Method for regenerating catalyst for the production of methacrylic acid and process for preparing methacrylic acid

A methacrylic acid and catalyst technology, applied in chemical instruments and methods, catalyst regeneration/reactivation, chemical elements of heterogeneous catalysts, etc., can solve the problems of incomplete and satisfactory catalytic activity of regenerated catalysts, and achieve excellent selection Sexual, high-converting effects

Inactive Publication Date: 2009-10-14
SUMITOMO CHEM CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] However, any of the above-mentioned conventional regeneration methods does not necessarily have a sufficient effect of restoring catalytic activity, and the catalytic activity of the obtained regenerated catalyst is not always satisfactory.

Method used

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  • Method for regenerating catalyst for the production of methacrylic acid and process for preparing methacrylic acid

Examples

Experimental program
Comparison scheme
Effect test

reference example 1

[0051] Preparation of Fresh Catalyst and Evaluation of Fresh Catalyst

[0052] 38.2kg cesium nitrate [CsNO 3 ], 27.4 kg of 75% by weight of orthophosphoric acid and 25.2 kg of 70% by weight of nitric acid were dissolved in 224 kg of ion-exchanged water heated to 40° C. to prepare solution A. Separately, 297kg ammonium molybdate tetrahydrate [(NH 4 ) 6 Mo 7 o 24 4H 2 O] was dissolved in 330kg of ion-exchanged water heated to 40°C, and then 8.19kg of ammonium metavanadate [NH 4 VO 3 ] suspended therein to prepare solution B. Solutions A and B were adjusted to 40 °C. After solution A was added dropwise to solution B while stirring, the mixture was further stirred in a closed container at a temperature of 120°C for 5.8 hours, and then 10.2 kg of antimony trioxide [Sb 2 o 3 ] and 10.2kg copper nitrate trihydrate [Cu(NO 3 ) 2 ·3H 2 O] Suspension in 23 kg deionized water. The mixture was then stirred at a temperature of 120° C. in a closed vessel for 5 hours. The mixtu...

Embodiment 1

[0061] Preparation of regenerated catalyst

[0062] Two hundred grams (200 g) of the deactivated catalyst obtained in Reference Example 1(c) was added to 400 g of ion-exchanged water and the mixture was stirred. The kinds and amounts of elements (consumed elements) missing from the deactivated catalyst compared with the fresh catalyst obtained in Reference Example 1(a) were determined from fluorescent X-ray analysis. Thus, 31.5 g of molybdenum trioxide (MoO 3 ) and 2.7 g of 75% by weight orthophosphoric acid to compensate for missing elements. Then add 69.2g ammonium nitrate (NH 4 NO 3 ), the mixture was heated to 70 °C and maintained at this temperature for 1 hour. Thereafter, 12.5 g of 25% by weight aqueous ammonia were added. After maintaining at a temperature of 70°C for 1 hour, the mixture was stirred at a temperature of 120°C for 5 hours in an airtight container. The molar ratio of ammonium ions to nitrate ions in the slurry is 1.2. The slurry was dried at a tempe...

Embodiment 2

[0067] Preparation of regenerated catalyst

[0068] A regenerated catalyst was obtained in the same manner as in Example 1(a), except that the amount of 25% by weight ammonia water was changed from 12.5 g to 16.9 g and the molar ratio of ammonium ions to nitrate ions was adjusted to 1.3. The BET specific surface area of ​​the regenerated catalyst is shown in Table 1.

[0069] Example 2(b)

[0070] Activity test of regenerated catalyst

[0071] The regenerated catalyst obtained in Example 2(a) was tested for activity in the same manner as in Reference Example 1(b) to determine conversion and selectivity. The results are shown in Table 1.

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Abstract

A catalyst for the production of methacrylic acid comprising a heteropolyacid compound containing phosphorus and molybdenum is regenerated by a method comprising the steps of heat-treating a mixture containing a deactivated catalyst, water, a nitrate ion and an ammonium ion having a molar ratio to the nitrate ion of 1.3 or less at a temperature of at least 100 DEG C., drying the mixture to obtain a dried catalyst, and calcining the dried catalyst. The regenerated catalyst has substantially the same catalytic activity as a fresh catalyst in a gas phase catalytic oxidation reaction of methacrolein, isobutylaldehyde, isobutane or isobutyric acid to prepare methacrylic acid.

Description

technical field [0001] The present invention relates to a method for regenerating catalysts for the production of methacrylic acid. The invention also relates to a process for the production of methacrylic acid using a catalyst regenerated by such a regeneration process. Background technique [0002] It is known that when a catalyst for producing methacrylic acid comprising a heteropolyacid compound containing phosphorus and molybdenum is used for a long time in a gas-phase catalytic oxidation reaction using methacrolein or the like as a raw material, the catalyst is deactivated because the catalyst The catalytic activity of the catalyst decreases due to heat load, etc. [0003] As a method for regenerating a deactivated catalyst, JP-A-61-283352 discloses a method comprising the steps of: dissolving or suspending the deactivated catalyst in water to prepare and 0.1-4.0 molar nitrate ions (the molar ratio of ammonium ions to nitrate ions is at least 1.75), then drying and c...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B01J31/40B01J31/34B01J31/18B01J31/36B01J38/02B01J38/74C07C57/05C07C57/055
CPCB01J27/199B01J27/285B01J27/19C07C51/252C07C51/215B01J23/002B01J38/66B01J31/4015B01J2523/00Y02P20/584C07C57/04B01J2523/15B01J2523/17B01J2523/51B01J2523/53B01J2523/55B01J2523/68
Inventor 大石嘉彦吉泽纯也白石英市
Owner SUMITOMO CHEM CO LTD
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