Method for producing acrylonitrile

Patent metadata

Field	Value
Publication number	US-11827585-B2
Application number	US-201917041264-A
Country	US
Kind code	B2
Filing date	Feb 19, 2019
Priority date	Mar 28, 2018
Publication date	Nov 28, 2023
Grant date	Nov 28, 2023

Abstract

A method for producing acrylonitrile, having: a catalyst treatment step of preparing a composite metal oxide catalyst including molybdenum, bismuth, and iron and including 50 ppm or more of carbon; and a vapor-phase catalytic oxidation step of subjecting propylene to ammoxidation reaction using the composite metal oxide catalyst to produce acrylonitrile.

First claim

The invention claimed is:

1. A method for producing acrylonitrile, comprising:
a catalyst treatment step of preparing a composite metal oxide catalyst comprising molybdenum, bismuth, and iron and comprising 50 ppm or more of carbon; and
a vapor-phase catalytic oxidation step of subjecting propylene to ammoxidation reaction using the composite metal oxide catalyst to produce the acrylonitrile,
wherein the catalyst treatment step has:
a pre-step of treating a composite metal oxide comprising molybdenum, bismuth, and iron under a reducing gas and oxygen atmosphere for 50 hours or longer; and
a post-step of circulating the composite metal oxide in a hopper with nitrogen or air.

2. The method for producing the acrylonitrile according to claim 1 , wherein
the composite metal oxide catalyst prepared in the catalyst treatment step comprises 5000 ppm or less of carbon.

3. The method for producing the acrylonitrile according to claim 1 , wherein
a calorific value of an exothermic peak having a peak top at 600° C. or higher in a DTA analysis is 80 J/g or less in the composite metal oxide catalyst prepared in the catalyst treatment step.

4. The method for producing the acrylonitrile according to claim 1 , wherein
the carbon comprised in the composite metal oxide catalyst in the vapor-phase catalytic oxidation step is 5000 ppm or less.

5. The method for producing the acrylonitrile according to claim 1 , wherein
an oxygen concentration at a discharge port of a fluidized bed reactor in the vapor-phase catalytic oxidation step is 0.2 to 1.0% by volume.

6. The method for producing the acrylonitrile according to claim 1 , wherein
a supply amount of starting material per unit catalyst amount (T-Py/T-Cat/hr) in the vapor-phase catalytic oxidation step is 0.08 to 0.11.

7. The method for producing the acrylonitrile according to claim 1 , comprising, before the vapor-phase catalytic oxidation step, a startup step of supplying oxygen to the fluidized bed reactor in which the composite metal oxide catalyst exists and increasing a temperature inside the fluidized bed reactor to 300° C. to 500° C.

Assignees

• Asahi Chemical Ind

Inventors

• Morii Kazunari
• Fukuzawa Akiyoshi

Classifications

• C07C253/26 Primary

  containing carbon-to-carbon multiple bonds, e.g. unsaturated aldehydes · CPC title

• B01J8/22

  gas being introduced into the liquid · CPC title

• B01J8/24

  according to "fluidised-bed" technique (B01J8/20 takes precedence) · CPC title

• B01J21/18

  Carbon · CPC title

• B01J23/8876

  Arsenic, antimony or bismuth · CPC title