CN102408291B - Method for reducing aromatic hydrocarbon by indirect hydrogen transfer - Google Patents

Abstract

The invention discloses a method for indirect hydrogen transfer reduction of aromatic hydrocarbons. Under the conditions of catalyst, hydrogen transfer medium and hydrogen, aromatic hydrocarbons are reduced to alkanes; the reduction reaction conditions are as follows: the ratio of catalyst to aromatic hydrocarbons is: 0.11 ～1g catalyst/0.05mol aromatic hydrocarbon; the dosage ratio of hydrogen transfer medium and aromatic hydrocarbon is: 0.005～0.05mol hydrogen transfer medium/0.05mol aromatic hydrocarbon; fill hydrogen to 0.2～4MPa, the reaction temperature is 50～180℃, the reaction time 1 to 7 hours. The reduction of aromatic hydrocarbons by the method of the invention has the characteristics of convenient operation and high efficiency.

Description

A method for indirect hydrogen transfer reduction of aromatic hydrocarbons

technical field

The invention relates to a method for indirect hydrogen transfer reduction of aromatic hydrocarbons.

Background technique

Aromatics are the main components of catalytic cracking (FCC) oil slurry. my country's catalytic cracking units produce a large amount of oil slurry every year. At present, there are many ways to use FCC oil slurry. Hydrogenation reduces it to saturated Reuse of hydrocarbons for catalytic cracking is a more efficient way of utilization. At present, the reduction of aromatics is mainly based on hydrogenation. It has been reported that Ru-NP/CDG was used as a catalyst to catalyze the hydrogenation of benzene (Carbon 49(4): 1326-1322). (CN101602644). The hydrogenation reduction of aromatics containing multiple benzene rings is relatively difficult, and there are few reports. It has been reported that Rh was used as a catalyst to catalyze the hydrogenation of anthracene (Journal of Physical Chemistry C, 113(46), 19782-19788). The aromatic ring hydrogenation methods reported above can all obtain higher conversion rates, but there are also common defects: due to the poor solubility of hydrogen in aromatic hydrocarbons, the hydrogenation conditions are relatively harsh (higher pressure or temperature, Or the reaction time is longer), and the reaction speed is slower.

Contents of the invention

The technical problem to be solved by the present invention is to provide a method for reducing aromatic hydrocarbons with convenient operation and high efficiency.

In order to solve the above-mentioned technical problems, the present invention provides a method for indirect hydrogen transfer reduction of aromatic hydrocarbons, under the conditions of the presence of catalyst, hydrogen transfer medium and hydrogen, aromatic hydrocarbons are reduced to alkanes;

Reduction reaction conditions are as follows:

The dosage ratio of catalyst to aromatic hydrocarbon is: 0.11～1g catalyst/0.05mol aromatic hydrocarbon;

The dosage ratio of hydrogen transfer medium and aromatic hydrocarbon is: 0.005～0.05mol hydrogen transfer medium/0.05mol aromatic hydrocarbon;

Hydrogen is charged to 0.2-4MPa, the reaction temperature is 50-180°C, and the reaction time is 1-7 hours.

As an improvement of the method for indirect hydrogen transfer reduction of aromatics of the present invention, the reduction reaction conditions are as follows:

The dosage ratio of catalyst and aromatic hydrocarbon is: 0.11～0.5g catalyst/0.05mol aromatic hydrocarbon;

The dosage ratio of hydrogen transfer medium and aromatic hydrocarbon is: 0.005～0.015mol hydrogen transfer medium/0.05mol aromatic hydrocarbon;

Charge hydrogen to 0.2-3MPa; the reaction temperature is 50-150°C, and the reaction time is 1-5 hours.

As a further improvement of the method for indirect hydrogen transfer reduction of aromatic hydrocarbons of the present invention: aromatic hydrocarbons are at least one of benzene, toluene, ethylbenzene, xylene, naphthalene, anthracene and biphenyl;

The alkane generated after benzene is reduced is cyclohexane, the alkane generated after toluene is reduced is methylcyclohexane, the alkane generated after ethylbenzene is reduced is ethylcyclohexane, and the alkane generated after xylene is reduced is Dimethylcyclohexane, the alkane generated after reduction of naphthalene is decahydronaphthalene, the alkane generated after reduction of anthracene is perhydroanthracene, and the alkane generated after reduction of biphenyl is dicyclohexane.

As a further improvement of the method for the indirect hydrogen transfer reduction aromatics of the present invention: the catalyst is Pt/C (5%wt, i.e. the weight content of Pt in Pt/C is 5%), Pd/C (5%wt, i.e. Pd The weight content of Pd in /C is 5%), Ru, Rh or Raney nickel.

As a further improvement of the method for indirect hydrogen transfer reduction of aromatic hydrocarbons of the present invention: the hydrogen transfer medium is carbazole or N-ethylcarbazole.

The method for indirect hydrogen transfer reduction of aromatic hydrocarbons of the present invention uses non-toxic carbazole or N-ethyl carbazole as a hydrogen transfer medium to increase the hydrogenation reaction rate, and the hydrogenation reaction conditions are milder, making the hydrogenation process more efficient and safe.

