Note: Descriptions are shown in the official language in which they were submitted.
ROTATING KILN AND APPARATUS FOR THERMAL CONVERSION OF ORGANIC WASTES,
METHOD FOR CONVERTING ORGANIC WASTES INTO USEFUL PRODUCTS, MANUFACTURING
OF ROTATING KILNS AND APPARATUS AND USES THEREOF
FIELD OF THE INVENTION
The present invention relates to rotating kiln and to polyvalent apparatus for
the thermal
conversion of a feed material into useful products.
The present invention relates also to the uses of the rotating kilns and of
the polyvalent apparatus
for the thermal conversion of an organic waste materials and/or waste oil
mainly into gas and/or
liquid and/or solid products that are useful and environmentally friendly.
The present invention further relates to processes for thermally converting of
an organic waste
materials and/or waste oil into valuable products.
The present invention additionally relates to manufacturing processes for
fabricating the rotating
kilns and for fabricating polyvalent apparatus and involving or not known
assembling methods.
PRIOR ART
WO 201114370 describes a reactor and its internals for thermal cracking of a
mixture, said
reactor comprises: a. a rotating kiln; b. a heating system; c. at least one
shelf of the reactor wall
with minimal stress due to thermal expansion; d. a charge of plates of
consistent shapes; e. means
for bringing the mixture to be cracked on the surface of at least part of the
plates; f. means for
removing the fine solids from the reactor either through entrainment with the
exiting vapours, or
through a separate solids exit; g. means for recovering the reaction and
straight run products and
It means for venting the gas obtained by the thermal cracking outside the
reactor zone. The
reactor is used for the thermal cracking of mixtures comprising organic
compounds and allow the
recovering of valuable by-products, some of them are reusable in an
environmental acceptable
form and/or way.
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W02014121369 describes a mobile plant, for thermally treating a feed stream,
comprising a first
unit designed for heating the feed oil (Unit I); ii. a second unit comprising
a rotating reactor
designed to perform the thermal processing (pyrolizing) of the feed oil and a
vapour solid
separator (Unit II); and iii. a third unit (Unit III) that is a product
separation unit and that is
preferably configured for recycling at least part of the treated feed stream
(heavy oil), recovered
in Unit III, into Unit I. The first unit and/or the second unit is (are)
configured for injecting a
sweep gas in the feed oil and/or in the rotating reactor, and/or the second
unit is configured in a
way that the rotating reactor may work under positive pressure. The processes
for thermally
treating a feed material by using a mobile plant. The uses of the processes
for various
environmental and non-environmental applications. Processes for manufacturing
the mobile
plants. Uses of oil containing resins (such as cracked and/or polarized oils)
for cleaning purposes
and other specialty applications.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 represents a portion of the flow sheet of a first embodiment of the
apparatus of the
invention wherein the pre-treatment module is designed for pre-treating a
mixture of waste oils
and of tires or plastics and wherein the central-module is of the rotating
kiln type.
Figure 2 represents the flow-sheet complementary to the flow sheet of the
detailed view of the
exit of the central module according to Figure 1, the corresponding exit pipe
extension from the
central module and the post-treatment module with the transit line, the seal
between the central
module and the post treatment module, the gas-solid separation equipment
operating at a
temperature close to the temperature at the exit of the central module, the
equipment extracting
solids from the remaining heavy oil fraction.
Figure 3 represents a embodiment of the invention used mostly when the
cracking unit is added
to an existing re-refinery or other such processing plant: a simplified Flow
Sheet showing: the
final cleaning of products vapours using a self-refluxing condenser (or
dephlegmator); the
condensing of the reactor products; and the separating the water and non
condensable gas from
the product oil.
Figure 4 represents a simplified Flow Sheet of an embodiment of the invention
wherein the
hydrocarbon vapours exiting the thermal cracking unit is cleaned in the
dephlegmator (or self
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Date Recue/Date Received 2022-12-29
refluxing condenser); then routed to a distillation column wherein the
products are cooled and
separated; the configuration of the distillation column may change with the
feed to the reactor
and with the desired product slate.
Figure 5 is a view of the inside of the rotating kiln used as central module
in the preferred
embodiment
Figure 6: Figure 6A is a front view of a screen/disc made of wire mesh and
Figure 6B is a front
view of a screen/disc made of a perforated disc; both screens/discs having a
significant hole in the
centre of the disc.
Figure 7 is detailed view of an embodiment of the invention showing the
horizontal positioning of
the rotating kiln referred to in the preferred embodiment, the slope of the
shelves and the
corresponding slope of the plates positioned on the shelves, the perforated
disk defining the end
zone of the reactor wherein hoppers/scoops collect the residual solid and dump
the residual
solids falling from the top hopper to the screen conveyor.
Figure 8 is a detailed view of an embodiment of the invention showing the
positioning of the
scoops and interaction with plates and hopper screen in reactor's zone close
to the exit of the
reactor on the side of the rotating kiln that is opposite of the feeding
entry.
Figure 9 is detailed view of the apparatus as referred to in the description
of the preferred
embodiment and wherein the rotating kiln, the extension of the rotating and
the transit line are
insulated.
