Catalyst grading method for preparation of maleic anhydride from n-butane by oxidation

A catalyst, n-butane technology, applied in the field of n-butane production of maleic anhydride, can solve the problems of reducing the effective volume of the reactor, increasing the product yield, reducing the production efficiency, etc., and achieves reducing the hot spot of the reaction, improving the efficiency, and suppressing a large number of concentrated exothermic effect

Active Publication Date: 2018-06-01
CHINA PETROLEUM & CHEM CORP +1
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  • Abstract
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  • Claims
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Problems solved by technology

[0009] USP4,855,459 proposes a method for preparing maleic anhydride by oxidation of n-butane, which is carried out by diluting and packing inert silica-alumina balls and catalysts, and reducing the hot spots of reaction by diluting and packing at the hot spots of the reaction tube. temperature, to improve the selectivity of maleic anhydride, the purpose of increasing the yield of maleic anhydride, and at the same time the stability period of the catalyst has been extended, but the unfavorable factor is the addition of inert materials, which reduces the effective volume of the reactor and also reduces the production efficiency
[0010] In the existing fixed-bed n-butane oxidation to maleic anhydride technology, catalysts with different activities are loaded in the reactor along the direction of reactant flow, so that when the catalyst is loaded, the catalytic activity changes along the feed direction according to the reaction requirements, so as to realize the oxidation The control of the reaction, the realization of improving the feed concentration of the reaction raw material n-butane reaches more than 2.0%, and the method of increasing the product yield has not been reported so far

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  • Catalyst grading method for preparation of maleic anhydride from n-butane by oxidation
  • Catalyst grading method for preparation of maleic anhydride from n-butane by oxidation
  • Catalyst grading method for preparation of maleic anhydride from n-butane by oxidation

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preparation example Construction

[0042] (2) Preparation of vanadium phosphorus oxygen catalyst

[0043] The vanadium phosphorus oxide obtained in step (1) is first shaped, and the shape of the obtained vanadium phosphorus oxygen catalyst can be a compressed tablet, a spherical shape, an extruded rod, etc., and the phase of the obtained catalyst precursor is (VOHPO 4 0.5H 2 o).

[0044] (3) Activation treatment of vanadium phosphorus oxygen catalyst

[0045] The shaped catalyst is placed in a tubular reactor, under the n-butane / air atmosphere with n-butane content of 0.6% (v), keep n-butane / air volume space velocity 500h -1 , the heating rate is 2°C / min, the activation temperature is raised from room temperature to 400°C for roasting treatment, and kept at 400°C for 40 hours, the activation process is completed, and the green vanadium phosphorus oxide catalyst of the present invention is obtained. The phase of the catalyst is (VO) 2 P 2 O7 phase, and a small amount of VOPO 4 Mutually.

[0046] The vanad...

Embodiment 1

[0050] exist figure 1 Add 442.95 kg of isobutanol, 29.53 kg of vanadium pentoxide, 0.3 kg of ferric nitrate hexahydrate, and 0.5 kg of zirconium nitrate into the reaction kettle shown with a stirring device and a reflux condensing device. High reaction temperature and kept at 100±2°C, carry out reflux reaction, keep reflux time for 4 hours, then add 47.50kg of phosphoric acid with a concentration of 85%, the phosphorus / vanadium molar ratio is 1.27, continue to reflux for 8 hours, and the reaction ends. After the reaction solution was cooled to room temperature, it was vacuum filtered, and the filter cake was rinsed with a small amount of isobutanol three times, then the filter cake was placed in an enamel tray and dried naturally at room temperature, dried in an oven at 100°C for 8 hours, and finally dried in a muffle furnace. Calcined at 250°C for 5 hours to obtain a dark brown catalyst precursor.

[0051] Add the catalyst precursor prepared above to graphite powder with a m...

Embodiment 2

[0055] exist figure 1Add 442.95 kg of isobutanol, 29.53 kg of vanadium pentoxide, 0.3 kg of ferric nitrate hexahydrate, and 0.5 kg of zirconium nitrate into the reaction kettle shown with a stirring device and a reflux condensing device. High reaction temperature and kept at 100±2°C, carry out reflux reaction, keep reflux time for 4 hours, then add 44.13kg of phosphoric acid with a concentration of 85%, the phosphorus / vanadium molar ratio is 1.18, continue to reflux for 8 hours, and the reaction ends. After the reaction solution was cooled to room temperature, it was vacuum filtered, and the filter cake was rinsed three times with a small amount of isobutanol to complete the reaction. The filter cake was put into an enamel dish and air-dried at room temperature, dried in an oven at 100°C for 8 hours, and finally calcined in a muffle furnace at 250°C for 5 hours to obtain a dark brown catalyst precursor.

[0056] Add the catalyst precursor prepared above to graphite powder wit...

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Abstract

The invention discloses a catalyst grading method for preparation of maleic anhydride from n-butane by oxidation. N-butane is mixed with air, and obtained mixed reaction gas flows in parallel throughthree or more vanadium phosphorus oxide catalyst beds connected in series, and is contacted with a vanadium phosphorus oxide catalyst for reaction under the oxidation reaction condition, wherein according to the contact sequence with the mixed reaction gas, the three or more catalyst beds connected in series perform graded loading according to the trend of the P/V molar ratio of the catalyst beingfirstly low, high and then low, so that activity distribution of the catalyst is balanced, and the activity of the catalyst is fully exerted. With the method, the n-butane concentration in feed can be increased, the reaction hot spot of the beds is reduced, temperature distribution of the beds is uniform, occurrence of side reactions is effectively inhibited, selectivity of a product is improved,and the yield of the product maleic anhydride is increased.

Description

technical field [0001] The invention relates to a method for preparing maleic anhydride from n-butane, in particular a method for preparing maleic anhydride by oxidation of n-butane with catalyst gradation, which can be used in the reaction of preparing maleic anhydride by n-butane oxidation using a fixed bed process process. Background technique [0002] Maleic anhydride, also known as maleic anhydride, is an important organic chemical raw material and the third largest organic anhydride in the world after phthalic anhydride and acetic anhydride. It is widely used in petrochemical, food processing, and pharmaceutical industries. , Building materials and other industries. Its specific applications include the manufacture of unsaturated polyester resins, alkyd resins, maleic acid (maleic acid), fumaric acid (fumaric acid), as well as pesticides, coatings, glass fiber reinforced plastics, lubricating oil additives, paper chemistry Product additives, surfactants, etc. The ad...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D307/60B01J27/198B01J35/02
CPCC07D307/60B01J27/198B01J35/026
Inventor 王海波刘新宇宋丽芝侯学伟勾连科程谨
Owner CHINA PETROLEUM & CHEM CORP
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