Detailed ways

Embodiment 1: the reduction of benzene

Add 3.9g (0.05mol) of benzene, 2.5g (0.013mol) of N-ethylcarbazole and 0.2g of Ru into the autoclave, fill with hydrogen to a pressure of 0.4MPa, raise the temperature to 50°C, and stir the reaction for 3 hours to end. After the temperature was lowered and the kettle was opened, 4.1 g of the product cyclohexane was obtained with a yield of 98% through distillation.

Comparative example 1, cancel the N-ethylcarbazole 2.5g in embodiment 1, all the other are completely with embodiment 1, obtain product cyclohexane 2.7g, yield is 64%.

Embodiment 2: the reduction of toluene

Add 4.6g (0.05mol) of toluene (0.05mol), 2g (0.012mol) of carbazole and 0.2g of Ru into the autoclave, fill with hydrogen to a pressure of 0.2MPa, the reaction temperature is 75°C, and the reaction is stirred for 5 hours to end. Product methylcyclohexane 2.5g, yield is 51%.

Comparative example 2, cancel the carbazole 2g in embodiment 2, all the other are completely with embodiment 2, obtain product methylcyclohexane 0.8g, yield is 16%.

Embodiment 3: the reduction of toluene

Add 4.6g (0.05mol) of toluene (0.05mol), 2g (0.012mol) of carbazole and 0.2g of Rh into the autoclave, fill with hydrogen to a pressure of 1MPa, the reaction temperature is 60°C, and the stirring reaction is completed for 2 hours. After cooling down and opening the kettle, the product is distilled 4.7 g of methylcyclohexane, the yield is 96%.

Comparative example 3, cancel the carbazole 2g in embodiment 3, all the other are completely with embodiment 3, obtain product methylcyclohexane 3.4g, yield is 69%.

Embodiment 4: the reduction of ethylbenzene

Add ethylbenzene 5.3g (0.05mol), carbazole 2g (0.012mol) and Rh 0.2g in the autoclave, fill hydrogen to pressure 1MPa, reaction temperature 60 ℃, end stirring reaction for 2 hours, after cooling and opening the kettle, through distillation, Product ethylcyclohexane 5.4g, yield is 96%.

Comparative example 4, cancel the carbazole 2g in embodiment 4, all the other are completely with embodiment 4, obtain product ethylcyclohexane 3.0g, yield is 54%.

Embodiment 5: the reduction of naphthalene

Add 6.4g (0.05mol) of naphthalene, 2.5g (0.013mol) of N-ethylcarbazole, and 0.3g of Raney nickel into the autoclave, fill with hydrogen to a pressure of 2MPa, and the reaction temperature is 120°C, and the reaction is completed after stirring for 1.5 hours, and the temperature is lowered Distilled under reduced pressure after the kettle was opened, the product decahydronaphthalene was 6.7g, and the yield was 97%.

Comparative example 5, cancel the N-ethylcarbazole 2.5g in embodiment 5, all the other are completely with embodiment 5, obtain product decahydronaphthalene 4.7g, yield is 68%.

Embodiment 6: the reduction of anthracene

Add 9.0 g (0.05 mol) of anthracene, 2.0 g (0.01 mol) of N-ethylcarbazole, and 0.3 g of Rh into the autoclave, fill with hydrogen to a pressure of 0.4 MPa, and the reaction temperature is 75 ° C. The reaction is completed after stirring for 5 hours. Distilled under reduced pressure after the still, the product perhydroanthracene was 9.2g, and the yield was 99%.

Comparative example 6, cancel 2.0g of N-ethylcarbazole in embodiment 6, all the other are exactly the same as embodiment 6, obtain product perhydroanthracene 6.8g, yield is 71%.

Embodiment 7: the reduction of biphenyl

Add 7.7g (0.05mol) of biphenyl, 2.0g (0.012mol) of carbazole and 0.3g of Rh in the autoclave, fill the hydrogen to a pressure of 1MPa, the reaction temperature is 75°C, and the stirring reaction is completed for 3 hours. Pressure distillation, product dicyclohexane 7.6g, yield is 92%.

Comparative example 7, cancel the carbazole 2.0g in embodiment 7, all the other are exactly the same as embodiment 7, obtain product dicyclohexane 5.6g, yield is 67%.

Example 8: Reduction of mixed aromatics

Add 3.9g (0.05mol) of benzene, 4.6g (0.05mol) of toluene, 6.4g (0.05mol) of naphthalene, 9.0g (0.05mol) of anthracene, 4.0g (0.02mol) of N-ethylcarbazole and Rh 0.5g, filled with hydrogen to pressure 2MPa, reaction temperature 150°C, stirring reaction for 4 hours to end, after cooling down and opening the kettle, vacuum distillation, the product cyclohexane 4.2g, the yield is 99%; methylcyclohexane 4.9g , the yield is 99%; decahydronaphthalene 6.8g, the yield is 98%; perhydroanthracene 9.5g, the yield is 99%.

