WO2023216458A1

WO2023216458A1 - Production process for hydrogenation of o-phenylenediamine

Info

Publication number: WO2023216458A1
Application number: PCT/CN2022/114156
Authority: WO
Inventors: 黄中桂; 方革新; 谢君; 姚尚喜; 江美玲; 孙叶萍; 殷金红; 方正贵; 杨华; 齐永发
Original assignee: 杨镭
Priority date: 2022-05-10
Filing date: 2022-08-23
Publication date: 2023-11-16
Also published as: CN114685282A; CN114685282B

Abstract

Provided is a production process for hydrogenation of o-phenylenediamine, comprising the following steps: adding a porous catalyst to an autoclave, adding o-nitroaniline and methanol in sequence, introducing hydrogen to replace the air in the autoclave three times, then heating to 100 °C, introducing hydrogen to 1.5 MPa, stirring at a constant speed of 1000 r/min, maintaining the system pressure at 0.8 MPa, incubating for 100 min for reaction, rectifying to give o-phenylenediamine, wherein the ratio of o-nitroaniline to methanol is controlled at 50 g:300 mL.

Description

A production process for hydrogenation and reduction of o-phenylenediamine

Technical field

The invention belongs to the technical field of o-phenylenediamine synthesis, and specifically relates to a production process of hydrogenation reduction of o-phenylenediamine.

Background technique

1,2-phenylenediamine, also known as o-phenylenediamine, is an organic compound with the chemical formula C6H8N2. It is a colorless monoclinic crystal at room temperature and becomes darker in air and sunlight. Slightly soluble in cold water, easily soluble in ethanol, ether and chloroform. It is an intermediate for dyes, pesticides, auxiliaries, photosensitive materials, etc., used in the manufacture of polyamide, polyurethane, carbendazim and thiophanate, reduced red GG, level dyeing Agent, anti-aging agent MB, and also used to prepare developers, surfactants, etc.

The existing o-phenylenediamine synthesis method uses o-nitroaniline and sodium sulfide as raw materials to synthesize o-phenylenediamine. After the reduction reaction is completed, the crude o-phenylenediamine is obtained through crystallization and centrifugation. The product content is 92%. Each ton of product produces waste water. 6 tons; product content is low, energy consumption is high, and the amount of three wastes is large.

technical problem

In order to solve the above technical problems, the present invention provides a production process for hydrogenation and reduction of o-phenylenediamine.

Technical solutions

本发明的目的可以通过以下技术方案实现：The object of the present invention can be achieved through the following technical solutions:

A production process for hydrogenation and reduction of o-phenylenediamine, including the following steps:

Add the porous catalyst to the autoclave, add o-nitroaniline and methanol in sequence, introduce hydrogen to replace the air in the autoclave three times, then raise the temperature to 100°C, fill with hydrogen to 1.5MPa, and stir at a constant speed of 1000r/min. Maintain the system pressure at 0.8MPa, perform a heat preservation reaction for 100 minutes, and perform distillation to obtain o-phenylenediamine. Control the dosage ratio of o-nitroaniline and methanol to 50g:300mL, and the dosage of porous catalyst is 0.1 of the weight of o-nitroaniline. -0.15%;

The porous catalyst includes the following steps:

Add PdCl2 to absolute ethanol, then add the porous carrier, stir at a constant speed for 30 minutes at room temperature, then transfer to a 100°C oven, dry for 12h, raise the temperature to 200°C, add nitrogen and hydrogen, the flow rate of nitrogen is 100mL/min, and hydrogen The flow rate is 10mL/min, and the reaction is kept for 2 hours to prepare a porous catalyst. Control the dosage ratio of PdCl2, porous carrier and absolute ethanol to 0.01-0 .02g:1g:10mL, the sum of the volumes of nitrogen and hydrogen is 15% of the oven volume.

The triblock copolymer is used as the template guiding agent and the phenolic prepolymer is used as the carbon source. After high-temperature roasting and carbonization, a porous carrier is formed. During the carbonization process, the skeleton shrinks and forms a porous structure. It is a carbon microstructure with a porous structure. ball, and then use the impregnation method to load the active component Pd on the porous carrier. By forming a porous structure, the contact area with the reaction system is increased, and the catalytic performance of the catalyst is further improved, thereby making o-phenylenediamine have the effect of Higher yield.

Further: the porous carrier includes the following steps:

Add the triblock copolymer into absolute ethanol, stir at a constant speed for 5 minutes, and then add the ethanol solution of the phenolic prepolymer.

