Title of Invention

METHOD AND APPARATUS FOR THE PRODUCTION OF ENROBED CATALYST PASTILLES OR FLAKES

Abstract The present development relates to a process for enrobing active catalytic materials with a protective coating to form pastilles, and to an apparatus for making the pastilles. The process comprises mixing an active catalyst powder with a hydrocarbon material in a low-shear jacketed blender at a temperature slightly above the congealing point of the hydrocarbon, and then making pastilles from the catalyst / hydrocarbon mixture while cooling the mixture to temperature below the congealing point of the hydro- carbon.
Full Text Cross-Reference to Related Applications
The present application is a continuation-in-part application related to U.S. Application Serial
Number 10/324,561 filed on December 18,2002 and incorporated herein in its entirety by reference.
Background
The present development relates to a process for enrobing active catalytic materials with a
protective coating to form pastilles, and to an apparatus for making the pastilles. The pastilles are
prepared using a low-shear jacketed blender and a pastillator. The resultant pastilles vary in shape
and have a diameter of from about 2 mm to about 100 mm and a thickness of 1 mm to 10 mm.
Heterogeneous catalysts often include an active phase that is unstable in air. For example,
highly reduced metal crystallites, such as cobalt crystallites having from about a 45% to about 90%
reduction, are pyrophoric and are susceptible to oxidation. Further, the heterogeneous catalyst may
be in the form of a reduced catalyst powder having a catalyst crystallite particle size of from about 50
microns to about 150 microns. This small particle size combined with the catalyst instability in air
can make the catalysts difficult to handle and can create safety hazards when the catalysts are being
loaded into a reactor. Heterogeneous catalysts can also experience a temperature rise from the
internal section of the catalyst which can cause oxidation of the active metal to an inactive metal
oxide. This oxidation is undesirable for the reaction and can cause sintering of the metal on the
catalyst as well. Thus, there is a need to find a means for protecting the reduced metal catalyst.
One common method used to protect the reduced metal catalyst is to form an oxide surface
film on the catalyst by treating the reduced catalyst in a mixture of air and an inert gas. This
procedure must be performed with extreme care because any surge of exotherm will cause sintering
of the metal on the catalyst. Usually, the procedure starts with a very low oxygen concentration in a
largely N2 (or other inert gas) stream; the oxygen concentration is then gradually increased by
increasing air/inert gas ratio over a period of time, typically from about 24 hours to about!50 hours.

In addition to the exotherm risks, another disadvantage of using this method for protecting the
catalyst is that a portion of the reduced metal is typically lost due to formation of metal oxides.
A more sophisticated method involves enrobing the reduced catalyst in oxygen impermeable
media such as organic solvents, oils, fats and waxes. The enrobing or coating material works as an
oxygen and moisture barrier to protect the metal being oxidized. By coating the catalyst, it is possible
to stabilize the active material and to make handling the material easier. Further, the enrobing
method allows essentially 100% of the reduced metal to be preserved.
The practice of coating or enrobing the active materials in a protective sheath is well known
in the prior art. As early as 1952, a method for improving the coating of reduced nickel catalysts was
taught in U.S. Patent 2,609,346 (issued to Faulkner on Sept. 2, 1952). In the '346 patent, reduced
nickel, usually containing a promoter, is dispersed in glyceride fat having a melting point from about
105°F up to about 150°F. The mixture of catalyst and fat is melted at a temperature of about 160°F to
about 175°F, and then is cast in a metal form cooled to a temperature of between 50°F and 60°F to
form a block of coated catalyst. Although this method produces an enrobed catalyst, the catalyst / fat
mixture is formed into relatively large shapes that must be rapidly cooled to ensure that the wax is
hardened throughout the block thereby preventing the catalyst from settling.
U.S. Patent 2,842,504 (issued to Jones on July 8, 1958) teaches a different method of coating
a catalyst. In the '504 patent, a nickel-kieselguhr hydrogenation catalyst is coated with a rubbery
polymer. The catalyst is added to a polymer / organic solvent solution and a rubber coat is formed on
the catalyst by driving the organic solvent off. U.S. Patent 3,453,217 (issued to Kozlowski et al on
July 1, 1969) describes a method of treating a catalyst with a liquid hydrocarbon having a boiling
point in the range of 410°F to 1200°F. The hydrocarbon is applied to the catalyst by discharging the
catalyst into a container containing the liquid hydrocarbon and then moving the catalyst out of the
container on a moving belt screen. If the process is carried out properly, the hydrocarbon fills the
micropores of the catalyst. A somewhat different approach is taught in U.S. Patent 6,294,498 (issued
to Darcissac et al on Sep. 25, 2001). In the '498 patent, a catalyst is coated with a protective layer

