Process for producing oxide catalysts

Patent metadata

Field	Value
Publication number	US-9731285-B2
Application number	US-81049308-A
Country	US
Kind code	B2
Filing date	Dec 11, 2008
Priority date	Dec 26, 2007
Publication date	Aug 15, 2017
Grant date	Aug 15, 2017

Abstract

An object of the present invention is to provide a process for producing an oxide catalyst used in a vapor-phase catalytic oxidation or vapor-phase catalytic ammoxidation reaction of propane or isobutene, which enables a catalyst demonstrating favorable yield to be stably produced. According to the present invention, there is provided a process for producing an oxide catalyst used in a vapor-phase catalytic oxidation or vapor-phase catalytic ammoxidation reaction of propane or isobutane, comprising the steps of: (i) preparing a catalyst raw material mixture containing Mo, V and Nb and satisfying the relationships of 0.1≦a≦1 and 0.01≦b≦1 when atomic ratios of V and Nb to one atom of Mo are defined as a and b, respectively; (ii) drying the catalyst raw material mixture; and (iii) calcining a particle, in which a content of the particle having a particle diameter of 25 μm or less is 20% by mass or less and a mean particle diameter is from 35 to 70 μm, in an inert gas atmosphere.

First claim

We claim:

1. A process for producing an oxide catalyst used in a vapor-phase catalytic oxidation or vapor-phase catalytic ammoxidation reaction of propane or isobutane, comprising the steps of:
(i) preparing a catalyst raw material mixture containing Mo, V and Nb and satisfying the relationships of 0.1≦a≦1 and 0.01≦b≦1 when atomic ratios of V and Nb to one atom of Mo are defined as a and b, respectively,
(ii) spray drying the raw material mixture to obtain catalyst precursor particles,
(iii) classifying the catalyst precursor particles having a mean particle diameter of from 45 to 65 μm in which a content of the precursor particles having a particle diameter of 25 μm or less is 8% by mass or less, and
(iv) pre-stage calcining the classified catalyst precursor particles in an inert gas atmosphere, wherein the pre-stage calcining is carried out continuously at a temperature from 250 to 400° C., to produce pre-stage calcined catalyst precursor particles having a reduction ratio of 8-12%,
(v) main calcining the pre-stage calcined catalyst precursor particles in an inert gas atmosphere, wherein the main calcining is carried out continuously at a temperature from 550 to 800° C.

2. The process for producing the oxide catalyst according to claim 1 , wherein the step (ii) is a step of spray drying the catalyst raw material mixture.

3. The process for producing the oxide catalyst according to claim 1 , wherein a recovery rate of the particle in the classifying step is 75% by mass or more.

4. The process for producing the oxide catalyst according to claim 1 , wherein the oxide catalyst is supported onto 10 to 80% by mass of silica in terms of SiO 2 , based on a total weight of oxides of constituent elements of the catalyst and the silica.

5. The process for producing the oxide catalyst according to claim 1 , wherein the step (iii) comprises a performing step of main calcining of pre-stage calcined catalyst precursor particles.

6. The process for producing the oxide catalyst according to claim 5 , wherein a temperature range of the main calcination is from 550 to 800° C.

7. The process for producing the oxide catalyst according to claim 5 , wherein a temperature range of the pre-stage calcination is from 250 to 400° C. and the temperature range of the main calcination is from 580 to 750° C.

8. The process for producing the oxide catalyst according to claim 5 , wherein the calcination is carried out while rotating a calcining device.

9. A process for producing an unsaturated acid or an unsaturated nitrile, comprising the step of:
bringing popane or isobutane into contact with an oxide catalyst obtained by the process according to claim 1 , so as to carry out a vapor-phase catalytic oxidation or vaper-phase catalytic ammoxidation reaction.

Assignees

• Tateno Eri
• Kaneta Masatoshi
• Asahi Kasei Chemicals Corp

Inventors

• Tateno Eri
• Kaneta Masatoshi

Classifications

• B01J23/34 Primary

  Manganese · CPC title

• B01J35/40 Primary

  characterised by dimensions, e.g. grain size (in a colloidal state B01J35/23; crystallite size B01J35/77) · CPC title

• B01J2523/57

  Tantalum · CPC title

• B01J27/0576

  Tellurium; Compounds thereof · CPC title

• B01J2523/41

  Silicon · CPC title