Continue stirring for 10 minutes to prepare a mixed solution. Transfer the mixed solution to a petri dish and let it stand at room temperature for 8 hours. Then transfer it to a 100°C drying oven for thermal polymerization for 24 hours. Grind it into powder and add it to a 650°C carbonization furnace under a nitrogen atmosphere. Calculate for 3 hours to prepare a porous carrier, and control the dosage ratio of the ethanol solution of the triblock copolymer, phenolic prepolymer and absolute ethanol to be 1-1.5g:5-6g:20mL.

Further: the phenolic prepolymer includes the following steps:

Add phenol into the three-necked flask, heat until melted, then add 25% mass fraction of sodium hydroxide aqueous solution, stir and react at a constant speed for 10 minutes, slowly add 35% mass fraction of formaldehyde aqueous solution dropwise, raise the temperature to 75°C, and keep the reaction for 1 hour. After the reaction is completed Cool to room temperature, add 10% mass fraction of dilute hydrochloric acid solution dropwise to adjust the pH until the system becomes neutral, dehydrate under reduced pressure, add absolute ethanol and centrifuge to remove sodium chloride to prepare phenolic prepolymer, control phenol and hydrogen oxidation The dosage ratio of sodium aqueous solution and formaldehyde aqueous solution is 20g:4.15-4.25g:35 .5mL.

beneficial effects

本发明的有益效果：Beneficial effects of the present invention:

The present invention is a production process of o-phenylenediamine hydrogenation and reduction. The hydrogenation method is used to reduce o-nitroaniline to produce o-phenylenediamine. The product content is more than 99.5%. After reduction, it is directly used in liquid distillation. One ton of product produces 0.36 tons of waste water; the product content is significantly increased, energy consumption is reduced, and the amount of three wastes is greatly reduced; the invention also prepares a porous catalyst, using triblock copolymer as a template guide agent, and the phenolic prepolymer is carbon Source, after high-temperature roasting and carbonization, a porous carrier is formed. During the carbonization process, the skeleton shrinks and forms a porous structure, so it is a carbon microsphere with a porous structure. The active component Pd is then loaded on the porous carrier using an impregnation method. By making a porous structure, the contact area with the reaction system is increased, and the catalytic performance of the catalyst is further improved, resulting in a higher yield of o-phenylenediamine in a shorter time.

Best Mode of Carrying Out the Invention

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

Example 1

The porous catalyst includes the following steps:

Add phenol into the three-necked flask, heat until melted, then add 25% mass fraction of sodium hydroxide aqueous solution, stir and react at a constant speed for 10 minutes, slowly add 35% mass fraction of formaldehyde aqueous solution dropwise, raise the temperature to 75°C, and keep the reaction for 1 hour. After the reaction is completed Cool to room temperature, add 10% mass fraction of dilute hydrochloric acid solution dropwise to adjust the pH until the system becomes neutral, dehydrate under reduced pressure, add absolute ethanol and centrifuge to remove sodium chloride to prepare phenolic prepolymer, control phenol and hydrogen oxidation The dosage ratio of sodium aqueous solution and formaldehyde aqueous solution is 20g:4.15g:35.5mL.

Add the triblock copolymer (Sigma Company) into absolute ethanol, stir at a constant speed for 5 minutes, and then add the phenolic prepolymer.

of ethanol solution, continue stirring for 10 minutes to prepare a mixed solution, transfer the mixed solution to a petri dish, let it stand at room temperature for 8 hours, then transfer it to a 100°C drying oven for heat polymerization for 24 hours, grind it into powder, and add it to a 650°C carbonization furnace. , calcined for 3 hours under a nitrogen atmosphere to prepare a porous carrier, and the dosage ratio of the ethanol solution of the triblock copolymer, phenolic prepolymer and absolute ethanol was controlled to 1g:5g:20mL.

Add PdCl2 to absolute ethanol, then add the porous carrier, stir at a constant speed for 30 minutes at room temperature, then transfer to a 100°C oven, dry for 12h, raise the temperature to 200°C, add nitrogen and hydrogen, the flow rate of nitrogen is 100mL/min, and hydrogen The flow rate is 10mL/min, the heat preservation reaction is 2h, a porous catalyst is prepared, and the dosage ratio of PdCl2, porous carrier and absolute ethanol is controlled to 0 .01g:1g:10mL, the sum of the volumes of nitrogen and hydrogen is 15% of the oven volume.