that is "atomized or dispersed on the catalyst by continuously stirring the catalyst and keeping it at a
temperature that is below the crystallization point of the coating material". Alternatively, the coating
material may be in a solution that is "atomized, sprayed or dispersed by continuously stirring the
catalyst at a temperature that is above the boiling point of the solvent of said solution." Each of these
methods result in the application of a protective coating on a catalyst. However, these methods either
require specialized coatings or relatively sophisticated handling to ensure that the coating is deposited
as intended.
Summary of the Invention
The present development relates to a process and an apparatus for enrobing an active catalyst
in a protective coating material and making distinct pastilles or flakes. The process comprises
blending, transferring, feeding and pastillation or flaking steps. An essentially constant temperature,
from about 0°F (at the congealing point) to about 50°F above the congealing point of the coating
material, is maintained during the blending, transferring and feeding steps. The temperature is
gradually decreased as the pastilles or flakes proceed through the pastillation or flaking step so that
the discharge temperature from the pastillator or flaker is from about 2°F to about 150°F lower than
the congealing point of the coating material.
The apparatus comprises a low-shearing jacketed blender and a pastillator. The low-shear
jacketed blender allows for gentle mixing action at a controlled constant temperature so that the
catalyst powder is submerged in the coating material in a softened state and the catalyst is uniformly
mixed with the coating material without the catalyst being ground or subjected to attrition. The
mentioned features of the blender are beneficial when a microspherical catalyst powder is used in
fluid bed applications.

Detailed Description of the Preferred Embodiment
The present development relates to a process and an apparatus for applying a protective
coating material over an active catalyst to form pastilles or flakes. According to the invention,
oxygen- or moisture-sensitive catalyst powder is combined with a coating material using a low-shear
jacketed blender, and the catalyst / coating mixture is then processed through a pastillator or flaker.
In the present development, the example blender used is a horizontal blender, but any piece of
equipment that can provide uniform, low-shear mixing may be used. As used herein, unless
otherwise specified, any reference to pastilles or drops, pastillation or pastillator should be interpreted
to apply as well to flakes, flaking or flaker, respectively.
The catalyst is preferably in a powdered, and optionally, reduced form. For example, in an
embodiment of the invention, the catalyst is a highly reduced cobalt crystallite having an average
particle size of from about 1 µ to about 225 µ and preferably from about 3 µ to about 150 µ. The
particle size may range from about 1 µ to about 200 µ the constraint on the upper limit being
determined by the dimensions of the opening to a feed port of the pastillator.
The hydrocarbon compound, or coating material, can be any material that can create an
oxygen- and/or moisture barrier for the catalyst. For example, the hydrocarbon may be selected from
epoxy resin, fatty acids, fatty alcohols, fatty esters, fatty stearates, hydrocarbon resins,
microcrystalline paraffins, paraffin wax, synthetic wax, polyesters, polyethylene glycol, polyethylene
waxes, polyglycols, polyvinyl alcohols, polystyrene, vegetable waxes, a wax obtained from processes
using coal, natural gas, bio-mass, or methanol as feedstock, wax blends and combinations thereof. A
preferred coating material is a synthetic wax, such as the wax from a Fischer-Tropsch reaction, that
contains a small amount antioxidant and is essentially free of inorganic contaminants such as sulfur,
chloride and heavy metals.
In the present invention, the coating material is selected based on, among other criteria, its
purity and its ability to form a solid at ambient temperature. Further, the coating material preferably
has a congealing point of from about 110°F to about 250°F, and more preferably from about 150°F to

