Process for the preparation of pulverulent heterogeneous substances

Abstract

A suspension, dispersion or emulsion is introduced into a burner. A two-stage after-treatment is then carried out. The resulting powder can be employed as a catalyst.

We claim:  
     
         1 . A process for the preparation of a pulverulent heterogeneous substance, comprising introducing a dispersion, suspension or emulsion into a turbulent or laminar burner, heating the dispersion, suspension or emulsion under reaction conditions established in said burner to obtain a reaction mixture powder, introducing said reaction mixture powder into a downstream flow through tube, treating said powder with a gas, optionally feeding said powder to a washer, a separator or a filter.  
     
     
         2 . The process according to  claim 1 , wherein said dispersion, suspension or emulsion is present in the high temperature flow through tubes reactor as a gas-borne group of particles.  
     
     
         3 . A process according to  claim 1 , further comprising heating the flow through tube by an exothermic combustion reaction which takes place in the tube.  
     
     
         4 . The process according to  claim 1 , further comprising heating the flow through the tube by feeding in non-combustible hot gases.  
     
     
         5 . The process according to  claim 1 , further comprising heating the flow through tube indirectly by heating up flow through tube walls adjacent a reaction space of said tube.  
     
     
         6 . The process according to  claim 1 , further comprising heating the flow through tube by electrical plasma and/or inductive plasma.  
     
     
         7 . The process according to  claim 1 , further comprising subjecting the flow through tube to a high-energy laser light beam and/or microwave energy.  
     
     
         8 . The process according to  claim 7 , further comprising, in addition to the dispersion, suspension or emulsion in the form of particles, feeding a non-combustible reactive gas or vapour to the flow through tube to produce a reaction product which is a highly dispersed nanostructured solid which adds on to the surface of the particles of the dispersion, suspension or emulsion.  
     
     
         9 . The process according to  claim 8 , wherein the reaction product formed thereby is a homogeneous molecular layer on the particles of the dispersion, suspension, or emulsion, the particles of the dispersion, suspension or emulsion being thereby coated with a mono- or multimolecular layer.  
     
     
         10 . The process according to  claim 8 , wherein the non-combustible reactive gas or vapour is at least one of a metal chloride or organometallic compound.  
     
     
         11 . The process according to  claim 1 , wherein the temperature of the reaction is above 1000° C.  
     
     
         12 . The process according to  claim 1  wherein the reaction temperature is 500 to 2000° C.  
     
     
         13 . The process according to  claim 1 , wherein the dispersion, suspension or emulsion is fed to the burner axially in co- or countercurrent or radially.  
     
     
         14 . The process according to  claim 13 , wherein the dispersion, suspension or emulsion is fed to the reaction space radially.  
     
     
         15 . The process according to  claim 1  wherein the powder is in a hot gas phase for at least 0.01 seconds.  
     
     
         16 . A pulverulent substance obtainable by the process according to  claim 1 .  
     
     
         17 . The use of a pulverulent substance according to  claim 16  as a catalyst.  
     
     
         18 . The use of a pulverulent substance according to  claim 16  as an oxygen store, NO x  store, C n H m , store for catalysis and adsorbents.  
     
     
         19 . The use of a pulverulent substance according to  claim 16  for the production of ductile ceramic components.  
     
     
         20 . The use of a pulverulent substance according to  claim 16  for the production of components with a quantum mechanics activity, in particular sensors, and photoelectrically active emitters.  
     
     
         21 . The use of a pulverulent substance according to  claim 16  for the production of glasses and glass ceramic.