Method and apparatus for producing metal oxide particles

Patent metadata

Field	Value
Publication number	US-9352965-B2
Application number	US-201113583159-A
Country	US
Kind code	B2
Filing date	Mar 7, 2011
Priority date	Mar 8, 2010
Publication date	May 31, 2016
Grant date	May 31, 2016

Abstract

There is provided a method and an apparatus for producing metal oxide particles, which produce metal oxide particles having a high photocatalytic activity with high yield. The method for producing metal oxide particles of the invention is characterized by including combining, in a reaction tube, a preheated metal chloride-containing gas with a preheated first gas which does not contain the metal chloride at a first junction to obtain a first combined gas, and combining the first combined gas with a preheated second gas which does not contain the metal chloride, at a second junction which is further downstream of the first junction, to obtain a second combined gas, wherein at least one of the metal chloride-containing gas and the first gas contains oxygen, and wherein the preheated metal chloride-containing gas is further heated in a region between the first junction and the second junction (referred to as first reaction zone), by combining the first gas with the metal chloride-containing gas at the first junction while setting the preheat temperature of the first gas at a temperature equal to or higher than the preheat temperature of the metal chloride-containing gas, and the first combined gas is further heated in a region downstream of the second junction by combining the second gas with the first combined gas at the second junction while setting the preheat temperature of the second gas at a temperature equal to or higher than the temperature of the first combined gas.

First claim

The invention claimed is:

1. A method for producing decahedral titanium oxide particles, the method comprising:
combining, in a reaction tube, a preheated titanium tetrachloride-containing gas with a preheated first gas which does not contain the titanium tetrachloride at a first junction to obtain a first combined gas, and
combining the first combined gas with a preheated second gas which does not contain the titanium tetrachloride, at a second junction which is further downstream of the first junction, to obtain a second combined gas,
wherein at least one of the titanium tetrachloride-containing gas and the first gas contains oxygen,
wherein the preheated titanium tetrachloride-containing gas is further heated in a first reaction zone which is a region between the first junction and the second junction by combining the first gas with the titanium tetrachloride-containing gas at the first junction while setting the preheat temperature of the first gas at a temperature higher than the preheat temperature of the titanium tetrachloride-containing gas, and the first combined gas is further heated in a region downstream of the second junction by combining the second gas with the first combined gas at the second junction while setting the preheat temperature of the second gas at a temperature higher than the temperature of the first combined gas,
the first gas contains one or more gases selected from the group consisting of oxygen gas, nitrogen gas, and argon,
the second gas contains one or more gases selected from the group consisting of oxygen gas, nitrogen gas, and argon, and
the preheat temperature of the titanium tetrachloride-containing gas is equal to or higher than 500° C. and equal to or lower than 750° C., wherein an insulating material is provided in a second zone which is a region in which the first combined gas and the preheated second gas are combined to form the second combined gas, and the second combined gas flows through, wherein the insulating material is wound around the outside of the second zone so as to maintain the temperature of the gas in the second zone, and wherein no heating device is provided inside a space surrounded by the insulting material.

2. The method for producing decahedral titanium oxide particles according to claim 1 , wherein the temperature of the first combined gas is equal to or higher than 700° C. and equal to or lower than 850° C.

3. The method for producing decahedral titanium oxide particles according to claim 1 , wherein the temperature of the second combined gas is equal to or higher than 800° C. and equal to or lower than 1150° C.

4. The method for producing decahedral titanium oxide particles according to claim 1 , wherein the preheat temperature of the first gas is equal to or higher than 700° C. and equal to or lower than 850° C.

5. The method for producing decahedral titanium oxide particles according to claim 1 , wherein the preheat temperature of the second gas is equal to or higher than 950° C. and equal to or lower than 1200° C.

6. The method for producing decahedral titanium oxide particles according to claim 1 , wherein the titanium tetrachloride-containing gas contains nitrogen gas.

7. The method for producing decahedral titanium oxide particles according to claim 1 , wherein the concentration of titanium tetrachloride contained in the first combined gas is set at 0.1% to 15% by volume.

8. The method for producing decahedral titanium oxide particles according to claim 1 , wherein the time for which the first combined gas remains in the first reaction zone is adjusted to 30 to 400 milliseconds.

9. The method for producing decahedral titanium oxide particles according to claim 1 , wherein the Reynolds number of the second combined gas is adjusted to 10 to 10,000.

Assignees

• Ohtani Bunsho
• Sugishita Noriyuki
• Kuroda Yasushi
• Univ Hokkaido Nat Univ Corp
• Showa Denko Kk

Inventors

• Ohtani Bunsho
• Sugishita Noriyuki
• Kuroda Yasushi

Classifications

• C01P2006/90

  Other properties not specified above · CPC title

• C01G1/02

  Oxides · CPC title

• C01B13/22 Primary

  of halides or oxyhalides · CPC title

• C01P2002/30

  Three-dimensional structures · CPC title

• C01G23/07

  Producing by vapour phase processes, e.g. halide oxidation · CPC title