Title: A Process for producing SCR Catalyst PlateType Structures
FIELD OF THE INVENTION:
This invention relates to a process for Producing SCR Catalyst Plate Type Structures
The present invention also relates to fabrication process or combining different
process/es together for manufacturing SCR (selective catalytic reduction) plate-type
structures with desired properties for de-NOx control in various applications including
coal-fired power plants.
BACKGROUND OF THE INVENTION:
Emission regulations for unbumed hydrocarbons, nitrogen oxides (NO, NO2 and N2O,
combinedly called NOx) and particulates are becoming more stringent throughout the
world.
The major sources of NOx from stationary sources are power generation, stationary
engines, industrial boilers, process heaters and gas turbines Post combustion
NOx control technologies that are currently being applied to coal-fired utility boilers
include selective non catalytic reduction (SNCR), selective catalytic reduction (SCR),
and combined SNCR/SCR systems (hybrid SNCR/SCR) respectively. SCR can be
applied as a stand-alone NOx control or with other technologies, including selective
non-catalytic reduction (SNCR) and combustion controls such as low NOx burner
(LNB) and flue gas recirculation (FGR).

SCR is typically implemented on stationary source combustion unit/s requiring a higher
level of NOx reduction than achievable by selective non-catalytic reduction (SNCR) or
combustion controls. SCR systems can be designed for NOx removal efficiencies upto
100%, though in practice, commercial coal, oil, and natural gas-fired SCR systems
are often designed to meet over 90% efficiency. However, the reduction may be less
than 90% whenSCR follows other NOx controls such as LNB or FGR that achieve
relatively low emissions on their own.
Either ammonia or urea may be used as the NOx reduction reagent in SCR systems.
Urea is generally converted to ammonia before injection. Majority electric utilities that
operate SCR systems use (-80%) use ammonia (anhydrous and aqueous), and -20%
use urea.
Catalytic combustion is the most accepted procedure to convert toxic exhaust gases
into less toxic or benign gases [1]. A typical reactortype for catalytic combustion of
volatile organic carbonsfVOCs) is a monolithic support that is characterized by verylow
pressure drop, even at high flow rate. Monoliths are normally shaped as honeycombs
or layered plates, and commonly composed of ceramic or metal materials [2], The
main drawbacks of ceramic monoliths are their susceptibility to thermal and
mechanical shock and high manufacturing cost. Therefore, application of metal
substrates as catalyst supports has gained significant interest recently. The primary
advantages of metal substrates are high thermal conductivity, high surface to volume
ratio, low pressure drop and low manufacturing cost.

Use of metal wire mesh as catalysts support is well documented in this field. Wire-
mesh catalysts have excellent mass and heat transfer performance of pellet-type
catalysts, with merits of low pressure drop and high effectiveness factor in the
monolith, therefore exhibiting a higher efficiency over honeycomb modules [5]. Various
techniques have also been reported. Applying thin catalytically active zeolite coatings
to fibrous substrates by several novel approaches have also been suggested [6,7].
Typical preparation procedures consist of immersing the support structure in an
aqueous solution containing the reactant for the in situ hydrothermal synthesis of
zeolite, after which the system is heated and the zeolite crystals grow on the surface
of the support. Zeolite coated metal wire mesh supports have been used in SCR
system for de-NOx with NH3 dosing The electrophoretic deposition (EPD) method has
been considered as another technique since it requires a short deposition time and
simple apparatus. It is based on the deposition of particles or colloid suspensions on
the surface of an electrode driven by an electric field [8] Vorob'eva et al. have tried
to prepare wiremesh coated with active alumina using electrophoretic deposition
(EPD) of alumina sol [9].
US20050085383 A1 dated April 21,2005 by JakobHoj& Claus Jorgensen[10] reported
a catalyst support material and catalysts made therefrom having improved resistance
towards erosion showing improved resistance towards erosion are used in flue gas
containing a large amount of particulate matter and for selective catalytic reduction of
nitrous oxides. The catalyst support contains at least 20% by weight of TiO2 being
present mainly in the anatase form. Furthermore, the catalyst support

