Method for extracting quinoline from coal tar wash oil

Abstract

The invention relates to a method for extracting quinoline from coal tar wash oil, which belongs to the field of chemical separation. According to the method, alcohol is used as a supercritical solvent to extract the quinoline from the wash oil in an intermittent supercritical reaction kettle, predistillation is performed to the wash oil to obtain a fraction containing the quinoline, and the fraction reacts with acid to obtain quinoline salt to be neutralized with ammonia water, so that a coarse quinoline product is obtained. The coarse quinoline product is mixed with a certain quantity of alcohol solution then to be added to the supercritical reaction kettle for supercritical extraction. After the coarse quinoline is extracted through the supercritical alcohol, a gas extraction phase and a liquid raffinate phase are obtained, and after the gas extraction phase and the liquid raffinate phase are separated and cooled by a gas-liquid separator, an extraction liquid and a raffinate liquid are obtained. After the extraction liquid is refined, a quinoline product is obtained. According to the method, an acidic salt solution is used for replacing sulfuric acid to enrich the quinoline so as to prevent industrial waste acid from polluting the environment, the production cost is greatly reduced, and the whole process is simple and controllable.

Description

technical field

[0001] The invention relates to a method for extracting quinoline from coal tar wash oil, which belongs to the field of chemical separation. Background technique

[0002] Coal tar is a liquid product obtained after carbonization and gasification of coal. It has a pungent odor and is black or dark brown viscous. Coal tar contains tens of thousands of organic compounds, more than 500 of which have been identified so far. Coal tar has a complex chemical composition and is widely used, some of which have great economic value.

[0003] Quinoline and isoquinoline are a class of important organic synthetic raw materials, commonly used in the preparation of dyes and photographic photosensitive pigment raw materials, rubber vulcanization accelerators, flotation agents, pickling corrosion inhibitors and pesticides, etc., in the pharmaceutical industry It is mainly used in the manufacture of niacin-based, 8-hydroxyquinoline-based and quinine-based drugs. It can also b...

Examples

Embodiment 1

[0024] Step 1. Take 200ml of coal tar washing oil and add it to a 500ml reaction kettle, connect a condenser, test the airtightness of the device, heat up, and cut the fraction between 235-240°C to obtain the quinoline-rich fraction;

[0025] Step 2: Mix 3 mol / L ammonium bisulfate solution and the quinoline-rich fraction at a mass ratio of 1:1, vibrate, and stand to separate into layers. After taking out the water layer, add an appropriate amount of 25% ammonia water to neutralize until the pH is 7, then stand and separate, and the obtained oil layer is the crude quinoline product containing quinoline.

[0026] Step 3: Take 30g of crude quinoline and 30g of ethanol and add them into a 100ml supercritical reactor after being mixed by a pre-mixer, and start heating after checking the tightness of the device. Control the pressure of the reactor to 7MPa, raise the temperature to 140°C at a constant rate of 20°C / min, turn on the condensed water to cool the stirring shaft, and the s...

Embodiment 2

[0031] Step 1. Take 200ml of coal tar washing oil and add it to a 500ml reaction kettle, connect a condenser, test the airtightness of the device, heat up, and cut the fraction between 235-240°C to obtain the quinoline-rich fraction;

[0032] Step 2: Mix 5 mol / L sodium hydrogen phosphate solution and quinoline-rich fraction at a mass ratio of 2:1, vibrate, and let stand to separate into layers. After taking out the water layer, add an appropriate amount of 25% ammonia water to neutralize until the pH is 6, then stand and separate the layers, and the obtained oil layer is the crude quinoline product containing quinoline.

[0033] Step 3: Get 30g of crude quinoline and 60g of methanol and add them into a 100ml supercritical reactor after being mixed by a pre-mixer, and start heating after checking the tightness of the device. Control the pressure of the reactor to 8MPa, raise the temperature to 150°C at a constant heating rate of 20°C / min, turn on the condensed water to cool the...

Embodiment 3

[0038] Step 1. Take 200ml of coal tar washing oil and add it to a 500ml reaction kettle, connect a condenser, test the airtightness of the device, heat up, and cut the fraction between 235-240°C to obtain the quinoline-rich fraction;

[0039] Step 2: Mix 4 mol / L phosphoric acid solution and quinoline-rich fraction at a mass ratio of 3:1, vibrate and stand to separate into layers. After taking out the water layer, add an appropriate amount of 25% ammonia water to neutralize until the pH is 6, then stand and separate the layers, and the obtained oil layer is the crude quinoline product containing quinoline.