Figure 10 is a detailed view of an embodiment of a rotating reactor that may
be used as central
module of the apparatus of the invention.
GENERAL DEFINITION OF THE INVENTION
Introduction
The polyvalent apparatus of the invention comprises at least 2 modules
(central module and post-
treatment module) and alternatively 3 modules (Pre-treatment module, central
module and post-
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treatment module) and is used for treating organic wastes, such as plastics
and tires, that are
optionally mixed with waste oil.
Mixtures of organic wastes, such as plastics and tires, are in a pre-treatment
module eventually
mixed with waste oil and are for example heated to dewater the mixture and
melt the solids in the
mixture, resulting in a hot liquid that may or not contain solids or partially
melted materials.
The hot liquid is thus pumped into a central module comprising a reactor
designed for the thermal
conversion of the mixture into valuable compounds; the mixture is thermally
cracked into
environmentally friendly and useful products.
Steam is optionally injected into the reactor feed stream, where it acts as
sweep gas, controls
reactor residence time, prevents secondary reactions, acts as stripping steam
in downstream
equipment, and provides an element of safety in case of a leak of hydrocarbon
vapours in the from
central module or in a post-treatment module treating the solid-gas mixture
exiting the central
module and/or the post-treatment module, and above their auto-ignition
temperatures.
The reactor is advantageously a rotating kiln, containing plates on which the
liquid mixture is
sprayed. The rotating kiln is inside a heated enclosure, such as a fired
heater, where the reactor
walls are heated externally. Shelves, attached to the inside wall of the
reactor, lift the plates,
keeping them against the hot reactor wall.
If the reactor is mounted horizontally, the shelves are advantageously slanted
with respect to the
axis to help advance solids, already present in the feed material or those
produced in the cracking
reactions, towards the reactor exit.
If the reactor is mounted slanted, the shelves are advantageously mounted
parallel with respect to
the central axis to help advance the solids, produced in the cracking
reactions, towards the reactor
exit.
Such rotating reactors are similar to those that have been made the subject-
matter inter alia of the
international patent application PCT/CA2011/050207 or those rotating kilns
that are obtained by
modifying those rotating kilns that have been made the subject-matter inter
alia of the
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international patent application PCT/CA2011/050207.
According to a preferred embodiment, the modified reactors of the present
invention differ from
those known in the prior art in that:
- at least one the internal shelves present in a reactor's zone defined by a
screen is inclined
in respect to the horizontal; and/or
- there is always a screen between the reactor's zone wherein plates are
moving and
reactor's zone wherein scoop are present for recovering residual solids such
as coke.
The residual solids resulting, in the central module, from thermal conversion
are, for example,
separated from the vapours in a box and/or in a cyclone situated in a second
heated enclosure.
The temperature of the products at the entry of the separating equipment is
advantageously kept
about or above the reactor exit temperature.
The line between the two heated enclosures is also advantageously kept about
or above the
reactor outlet temperature with an extension of the second heated enclosure. A
cleanout door is
advantageously provided on this line to remove deposits for example when the
plant is shut down.
Another alternative embodiment is constituted by having a sweeper broom that
can be
alternatively moved back and forth inside the transit channel. This broom
being designed to
scrape the inside wall of transit line, even during operation of the
apparatus.
The vapours exiting the gas-solids separating equipment is routed to an
equipment of the flash
drum type with a self-refluxing condenser mounted above it to scrub the
reactor products and
remove residual solids.
The clean vapours exiting from the self-refluxing condenser are condensed and
separated into
products such as wide range diesel, heavy oil, naphtha and gas in an equipment
of the distillation
column type.
The heating and/or the insulation of the extension between the exit of the
central module and the
transit line, and/or of the transit line is important to optimize the solid-
gas separation.
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A first object of the present invention is constituted by polyvalent apparatus
for the thermal
conversion of a feed material into useful products. The apparatus comprising:
a) a central module for thermal conversion of the feed material into a solid-
gas mixture;
and
b) post-treatment module for performing a solid-gas separation on the solid-
gas mixture
exiting the central module,
and being characterized in that the post treatment module is configured to
perform the solid-gas
separation, substantially without any condensation of the gas present in the
solid gas-mixture
exiting the central module.
A second object of the present invention is constituted by polyvalent
apparatus for the thermal
conversion of a feed material into useful products, said apparatus comprising:
a) a pre-treatment module for preparing, from the feed material, a feedstock
that will be
liquid or partially solid and/or partially heterogenic and/or partially
dewatered and/or
heated;
b) a central module for thermal conversion of the pre-treated feedstock into
a solid-gas
mixture; and
c) a post-treatment module for performing a solid-gas separation on the solid-
gas mixture
exiting the central module,
and being characterized in that the post-treatment module is configured to
perform the solid-gas
separation, substantially without any condensation of the gas present in the
solid gas-mixture
exiting the central module.
According to a preferred embodiment, the rotating kilns constituting of the
central module are
characterized by the fact that the internal wall of the rotating kiln are
equipped with slanted
shelves in order to facilitate moving of residual solids produced in the
reactor and/or the moving
of the inert solid present in the feed material, to the corresponding
recovering zone of the rotating
kiln. This phenomena is called the solid migration to the exit of the reactor.
