U.S. patent application number 15/362102 was filed with the patent office on 2017-03-16 for system and process for converting plastics to petroleum products.
The applicant listed for this patent is JBI INC.. Invention is credited to John William BORDYNUIK.
Application Number | 20170073584 15/362102 |
Document ID | / |
Family ID | 44511564 |
Filed Date | 2017-03-16 |
United States Patent
Application |
20170073584 |
Kind Code |
A1 |
BORDYNUIK; John William |
March 16, 2017 |
SYSTEM AND PROCESS FOR CONVERTING PLASTICS TO PETROLEUM
PRODUCTS
Abstract
A system and process for converting plastics and other heavy
hydrocarbon solids into retail petroleum products are provided. The
plastics are processed by melting, pyrolysis, vapourization, and
selective condensation, whereby final in-spec petroleum products
are produced. The system provides a reactor for subjecting the
plastics to pyrolysis and cracking hydrocarbons in the plastics to
produce a plastics vapour comprising hydrocarbon substituents; one
or more separation vessels for separating the plastics vapour into
hydrocarbon substitutents based on boiling points of the
hydrocarbon substituents; one or more condensers for condensing the
hydrocarbon substituents into one or more petroleum products; and
means for collecting the one or more petroleum products. Fuels
generated during the process can be recycled for use upstream in
the process.
Inventors: |
BORDYNUIK; John William;
(Thorold, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
JBI INC. |
NIAGARA FALLS |
NY |
US |
|
|
Family ID: |
44511564 |
Appl. No.: |
15/362102 |
Filed: |
November 28, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14235602 |
May 26, 2014 |
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PCT/US2011/046783 |
Aug 5, 2011 |
|
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15362102 |
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61512733 |
Jul 28, 2011 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C10G 2400/04 20130101;
C10G 2300/4081 20130101; C10G 2400/28 20130101; C10G 1/02 20130101;
C10L 1/08 20130101; C10L 1/04 20130101; C10B 47/06 20130101; C10L
1/06 20130101; C10B 53/07 20130101; C10G 1/10 20130101; C10G
2300/1003 20130101; C10G 2400/08 20130101; C10G 2400/02 20130101;
C10G 2300/4006 20130101 |
International
Class: |
C10B 53/07 20060101
C10B053/07; C10G 1/10 20060101 C10G001/10; C10G 1/02 20060101
C10G001/02; C10B 47/06 20060101 C10B047/06 |
Claims
1. A process for processing plastics into one or more petroleum
products, the process comprising: providing plastics to a pyro
lysis reactor; subjecting the plastics to pyrolysis and cracking to
produce a plastics vapour, plastics liquids and plastics solids
comprising hydrocarbon substituents; separating the plastics vapour
in a separation vessel to form a first liquid petroleum product
from a gaseous petroleum product; and condensing the gaseous
petroleum product into a second liquid petroleum product.
2. The process of claim 1, further comprising melting the plastics
in a premelting reactor prior to pyrolysis.
3. The process of claim 2, further comprising refluxing the
plastics liquids and plastics solids in the pyrolysis reactor for
further pyrolysis and cracking.
4. The process of claim 1, further comprising refluxing the
plastics liquids and plastics solids in the pyrolysis reactor for
further pyrolysis and cracking.
5. The process of claim 1, wherein the pyrolysis of the plastics is
at a temperature of 340 to 445.degree. C., 350 to 425.degree. C.,
or 400.degree. C.
6. The process of claim 2, wherein the pyrolysis of the plastics is
at a temperature of 340 to 445.degree. C., 350 to 425.degree. C.,
or 400.degree. C.
7. The process of claim 3, wherein the pyrolysis of the plastics is
at a temperature of 340 to 445.degree. C., 350 to 425.degree. C.,
or 400.degree. C.
8. The process of claim 4, wherein the pyrolysis of the plastics is
at a temperature of 340 to 445.degree. C., 350 to 425.degree. C.,
or 400.degree. C.
9. The process of claim 2, wherein the melting of the plastics is
at a temperature of 250.degree. C.,
10. The process of claim 1, wherein the petroleum products are
diesel, gasoline, furnace fuel, kerosene, propane, butane, ethane
or methane.