Example 2

The porous catalyst includes the following steps:

Add phenol into the three-necked flask, heat until melted, then add 25% mass fraction of sodium hydroxide aqueous solution, stir and react at a constant speed for 10 minutes, slowly add 35% mass fraction of formaldehyde aqueous solution dropwise, raise the temperature to 75°C, and keep the reaction for 1 hour. After the reaction is completed Cool to room temperature, add 10% mass fraction of dilute hydrochloric acid solution dropwise to adjust the pH until the system becomes neutral, dehydrate under reduced pressure, add absolute ethanol and centrifuge to remove sodium chloride to prepare phenolic prepolymer, control phenol and hydrogen oxidation The dosage ratio of sodium aqueous solution and formaldehyde aqueous solution is 20g:4.20g:35.5mL.

Add the triblock copolymer (Sigma Company) into absolute ethanol, stir for 5 minutes at a constant speed, add the ethanol solution of the phenolic prepolymer, and continue stirring for 10 minutes to prepare a mixed solution. Transfer the mixed solution to a petri dish and let stand at room temperature. Leave it for 8 hours, then transfer it to a 100°C drying oven for thermal polymerization for 24 hours, grind it into powder, add it to a 650°C carbonization furnace, and roast it for 3 hours under a nitrogen atmosphere to prepare a porous carrier. Control the ethanol content of the triblock copolymer and phenolic prepolymer. The dosage ratio of solution and absolute ethanol is 1.2g:5.5g:20mL.

Example 3

The porous catalyst includes the following steps:

Add phenol into the three-necked flask, heat until melted, then add 25% mass fraction of sodium hydroxide aqueous solution, stir and react at a constant speed for 10 minutes, slowly add 35% mass fraction of formaldehyde aqueous solution dropwise, raise the temperature to 75°C, and keep the reaction for 1 hour. After the reaction is completed Cool to room temperature, add 10% mass fraction of dilute hydrochloric acid solution dropwise to adjust the pH until the system becomes neutral, dehydrate under reduced pressure, add absolute ethanol and centrifuge to remove sodium chloride to prepare phenolic prepolymer, control phenol and hydrogen oxidation The dosage ratio of sodium aqueous solution and formaldehyde aqueous solution is 20g:4.25g:35.5mL.

Add the triblock copolymer (Sigma Company) into absolute ethanol, stir for 5 minutes at a constant speed, add the ethanol solution of the phenolic prepolymer, and continue stirring for 10 minutes to prepare a mixed solution. Transfer the mixed solution to a petri dish and let stand at room temperature. Leave it for 8 hours, then transfer it to a 100°C drying oven for thermal polymerization for 24 hours, grind it into powder, add it to a 650°C carbonization furnace, and roast it for 3 hours under a nitrogen atmosphere to prepare a porous carrier. Control the ethanol content of the triblock copolymer and phenolic prepolymer. The dosage ratio of solution and absolute ethanol is 1.5g:6g:20mL.

Add PdCl2 to absolute ethanol, then add the porous carrier, stir at a constant speed for 30 minutes at room temperature, then transfer to a 100°C oven, dry for 12h, raise the temperature to 200°C, add nitrogen and hydrogen, the flow rate of nitrogen is 100mL/min, and hydrogen The flow rate is 10mL/min, the heat preservation reaction is 2h, a porous catalyst is prepared, and the dosage ratio of PdCl2, porous carrier and absolute ethanol is controlled to 0 .02g:1g:10mL, the sum of the volumes of nitrogen and hydrogen is 15% of the oven volume.

Example 4

Add the porous catalyst to the autoclave, add o-nitroaniline and methanol in sequence, introduce hydrogen to replace the air in the autoclave three times, then raise the temperature to 100°C, fill with hydrogen to 1.5MPa, and stir at a constant speed of 1000r/min. Maintain the system pressure at 0.8MPa, perform a heat preservation reaction for 100 minutes, and perform distillation to obtain o-phenylenediamine. Control the dosage ratio of o-nitroaniline and methanol to 50g:300mL, and the dosage of porous catalyst is 0.1 of the weight of o-nitroaniline. %, after testing, the yield of o-phenylenediamine is 99.5%;

Example 5

Add the porous catalyst to the autoclave, add o-nitroaniline and methanol in sequence, introduce hydrogen to replace the air in the autoclave three times, then raise the temperature to 100°C, fill with hydrogen to 1.5MPa, and stir at a constant speed of 1000r/min. Maintain the system pressure at 0.8MPa, perform a heat preservation reaction for 100 minutes, and distill to obtain o-phenylenediamine. Control the dosage ratio of o-nitroaniline and methanol to 50g:300mL, and the dosage of porous catalyst is 0.12 of the weight of o-nitroaniline. %, after testing, the yield of o-phenylenediamine was 99.6%;