More preferably, the angle (a) defined by the main axle of the rotating kiln
and by the direction of
a shelf is such as to facilitate the migration of the solids such as the inert
solids and/or those
produced during the thermal processing to the reactor's zone designed for the
recovering of the
solids and to avoid substantial damage of parts of the rotating kiln such as
the screens present
inside the rotating kiln for keeping each set of plate within a specific zone.
This angle (a) is
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preferably comprised between 2 and 45 degrees, and more advantageously between
3 and 10
degrees, more advantageously this angle is about 6 degrees. The angle
depending inter alia of the
nature of the feedstock.
According to another preferred embodiment of the invention, the rotating kiln
is equipped with at
least one screen/disc protecting the scoop.
Preferably the screen/disc has at least one restrictive holes that is
sufficiently big to allow the
transit of the residual solids produced in the reactor but too small to enable
the plates moving
inside the rotating kiln to go through the screen. The screen/disc may be
perforated and/or have
other holes that may be greater.
Advantageously, the restrictive hole(s) is (are) positioned on the peripheral
area of the
disc/screen.
The screens/discs are preferably positioned in order to create sections in
order to avoid migration
of the plates and/or in order to reinforce the structure of the rotating kiln.
At least one of the
section created by the discs will contain scoops and will be aimed to protect
the scoops that
recover the residual solids. The scoop section is a section having
advantageously no plate.
The distance between two discs is dependent upon: the size of the reactor
and/or the number and
the size of the plates and/or of the feed material and/or the number and slope
of the shelves
and/or the operating temperature of the kiln and/or of the desired product
slate.
The feed material may advantageously include mostly organic waste materials
and/or waste oil.
The feed material may also comprise at least one chemical agent such as
detergents that may
comprise phosphorous and/or sulfur.
The post-treatment module is advantageously configured for keeping the solid-
gas mixture at a
temperature above or about the temperature of the gas at the exit of the
central module, but when
the temperature is above the temperature at the exit of the central module,
the temperature is
inferior to the cracking temperature of the gas present in the solid-gas
mixture.
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The post-treatment module may also be configured for keeping the solid-gas
mixture at a
temperature slightly under the temperature of the gas at the exit of the
central module; but, in this
case, the difference between both temperatures is preferably lower or equal to
10 (preferably to
5, more preferably about 1) degree(s) Celsius.
The difference between the temperature in the post-treatment module and the
temperature at the
exit of the central module is preferably inferior or equal to 10 degrees
Celsius.
According to a preferred embodiment those polyvalent apparatus, comprise means
for injecting
steam inside the feed material and/or inside the feedstock, and/or inside the
pre-treatment
module and/or inside the central module.
The post-treatment module is advantageously positioned close to the exit of
the central module.
Those polyvalent apparatus, allow the thermal conversion to be performed with
a reduced
residence time ranging from example from 2 seconds to 120 minutes.
The organic waste material that may be treated by those polyvalent apparatus
are, for example,
those selected among the group constituted by plastics, tires, rubber, waste
oils and mixtures
thereof. A feed material that is, in the pre-treatment zone, is an heterogenic
mixture and that is
heated for at least partial dewatering and/or for at least partial melting of
the solids, is
advantageously treated by the polyvalent apparatus of the invention.
According to a preferred embodiment of the invention, the feed material,
resulting from the
treatment(s) in the pre treatment module is a hot liquid that may still or not
contain solids or
partially melted solids.
Polyvalent apparatus of the invention are, advantageously, configured for the
temperature of the
feed material resulting from the treatment(s) in the pre treatment module
being advantageously
comprised between 90 and 350 degrees Celsius.
The polyvalent apparatus are configured in a way that the feed material, or
the feed stock, directly
feed into the central module, is thermally cracked into environmentally
friendly and useful
products.
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The polyvalent apparatus presents the advantage to be able to treat
undesirable chemicals
present in the feed material or present in the feed stock in order to destroy
the undesirable
chemicals during thermal cracking.
According to a preferred embodiment, steam is directly injected into the hot
liquid resulting from
the thermal treatments performed on the feed material in the pre-treatment
module and/or
steam is injected in the central module, preferably in the feedstock or at any
place in the central
module. Steam can also be injected at any stage of the process. Although steam
is the preferred
inert gas used in the process, other gasses such as recycle gas from the
process or nitrogen can
also be used.
Preferably, the polyvalent apparatus is configured in order for the steam to
be injected at a
pressure sufficient to create a sweep gas effect in the central module. The
steam thus acts as a
sweep gas and/or is used to controls reactor residence time and/or is used to
prevent secondary
reactions and/or acts as stripping steam in downstream equipment and/or
provides an element
of safety in case of a leak of hydrocarbon vapours for example at the exit of
the central module and
above their auto-ignition temperatures. Steam, injected into the reactor feed
stream, can improve
the flow regime in the feed line, and prevent premature cracking as well as
plugging of the feed
spray nozzles.