[0040] Step 3: Take 20g of crude quinoline and 60g of deionized water and mix them with a pre-mixer, then add them to a 100ml supercritical reactor, and start heating after checking the tightness of the device. Control the pressure of the reactor to 9MPa, raise the temperature to 145°C at a constant heating rate of 20°C / min, turn on the condensed water to cool the stirring ...

technical field

[0001] The invention relates to a method for extracting quinoline from coal tar wash oil, which belongs to the field of chemical separation. Background technique

[0002] Coal tar is a liquid product obtained after carbonization and gasification of coal. It has a pungent odor and is black or dark brown viscous. Coal tar contains tens of thousands of organic compounds, more than 500 of which have been identified so far. Coal tar has a complex chemical composition and is widely used, some of which have great economic value.

[0003] Quinoline and isoquinoline are a class of important organic synthetic raw materials, commonly used in the preparation of dyes and photographic photosensitive pigment raw materials, rubber vulcanization accelerators, flotation agents, pickling corrosion inhibitors and pesticides, etc., in the pharmaceutical industry It is mainly used in the manufacture of niacin-based, 8-hydroxyquinoline-based and quinine-based drugs. It can also b...

Examples

Embodiment 1

[0024] Step 1. Take 200ml of coal tar washing oil and add it to a 500ml reaction kettle, connect a condenser, test the airtightness of the device, heat up, and cut the fraction between 235-240°C to obtain the quinoline-rich fraction;

[0025] Step 2: Mix 3 mol / L ammonium bisulfate solution and the quinoline-rich fraction at a mass ratio of 1:1, vibrate, and stand to separate into layers. After taking out the water layer, add an appropriate amount of 25% ammonia water to neutralize until the pH is 7, then stand and separate, and the obtained oil layer is the crude quinoline product containing quinoline.

[0026] Step 3: Take 30g of crude quinoline and 30g of ethanol and add them into a 100ml supercritical reactor after being mixed by a pre-mixer, and start heating after checking the tightness of the device. Control the pressure of the reactor to 7MPa, raise the temperature to 140°C at a constant rate of 20°C / min, turn on the condensed water to cool the stirring shaft, and the s...

Embodiment 2

[0031] Step 1. Take 200ml of coal tar washing oil and add it to a 500ml reaction kettle, connect a condenser, test the airtightness of the device, heat up, and cut the fraction between 235-240°C to obtain the quinoline-rich fraction;

[0032] Step 2: Mix 5 mol / L sodium hydrogen phosphate solution and quinoline-rich fraction at a mass ratio of 2:1, vibrate, and let stand to separate into layers. After taking out the water layer, add an appropriate amount of 25% ammonia water to neutralize until the pH is 6, then stand and separate the layers, and the obtained oil layer is the crude quinoline product containing quinoline.

[0033] Step 3: Get 30g of crude quinoline and 60g of methanol and add them into a 100ml supercritical reactor after being mixed by a pre-mixer, and start heating after checking the tightness of the device. Control the pressure of the reactor to 8MPa, raise the temperature to 150°C at a constant heating rate of 20°C / min, turn on the condensed water to cool the...

Embodiment 3

[0038] Step 1. Take 200ml of coal tar washing oil and add it to a 500ml reaction kettle, connect a condenser, test the airtightness of the device, heat up, and cut the fraction between 235-240°C to obtain the quinoline-rich fraction;

[0039] Step 2: Mix 4 mol / L phosphoric acid solution and quinoline-rich fraction at a mass ratio of 3:1, vibrate and stand to separate into layers. After taking out the water layer, add an appropriate amount of 25% ammonia water to neutralize until the pH is 6, then stand and separate the layers, and the obtained oil layer is the crude quinoline product containing quinoline.

[0040] Step 3: Take 20g of crude quinoline and 60g of deionized water and mix them with a pre-mixer, then add them to a 100ml supercritical reactor, and start heating after checking the tightness of the device. Control the pressure of the reactor to 9MPa, raise the temperature to 145°C at a constant heating rate of 20°C / min, turn on the condensed water to cool the stirring ...