contains diatomaceous earth in an amount of at least 2% and less than 80% by weight
of the catalyst support. In one embodiment catalysts made from said catalyst support
contain oxides or sulfates of base metals from the group of V, W, Mn, Nb, Mo, Ni, Fe
or Cu. Another option is a catalyst prepared from said catalyst support containing Pt
or Pd. Said catalysts are used for treatment of a flue gas. Similar reports are also
available in patent numbers, e g.,
CN1628906A [111, DE602004025657D1 [12].EP1524024A1 [13], EP1524024B1
[14], US7431904 [15] respectively.
Patent number KR101659818(B1) by Nano Co. Ltd., Korea [16] described a
manufacturing method of plate type selective catalytic reduction catalyst for DeNOx
and plate type selective catalysts reduction catalysts capable of removing a nitrogen
oxide included in exhaust gas. The method includes, a catalyst manufacturing step of
manufacturing a hill for a catalyst; a catalyst application step of dropping the hill onto
a mesh and then inserting the hill into a gap between an upper roll and a lower roll,
rotating near each other, to pressurize and apply the hill; a dry step of drying the mesh
to which the hill is applied in the catalyst application step; a forming step of curving
and forming the mesh, dried in the dry step, into a predetermined shape; a cutting step
of cutting the mesh, curved in the forming step, in a predetermined standard; a
stacking step of stacking the mesh, cut in the cutting step, in a block of which both
sides are opened; and a thermal treatment step of thermally treating the block in which
the mesh is stacked.

As per the patent number CN206082177U dated 12.4.2017 [17], the utility model
relates to a plate type catalyst unit case for horizontal gas pass belongs to the
combustion apparatus, including casing, catalystmonolithic, support piece and
distance piece, in which the casing lateral wall is to be provided with
the fabricationhole, support piece installs at both ends in the fabrication hole, and
the catalyst monolithic through support piece hang the hole hang locate the casing in,
through distance piece separation and spacing between the
adjacent catalyst monolithic.
Another patent number CN103349981 (A) by Jiangsu Wonder Environmental Prot
Technology Co. Ltd. [18] describes the manufacturing of plate-type SCR de-nitration
catalyst, and preparation method and application thereof. The method comprises the
steps of kneading, aging, stretching production of a steel mesh, coating and baking,
wherein in the kneading step, mixing step by step is adopted, that is TiO2-W-1, TiO2-
D-2, deionized water, ammonia water, ammonium heptamolybdate, clay, an
ammonium metavanadate solution, hydroxyethyl cellulose and polyethylene oxide are
added into a mixer for kneading; the coating step is that the ageing material is
uniformly coated on the stainless steel wire mesh.
Usage of metal wire mesh for de-NOX catalyst is also reported by Jie Yao [19]. Both
flat and corrugated wire mesh sheets were coated with aluminium powder by using
electrophoretic deposition (EPD) method. Controlled thermal sintering of coated
samples yielded uniform porous aluminium layer with a thickness of 100 µm that was

attached firmly on the wire meshes. Subsequent controlled calcination formed a finite
thickness of AI203 layer on the outer surface of each deposited aluminium particles,
which resulted in the formation of AI203/AI double-layered composite particles that
were attached firmly on the wire surface to form a certain thickness of porous layer.A
rectangular-shaped wire-mesh honeycomb (WMH) module with triangular-shaped
channels was manufactured by packing alternately the flat sheet and corrugated sheet
of the AI203/AI-coated wire meshes. This WMH was further coated with V205-Mo03-
W03 catalyst by wash-coating method to be applied for the selective catalytic
reduction (SCR) of NO with NH3. With an optimized catalyst loading of 16wt%, WMH
catalyst module shows more than 90% NOx conversion at 240°C and almost complete
NO conversion at temperatures higher than 300°C at GHSV 5,000 h-1.
Patent number, DE 102014215112A1 by Johnson Matthey PLC, Germany (Inventor
Juergen Bauer) [20] describes a method for preparing a catalyst and a catalyst-
products, in particular for exhaust gas purification.As per this method, SCR DE-NOX
catalyst material is formed by combining functional particles, catalytically inactive pore
former (an inorganic porous materials, which in particular at least a mesoporosity,
preferably having a macroporosity), a catalytically active material having the functional
particles etc.

