Catalyst for m-toluidine prepared from m-nitrotoluene through gas phase hydrogenation, preparation method and regeneration method thereof

A technology of nitrotoluene and catalyst, which is applied in the field of catalyst for preparing m-toluidine by gas-phase hydrogenation of m-nitrotoluene and its preparation field, which can solve problems such as high equipment operation and maintenance costs, difficulties in continuous production, and non-existence of regeneration methods , to achieve the effects of long service life, simple preparation process and regeneration process, and high selectivity

Inactive Publication Date: 2010-06-16
NANJING UNIV OF SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The disadvantage is that the reactants must be separated from the catalyst and solvent, so the equipment operation and maintenance costs are high, continuous production is difficult and the efficiency is low
At present, the

Method used

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  • Catalyst for m-toluidine prepared from m-nitrotoluene through gas phase hydrogenation, preparation method and regeneration method thereof
  • Catalyst for m-toluidine prepared from m-nitrotoluene through gas phase hydrogenation, preparation method and regeneration method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0013] Catalyst composition: Cu accounted for 10% SiO 2 90%

[0014] Preparation method: Weigh 12.9g Cu(NO 3 ) 2 .6H 2 O and 25g silica gel, in Cu(NO 3 ) 2 .6H 2 Add 50ml of distilled water to O until it is completely dissolved; add 50ml of ammonia solution with a weight percentage of 10-25% until no precipitation is formed in the solution; adjust the pH value to 8-10, add silica gel to the prepared solution, and Stir mechanically at ~80°C for 2-10 hours; filter and wash the obtained solution until the filtrate is colorless and dry at 110-130°C for 3-5 hours, then roast it at 300-500°C for 3-5 hours After 6 hours, Cu accounted for about 10% in the obtained catalyst based on the weight of the catalyst.

Embodiment 2

[0016] Catalyst composition: Cu accounted for 20% SiO 2 80%

[0017] Preparation method: Weigh 29.2g Cu(NO 3 ) 2 .6H 2 O and 25g silica gel, in Cu(NO 3 ) 2 .6H 2 O Add 50ml of distilled water until it is completely dissolved; add 50ml of ammonia solution with a weight percentage of 10-25%, until no precipitation is formed in the solution; adjust the pH value to 8-10, add silica gel to the prepared solution, at 50- Stir mechanically at 80°C for 2-10 hours; filter and wash the obtained solution until the filtrate is colorless and dry at 110-130°C for 3-5 hours, then roast it at 300-500°C for 3-6 hours At this time, Cu accounted for about 20% of the obtained catalyst based on the weight of the catalyst.

Embodiment 3

[0019] Catalyst composition: Cu accounted for 30% SiO 2 70%

[0020] Preparation method: Weigh 49.6g Cu(NO 3 ) 2 .6H 2 O and 25g silica gel, in Cu(NO 3 ) 2 .6H 2 Add 50ml of distilled water to O until it is completely dissolved; add 50ml of ammonia solution with a weight percentage of 10-25% until no precipitation is formed in the solution; adjust the pH value to 8-10, add silica gel to the prepared solution, and Stir mechanically at ~80°C for 2-10 hours; filter and wash the obtained solution until the filtrate is colorless and dry at 110-130°C for 3-5 hours, then roast it at 300-500°C for 3-5 hours After 6 hours, Cu accounted for about 30% of the obtained catalyst based on the weight of the catalyst.

[0021] Process implementation: use m-nitrotoluene fixed-bed gas-phase hydrogenation reactor to evaluate the catalyst, put 5ml of the prepared catalyst into the fixed-bed reactor, and first carry out constant temperature treatment of the catalyst: after the other gases in...

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Abstract

The invention discloses a catalyst for m-toluidine prepared from m-nitrotoluene through gas phase hydrogenation, a preparation method and a regeneration method thereof. In the catalyst, SiO2 is used as a carrier and copper is used as a main active ingredient; and based on the weight of the catalyst, Cu accounts for 10 to 30 percent and the balance is SiO2. The method for preparing the catalyst comprises the following steps: weighing copper nitrate and silica gel; adding distilled water into the copper nitrate until the copper nitrate is fully dissolved; adding solution of ammonia water into the mixture until no precipitate is generated in the solution; adjusting the pH value; adding the silica gel into the prepared solution and stirring the solution; filtering and washing the obtained solution until the filtrate becomes colorless; and finally drying and baking the filtrate to obtain the catalyst. The catalyst after being inactivated can be regenerated through an air oxidizing roasting method. The catalyst has the advantages of long service life, excellent catalytic activity, high selectivity, simple preparation and regeneration methods and low cost, and wide application.

Description

technical field [0001] The invention relates to a catalyst, a preparation method and a regeneration method thereof, in particular to a catalyst for preparing m-toluidine by gas-phase hydrogenation of m-nitrotoluene, a preparation method and a regeneration method thereof. Background technique [0002] The mononitration of toluene is the first step in TNT production, and 60% o-nitrotoluene, 36% p-nitrotoluene and 4% m-nitrotoluene can be obtained. TNT can be obtained after nitration of o- and p-nitrotoluene, but no TNT can be obtained after nitration of m-nitrotoluene. The existence of m-nitrotoluene is unavoidable, it affects the product quality of TNT, and increases the content of nitro compounds in wastewater. The m-nitrotoluene is separated by the separation device, which can solve the above problems, but the problem of m-nitrotoluene is brought along with it. The production of 100,000 tons of mononitrotoluene will produce about 4,000 tons of m-nitrotoluene. As the deve...

Claims

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Application Information

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IPC IPC(8): B01J23/72C07C209/36C07C211/47B01J23/94B01J21/08
CPCY02P20/584
Inventor 叶志文吕春绪
Owner NANJING UNIV OF SCI & TECH
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