about 225°F. As used herein, the congealing point refers to the hardening or softening characteristics
of the hydrocarbon or coating material. The congealing point is obtained by solidification of liquid
based on ASTM-938 or equivalent methods. The solidification characteristics of wax can also be
expressed as drop melting point (ASTM-3954 and ASTM-D127) or cooling curve (ASTM-D87). The
difference between congealing point and melting point is highly dependent on molecular weight and
molecular weight distribution of the individual hydrocarbon compound. Melting point could be
several degrees higher than congealing point.
According to the invention, the catalyst powder is combined with the coating material using
the low-shear jacketed blender. As is known in the art, the blender with the coating material is
purged with an inert gas and the catalyst powder is then added. If, as is the case with the prior art
enrobed catalysts, the catalyst material is in the form of flakes or generally has a form in which the
density of the catalyst is lower than the density of the coating material, e.g. the density of the catalyst
may be about 0.3 g/cc and the density of the coating material is about 0.7 g/cc, then settling is not a
problem. In the present invention, however, the catalyst may be in the form of particles that generally
have a density greater than density of the coating material, e.g. the density of the catalyst is generally
about 1.2 g/cc and the density of the coating material is about 0.7 g/cc, so that settling can occur if the
wax is not kept in a "semi-solid" state. To maintain the semi-solid state, the temperature of the low-
shear jacketed blender, such as without limitation a Ross horizontal blender (Ross Paddle Blender,
Ross Ribbon Blender or Ross Cylindrical Drier), is heated to and held at a temperature that is from
about 0°F (at the congealing point) to about 50°F above the congealing point of the coating material.
The coating material is manually or automatically fed to the low-shear jacketed blender, as is
known in the art. The coating material does not need to be heated prior to its introduction to the
blender. In the blender, the coating material is heated to a semi-solid state, wherein the material is
softened or molten, but not a liquid. The entire system is then purged with an inert gas, such as N2.
The semi-solid unseparated mixture deposits at the blender end of the pastillator a plurality of drops
or flakes of the mixture.

The catalyst powder is then blended into the coating material. The concentration of the
catalyst relative to the coating material can vary depending on the catalyst, the coating material and
the anticipated method of use, and may range in concentration from essentially no catalyst powder
(pure wax pastilles) to concentrations of up to about 65 wt%. In one example, a highly reduced
alumina supported cobalt crystallite having an average particle size of from about 50 µ to about 150 µ
is mixed into a synthetic paraffin wax at an average concentration of about 57 wt% catalyst.
The low shear mixing from the blender combined with proper paddle clearance allows the
reduced catalyst powder to be submerged into the coating material and to be uniformly dispersed
throughout the coating material without grinding or milling of the catalyst. As is known in the art, the
blender includes internal paddles or ribbons that rotate to produce the mixing action. As the paddles
rotate, there is a risk that the catalyst can be ground or milled by the action of the paddles against the
internal wall of the blender. Thus, in the present invention, th'e rotation direction, rotation speed, and
design as well as the clearance between the tips of rotating paddles or ribbons and the interior wall of
the blender is set to minimize the catalyst attrition.
The mixing intensity may vary but should be selected to minimize damage to the catalyst. In
one example, the mixing intensity is set at from about 3 to about 10 revolutions per minute.
Typically, the residence time in the blender is from about 2 minutes to about 120 minutes, and
preferably is from about 2 minutes to about 90 minutes.
After mixing in the blender, the blended material is transferred through piping and by a series
of low shear pumps that each aid in the prevention of material settling and separating until the
blended material is fed into a pastillator, such as the Sandvik Rotoformer Serial 81750/88. The
piping and pumps are jacketed and/or heat-traced to maintain essentially the same temperature as the
blender or a temperature sufficient to maintain the hydrocarbon coating material in the semi-solid or
molten phase. Here, as in the blender, because the catalyst particles being enrobed have a greater
density than the coating material, if the coating material is overheated, it is possible to have the
catalyst settle out of the coating material. Thus, it is a key feature of the development that the

temperature be maintained such that the coating material is in the semi-solid state during the transfer
process.
In the pastillator, the catalyst / coating mixture is deposited drop-wise through a feed port by
a Rotoformer onto a steel belt cooler, forming a plurality of pastilles or flakes. The belt cooler carries
the pastilles or flakes a predetermined length across a water cooled bed. Because the belt cooler is
chilled along the majority of its length, by the time the pastilles reach the end of the belt and they are
discharged from the pastillator, the hydrocarbon phase of the pastille has solidified to form distinct
particles of active catalyst powder dispersed within the coating material. The discharge temperature is
preferably from about 2°F to about 150°F lower than the congealing point of the coating material.
The size of the pastilles or flakes to be formed can be modified by altering the size of the
opening from the Rotoformer. Further, the resultant particles can have a variety of shapes, such as
spherical, hemispherical, ellipsoidal, oval, domed, any other shapes known in the art of pastillation,
including flakes, and combinations thereof. The pastilles preferably have a diameter of from about 2
mm to about 100 mm and a thickness of from about 1 mm to about 10 mm.
The pastille preparation method of the present invention is intended for use in enrobing active
catalyst in a protective material. The method differs from the catalyst enrobing methods of the prior
art by allowing relatively large catalyst particles to be enrobed in a hydrocarbon coating. Further, the
present invention provides a method wherein the catalyst particles are essentially unaffected by the
enrobing process, i.e. they are not ground or subject to attrition in the process. The catalysts enrobed
by the method can be used for a number of applications, including but not limited to fluid bed or
slurry bed or bubble column reactor applications.
It is understood that the composition of the pastilles and the specific processing conditions
may be varied without exceeding the scope of this development.