Fabrication of SCR catalyst modules using metal wire mesh supported structures by
numerous technologies involving various conceptual fabrication methods and
processes is a continued interest. In this context, this invention descnbes a fabrication
process by combining so-called 'Roller-assisted Technique' and "Uni-axial Pressing
technique' respectively for forming metallic wire-mesh supported SCR (selective
catalytic reduction for de-NOx) plate-type catalyst structures by utilizing specified
support structure, SCR catalyst material, binder system, processing parameters,
drying & firing conditions thereof in the fabrication process, in which SCR catalyst plate
structures could be fabricated that has NOx (nitrogen oxide gases in isolation or in
combination) to elemental nitrogen conversion efficiency in the range of 85 - 90% with
space velocity in the range of 1500 - 2000 per hour having erosion rate of the plates
in the range of 0.01 - 0.05 g/min, by following the steps as explained in the following.
OBJECTS OF THE INVENTION:
An object of the present invention is to propose a process for producing SCR catalyst
plate type structure.
Another object of the present invention is to propose a process for forming metallic
wire mesh supported SCR catalyst plate-type structures by combining so-called
'Roller-assisted casting Technique' and "Uni-axial Pressing technique' respectively.

Yet another object of the present invention is to propose a fabrication process by
defining specified combination/s of fabrication technique so as to manufacture SCR
catalysts plate-type structures associated with specific properties therein.
Further object of the present invention is to propose a process for producing SCR
catalyst plate type structures which is efficient for de-NOx applications including coal-
fired power plants and erosion properties of the product
BRIEF DESCRIPTION OF THE INVENTION:
This invention relates to a process for producing SCR catalyst plate type structures
comprising:
providing metallic wire-mesh support material preparing the formulation of SCR
catalyst material,
preparing a binder formulation
preparing SCR catalyst dough/paste/noodles by mixing SCR catalysts + powder,
inorganic binder and homogenizing the mix for 6 to 10 hrs to produce
applying the resistant SCR catalyst noodles on the surface of the said metallic wire-
mesh to form monolith structure,
subjecting the said monolith structure to the step of fabrication to form different
shapes, drying the said SCR catalyst plates with different shapes at a temperature
range of 60-100°C for a period of 6 to 12 hours,
subjecting the dried SCR catalyst to the step of firing at a temperature range of 500-
650°C in a kiln for a period of 3 to 6 hours.

DETAILED DESCRIPTION OF THE INVENTION:
As per the invention, the following steps are to be followed in order to fabricate metal
wire mesh supported SCR (selective catalytic reduction) catalyst plate-type structure
by following a so-called 'combo technique for the purpose of de-NOx applications by
using specified i) Standard metallic wire mesh support material, ii) standard SCR
catalyst material, iii) Binder formulation for the SCR catalyst, iv) Preparation of SCR
catalyst dough/paste/noodles, v) SCR catalyst Monolith structure forming method, vi)
SCR catalyst structure physical profiling method by Uni-axial pressing method, vii)
Drying & Firing of the green SCR catalyst structures, so as to yield the final product,
i.e., SCR plate-type catalyst structures at the end of the fabrication process and finally
viii) Testing of the SCR catalyst plates to confirm specified levels of conversion
efficiency of NOx gas, erosion resistance of the catalyst structure, bond strength etc.
respectively
The following sections describe each step of the fabrication process
sequentially:
i) Metallic Wire Mesh Support Material:
The support material in the described fabrication process is metallic wire mesh
type structure in which stainless steel wire mesh could preferably be used.
Stainless steel wire mesh with grades of SS304, SS316, SS430 etc.
respectively or similar metallic wire mesh structural materials with counter
properties, i.e., a) number of opening per inch in the range of 20-26, b)

