble substances to obtain dried substances; dissolving the dried substances with organic solvents, and conducting recrystallization to obtain high-purity tetrahydro-2-ethyl anthraquinone. The method of the invention not only solves the problems of time consuming and labor consuming property and low conversion rate when synthesizing tetrahydro-2-ethyl anthraquinone by autoclave reaction, but also reduces the cost, shortens the operation time. Tetrahydro-2-ethyl anthraquinone prepared by the method of the invention has a purity of more than 99.5%, and can be used as a tetrahydro-2-ethyl anthraquinone standard sample for analyzing the working solution for hydrogen peroxide.

Description

technical field

[0001] The invention belongs to the field of organic matter separation, and in particular relates to a method for preparing tetrahydro-2-ethylanthraquinone from an anthraquinone method to produce hydrogen peroxide working solution. Background technique

[0002] Tetrahydro-2-ethylanthraquinone is a yellow needle-like crystal, and its pure product has a melting point of 168°C-169°C. Insoluble in water, easily soluble in non-polar solvents such as benzene, toluene, heavy aromatics, dichloroethane, dioxane, ether, etc., hardly soluble in polar solvents such as methanol, ethanol, trioctyl phosphate (TOP) and acetone solvent. Insoluble in concentrated hydrochloric acid, nitric acid and caustic alkali, but soluble in concentrated sulfuric acid and presents a blood-red solution. After diluting with water, a yellow precipitate can be re-precipitated.

[0003] The production of hydrogen peroxide by the anthraquinone method is to dissolve alkyl anthraquinone as a carr...

Examples

Embodiment 1

[0032] Take 400mL hydrogen peroxide working solution, adjust the oil bath to 160°C on a rotary evaporator, adjust the vacuum pump to 0.2MPa, distill under reduced pressure for 6 hours, and cool to obtain the evaporated product of the working solution. Take 30g of the evaporated matter and add 15mL of absolute ethanol, stir well at 8°C for 0.5h until the insoluble matter in the evaporated matter is completely powdery, filter with suction, and dry the insoluble matter at 60°C to obtain a dry matter, which is Dissolve in N-methylpyrrolidone, the quality of N-methylpyrrolidone is 10 times of the dry matter, stir to dissolve the dry matter completely, add distilled water drop by drop to the solution, stir while adding, until there is a small amount of yellow precipitate Precipitate, filter with suction, wash the yellow precipitate with a large amount of distilled water, and dry to obtain tetrahydro-2-ethylanthraquinone with a purity of 98%.

Embodiment 2

[0034]Take 400mL hydrogen peroxide working solution, adjust the oil bath to 160°C on a rotary evaporator, adjust the vacuum pump to 0.2MPa, distill under reduced pressure for 6 hours, and cool to obtain the evaporated product of the working solution. Take 30g of the evaporated matter and add 15mL of absolute ethanol, stir well at 8°C for 0.5h until the insoluble matter in the evaporated matter is completely powdery, filter with suction, and dry the insoluble matter at 60°C to obtain a dry matter, which is Dissolve in N-methylpyrrolidone, the mass of N-methylpyrrolidone is 10 times that of the dry matter, stir to dissolve the dry matter completely, add distilled water drop by drop to the solution, stir while adding, until there is a large amount of yellow precipitate Precipitation, suction filtration, so that the obtained recrystallization is about half of the amount of dry matter put into it, recrystallize the first recrystallization again, the quality of the second recrystalli...

Embodiment 3

[0036] Take 400mL hydrogen peroxide working solution, adjust the oil bath to 160°C on a rotary evaporator, adjust the vacuum pump to 0.2MPa, distill under reduced pressure for 6 hours, and cool to obtain the evaporated product of the working solution. Take 30g of the evaporated matter and add 15mL of n-hexane, fully stir at 8°C for 0.5h until the insoluble matter in the evaporated matter is completely powdery, filter with suction, dry the undissolved matter at 60°C to obtain a dried matter, dissolve the dried matter Add the acetone to acetone, the quality of acetone is 10 times that of the dry matter, stir to dissolve the dry matter completely, add distilled water drop by drop to the solution, stir while adding, until a large amount of yellow precipitates are precipitated, filter with suction, and remove the yellow precipitate with Wash with copious amounts of distilled water and dry. After three recrystallizations, tetrahydro-2-ethylanthraquinone with a purity of 98% can be o...