Example 6

Add the porous catalyst to the autoclave, add o-nitroaniline and methanol in sequence, introduce hydrogen to replace the air in the autoclave three times, then raise the temperature to 100°C, fill with hydrogen to 1.5MPa, and stir at a constant speed of 1000r/min. Maintain the system pressure at 0.8MPa, perform a heat preservation reaction for 100 minutes, and perform distillation to obtain o-phenylenediamine. Control the dosage ratio of o-nitroaniline and methanol to 50g:300mL, and the dosage of porous catalyst is 0.15 of the weight of o-nitroaniline. %, after testing, the yield of o-phenylenediamine was 99.7%;

Comparative example 1

This comparative example uses o-nitroaniline and sodium sulfide as raw materials to synthesize o-phenylenediamine. o-nitroaniline reacts with sodium sulfide solution at a pressure of 100kPa and a reaction temperature of 105°C. The reaction time is 3 hours to obtain o-phenylenediamine. After detection The yield of o-phenylenediamine was 92%.

In the description of the specification, reference to the terms "one embodiment," "example," "specific example," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one aspect of the invention. in an embodiment or example. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The above contents are only examples and explanations of the present invention. Those skilled in the art may make various modifications or supplements to the described specific embodiments or substitute them in similar ways, as long as they do not deviate from the invention or exceed the rights of the present invention. The scope defined in the claims shall belong to the protection scope of the present invention.

Claims

A production process for hydrogenation and reduction of o-phenylenediamine, which is characterized in that it includes the following steps:

Add the porous catalyst to the autoclave, add o-nitroaniline and methanol in sequence, introduce hydrogen to replace the air in the autoclave three times, then raise the temperature to 100°C, fill with hydrogen to 1.5MPa, and stir at a constant speed of 1000r/min. Maintain the system pressure at 0.8MPa, perform a heat preservation reaction for 100 minutes, and perform distillation to obtain o-phenylenediamine. Control the dosage ratio of o-nitroaniline and methanol to 50g:300mL, and the dosage of porous catalyst is 0.1 of the weight of o-nitroaniline. -0.15%;

The porous catalyst includes the following steps:

Add PdCl2 to absolute ethanol, then add the porous carrier, stir at a constant speed for 30 minutes at room temperature, then transfer to a 100°C oven, dry for 12h, raise the temperature to 200°C, add nitrogen and hydrogen, the flow rate of nitrogen is 100mL/min, and hydrogen The flow rate was 10 mL/min, and the reaction was incubated for 2 h to prepare a porous catalyst.
A production process for hydrogenation reduction of o-phenylenediamine according to claim 1, characterized in that: controlling the dosage ratio of PdCl2, porous carrier and absolute ethanol to 0.01-0.02g:1g:10mL, nitrogen The sum of the volumes of hydrogen and hydrogen is 15% of the oven volume.
A production process for o-phenylenediamine hydrogenation reduction according to claim 1, characterized in that: the porous carrier includes the following steps:

Add the triblock copolymer into absolute ethanol, stir for 5 minutes at a constant speed, add the ethanol solution of the phenolic prepolymer, and continue stirring for 10 minutes to prepare a mixed solution. Transfer the mixed solution to a petri dish and let it stand at room temperature for 8 hours. Transfer to a 100°C drying oven and heat-polymerize for 24 hours, grind it into powder, add it to a 650°C carbonization furnace, and roast it for 3 hours under a nitrogen atmosphere to prepare a porous carrier.
A production process for hydrogenation reduction of o-phenylenediamine according to claim 3, characterized in that: the dosage ratio of the ethanol solution of the triblock copolymer, the phenolic prepolymer and the absolute ethanol is controlled to be 1-1. 5g:5-6g:20mL.
A production process for o-phenylenediamine hydrogenation reduction according to claim 3, characterized in that: the phenolic prepolymer includes the following steps:

Add phenol into the three-necked flask, heat until melted, then add 25% mass fraction of sodium hydroxide aqueous solution, stir and react at a constant speed for 10 minutes, slowly add 35% mass fraction of formaldehyde aqueous solution dropwise, raise the temperature to 75°C, and keep the reaction for 1 hour. After the reaction is completed Cool to room temperature, add 10% mass fraction of dilute hydrochloric acid solution dropwise to adjust the pH until the system becomes neutral, dehydrate under reduced pressure, add absolute ethanol and centrifuge to remove sodium chloride to prepare phenolic prepolymer.
A production process for hydrogenation reduction of o-phenylenediamine according to claim 5, characterized in that: the dosage ratio of phenol, sodium hydroxide aqueous solution and formaldehyde aqueous solution is controlled to 20g:4.15-4.25g:35. 5mL.