Method for producing metal oxides by means of spray pyrolysis

Patent metadata

Field	Value
Publication number	US-2019352189-A1
Application number	US-201716476274-A
Country	US
Kind code	A1
Filing date	Dec 20, 2017
Priority date	Jan 9, 2017
Publication date	Nov 21, 2019
Grant date	—

Abstract

A process for producing a metal oxide powder by flame spray pyrolysis where
a) a stream of a solution containing at least one oxidizable or hydrolysable metal compound is atomized to afford an aerosol by means of an atomizer gas, b) this aerosol is brought to reaction in the reaction space of the reactor with a flame obtained by ignition of a mixture of fuel gas and air, c) the reaction stream is cooled and d) the solid product is subsequently removed from the reaction stream, wherein e) the reaction space comprises one or more successive double-walled internals, wherein the wall of the double-walled internal facing the flame-conducting region of the reaction space comprises at least one slot through which a gas or vapour is introduced into the reaction space in which the flame is burning and f) the slot is arranged such that this gas or vapour brings about a rotation of the flame.

First claim

1 - 14 . (canceled)

15 . A process for producing a metal oxide powder by flame spray pyrolysis, comprising the steps of:
a) using an atomizer gas to atomize a stream of a solution and thereby produce an aerosol, wherein the solution comprises at least one oxidizable or hydrolysable metal compound; b) reacting the aerosol of step a) in a reaction space of a reactor with a flame obtained by ignition of a mixture of fuel gas and air to produce a reaction stream; c) cooling the reaction stream; d) removing a solid product from the cooled reaction stream of step c); wherein:
i) the reaction space comprises one or more successive double-walled internals, wherein the wall of the double-walled internal facing the flame-conducting region of the reaction space comprises at least one slot through which a gas or vapour is introduced into the reaction space in which the flame is burning; and
ii) the slot is arranged such that this gas or vapour brings about a rotation of the flame.

16 . The process of claim 15 , wherein the internal comprises at least two slots.

17 . The process of claim 15 , wherein the slot length/slot width ratio is 10:1-200:1.

18 . The process of claim 15 , wherein the reaction space diameter/total slot area ratio is 15:1-200:1.

19 . The process of claim 15 , wherein, when viewed in longitudinal section of an internal, the angle α of a slot to the vertical is 15°≤α≤60°.

20 . The process of claim 15 , wherein the angle β, which describes the angle between the section axis of the slot to the circle perpendicular of the centre, is 30°≤β≤60°.

21 . The process of claim 15 , wherein the gas is a fuel gas.

22 . The process of claim 15 , wherein the gas is an oxygen-containing gas.

23 . The process of claim 15 , wherein the metal component of the metal compound is selected from the group consisting of Ag, Al, Au, B, Ba, Ca, Cd, Ce, Co, Cr, Cu, Dy, Fe, Ga, Ge, Hf, In, La, Li, Mg, Mn, Mo, Nb, Ni, Pd, Rh, Ru, Sc, Si, Sm, Sn, Sr, Ta, Ti, V, Y, Yb and Zn.

24 . The process of claim 15 , wherein the solution contains zinc, titanium or calcium as the metal of the metal compound.

25 . The process of claim 15 , wherein the solution contains Li, La and Zr as the metal of the metal compound.

26 . The process of claim 15 , wherein the solution contains Li and Ni as the metal of the metal compound.

27 . The process of claim 15 , wherein the gas supplied via a slot in an internal lengthens the average residence time of the reaction mixture in the reaction space by at least a factor of 1.2 compared to a reaction space comprising none of these internals.

28 . The process of claim 15 , wherein the gas entry velocity from a slot of an internal into the reaction space is at least 10 Nm/s.

29 . The process of claim 15 , wherein the internal comprises four slots.

30 . The process of claim 15 , wherein the angle β is 40°≤β≤50°.

31 . The process of claim 16 , wherein the slot length/slot width ratio is 10:1-200:1.

32 . The process of claim 16 , wherein the reaction space diameter/total slot area ratio is 15:1-200:1.

33 . The process of claim 16 , the solution contains zinc, titanium or calcium as the metal of the metal compound.

34 . The process of claim 16 , wherein the solution contains Li, La and Zr as the metal of the metal compound.

Assignees

• Evonik Degussa Gmbh

Inventors

• Kress Peter
• Katusic Stipan
• Wiegand Armin
• Alff Harald
• Hagemann Michael

Classifications

• B01J19/26

  Nozzle-type reactors, i.e. the distribution of the initial reactants within the reactor is effected by their introduction or injection through nozzles · CPC title

• B01J10/002

  carried out in foam, aerosol or bubbles · CPC title

• B01J4/002

  Nozzle-type elements (nozzle-type reactors B01J19/26) · CPC title

• C01G25/006 Primary

  Compounds containing zirconium, with or without oxygen or hydrogen, and containing two or more other elements · CPC title

• C01F11/04

  by thermal decomposition · CPC title