According to an advantageous embodiment, the polyvalent apparatus are
configured in a way that
the post-treatment module comprises a transit line, directly connected to the
gas-solid mixture
exit of the central module, for bringing the gas-solid mixture into the also
heated post-treatment
module.
According to another preferred embodiment, the polyvalent apparatus is
equipped with:
- the transit line connecting the two heated enclosures constituting of the
central
module and of the post-treatment module; and
- an extension of the second heated enclosure and/or of the central module
having the
function of assuring the connection with an end of the transit line, said
extension being also
kept at or above the reactor outlet temperature.
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The transit line between the two heated enclosures is also advantageously kept
at a temperature
slightly below or above ( for example: + or - 5 degrees Celcius or for example
5 % above or
below) the temperature of the gas at the exit of the central module.
According to another preferred embodiment, the polyvalent apparatus:
- the line between the two heated enclosures is equipped with an automatic or
manual cleanout device, such as a door, provided on this line to remove
deposits for
example when the plant is shut down; and
-the sealing of the connection between the extension of the Central module and
the end of
the connection line being preferably assumed by a ring (preferably a metallic
ring) and by a
seal (preferably of the graphite type and of the asbestos's type) .
As a matter of exemplification, the transit line is in the form of a cylinder,
has a length L and an
internal diameter D and the Ratio L/D is advantageously lower or equal to 2.
As another example, the length of the transit line is lower or equal to 10
meters.
According to a preferred embodiment, the central module is of the rotating
kiln type, and
preferably of the type that has been made the subject-matter of international
patent application
PCT/CA2011/050207.
The rotating kiln advantageously contains plates on which the liquid mixture
is sprayed.
According to another preferred embodiment, the rotating kiln is at least
partially, and preferably
mainly, and more preferably completely inside a heated enclosure, such as a
fired heater, and
wherein the reactor walls are advantageously heated externally.
The shelves are preferably attached to the inside wall of the reactor, lift
the plates when the
reactor is rotating and keep them against the hot reactor wall when the
reactor is rotating.
In a preferred embodiment:
- the reactor is mounted slanted, the shelves are parallel to the central axis
to help to
advance the solids, produced in the cracking reactions, towards the reactor
exit; and
- the reactor is mounted horizontal, the shelves are slanted with respect to
the axis to
help advance the solids, produced in the cracking reactions, towards the
reactor exit.
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The rotating equipment is attached to the kiln end but must be out of the
heated housing to
preserve the support and/or of the ball bearings of the support rollers.
According to another advantageous embodiment, the central module include a
first zone placed in
a heated enclosure and a second zone that is outside the heated enclosure but
insulated internally
to keep the solid-gas mixture, produced in the first zone, hot until entering
a solid-gas separation
equipment.
The central module preferably include a first zone placed in a heated
enclosure and a second zone
that is outside the heated enclosure but insulated internally to keep the
reactor products at a
temperature slightly (for example 3 %) above the temperature inside the first
zone.
According to a preferred embodiment, the polyvalent apparatus are configured
in a way that the
solids resulting from the thermal processing in the central module are
separated from the vapours
in gas-solids separation equipment, preferably in a box and/or in a cyclone,
situated in a second
heated enclosure placed downstream to the central module.
Preferably, the temperature of the products at the exit of the separating
equipment is
advantageously kept at or above the reactor exit temperature.
Polyvalent apparatus allows the clean vapours exiting from the post treatment
module are
condensed and separated into products such as gas, light oils, fuel oils.
According to a preferred embodiment, the polyvalent apparatus are considered
in a way that the
separating equipment is configured to be connected with an equipment of the
distillation column
type.
According to another advantageous embodiment, the polyvalent apparatus are
configured in way
that the vapours, exiting the gas-solids separating equipment are routed to an
equipment of the
flash drum type, said equipment of the flash drum type having preferably a
self-refluxing
condenser mounted above it to scrub the reactor products and to remove
residual solids.
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The polyvalent apparatus are preferably configured in a way that the clean
vapours exiting from
the post treatment module, are condensed and separated in an equipment of the
distillation
column type.
According to a preferred embodiment of the first and second object of the
invention, of a
particular interest are the polyvalent apparatus wherein the rotating kill
comprises:
a. at least one shelf of the reactor wall;
b. a charge of plates of consistent shapes;
c. means for bringing the mixture to be cracked on the surface of at least
part of the plates;
d. means for removing the fine solids from the reactor;
e. means for recovering the reaction and straight run products; and
h. means for venting the gas obtained by the thermal cracking outside the
reactor zone.
A third object of the present invention is the use of the polyvalent apparatus
according to the
first or according to the second object of the invention for the thermal
conversion of an organic
waste materials and/or waste oil into the valuable products that are
preferably gas, light oils, and
fuels and speciality products.
Of a particular interest for the thermal conversion of an organic waste
materials and/or waste oil
into Wide Range Diesel, Wide Range Diesel being defined by reference to Number
1 to Number 6
diesels, and by reference to marine oil specifications and/or to heating oil
specifications.