standard wire thickness gauge in the range of 20-26, c)overall thickness in the
range of 0.4-1.0 mm, d) aperture of the mesh in the range of 0.4-1 0 mm etc,
could be used for fabricating the stainless steel wire-mesh supported SCR
(selective catalytic reduction for de-NOx) catalyst plate-type structures.
In order to toughen the support structure and wherever toughened base
structure is a necessity for applications, the wire mesh structure could be heat
treated in an electric or gas firing furnace at any set temperature in the
temperature range of 600-750°C in air for a period of 1-2 hours prior use.
Alternatively, such wire mesh structures without any heat treatment could be
used. As described previously in another of our patent application, the heat
treatment process toughens the stainless steel wire mesh structure, which
produces stiffer SCR plate structure at the end and heat treatment of the metal
mesh could be used depending on the criteria of toughness of the structure.
ii) SCR Catalyst Material:
The SCR catalyst material is a standard vanadia-based material that is
dispersed in titania (anatase crystallographic form) and other constituents
having specific surface area in the range of 90-120 m2/g.
iii) Binder Formulation of the SCR Catalyst:
SCR catalyst material which is to be applied on the surface of the metallic wire
mesh structure in the forming process, cannot be applied without the aid

of a binder. The binder formulation in this invention is described as a
combination of: a) inorganic binder in the weight range of 9.0 -12%, b) organic
binder in the weight range of 1-3% and c) polymeric binder in the weight range
of 1-5% respectively. The specific combination of the above three types of
binders comprise the "Binder Formulation" of the SCR catalyst,
The inorganic binder comprise a mixture of a) clay (3-5 w%), b) bentonite (3-5
w%), c) glass fiber (1-3 w% and d) colloidal silica (0.5 - 1.0 w%) respectively.
While the organic binder comprise carbomethoxy cellulose (CMC) in the range
of 0.5 - 2.0 w%, which could be used either as 'solid powder' or in the form of
an aqueous solution. While the polymeric binder is a combination of a) poly-
ethelene glycol (PEG) having molecular weight in the range of 400-1200,
preferably around 600 ( 2-A w%) and b) polyvinyl alcohol (PVA) having
molecular weight in the range of 50,000-200,000, preferably around 125,000
(1-5 w%) respectively. PVA is to be used in the form of an aqueous solution
only having concentration in the range of 1-5 w%.
The constituents of the binder is added in specific step/s in the course of
fabrication of SCR plate-type catalyst structure in desired proportion as per the
above weight range in the binder formulation, which is discussed in the
subsequent section.
iv) Preparation of SCR catalyst Douah/Paste/Noodles:
In order to prepare SCR catalyst in the form of 'dough' or 'paste', the SCR
catalyst powder is first mixed with inorganic binder in desired proportions and
then homogenised/mixed by using a ball mill machine for a period of 6-10

hours. The resultant milled powder is further mixed with organic binder followed
by polymeric binder in desired proportions by using a 'Sigma Blade Mixer' or
'Sigma Kneader Machine' for a period of another 1-2 hours after which SCR
catalyst paste or a dough resulted. The moisture level of the SCR dough is
maintained in the range of 20-30w% by adding de-ionized water either
separately or by adding de-ionized water with the polymeric binder, PVA.
After the SCR catalyst paste is formed and paste is extruded in the form of
noodles having the diameter in the range of 1-10 mm. The noodle form of the
SCR catalyst paste facilitates the distribution of catalyst material uniformly in
the plate structure in the course of fabrication, though formation of noodle is not
a mandatory condition.
v) Forming of Monolith SCR catalyst flat monolith structure:
In this step, the resultant SCR catalyst noodles are to be applied on the surface
0f the selected metallic wire mesh structure by maintaining uniform thickness
throughout the plate structure by using the so-called in-house designed "Roller-
assisted Casting Machine". In order to do this, the selected metallic wire mesh
structure with defined properties, i.e., aperture size, overall thickness, number
of opening/per unit inch, standard wire thickness gauge etc is allowed to pass
in between the two rollers in the said "Roller-assisted Casting Machine" in a
manner that the SCR catalyst noodles are coated on