11. The process of claim 1, wherein the separation of the plastics
vapour in the separation vessel is at about 240.degree. C. to about
300.degree. C.
12. The process of claim 2, wherein the separation of the plastics
vapour in the separation vessel is at about 240.degree. C. to about
300.degree. C.
13. The process of claim 3, wherein the separation of the plastics
vapour in the separation vessel is at about 240.degree. C. to about
300.degree. C.
14. The process of claim 4, wherein the separation of the plastics
vapour in the separation vessel is at about 240.degree. C. to about
300.degree. C.
15. The process of claim 5, wherein the separation of the plastics
vapour in the separation vessel is at about 240.degree. C. to about
300.degree. C.
16. The process of claim 6, wherein the separation of the plastics
vapour in the separation vessel is at about 240.degree. C. to about
300.degree. C.
17. The process of claim 7, wherein the separation of the plastics
vapour in the separation vessel is at about 240.degree. C. to about
300.degree. C.
18. The process of claim 8, wherein the separation of the plastics
vapour in the separation vessel is at about 240.degree. C. to about
300.degree. C.
19. The process of claim 9, wherein the separation of the plastics
vapour in the separation vessel is at about 240.degree. C. to about
300.degree. C.
20. The process of claim 10, wherein the separation of the plastics
vapour in the separation vessel is at about 240.degree. C. to about
300.degree. C.
Description
CROSS-REFERENCE
[0001] The present application is a division of U.S. patent
application Ser. No. 14/235,602, filed on May 26, 2014, entitled
"SYSTEM AND PROCESS FOR CONVERTING PLASTICS TO PETROLEUM PRODUCTS",
which itself is the U.S. National Stage of International Patent
Application No. PCT/US2011/046783 filed on Aug. 5, 2011, entitled
"SYSTEM AND PROCESS FOR CONVERTING PLASTICS TO PETROLEUM PRODUCTS",
which claims priority to U.S. Provisional Patent Application No.
61/512,733, filed Jul. 28, 2011, entitled "SYSTEM AND PROCESS FOR
CONVERTING PLASTICS TO PETROLEUM PRODUCTS". The entirety of each of
the foregoing applications is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The invention relates to a system and process for converting
plastics and other heavy hydrocarbon solids into retail petroleum
products by subjecting the plastics to melting, pyrolysis,
vapourization, and selective condensation, whereby final in-spec
petroleum products are produced. The system and process is energy
efficient, as fuels generated during the process are recycled for
use upstream in the process.
BACKGROUND
[0003] Plastic materials represent a valuable source of
petroleum-based fuels. Plastics are comprised of hydrocarbons
which, when broken down into their substituent compounds, can be
used as diesel fuel, gasoline, furnace oil, kerosene, or lower
carbon-chain fuels such as methane, butane and propane. The
recycling of plastic materials to generate fuel is important for
reducing the dependency on obtaining petroleum using costly and
environmentally hazardous drilling and extraction means.
[0004] Methods of processing plastics into petroleum fuels are
known. These are described in, for example, U.S. Pat. No.
4,851,601; U.S. Pat. No. 5,414,169; U.S. Pat. No. 5,608,136; U.S.
Pat. No. 5,856,599; U.S. Pat. No. 6,172,271; U.S. Pat. No.
6,866,830; U.S. Pat. No. 7,531,703; US Patent Publication
2009/0062581; US Patent Publication 2010/0018116; Chinese patent
publication CN 101050373; Chinese patent publication CN 1824733;
Japanese patent publication 07331251; Japanese patent publication
09316459; Japanese patent publication 11 138125; Japanese patent
publication 2003301184; Japanese patent publication 2009209278;
Japanese patent publication 2010059329; and PCT publication WO
2000/064997. Typical methods use external sources of fuel to melt
and pyrolize plastics into the substituent compounds. The materials
are often separated using distillation columns and other means.
Generally, previous methods have been inefficient at generating
higher quantity and quality on-specification petroleum products.