Advantageous uses of the invention are those for:
- treating wastes oils such as used lubricating oils, form oils, metal
treating oils, refinery or
transportation oil tank bottoms; and/or
- destroying hazardous and/or toxic products; and/or
- reusing waste products in an environmental acceptable form and/or way;
and/or
- recovering oil from oil spills.
Of a particular interest are those uses of a process for treating used oils
and to prepare:
= a fuel, or a component in a blended fuel, such as a home heating oil, a
low sulphur
marine fuel, a diesel engine fuel, a static diesel engine fuel, power
generation fuel, farm
machinery fuel, off road and on road diesel fuel; and/or
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= a cetane index enhancer; and/or
= a drilling mud base oil or component; and/or
= a solvent or component of a solvent; and/or
= a diluent for heavy fuels, bunker or bitumen; and/or
= a light lubricant or component of a lubricating oil; and/or
= a cleaner or a component in oil base cleaners; and/or
= a flotation oil component; and/or
= a wide range diesel; and/or
= a clarified oil; and/or
= a component in asphalt blends.
A fourth object of the present invention is the manufacturing processes for
fabricating those
apparatus defined in the first and in the second object of the invention, and
in particular those
manufacturing processes involving known assembling methods such as welding,
screwing,
sticking.
A fifth object of the present invention is constituted by processes for
thermally converting of
organic waste materials and/or waste oil into valuable products, which process
comprises the
steps of:
- a) feeding a reactor and its internals with said mixture,
- b) heating said reactor and its internals at a temperature corresponding to
the cracking
temperature of the mixture; and
- c) recovering of the products resulting from the cracking and for their
elimination of said
reactor,
wherein the mixture to be pyrolysed is brought in contact with at least part
of the surface of the
plates of the charge and result in a reaction and vaporization of the feed and
products allowing the
removal of the mixture in the gas and solids phases, and wherein at least part
of the plates of the
charge moves during the rotation of the reactor.
Of a particular interest, are those processes wherein the mixtures to be
treated include organic
compounds having the following thermodynamic and physical features: a specific
gravity
between 0.75 and 2.2, preferably between 0.75 and 1.1, and/or atmospheric
distillations between
20 C and 9 50 C as per ASTM 1160.
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According to advantageous embodiments of the processes of the invention, the
average residence
time in the reactor ranges from 2 seconds to 2 hours, advantageously from 3
seconds to 15
minutes, preferably from 50 seconds to 15 minutes, and more preferably from 90
seconds to 10
minutes.
Of a particular interest are those processes wherein the heating temperature
in the reactor ranges
from 350 C to 550 C, preferably from 390 C to 460 C, more preferably from 420
C and 455 C and,
more advantageously, is about 425 C when used lube oils are treated.
Of a particular interest are those processes treating plastics and wherein the
heating temperature
in the reactor ranges from 150 C to 550 C, preferably from 150 to 450 C, and
more preferably in
the case of PEP is about 180 C. The temperature ranges depending upon the type
of plastics to be
treated by the processes of the invention.
Of a particular interest are those processes treating rubber and wherein the
heating temperature
in the reactor ranges from 350 C to 525 C, advantageously from 400 C to 500 C,
more
advantageously, is about 450 C.
According to a preferred embodiment, the rotation speed of the central module
(for example of
the rotating reactor) ranges from 0.5 rpm to 10 rpm more preferably from 1 rpm
to 5 rpm, and is
more advantageously about 3 rpm.
According to another preferred embodiment, the various fractions generated by
the cracking are
recovered as follows:
- by liquid fraction is recovered by distillation;
- gaseous fraction is recovered by distillation; and
- by solid fraction is recovered for example: by reduction of the speed of the
gas, in baffle, in
cyclones, and self refluxing condenser.
Among the numerous advantages of the processes of the invention, when applied
to used oil, the
followings are:
- the amount of the recovered liquid fraction represents between 80% and 100%
weight of
the reactor feed;
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- the amount of the recovered gaseous fraction represents between 0% weight
and 10%
weight of the reactor feed; and
- the amount of the recovered solid fraction represents between 0% weight and
8% weight
Among the numerous advantages of the processes of the invention, when applied
to plastic, the
followings are:
- the amount of the recovered liquid fraction i.e. of diesel represents
between 70% and 90%
weight of the reactor feed;
- the amount of the recovered gaseous fraction i.e. of the recovered vapours
represents
between 2 to 10 % weight and of the recovered naphtha represents between 2 and
15 %
weight of the reactor feed; and
- the amount of the recovered solid fraction i.e. of recovered coke represents
between 1 and
10 % weight.
In the case wherein the feed material is plastic, the temperature in the
central module is
advantageously comprised between 150 and 550 degrees Celsius, depending upon
the type of
plastics. The overall yield is also dependent upon the type of plastic
treated.
Among the numerous advantages of the processes of the invention, when applied
to rubber, the
followings are:
- the amount of the recovered liquid fraction i.e. wide range diesel
represents between 45 %
and 55 % weight of the reactor feed;
- the amount of the recovered gaseous fraction, mainly gas and naphtha,
represents between
10 % weight and 20% weight of the reactor feed; and
- the amount of the recovered solid fraction i.e. the carbon black represents
between 30 %
weight and 40 % weight
In the case wherein the feed material is rubber, the temperature in the
central module is
advantageously comprised between 350 and 525 degrees Celsius.