the surface of the metallic wire mesh support structures with a desired thickness
uniformly thereby resulting green structures of the monolith flat-type SCR
catalyst plates Furthermore, as mentioned previously, if required and
depending on the application area, metallic wire mesh structure could also be
heat treated in the temperature range of 600-750°C for a period of 1-2 hours in
order to harden the wire mesh prior applying SCR catalyst noodles on the wire
mesh surface in which more hardened SCR catalyst plate green structures are
obtained at the end of the process
vi) Specific Profiling off SCR Catalyst Structures:
In this step in the fabrication process, the derived monolith SCR catalyst flat-
type plate green structures are profiled into numerous shapes like, "V", or
"Z" or "S" etc. in the green form itself by using a 'uni-axial pressing technique'
with desired physical profile/s of any suitable metallic die. Accordingly, the
green structures could be profiled into various shapes as mentioned, like
V, or "Z" or "S" etc. in the green form itself. These profiles help to maintain
desired pitch level of the plates in the module assembly, besides ease of
convenience in maintaining physical array of assembled SCR catalyst
plates in modules with predetermined design for actual De-NOx
application/s.

vii) Drying & Firing of the Green SCR catalyst structures:
As the derived SCR catalyst plate structure is green, which is to be dried in
order to obtain dried plates within the moisture level 2 +1 w%. The green
SCR catalyst plates are dried in an oven (electrical or gas fired) at any set
temperature in the temperature range of 60°-100°C for a period of 6-12
hours, which gives dried plates with a moisture level 2 +1 w%
The dried SCR catalyst plates are fired in order to remove the organic and
polymeric binders from the structures. The dried plates are to be fired at any
set temperature in the temperature range of 500°-650°C in a kiln (electrically
heated or gas-fired or similar kilns) for a period of 3 - 6 hours holding at the
set temperature by maintaining a rate of heating of 1-2°/minute and by
maintaining a rate of cooling of 1-2°/minute. The fired plates are the final
product which is called metal supported SCR catalyst plate-type structures
for De-NOx applications.
viii) Testing of the SCR Catalyst Plate Structures:
In order to confirm the efficiency of NOx conversion and specific erosion
profiles, the fired SCR catalyst plates undergo NOx conversion test, air jet
erosion test(erosion profile) and counter tests etc,
In NOx conversion test, the fired SCR catalyst plates of specific dimensions
are inserted in a test ng in a manner that uniformity in the pitch

between the plates plays are maintained As per the testing protocol,
around 11 number of SCR catalyst plates with a Z, S, V or any other profile
having dimensions of 65mmx120mm are stacked in the test rig that
confirmed a De-NOx efficiency in the range of 85 - 95% with a space velocity
in the range of 1500 - 2000 per hour.
In case of air jet erosion test, the SCR catalyst plates with the dimension of
30mmx30mm is placed against the flow stream of air and abrasive sands
with a velocity of 35m/s was allowed to hit by varying the angle between the
flow stream and the position of the plate with multiple angles namely 15°,
30°, 45°, 60°,75° & 90°respectively. The erosion rate of the SCR catalyst
plates were in the range of 0 01 -0.05g/min comprising angles of
impingement at specific levels of 15°, 30°, 45°, 60°, 75° & 90° respectively,
in which the erosion increases with the increase in angle of impact until 90°'
angle at which the erosion was found to be maximum.
The process could be better understood in terms of examples as given in
the below.