They have often required higher temperatures to effectively crack
the hydrocarbon substituents which, counterproductively, requires
more energy input than is generated.
[0005] There remains a need, therefore, for a system and method for
producing oil from petroleum-based products, such as plastics.
[0006] This background information is provided for the purpose of
making known information believed by the applicant to be of
possible relevance to the present invention. No admission is
necessarily intended, nor should be construed, that any of the
preceding information constitutes prior art against the present
invention.
SUMMARY
[0007] The present system and process attempt to address the
problems encountered with previous systems and processes for
converting plastics to petroleum products.
[0008] The present invention provides a system and process for
converting plastics into industrial quality petroleum fuels. In
accordance with one aspect of the present invention there is
provided a system for processing plastics into one or more
petroleum products, the system comprising: a) a reactor for
subjecting the plastics to pyro lysis and cracking hydrocarbons in
the plastics to produce a plastics vapour comprising hydrocarbon
substituents; b) one or more separation vessels for separating the
plastics vapour into hydrocarbon substitutents based on boiling
points of the hydrocarbon substituents; c) one or more condensers
for condensing the hydrocarbon substituents into one or more
petroleum products; and d) means for collecting the one or more
petroleum products.
[0009] In accordance with another aspect of the present invention
there is provided a process for processing plastics into one or
more petroleum products, the process comprising: providing plastics
to a pyrolysis reactor; subjecting the plastics to pyrolysis and
cracking to produce a plastics vapour, plastics liquids and
plastics solids comprising hydrocarbon substituents; separating the
plastics vapour in a separation vessel to form a first liquid
petroleum product from a gaseous petroleum product; and condensing
the gaseous petroleum product into a second liquid petroleum
product.
[0010] Advantageously, the system and process of the present
invention provides a closed loop, which allows the generation not
only of on-specification petroleum products, but also petroleum
fuels for use within the system and process itself. Further, less
input fuel is required, providing environmental and cost
benefits.
BRIEF DESCRIPTION OF THE FIGURES
[0011] FIG. 1 shows an overview of a system in accordance with the
present invention.
[0012] FIG. 2 shows a premelt system for use in a system and
process according to the present invention.
[0013] FIG. 3 shows a pyro lysis reactor for use in a system and
process according to the present invention.
[0014] FIG. 4 shows a catalyst tower for use in a system and
process according to the present invention.
DETAILED DESCRIPTION
[0015] In accordance with one aspect of the present invention,
there is provided a system for processing plastics into one or more
petroleum products, the system comprising: a) a reactor for
subjecting the plastics to pyro lysis and cracking hydrocarbons in
the plastics to produce a plastics vapour comprising hydrocarbon
substituents; b) one or more separation vessels for separating the
plastics vapour into hydrocarbon substitutents based on boiling
points of the hydrocarbon substituents; c) one or more condensers
for condensing the hydrocarbon substituents into one or more
petroleum products; and d) means for collecting the one or more
petroleum products.
[0016] The present invention also provides a process for processing
plastics into one or more petroleum products, the process
comprising: providing plastics to a pyrolysis reactor; subjecting
the plastics to pyrolysis and cracking to produce a plastics
vapour, plastics liquids and plastics solids comprising hydrocarbon
substituents; separating the plastics vapour in a separation vessel
to form a first liquid petroleum product from a gaseous petroleum
product; and condensing the gaseous petroleum product into a second
liquid petroleum product.
[0017] The entire process is typically performed at atmospheric
pressure.
[0018] As used herein, "plastics" refers generally to synthetic or
semi-synthetic plastic-based materials, such as those comprising
polymers of high molecular mass, which are derived primarily from
petroleum and natural gas. Examples include high density
polyethylene (HDPE), low density polyethylene (LDPE), polypropylene
(PP), polyethylene terephthalate (PET), polystyrene (PS),
polyvinylchloride (PVC), polyurethanes, cellulose-based plastics,
and the like.
[0019] As used herein, "petroleum" refers generally to
hydrocarbon-based flammable liquids that are used as fuels, such
as, for example, diesel fuel, naphtha, gasoline, kerosene, methane,
ethane, propane, butane, and the like.