WE CLAIM:
1. An active catalyst having a protective coating material wherein the catalyst is prepared
by the process comprising the steps of:
(a) heating a hydrocarbon material, such as herein described, having a
congealing point in a low-shear jacketed blender, and then purging the system
with an inert gas, combining the hydrocarbon material with a powdered
crystalline cobalt catalyst in the low-shear jacketed blender, wherein said
powdered catalyst has a particle size in the range of from 1 urn to 200 urn,
and forming a mixture wherein said catalyst is uniformly dispersed throughout
said hydrocarbon, said low-shear jacketed blender being selected to minimize
catalyst attrition and being set to maintain a temperature that is from 0°C to
28°C (0°F to 50°F) above the congealing point of said hydrocarbon material;
(b) transferring said mixture from said low-shear jacketed blender to a pastillator
at a temperature sufficient to maintain said hydrocarbon material in a semi-
solid phase; and
(c) depositing at a blender end of said pastillator a plurality of drops of said
mixture onto a steel belt cooler of predetermined length, and transporting said
drops to a discharge end of said pastillator while cooling said drops to a
temperature low enough to solidify said hydrocarbon phase to form pastilles.

2. The catalyst as claimed in claim 1, wherein said hydrocarbon material has a
congealing point of from 43°C to 121°C (110°F to 250°F).
3. The catalyst as claimed in claim 1 or 2, wherein said hydrocarbon material has a
congealing point of from 66°C to 107°C (150°F to 225°F).
4. The catalyst as claimed in any of claims 1 to 3, wherein said hydrocarbon material is
selected from epoxy resin, fatty acids, fatty alcohols, fatty esters, fatty stearates, hydrocarbon

resins, microcrystalline paraffins, synthetic wax, paraffin wax, polyesters, polyethylene glycol,
polyethylene waxes, polyglycols, polyvinyl alcohols, polystyrene, vegetable waxes, a wax
obtained from processes using coal, natural gas, bio-mass, or methanol as feedstock, a
synthetic wax produced from a Fischer-Tropsch reaction, wax blends and combinations
thereof.
5. The catalyst as claimed in any of claims 1 to 4, wherein said powdered catalyst is
reduced.
6. The catalyst as claimed in any of claims 1 to 5, wherein said powdered catalyst has an
average particle size of from 3 urn to 150 urn.
7. The catalyst as claimed in any of claims 1 to 6, wherein the density of the catalyst is
greater than the density of the hydrocarbon material.
8. The catalyst as claimed in any of claims 1 to 7, wherein said low shear jacketed
blender maintains a temperature that is from 0°C to 11°C (0°F to 20°F) above the congealing
point of said hydrocarbon material.
9. The catalyst as claimed in any of claims 1 to 8, wherein, for preparation thereof, said
blender has at least one paddle and said paddle is positioned within said blender so as to
minimize attrition of said catalyst.
10. The catalyst as claimed in any of claims 1 to 9, wherein, for preparation thereof, said
pastillator has a discharge temperature that is from 1°C to 83°C (2°F to 150°F) lower than the
congealing point of said hydrocarbon material.
11. The catalyst as claimed in any of claims 1 to 10, wherein, for preparation thereof, said
pastille comprises up to 65 wt% catalyst.
12. The catalyst as claimed in any of claims 1 to 11, wherein, for preparation thereof, said
pastilles have a diameter of from 2 mm to 100 mm and a thickness of from 1 mm to 10 mm.

13. The catalyst as claimed in any of claims 1 to 12, wherein, for preparation thereof, said
pastilles are spherical, hemispherical, ellipsoidal, oval, domed, flakes and combinations
thereof.
14. A process for preparing an active catalyst having a protective coating material
comprising the steps of:

(a) heating a hydrocarbon material, such as herein described, having a
congealing point in a low-shear jacketed blender, and then purging the system
with an inert gas, combining the hydrocarbon material with a powdered
crystalline cobalt catalyst in the low-shear jacketed blender, and forming a
mixture wherein said catalyst is uniformly dispersed throughout said
hydrocarbon, said low-shear jacketed blender being selected to minimize
catalyst attrition and being set to maintain a temperature that is from 0°C to
28°C (0°F to 50°F) above the congealing point of said hydrocarbon material;
(b) transferring said mixture from said low-shear jacketed blender to a pastillator
at a temperature sufficient to maintain said hydrocarbon material in a semi-
solid phase; and
(c) depositing at a blender end of said pastillator a plurality of drops of said
mixture onto a steel belt cooler of predetermined length, and transporting said
drops to a discharge end of said pastillator while cooling said drops to a
temperature low enough to solidify said hydrocarbon phase to form pastilles.