EXAMPLE!;
In this example, the following steps are to be followed in order to fabricate metal
wire mesh supported SCR (selective catalytic reduction) catalyst plate-type
structure for the purpose of de-NOx applications. The following are the specific
steps , i.e., i) specifying base metallic wire mesh support structure material, ii)
specifying the formulation of SCR catalyst material, iii) specifying the binder
formulation for the SCR catalyst, iv) specifying the procedure for the preparation
of SCR catalyst dough/paste/noodles, v) specifying the forming method &
fabrication parameters, vi) specifying specific the profiling of SCR catalyst
structure, vii) specifying the drying of the green SCR catalyst structures, viii)
specifying the firing of the dried SCR catalysts structures so as to yield the final
product, i.e., SCR catalyst plate-type structures, ix) Conducting the testing of
the SCR catalyst plates to confirm specified levels of conversion efficiency of
NOx gas, erosion resistance of the catalyst structure etc.


Ml Specifying the Binder formulation for the SCR catalyst:

nil Specifying the Procedure for the Preparation of SCR catalyst
Doug h/Pas te/N oodles:


jv) Forming Method in the 'Roller-assisted Casting Technique' to
obtain SCR catalyst monolith structure:

v) Specifying the Profiling of the SCR Catalyst Plate Structure by Uni-
axial Pressing Method:


vj] Specifying the Drying of the SCR Catalyst Green Plates:

vii] Specifying the Firing of the SCR Catalyst Dried Plates:


villi Testing of the final Product. SCR Catalyst Plate Structure:


EXAMPLE 2:
In this example, most of the parameters remain the same except in few exceptions as
described in the following:
I. Metal mesh support structure is altered
II. Binder formulation is altered

III. Casting speed is altered
IV. Profile of the plates is altered
V. Firing temperature is altered
jj Specifying the base metallic wire mesh support structure:


i]l Specifying the Binder formulation for the SCR catalyst;

iii} Specifying the Preparation of SCR catalyst Douqh/Paste/Noodles:


jyl Formtng Mathod in the 'RoHar-assiatBd Casting Technique1 to obtain
SCR catalyst monolith structure:

yj Specifying the Profiling of the SCR Catalyst Plate Structure by Uni-
axial Pressing Method:


v[l Drying of the SCR Catalyst Green Plates:

vii) Firing of the SCR Catalyst Dried Plates:


viii) Testing of the final Product. SCR Catalyst Plate Structure:


EXAMPLE 3:
In this examples, most of the parameters remain the same as example 1 except in few
exceptions as described in the following:
i) Metal mesh support structure is altered
ii) Binder formulation is altered
iii) Casting speed is altered
iv) Profile of the plates is altered
v) Firing temperature is altered
j) Characteristics of base metallic wire mesh structure


HI Binder formulation for the SCR catalyst:

ii|) Preparation of SCR catalyst Dough/Paste/Noodles:


iyj Forming Method in the RoUar^asslstfld Casting Technique' to obtain
SCR catalyst monolith structure:

yj Specific Profiling of the SCR Catalyst Plate Structure by Uni-axial
Pressing Method:


vil Drvina of the SCR Catalyst Green Plates:

vii) Firing of the SCR Catalyst Dried Plates:


Viih Testing of the final Product. SCR Catalyst Plate Structure:


WE CLAIM:
1. A process for producing SCR catalyst plate type structures comprising:
providing metallic wire-mesh support material preparing the formulation of SCR
catalyst material,
preparing a binder formulation
preparing SCR catalyst dough/paste/noodles by mixing SCR catalysts + powder,
inorganic binder and homogenizing the mix for 6 to 10 hrs to produce
applying the resistant SCR catalyst noodles on the surface of the said metallic wire-
mesh to form monolith structure,
subjecting the said monolith structure to the step of fabrication to form different
shapes, drying the said SCR catalyst plates with different shapes at a temperature
range of 60-100°C for a period of 6 to 12 hours,
subjecting the dried SCR catalyst to the step of firing at a temperature range of 500-
650°C in a kiln for a period of 3 to 6 hours.
2. The process as claimed in claim 1, wherein the said metallic wire-mesh support
material is stainless steel wire mesh having number of opening per inch in the
range of 20-26, b) standard wire thickness gauge in the range of 20-26, c)
overall thickness in the range of 0.4-1.0 mm, d) aperture of the mesh in the
range of 0.4-1 0 mm etc.
3. The process as claimed in claim 1, wherein the said SCR catalyst material is
vanadia-based material dispersed in titania and other constituents having
specific area in the range of 90-120 m2/g,

