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Integrated member type methyl aromatic hydrocarbon selective oxidizing catalyst and its preparation and use

A technology for methyl aromatic hydrocarbons and oxidation catalysts, applied in the direction of metal/metal oxide/metal hydroxide catalysts, physical/chemical process catalysts, catalyst carriers, etc., can solve the problem of reducing device capacity, catalyst activity and selectivity to be improved , Catalyst failure and other problems, achieve the effect of overcoming environmental problems, good industrial application prospects, and high selectivity

Inactive Publication Date: 2006-08-23
ZHEJIANG UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

But in the industrial application, there are also the following problems: ① the activity and selectivity of the catalyst need to be improved; ② the reaction is a strong exothermic reaction, the temperature of the catalyst bed is difficult to control, and the complete oxidation reaction is difficult to eliminate; ③ the catalyst is in Easy to deactivate and sinter under long-term high temperature environment
[0006] Although the fluidized bed reactor commonly used in industry [Chinese patent CN1214959] can solve the heat transfer problem of the catalyst bed, it requires higher mechanical strength of the catalyst, and the vanadium catalyst supported by the metal oxide carrier is Fragile in the bed, easy to lose active substances
When the granular catalyst undergoes a strong exothermic reaction in a fixed bed reactor, local "hot spots" will inevitably appear in the bed. Usually, the "hot spots" are sensitive to process parameters, and the most common is the local overheating of the entire catalyst bed. The axial and radial temperature difference of the bed increases, which leads to the rapid failure of the catalyst and the complete oxidation of the reaction material
In order to solve this problem, many researchers have improved the structure of the fixed-bed reactor, such as adding heat conducting sheets or other components in the catalyst bed [Chinese patent CN2415831]. Unable to solve the large temperature difference between the axial and radial directions; secondly, the catalyst is inertly diluted [such as patent US3801634, JP53-30688B, JP85485], and the catalyst is diluted with inert particles in the catalyst bed (using different dilution ratios), although this method is better The axial temperature uniformity of the catalyst bed is greatly improved, but the high temperature in the catalyst particles cannot be eliminated, and the production capacity of the device is reduced; the heat transfer of the molten salt outside the tube [patents US4256783, US3147084] is the current industry for strong exothermic The reaction technology is widely used. Although it can basically remove the heat from the part of the catalyst close to the tube wall, if the thermal conductivity of the catalyst particles themselves is not good, the particles are piled up on each other, and the high temperature inside the particles and the radial temperature gradient of the reactor cannot be eliminated.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0035] 10 grams of vanadium pentoxide, 5 grams of phosphorous acid, 1.2 grams of antimony trioxide, 0.2 grams of aluminum nitrate, 0.2 grams of chromium nitrate, and 0.3 grams of potassium nitrate were dissolved in 500 ml of deionized water to prepare solution (1); take 11 grams of oxalic acid Dissolve in 100ml deionized water to prepare solution (2).

[0036] Use an oil bath to control the temperature of the solution (1) at 100-110° C., stir and reflux. Solution (2) was slowly added dropwise to solution (1) to obtain solution (3). After the dropwise addition, continue heating and stirring the solution (3) until the solution becomes clear, distill the solution (3) under reduced pressure at 60° C., remove part of the water, concentrate 600ml to 300ml, and obtain the catalyst precursor for use. Take the specific surface area as 200~300g / m 2 γ-Al 2 o 3 Add 100 grams of powder into 200ml of deionized water, stir, and add nitric acid dropwise to adjust the pH of the suspension ...

Embodiment 2

[0043] The catalyst precursor was prepared according to the method of Example 1 for use.

[0044] Prepare 200ml AlCl of 1M 3 Aqueous solution, slowly added dropwise to 800ml ammonia solution of 10wt%, and accompanied by vigorous stirring, after the precipitation reaction was completed, continued to stir for 3h, aging for 5h, to obtain Al(OH) 3 Precipitate the suspension, after filtering, the filter cake is washed 3 times with 500ml deionized water, and then made into 1.1g / ml concentration of Al(OH) 3 colloidal solution.

[0045] The metal corrugated thin plate material is FeCrAl alloy, 80mm×80mm×0.1mm (length×width×thickness) specifications, soaked in 2wt% sulfuric acid for 30min, washed twice with 100ml deionized water, and then in the muffle furnace at 850 ℃ air Calcined at lower temperature for 10h to obtain Al on the surface 2 o 3 Whisker material.

[0046] Metal sheet support directly immersed in Al(OH) 3 Colloidal solution, impregnated at least 4 times, and then ba...

Embodiment 3

[0049] The catalyst precursor was prepared according to the method of Example 1 for use.

[0050] Be prepared with the Al(OH) of 1.1g / ml concentration according to the method for embodiment 2 3 The colloidal solution is ready for use.

[0051]The wire mesh material is 316L stainless steel 3×7cm, the hole size is 30 mesh, the wire mesh is soaked in 2% sulfuric acid for 1 hour, and then washed with 100ml deionized water. Coating a layer of Al on the surface of the screen by electrophoretic deposition (EPD) 2 o 3 , the specific preparation process of the EDP method is: take 0.8 grams of aluminum powder (average particle size is 5um), 0.0032 grams of polyacrylic acid (PAA) and 0.02 grams of triethylamine (TEA) into 400ml of ethylene glycol, stir to form aluminum powder suspension , and then treated under ultrasonic for 30 minutes, using 30-mesh wire mesh as electrodes, the distance between electrodes was 1 cm, the working voltage was 100 V, and the deposition time was 2 minutes...

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PUM

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Abstract

The integrated member type catalyst for selective oxidation of methyl aromatic hydrocarbon includes carrier, adhesive and active component. The active component is attached via the adhesive onto the carrier, and the carrier is porous honeycomb ceramic material, metal screen or corrugated metal sheet. The active component has the general expression of V1PaXbAlcMdCreOn. The catalyst is superior to available one, which has environmental pollution caused by liquid phase oxidation, complete oxidation and catalyst deactivation of 'hot point' in the catalyst bed, and has high selectivity and excellent industrial application foreground.

Description

(1) Technical field [0001] The invention relates to an integral component type methyl aromatic hydrocarbon selective oxidation catalyst and its preparation and application, in particular to a catalyst for the oxidation and ammoxidation of toluene and picoline side chain methyl groups. (2) Background technology [0002] The selective oxidation of the side chains of methyl aromatic hydrocarbons is a very important step in the synthesis of fine chemical intermediates. The synthesized aromatic aldehydes, acids, nitriles, etc. can be used in textiles, pesticides, medicine, rubber, food and other fields. The industrially synthesized technical routes are mainly liquid-phase oxidation [Bo.HemantV, et al.Ind Eng Chem Prod Res Dev, 1984, 23(3): 455-458] and electrochemical oxidation [Zhu Xian et al., Journal of Shanghai University ( Natural Science Edition), 2001, 7(1): 73-76]. Although these synthetic routes are mature in technology, they will cause serious environmental problems, ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B01J27/14B01J23/00B01J21/00B01J32/00C07B41/00C07B43/00
Inventor 陈银飞卢晗锋黄海凤刘华彦
Owner ZHEJIANG UNIV OF TECH
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