Porous ceramics in filtration and related applications

Ceramic filters are available in a wide range of geometries and materials.
For the cleaning of process liquids and separation of materials in food, pharmaceutical, and chemical industry as well as environmental technology, cut-offs in the range between nanometers and micrometers are realized using ceramic membranes.
Gas separation membranes are currently in development. Ceramic membranes have the particular advantages of high pressure resistance, aging resistance in the operation and cleaning process as well as high reliability and good permeability in narrow cut-offs. However, the high investment costs and unfavorable packing densities with need for high filtration surfaces are disadvantageous.
In order to remove dusts from hot gases, e.g. modern combustion or gasification of pulverized coal and recovery of materials from hot exhaust gases, cleanable ceramic filter cartridges are used up to an operating temperature of 800 °C.

Furnaces and small combustors which are operated with wood, wood pellets or with other renewable or fossil resources must partly be equipped or retrofitted with filters due to the tightened environmental requirements. It is the particular challenge to develop a filter concept which allows an economical operation of the combustor or furnace.
In smelting metallurgy and foundry industry ceramic filters are widely used as depth filters to clean and quiet metal melts.
Alongside these classic filtration applications porous ceramics are also used for the gassing of liquids and metal melts or as carriers for biofilters.

 

Services offered

 

• Application-oriented development of ceramic filter systems: characterization of ceramic filters (composition, pore characteristic, permeability, strength, corrosion stability, cut-offs)
  
• Modification of ceramic filter materials and membrane systems
  
• Development and optimization of single technological steps for the manufacturing of ceramic filters
  
• Prototype manufacturing

 

Technical equipment

 

• Systems and equipment for the manufacturing of ceramic supports and membranes (extrusion, tape casting)
  
• Membrane coatings by dip and spin coating, spraying, and pressure filtration
  
• Measurement and analysis devices for the characterization of filters and filter systems (porosimeter, porometer, test stand for pressure loss, cross flow filtration system up to 6 bar) 
  

 

Examples and references

 

• Development of SiC microfiltration membranes with high corrosion and wear resistance
  
• Development of cofiring-capable, cost-efficient cross-flow microfiltration modules for series applications
  
• Precursor-based ultra and nanofiltration membranes consisting of non-oxide ceramics
  
• Thermally regenerative dust filters for domestic application
  
• Filter for wood-fired furnaces
  
• Composition optimization for the manufacturing of melt filters
  
• Creep and corrosion resistant filters for dust removal in hot gases (PFBC, IGCC)