The present development relates to a process for enrobing active catalytic materials with a protective coating to form
pastilles, and to an apparatus for making the pastilles. The process comprises mixing an active catalyst powder with a hydrocarbon
material in a low-shear jacketed blender at a temperature slightly above the congealing point of the hydrocarbon, and then making
pastilles from the catalyst / hydrocarbon mixture while cooling the mixture to temperature below the congealing point of the hydro-
carbon.

Documents:

01835-kolnp-2006 abstract.pdf

01835-kolnp-2006 claims.pdf

01835-kolnp-2006 correspondence others.pdf

01835-kolnp-2006 description (complete).pdf

01835-kolnp-2006 form-1.pdf

01835-kolnp-2006 form-3.pdf

01835-kolnp-2006 form-5.pdf

01835-kolnp-2006 international publication.pdf

01835-kolnp-2006 international search report.pdf

01835-kolnp-2006-correspondence others-1.1.pdf

01835-kolnp-2006-correspondence-1.2.pdf

01835-kolnp-2006-form-18.pdf

01835-kolnp-2006-gpa.pdf

01835-kolnp-2006-international search authority report-1.1.pdf

01835-kolnp-2006-priority document.pdf

1835-KOLNP-2006-AMANDED CLAIMS.pdf

1835-KOLNP-2006-AMANDED PAGES OF SPECIFICATION.pdf

1835-KOLNP-2006-ASSIGNMENT.pdf

1835-KOLNP-2006-CORRESPONDENCE-1.1.pdf

1835-KOLNP-2006-CORRESPONDENCE.pdf

1835-KOLNP-2006-DESCRIPTION (COMPLETE).pdf

1835-KOLNP-2006-EXAMINATION REPORT.pdf

1835-KOLNP-2006-FORM 1.pdf

1835-KOLNP-2006-FORM 18-1.1.pdf

1835-KOLNP-2006-FORM 2.pdf

1835-KOLNP-2006-FORM 3-1.1.pdf

1835-KOLNP-2006-FORM 3.pdf

1835-KOLNP-2006-FORM 5-1.1.pdf

1835-KOLNP-2006-GPA-1.1.pdf

1835-KOLNP-2006-GRANTED-ABSTRACT.pdf

1835-KOLNP-2006-GRANTED-CLAIMS.pdf

1835-KOLNP-2006-GRANTED-DESCRIPTION (COMPLETE).pdf

1835-KOLNP-2006-GRANTED-FORM 1.pdf

1835-KOLNP-2006-GRANTED-FORM 2.pdf

1835-KOLNP-2006-GRANTED-SPECIFICATION.pdf

1835-KOLNP-2006-OTHERS-1.1.pdf

1835-KOLNP-2006-OTHERS.pdf

1835-KOLNP-2006-PETITION UNDER RULE 137.pdf

1835-KOLNP-2006-REPLY TO EXAMINATION REPORT-1.1.pdf

1835-KOLNP-2006-REPLY TO EXAMINATION REPORT.pdf

1835-KOLNP-2006-TRANSLATED COPY OF PRIORITY DOCUMENT.pdf


Patent Number 251682
Indian Patent Application Number 1835/KOLNP/2006
PG Journal Number 13/2012
Publication Date 30-Mar-2012
Grant Date 28-Mar-2012
Date of Filing 30-Jun-2006
Name of Patentee SUD-CHEMIE, INC.
Applicant Address 1600, WEST HILL STREET, LOUISVILLE, KY 40210
Inventors:
# Inventor's Name Inventor's Address
1 BRADEN, JEFF 3626, BUDD ROAD, NEW ALBANY, IN 47150
2 O'BRIEN ROBERT 703, BELL ROCK PLACE, LOUISVILLE, KY 40243
3 SCHNEIDER, PAUL 1923, HURSTBOURNE CIRCLE LOUISVILLE, KY 40220-1642
4 MCLAUGHLIN, PATRICK 1739, FLORENCE AVENUE, NEW ALBANY, IN 47150
5 STACK, JOSEPH 3712, FIRETHORN DRIVE, LAGRANGE, KY 40031
6 WOLFE, DAVID 7809, CROWN TOP ROAD, LOUISVILLE, KY 40241
7 HU, XIAODONG D. 7201, WOOD BRIAR ROAD LOUISVILLE, KY 40243
PCT International Classification Number B01J 33/00
PCT International Application Number PCT/US2004/040796
PCT International Filing date 2004-12-03
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 10/750,354 2003-12-31 U.S.A.