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Print version | Main page > Institute > Structure of Institute of Catalysis > Research Departments > ... > R&D > Monolithic supports and catalysts

Monolithic honeycomb supports and catalysts

Development of scientific basis for the production of monolith supports and catalysts. Establishment of the first national production facility


      We develop methods for preparation of monolithic of unique chemical composition and in a series of special geometry. For this purpose we have all nesessary laboratory scale equipment: mixer for the preparation of extrusion masses, laboratory extruder, desiccator and ovens for the monolith thermal treatment (up to 1600oC). For the preparation of monolith supports with standard dimensions (diameter - 10, 20 and 45 mm) several dies were designed and manufactured.

Geometric characteristics of the dies

  Type 1 Type 2 Type 3
Diameter 10 mm 20 mm 45 mm
Channel size 1x1 mm 1x1 mm 2x2 mm
Wall thickness 0.25 mm 0.5 mm 0.5 mm

The elements of die for the monolith structure preparation
with diameter of 20 mm extrusion are presented.

      At present more than five types of monolithic supports with the optimal physicochemical properties are prepared and tested both in BIC and other laboratories in frame of our co-operation projects.

  • Anatase;
  • Zirconium oxide;
  • Alumina;
  • Alumosilicate;
  • Zeolite;
  • Other.

Two types of the binder were used for the extrusion masses preparation:

  1. Sol of aluminum hydroxide with a pseudoboehmite structure. This sol formed during the reaction between the hydroxide and nitric acid served both as a binder and as a source of γ-Al2O3 after calcination.
  2. The pillared clay of montmorillonite type in Na- and Ca-form. Using of montmorillonite provides high mechanical strength and absence of defects during drying and calcination of monoliths. The Ca- and Na-forms of montmorillonite provides better plastic properties of extrusion masses.

Properties of the monoliths

Main
components
/ToC
SBET m2/g Phase composition
at ToC
Mech. Strength, kg/cm2 Pore volume
(water), cm3/g
TiO2 / 700oC 86 TiO2(anatase) + Al2O3*SiO2 8 0.36
TiO2 + ZrO2 / 700oC 69 TiO2(anatase) + ZrO2(cub.) + Al2O3*SiO2 13 0.36
Alumosilicate / 700oC 33 Al2O3*SiO2 + α-SiO2 19.5 0.12
Al2O3 / 600oC 190 γ-Al2O3 28 0.34
H-ZSM-5 / 600oC 350 H-ZSM-5 + Al2O3*SiO2 20 0.4

      The monoliths based on TiO2, ZrO2, and Al2O3 still possess relatively high surface area and acceptable mechanical strength that allows their application as supports for monolith catalysts.


Washcoated monolith supports

Initial materials for preparation of the washcoating

  • Powder of alumina of γ, β, θ and α-modifications
  • Powder of titania of rutile or anatase modification
  • Ultra-dispersed powder of zirconia stabilized by yttria

Washcoated supports

  • Thickness of the washcoating in the range of 10-100 μm;
  • High adhesion and cohesion strength of the washcoating layers tested against action of ultrasound, thermal shock and attrition in a fluidized bed of abrasive powder.

Shematic presentaion of monolith
channel with supported washcoating layer.

Micrograph of cross-section view of washcoating layer on monolith surface with different enlargement.

Monolithic honeycomb supports and catalysts

Advantages

  • Low pressure drop
  • High thermal stability and mechanical strength
  • Beter performance in many processes

Description
Monolithic supports and catalysts are produced as tetra- and hexahedral prisms, parallelepipeds and cylinders.

Technical parameters

 Face sizes
 25-150 mm

 Cylinder diameter
 25-50 mm

 Channel sizes
 form 1x1 to 10x10 mm2

 Wall thickness
 0.25-1.2 mm

 Monolith length
 50-1000 mm

Technologies are Adopted on Pilot Scale:
SUPPORTS

  • Cordierite, ultraporcelain and aluminosilicate
  • Composite materials based on TiO2, TiO2 dopped by of Al, Nb, La, Ce oxides and zeolites

Catalysts

  • Supported (active components such as Cu, Mg, and Co chromites, perovskites, Pt, Pd, and Cu, Mn, V oxides are introduced by impregnation)
  • Washcoated catalysts containing active composite systems ( V2O5/TiO2, V2O5-WO3/TiO2, CuO-TiO2and metal-substituted zeolites)
  • Catalysts obtained by mixing active components then shaped as monoliths

Technologies for preparing honeycomb monolithic supports and catalysts are covered by the Russian patents.

Application Areas

  • DeNOx process for cleaning flue gases produced by power plants, boiler houses and diesel power plants
  • Purification of industrial waste gases from CO, and VOCs
  • Direct oxidation of H2S to sulfur, purification of waste gases from Claus process
  • Partial oxidation and oxidative dehydrogenation of hydrocarbons
  • Oxidative methane coupling

Service

  • Monolithic may be used in the form of one block or as cassette composed of a few blocks.



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