Method and catalyst for preparing benzene and cyclohexane by liquid-phase catalytic hydrogenation of chlorinated aromatic hydrocarbons

A technology of chlorinated aromatics and liquid phase catalysis, which is applied in chemical instruments and methods, metal/metal oxide/metal hydroxide catalysts, physical/chemical process catalysts, etc., and can solve difficult large-scale industrial production and poor catalyst stability , complex product components, etc., to achieve the effects of high production efficiency, simple regeneration, and low reaction temperature

Active Publication Date: 2017-05-10
NINGBO INST OF MATERIALS TECH & ENG CHINESE ACADEMY OF SCI +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The aforementioned methods are gas-phase catalytic hydrodechlorination of chlorinated aromatic hydrocarbons, high reaction temperature, high energy consumption, easy to generate hot spots to cause catalyst deactivation, complex product components, difficult separation, poor catalyst stability, and difficult large-scale industrial production

Method used

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Examples

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preparation example Construction

[0043] And in a more specific embodiment of the present invention, the preparation method of the catalyst that adopts can comprise following concrete steps:

[0044] (1) Add a certain amount of binder drop by drop, mix the additives Ag, Bi, Co or Na nitrate or carbonate and pseudo-boehmite powder evenly, extrude into strips, dry at 120°C for 12h, and Calcined at 750-1150°C for 2-5 hours to obtain Al with additives 2 o 3 Carrier, the binder is an aqueous solution of nitric acid, and the mass fraction of nitric acid is 1% to 20%;

[0045] (2) Soak the additive-containing carrier prepared in step (1) in organic solvent decane, methanol or ethylene glycol for 4 to 12 hours;

[0046] (3) dissolving the inorganic salt precursor of Pd, Pt or Ru in inorganic acid, and configuring it into a 10 mg / ml acid solution, wherein the inorganic acid is one of hydrochloric acid, nitric acid or sulfuric acid;

[0047] (4) Weigh a certain amount of the prepared Pd, Pt or Ru acid solution in ste...

Embodiment 1

[0051] (1) The preparation process of the catalyst of the method for preparing benzene and cyclohexane by liquid-phase catalytic hydrogenation of chlorinated aromatics in this embodiment comprises the following steps:

[0052] (a) Take by weighing 100g of pseudo-boehmite powder and fully mix with a certain amount of silver nitrate powder, then add a certain amount of nitric acid aqueous solution with a mass fraction of 5wt% dropwise to fully mix silver nitrate and pseudo-boehmite powder , extruded into a Raschig ring with a particle size of 6mm, dried at 120°C for 12h, and calcined at 850°C for 4 hours, with a specific surface area of ​​250m 2 / g, to obtain Al containing 0.1wt% Ag additive 2 o 3 carrier;

[0053] (b) Soak the auxiliary-containing carrier prepared in step (a) in the organic solvent methanol for 8 hours;

[0054] (c) PdCl 2 Dissolved in concentrated hydrochloric acid, configured into a 10mg / ml acid solution;

[0055] (d) take a certain amount of PdCl prepar...

Embodiment 2

[0064] (1) The preparation steps of the catalyst of the method for preparing benzene and hexanaphthene by liquid-phase catalytic hydrogenation of present embodiment hexachlorobenzene:

[0065] (a) Take 100g of pseudo-boehmite powder and fully mix it with a certain amount of silver nitrate powder, then add a certain amount of nitric acid aqueous solution with a mass fraction of 10wt% dropwise to fully mix the silver nitrate and pseudo-boehmite powder , extruded into a Raschig ring with a particle size of 6mm, dried at 150°C for 12h, and calcined at 1050°C for 4 hours, with a specific surface area of ​​150m 2 / g, to obtain Al containing 0.1wt% Ag additive 2 o 3 carrier;

[0066] (b) Soak the auxiliary-containing carrier prepared in step (a) in the organic solvent methanol for 8 hours;

[0067] (c) PdCl 2 Dissolved in concentrated hydrochloric acid, configured into a 20mg / ml acid solution;

[0068] (d) take a certain amount of PdCl prepared by step (c) 2 acid solution, slow...

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Abstract

The invention discloses a method and a catalyst for preparing benzene and cyclohexane by catalytically hydrogenating liquid phase of aryl chloride. The method comprises the following steps: providing a trickle bed reactor filled with a catalyst subjected to reduction treatment; dissolving the aryl chloride into an organic solvent to form an aryl chloride hot solution; and inputting the aryl chloride hot solution and hydrogen into the trickle bed reactor in a liquid phase form and a gas state form so that the aryl chloride hot solution and the hydrogen are subjected to hydrodechlorination reaction under the action of the catalyst to generate a product, wherein the product contains the benzene and the cyclohexane. Furthermore, the product is subjected to gas-liquid separation and distillation refining to obtain a hydrogenated product and the separated organic solvent and hydrogen are circularly used. By virtue of the process disclosed by the invention, the aryl chloride, which is difficult to degrade, is converted into the benzene and the cyclohexane which have the high additional value; the conversion rate of the aryl chloride is high, the side reaction is few, the service life of the catalyst is long and the environmental pollution is little; and the method is a green process capable of changing wastes into valuable things, and has a good application prospect and great economic benefits.

Description

technical field [0001] The invention relates to a method for catalytic hydrogenation of chlorinated aromatics, in particular to a method for preparing benzene or cyclohexane by liquid-phase catalytic hydrogenation of chlorinated aromatics. Background technique [0002] As basic raw materials or intermediates of organic synthesis, chlorinated aromatics are widely used in chemical industry, pesticides, medicines, dyes and other industries. However, chlorinated aromatics are chemically stable and can persist in environmental media such as water, soil, and sediment for several years. Even decades or longer. In addition, studies have found that a variety of chlorinated organic compounds will pose serious threats to the environment and ecosystems. For example, hexachlorobenzene can affect the liver and nervous system, causing organ function damage and skin damage. It is one of human carcinogens, because of its serious harm , photolysis, chemical decomposition and biodegradation a...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): B01J23/50B01J23/644B01J23/89B01J23/58C07C1/26C07C1/30C07C13/18C07C15/04
CPCY02P20/52
Inventor 周生虎周强钟骏良夏林兵于洪波
Owner NINGBO INST OF MATERIALS TECH & ENG CHINESE ACADEMY OF SCI
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