Comparative example 8, cancel 4.0g of N-ethylcarbazole in embodiment 8, all the other are completely with embodiment 8, obtain product cyclohexane 3.3g, yield is 78%; Methylcyclohexane 3.3g, yield 68%; decahydronaphthalene 5.2g, the yield is 75%; perhydroanthracene 6.7g, the yield is 70%.

Example 9: Reduction of mixed aromatics

Add 3.9g (0.05mol) of benzene, 4.6g (0.05mol) of toluene, 6.4g (0.05mol) of naphthalene, 9.0g (0.05mol) of anthracene, 4.0g (0.02mol) of N-ethylcarbazole and Ru 0.5g, filled with hydrogen to pressure 3MPa, reaction temperature 80°C, stirring reaction for 4 hours to end, after cooling down and opening the kettle, vacuum distillation, product cyclohexane 3.4g, yield 80%; methylcyclohexane 3.8g , the yield is 78%; decahydronaphthalene 5.0g, the yield is 72%; perhydroanthracene 7.9g, the yield is 82%.

Comparative example 9, cancel 4.0g of N-ethylcarbazole in embodiment 9, all the other are completely with embodiment 9, get product cyclohexane 2.1g, yield is 50%; Methylcyclohexane 2.2g, yield is 45%; decahydronaphthalene 3.9g, the yield is 56%; perhydroanthracene 5.2g, the yield is 54%.

Embodiment 10: the reduction of naphthalene

Add naphthalene 6.4g (0.05mol), carbazole 2g (0.012mol) and Pt/C 0.5g (the weight content of Pt in this Pt/C is 5%) in autoclave, fill hydrogen to pressure 2MPa, reaction temperature 120 ℃, the stirring reaction was completed for 3 hours, and after the temperature was lowered and the kettle was opened, the product decahydronaphthalene was 6.2 g, and the yield was 90%.

Comparative example 10, cancel the carbazole 2g in embodiment 10, all the other are completely with embodiment 10, obtain product decahydronaphthalene 4.8g, yield is 70%.

Embodiment 11, the reduction of naphthalene

Add naphthalene 6.4g (0.05mol), N-ethylcarbazole 2.5g (0.013mol) and Pd/C 0.5g (the weight content of Pd in this Pd/C is 5%) in autoclave, fill hydrogen to pressure 2 MPa, the reaction temperature is 120°C, the reaction is stirred for 2.5 hours and the reaction is completed. After the temperature is lowered and the kettle is opened, the product is 6.3 g of decahydronaphthalene, and the yield is 92%.

Comparative example 11, cancel the N-ethylcarbazole 2.5g in the embodiment 11, all the other are completely the same as the embodiment 11, obtain the product decahydronaphthalene 4.5g, the yield is 65%.

Finally, it should be noted that the above examples are only some specific embodiments of the present invention. Obviously, the present invention is not limited to the above embodiments, and many variations are possible. All deformations that can be directly derived or associated by those skilled in the art from the content disclosed in the present invention should be considered as the protection scope of the present invention.

Claims (3)

1. The method for indirect hydrogen transfer reduction of aromatic hydrocarbons, characterized in that: under the conditions of catalyst, hydrogen transfer medium and hydrogen, aromatic hydrocarbons are reduced to alkanes; The reduction reaction conditions are as follows: The dosage ratio of catalyst and aromatic hydrocarbon is: 0.11~1g catalyst/0.05mol aromatic hydrocarbon; The dosage ratio of hydrogen transfer medium and aromatic hydrocarbon is: 0.005~0.05 mol hydrogen transfer medium/0.05mol aromatic hydrocarbon; Fill hydrogen to 0.2~4MPa, the reaction temperature is 50~180℃, and the reaction time is 1~7 hours; The catalyst is Pt/C, Pd/C, Ru, Rh or Raney nickel; the weight content of Pt in the Pt/C is 5%, and the weight content of Pd in the Pd/C is 5%; The hydrogen transfer medium is carbazole or N-ethylcarbazole. 2. the method for indirect hydrogen transfer reduction aromatics according to claim 1, is characterized in that: The reduction reaction conditions are as follows: The dosage ratio of catalyst and aromatic hydrocarbon is: 0.11~0.5g catalyst/0.05mol aromatic hydrocarbon; The dosage ratio of hydrogen transfer medium and aromatic hydrocarbon is: 0.005~0.015 mol hydrogen transfer medium/0.05mol aromatic hydrocarbon; Inflate with hydrogen to 0.2~3MPa; the reaction temperature is 50~150℃, and the reaction time is 1~5 hours. 3. according to the method for the described indirect hydrogen transfer reduction aromatics of claim 1 and 2, it is characterized in that: The aromatic hydrocarbon is at least one of benzene, toluene, ethylbenzene, xylene, naphthalene, anthracene and biphenyl; The alkane generated after benzene is reduced is cyclohexane, the alkane generated after toluene is reduced is methylcyclohexane, the alkane generated after ethylbenzene is reduced is ethylcyclohexane, and the alkane generated after xylene is reduced is Dimethylcyclohexane, the alkane generated after reduction of naphthalene is decahydronaphthalene, the alkane generated after reduction of anthracene is perhydroanthracene, and the alkane generated after reduction of biphenyl is dicyclohexane.