The sulfur being mainly in the carbon black
The processes of the invention may be operated in a continuous or in semi
batch mode or in a
batch mode.
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A sixth object of the present invention is constituted by rotating kilns
characterized in that they
have at one end of the reactor an extension that is configured to be at least
partially heated and to
constitutes the exit of the solid-gas mixtures produced in the rotating
reactor.
The rotating kilns of the invention are preferably obtained by modification of
a rotating kiln as
described in the first object, or as described in the second object of the
invention or as disclosed in
the description of international patent application PCT/CA2011/050207 as
originally filed.
The rotating kiln of the invention are further connected in a way that the
extension is connectable
with a transit line that is advantageously heated and/or insulated and
configured to bring solid-
gas mixtures exiting the rotating kiln to a heated post-treatment module
configured to separate
gas and solids present in the solid-gas mixture.
In a preferred embodiment, the extension has the form of a cylinder.
PREFERRED EMBODIMENTS OF THE INVENTION
The following preferred embodiment illustrated by Figures 1 to 5 and by the
details thereafter
provided. The preferred embodiment is given as a matter of illustration only
and should not be
constructed as constituting a limitation of the scope of the invention in its
generality.
Figure 1 represents the partial of the flow sheet of a first embodiment of the
apparatus of the
invention wherein the pre-treatment module 110 is designed for pre-treating a
mixture 112 of
waste oils and of tires or plastics (mixed in mixing tank 114 and directed to
the pre-treatment
module 110 through pump or screw conveyor 116) and wherein the central-module
118 is of the
rotating kiln type equipped with heater 120 (where pre-treated material is
transferred from pre-
treatment-module 110 through pump 122). Arrow 124 indicate transfer of waste
and light oil
product from pre-treatment to cooling and separation, arrow 126 indicate the
injection of steam
and arrow 128 indicate transfer of the product to post-treatment module (not
shown).
Figure 2 represents the flow-sheet complementary to the flow sheet of the
detailed view of the
exit (arrow 128) of the central module 118 according to Figure 1, the
corresponding exit pipe
extension from the central module 118 and the post-treatment module with the
transit line, the
seals 204 and 204a between the central module's enclosure 200, the reactor 201
and the post
treatment module 211, the gas-solid separation equipment operating at a
temperature close to the
16
Date Recue/Date Received 2022-12-29
temperature at the exit of the central module, the equipment extracting solids
from the remaining
heavy oil fraction. The gas transfer is shown on 203 and the solids exit from
the shovels 202 to the
hopper 207 then the screw conveyor 208 to exit at the opening 207a. The post-
treatment module
include the diverter 209 and the cyclone 212 all in the second heated
enclosure 211 where there
are flames 214, and cyclone condenser 213. The gases from the flames in the
heated enclosures
are evacuated by chimneys 205 205a. The tubes between the two modules have
expansion joints
206.
Figure 3 represents a embodiment of the invention used mostly when the
cracking unit is added
to an existing re-refinery or other such processing plant. Figure 3 is a
simplified Flow Sheet
showing: the final cleaning of products vapours 300 from a previous processing
step into flash
drum 310 using a self-refluxing condenser 320 (or dephlegmator); the
condensing of the reactor
products through cooler 330 towards a 3-phase accumulator 340; and the
separating of the water
350 and non condensable gas 360 from the product oil 370. Arrow 380 indicate
the flux of heavy
oil towards storage.
Figure 4 represents a simplified Flow Sheet of an embodiment of the invention
wherein the
hydrocarbon vapours 300 exiting the thermal cracking unit is cleaned in the
dephlegmator 320
(or self refluxing condenser), similar to Figure 3 but then routed to a
distillation column 400
wherein the products are and separated to heavy-oil 380, wide range diesel 370
and lighter
portions. The lighter portions are directed to the cooler 330 and 3-phase
accumulator 340 where
it is further separated to gas to fuel the reactor 360, to water in storage or
treatment 350 and to
naphta to use as fuel or to be sold. Some of the naphta is refluxed to the
distillation column. The
configuration of the distillation column may change with the feed to the
reactor and with the
.. desired product slate.
As apparent on Figure 5, the central module comprises an indirectly fired
rotating kiln (1) that is
represented in the sectional view of Figure 5 and obtained from the rotating
kiln described in
details in the preferred embodiment of international patent application
PCT/CA2011/050207 and
wherein by addition of the insulated and removable extension as represented in
Figure 2 at the
exit of the reactor heated enclosure, containing a charge of metal plates (2)
that are lifted by one
or more narrow shelves (3) as the reactor rotates. The shelves are wide enough
to hold two plates
one against the wall, and a second one against the first plate. The plates are
flat pieces of metal of
regular shapes. The heat (5) coming through the reactor wall heats the plates
as they are dragged
and lifted against the reactor wall by one or more narrow shelves. As the
rotation continues, the
17
Date Recue/Date Received 2023-09-12
plates fall off the shelves or off the plates below them, and flip as they
fall, presenting the hot
surface to the oil jet (4) projected unto the plates (5).