4. The process as claimed in claim 1, wherein the said binder formulation is a
combination of inorganic binder in the weight range of 9.0 - 12%, b) organic
binder in the weight range of 1-3% and c) polymeric binder in the weight range
of 1 -5% respectively.
5. The process as claimed in claim 4, wherein the said inorganic binder comprises
of a mixture of 3 to 5 wt% of clay, 3 to 5 wt% of bentonite, 1 to 3 wt% of glass
fiber and 0.5 to 1 wt% colloidal silica.
6. The process as claimed in claim 4, wherein the said organic binder is 0.5 to 2
w% carbomethoxy cellulose (CMC).
7. The process as claimed in claim 4, wherein the said polymeric binder is a
combination of 2-4 wt% of a poly-ethelene glycol (PEG) having molecular
weight in the range of 400-1200 and 1-5 wt% of polyvinyl alcohol having
molecular weight in the range of 50,000 to 200,000
8. The process as claimed in claim 6, wherein said organic binder, carbomethoxy
cellulose(CMC) can be used in the solid powder form or in the form of an
aqueous solution.
9. The process as claimed in claim 7, wherein the said PVA is used in the form of
an aqueous solution having concentration in the range of 1-5 wt%

10. The process as claimed in claim 1, wherein the said SCR catalyst
noodles/paste/dough is prepared by mixing SCR catalyst powder with inorganic
binder in desired proportions and then homogenised/mixed by using a ball mill
machine for a period of 6-10 hours, the resultant milled powder is further mixed
with organic binder followed by polymeric binder in desired proportions by using
a 'Sigma Blade Mixer" or 'Sigma Kneader Machine' for a period of another 1-2
hours after which SCR catalyst paste or a dough resulted, and the moisture
level of the SCR dough is maintained in the range of 20-30w% by adding de-
ionized water either separately or by adding de-ionized water with the polymeric
binder, PVA and the said paste is the extruded to form noodles.
11. A process according the Claim 1, SCR catalyst noodles are applied on the
surface of the selected metallic wire mesh structure by using the so-called
"Roller-assisted Casting Machine" by passing the selected wire mesh structure
in between the two rollers in the said "Roller-assisted Casting Machine" in a
continuous mode thereby resulting green structures of the SCR catalyst plates.
12. A process according the Claim 1, the derived SCR catalyst plate-type structure
are physically profiled into numerous shapes like, "V", or "Z" or "S" etc. in the
green form with the assistance of "Uni-axial Pressing Method" by using desired
stainless steel die, which is used for specific profiling
13. A process according the Claim 1, the derived green SCR catalyst plate structure
is dried in an oven (electrical or gas fired) at any set temperature in the
temperature range of 60°-100°C for a period of 6-12 hours, which gives dried
plates with a moisture level 2 + 1 w%.
14. A process according the Claim 1, the dried SCR catalyst plates are fired at any
set temperature in the temperature range of 550° - 625°C in a kiln (electrically
heated or gas-fired or similar kilns) for a period of 3 - 6 hours holding at the set

■
temperature by maintaining a rate of heating of 1-2°/minute and by maintaining
a rate of cooling of 1-2°/minute. The fired plates are the final product which is
called metal supported SCR catalyst plate-type structures for De-NOx
applications including NOx control in coal-fired power plants.
15. A process according the Claim 11, the derived SCR catalyst plates has a
conversion efficiency in the range of 85 - 95% having space velocity in the range
of 1500 - 2000 per hour and with erosion rate in the range of 0.01 - 0.05g/min
comprising angles of impingement at specific levels of 15°, 30°, 45°, 60°, 75° &
90° respectively.