technical field

[0001] The invention belongs to the field of organic matter separation, and in particular relates to a method for preparing tetrahydro-2-ethylanthraquinone from an anthraquinone method to produce hydrogen peroxide working solution. Background technique

[0002] Tetrahydro-2-ethylanthraquinone is a yellow needle-like crystal, and its pure product has a melting point of 168°C-169°C. Insoluble in water, easily soluble in non-polar solvents such as benzene, toluene, heavy aromatics, dichloroethane, dioxane, ether, etc., hardly soluble in polar solvents such as methanol, ethanol, trioctyl phosphate (TOP) and acetone solvent. Insoluble in concentrated hydrochloric acid, nitric acid and caustic alkali, but soluble in concentrated sulfuric acid and presents a blood-red solution. After diluting with water, a yellow precipitate can be re-precipitated.

[0003] The production of hydrogen peroxide by the anthraquinone method is to dissolve alkyl anthraquinone as a carr...

Examples

Embodiment 1

[0032] Take 400mL hydrogen peroxide working solution, adjust the oil bath to 160°C on a rotary evaporator, adjust the vacuum pump to 0.2MPa, distill under reduced pressure for 6 hours, and cool to obtain the evaporated product of the working solution. Take 30g of the evaporated matter and add 15mL of absolute ethanol, stir well at 8°C for 0.5h until the insoluble matter in the evaporated matter is completely powdery, filter with suction, and dry the insoluble matter at 60°C to obtain a dry matter, which is Dissolve in N-methylpyrrolidone, the quality of N-methylpyrrolidone is 10 times of the dry matter, stir to dissolve the dry matter completely, add distilled water drop by drop to the solution, stir while adding, until there is a small amount of yellow precipitate Precipitate, filter with suction, wash the yellow precipitate with a large amount of distilled water, and dry to obtain tetrahydro-2-ethylanthraquinone with a purity of 98%.

Embodiment 2

[0034]Take 400mL hydrogen peroxide working solution, adjust the oil bath to 160°C on a rotary evaporator, adjust the vacuum pump to 0.2MPa, distill under reduced pressure for 6 hours, and cool to obtain the evaporated product of the working solution. Take 30g of the evaporated matter and add 15mL of absolute ethanol, stir well at 8°C for 0.5h until the insoluble matter in the evaporated matter is completely powdery, filter with suction, and dry the insoluble matter at 60°C to obtain a dry matter, which is Dissolve in N-methylpyrrolidone, the mass of N-methylpyrrolidone is 10 times that of the dry matter, stir to dissolve the dry matter completely, add distilled water drop by drop to the solution, stir while adding, until there is a large amount of yellow precipitate Precipitation, suction filtration, so that the obtained recrystallization is about half of the amount of dry matter put into it, recrystallize the first recrystallization again, the quality of the second recrystalli...

Embodiment 3

[0036] Take 400mL hydrogen peroxide working solution, adjust the oil bath to 160°C on a rotary evaporator, adjust the vacuum pump to 0.2MPa, distill under reduced pressure for 6 hours, and cool to obtain the evaporated product of the working solution. Take 30g of the evaporated matter and add 15mL of n-hexane, fully stir at 8°C for 0.5h until the insoluble matter in the evaporated matter is completely powdery, filter with suction, dry the undissolved matter at 60°C to obtain a dried matter, dissolve the dried matter Add the acetone to acetone, the quality of acetone is 10 times that of the dry matter, stir to dissolve the dry matter completely, add distilled water drop by drop to the solution, stir while adding, until a large amount of yellow precipitates are precipitated, filter with suction, and remove the yellow precipitate with Wash with copious amounts of distilled water and dry. After three recrystallizations, tetrahydro-2-ethylanthraquinone with a purity of 98% can be o...

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