The plates carry the heat from the reactor walls and provide a hot surface
where the reactions
take place. The plates are lifted and kept against the reactor walls by
shelves (3). Depending on
the thickness of the plates, the shelves can be designed to hold one, two or
more plates. As the
kiln rotates, the plates fall off the shelves or off the plates below,
presenting the face that was
against the reactor wall to the oil spray.
As they slide over each other, the metal plates become a surface that protects
the reactor walls
from contact with the relatively cold oil spray and the resulting thermal
shock Also, as they slide
down the reactor, the plates scrape the reactor walls and each other clean of
coke. The coke
released is entrained out of the reactor with the hydrocarbon gas.
The shelves may be directly attached to the reactor wall or they may be
attached to the reactor
walls with clamps (6) to reduce stress due to the differential thermal
expansion between the
reactor walls and the shelves. The clamps are spaced in such a way that, even
at the hottest
reactor temperature, the shelves are strong enough to support hot the plates
on it Depending on
the spacing between the shelves, there may be only one double row of plates
per shelf or several
rows one on top of each other. Both the plates and shelves increase the heat
transfer area from the
heat source to the reaction site.
The clamps (6) are shaped like a T (figures 4 and 5). The base of the T (7) is
welded to the
rotating kiln walls. The cross bar or top of the T (8) is U shaped to receive
the shelve (3) ends,
leaving room for the thermal expansion of the shelves, both longitudinally and
perpendicular to
the reactor wall. Bolts (9) close off the U brackets and keep the shelves from
falling out of the
brackets. The branches of top of the T (6) are wide enough to allow for the
thermal expansion of
the shelves within them, while providing strength and support for the load of
1, 2 or more layers
of the metal plates along the full length of the shelves in the reactor, and
as many rows as the
spacing between the shelves will accommodate.
Figure 7 is a detailed view of an embodiment of the invention showing the
horizontal positioning
of the rotating kiln 700 referred to in the preferred embodiment, the slope of
the shelves 710 and
the corresponding slope of the plates 720 positioned on the shelves 710, the
perforated disk 730
18
Date Recue/Date Received 2022-12-29
defining the end zone of the reactor wherein hoppers/scoops 740 collect the
residual solid and
dump the residual solids falling from the top hopper to the screw conveyor
750.
As apparent on Figure 8, scoops (10) are attached to the kiln wall at the exit
end of the kiln to
.. remove heavier coke that may have deposited on the bottom of the kiln. The
scoops are pipe
sections with one end closed, and the other end cut on a slant, to allow any
hydrocarbon vapours
to escape before the coke falls into the hopper (11). The scoops are sized
small enough so that the
metal plates cannot enter with the coke. As the reactor rotates, the scoops
turn upside down and
dump their load of coke into a hopper mounted on the solids exit tube (12). To
ensure that none of
the plates block the coke exit from the reactor, the hopper has a metal grid
(13) that will deflect
any plate towards the bottom of the kiln. The solids exit tube (12) has a
screw conveyor (15) to
push the coke out of the reactor. The solids exit tube can be above the vapour
exit tube (14),
within the vapour exit tube or even at separate ends. There must be at least
two exits from the
kiln, or one oversized exit, to ensure that the reactor exit is never
obstructed. In normal
.. operation, the coke will exit the reactor mostly through the vapour exit
(14). The scoops are
required when the feed to the kiln is interrupted and there is no vapour to
carry the coke out, or
when the coke is wet or heavy.
Figure 9 is a detailed view of the apparatus as referred to in the description
of the preferred
embodiment wherein the end of rotating kiln 700, as in Figure 7 is shown,
including perforated
disks 730, hopper 740 and screw conveyor 750, wherein the extension of the
rotating kiln 900
and the transit line (not shown) are insulated with insulation 920.
Figure 10 is a detailed view of an embodiment of a rotating reactor that may
be used as central
.. module of the apparatus of the invention. Figure 10 shows the heated
enclosure 1000 with feed
line 1010 bringing the VTAE coming in the opposing end of the vapours and coke
exit. A feedline
line support 1020 with the detail showing the attachment to the reactor wall
1021 and the
support 1022 being rods attached to a support ring are illustrated. The
support rods are protected
from the plates by perforated disk 1030. The detail shows center hole 1031 to
let the vapours thru
.. and perforations 1032 small enough so that the plates 1040 cannot go thru
but large enough to let
the solids pass. The shelves push the plates 1050 when the reactor turns. The
solids when they
reach the end of the reactor are picked up by the shovels 1060 which dump the
solid in the hopper
1070. The solids are taken by the screw 1080 to the diverter 1090 where they
drop down to the
exit for the coke 1100. The vapours in the diverter 1090 and cyclone 1130 are
kept at the
temperature higher by the second heated enclosure 1110 which keeps he vapours
inside the two
19
Date Recue/Date Received 2023-09-12
higher than in the reactor. The vapours from the diverter 1090 go to the
cyclone were the coke
entrained is separated from the solids to get clean hydrocarbon.
Example 1
There is a growing concern for used oil re-refiners in Europe and North
America. About 15% of
the oil entering their plants is vacuum tower bottoms, where most of the
hazardous components
of used oils are concentrated. VTAE, Vacuum Tower Asphalt Extender, is
currently sold as an
additive to asphalt binders. However, this practice is banned in a growing
number of j urisdictions.
By using a typical use lubricating oil (ULO) having the features thereafter
defined and a
demonstration unit processing ULO including as central module a rotating kiln
(size of the heated
part: diameter 10 feet and length 8 feet) and a post-treatment module as
represented on Figure 7
of the present invention, the corresponding results thereby obtained are
thereafter summarized.
The feed VTAE distillation was taken from the heaviest 50% of the ULO. It was
entered as 850
Kg/hr, at 3000C and 2 atmospheres.
The VTAE stream was specified with a specific gravity of 0.95 and an ASTM D-
2887 distillation as
follows:
% weight vaporized Temperature 0C
0 425
10 435
20 445
455
25 40 465
50 475
60 490
70 510
80 535
30 100 605
34 Kg/hr of steam at 180 C and 10 atmospheres was mixed with the VTAE, and the
resulting
mixture was introduced into the reactor. The reactor operates at 510 C and a
positive pressure of
127 KPa.
Date Recue/Date Received 2022-12-29
Comparative analysis of the input and of the output shows substantially a
complete removal of the
coke particles, about 7 microns and over, from the reactor products.
By keeping the transit line/tunnel and the cyclone (post treatment module)
heated, fouling and
plugging are reduced. The recovering of the residual solids before
condensation prevents the
return of metal, such as zinc, into the product oils.
The reactor products exit the reactor as vapours or solids. The amount and
composition of the
reactor products are calculated using the disappearance of the heavier portion
of ULO in the
demonstration unit, and the difference between the cuts entering the reactor
and the same cuts
exiting the reactor as gas, naphtha, gasoil, heavy oil and coke.
The 30 Kg/hr non-condensable gas was pared down from the actual gas produced
in the
demonstration plant, and entered as:
Methane 20% wt
Ethane 18% wt
Propane 20% wt
Butane 1% wt.
Pentane 7% wt.
Hexane 30% wt.
Sulphur 4% wt.
The 34 Kg/hr steam entering the reactor exits without transformation. The 85
Kg/hr solids are
entered as carbon. In fact the coke exiting the reactor in the demonstration
unit was about 50%
carbon, 40% metals and 10% sulphur.
The remainder of the reactor products will be condensed into fuels. They were
entered as three
different streams: 90 Kg/hr naphtha, 550 Kg/hr gasoil and 95 Kg/hr heavy oil.
Heavy
% wt. distilled Naphtha Gasoil Oil
0 30 120 340
5 150 360
21
Date Recue/Date Received 2022-12-29
45 170 390
200 400
75
50 90 270 440
70 110
80 350 490
90 140 370 530
95 390 550
100 180 420 590
In a first embodiment, the solids are separated from the reactor products and
the vapours are
cooled and condensed into three phases: non-condensable gas, liquid oil and
water.
5 In a second embodiment, the solids are separated from the reactor
products and the vapours are
distilled into 42 1<g/hr non-condensable gas, 31 Kg/hr water, 90 Kg/hr
naphtha, 565 Kg/hr gasoil
and 71 Kg/hr heavy oil. Note 3 kg of water exits with the gas.
Heavy
% wt. distilled Naphtha Gasoil Oil
C
0 -40 130 328
5 31 159 356
10 46 180 380
20 58 206 395
30 71 233 410
50 95 281 439
70 117 338 468
80 127 360 490
90 137 382 531
95 147 410 572
100 160 427 590
The first embodiment will be for a unit that treats VTAE from an existing re-
refinery that already
10 has a products distillation column.
22
Date Recue/Date Received 2022-12-29
In the second embodiment, the distillation column was designed to meet
European standards for
the transportation of diesel fuels: a Flash Point of 55 C, and 80% distilled
at 360 C.
From the precedings it may be deduced that it is possible to thermally crack
VTAE, while
destroying the harmful products in ULO.
ADVANTAGES OF THE INVENTION
Those apparatus and those rotating kiln of the invention, having when compared
to the
conversion apparatus and to the rotating kiln of the prior art, at least one
of the following
properties:
- an improved overall efficiency;
- an improved safety;
- an improved length for operation without maintenance; and
- a reduced energy consumption;
- ease of manufacturing and maintenance;
- better protection for supports of the rotating reactor, such as the rollers
and the bearing
inside of the roller supporting the rotating kiln; and
- better product's slate both in quality and quantity.
Moreover, the post treatment module is simplified and very efficient,
particularly in respect of
very low rate of residual solid in the recovered gas.
Although the present invention has been described with the aid of specific
embodiments, it should
be understood that several variations and modifications may be grafted onto
said embodiments
and that the present invention encompasses such modifications, usages or
adaptations of the
present invention that will become known or conventional within the field of
activity to which the
present invention pertains, and which may be applied to the essential elements
mentioned above.
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Date Recue/Date Received 2022-12-29