[0020] An overview of a system according to the present invention
is generally shown in FIG. 1. The system comprises components for
treating and converting waste plastics to petroleum products. It is
understood that modifications within the system--such as, for
example, the dimensions of the individual components, number of
components within the system, or types of materials used for the
components--may be contemplated within the scope of invention.
[0021] As shown in the embodiment of FIG. 1, the system comprises
one or more conveyor belts 21 for introducing plastics 22 into the
system. The plastics feedstock which is added to the system can
come from any number of sources, such as directly from sanitation
trucks used for collecting waste plastics from residential or
industrial locations. The plastics can include plastic containers
(such as beverage and food containers), plastic scrap, grocery
bags, and the like, and of different sizes and shapes. Soft and
hard plastics can similarly be processed. Plastics feedstock
containing contaminants, such as metals, halogenated hydrocarbons
and other undesirable materials, may also be processed, but larger
contaminating items are preferably removed by hand from the
conveyor belt. The plastics are placed onto the conveyor belt in
loose or packaged baled form, and can be added directly from a
receptacle or into a hopper 200 to facilitate the process. The
conveyor belts 21 are sufficiently long and wide to accept plastics
of a wide range of sizes. The one or more conveyor belts 21 lead to
a feed 24 which guides the plastics to feeder 201. Alternatively,
the feed can include a shredder 25 for reducing the plastics into
smaller material.
[0022] FIG. 2 illustrates a pre-melt reactor. Before undergoing
pyrolysis, the plastics 22 can transported through a conveyor 100
into a pre-melt reactor 2 (hereinafter "premelter"). The premelter
2 is part of a pre-melt system generally shown in FIG. 2. The
premelter 2 melts the plastics feedstock 5 to provide a liquid
material to facilitate extraction of petroleum therefrom. It can
also be used to separate contaminants from the plastics.
[0023] The premelter 2 is housed within a heating chamber 3. The
premelter 2 is heated to about 250.degree. C. to 340.degree. C. to
melt the plastics therein and boil off any undesired contaminants.
Desirably, the heat for the heating chamber 3 can be provided from
hot air that has been used to heat the reactor (see below) via a
flue gas pipe 4 connected to the heating chamber 3.
[0024] The premelter 2 is typically a rotary kiln. At the end of
the screw feeder 100 a rotary seal can be provided attach the screw
feeder 100 to the premelter 2. In one embodiment, the premelter 2
has a diameter of about 7 feet and a length of about 18-20 feet.
However, the premelter 2 can be much larger depending on the
application and the need for higher throughput, such as having a
diameter of about 8 feet and length of about 60 feet, for example.
Within the premelter 2, the plastic feedstock 5 is liquefied to
produce liquefied plastics, non-aqueous vapours (which can include
halides, if present in the feedstock), water vapour, and
contaminant solids, such as metals. Optionally, a lifter 9 is
present in the premelter 2 to shuttle molten plastic and residue
from the bottom 8 of the premelter 2 for removal thereform. An
outlet screw 19, which can be similar to the screw feeder 100 at
the entry to the premelter 2, transports molten plastic from the
premelter 2. The outlet screw 19 is within a larger pipe sleeve in
such a way that waste solids, unmelted plastics, and other solid
and liquid residue settle to the bottom of the outlet screw 19,
while residue vapour which is collected in the pipe sleeve 16 and
sent to a residue condenser 17. Condensed vapour and residue are
collected from the residue condenser 17. A residue removal tank 11
is positioned below the outlet screw 19 to collect the residue 12.
Solid residue is collected in residue barrel 13 via a residue screw
15 and may contain acids or other vendible products, or can be
discarded. Liquid residue is removed from the residue removal tank
11 via a liquid plastics pump 16, and sent to the pyro lysis
reactor.
[0025] FIG. 3 illustrates one embodiment of a pyro lysis reactor
(hereinafter "reactor") in accordance with the present invention.
Liquid plastics from the pre-melt system (if used) is pumped to the
reactor 27 via pipe 20. The liquid plastics is essentially free of
halogens, water and most contaminants. If no pre-melt system is
used, a conveyor 21 similar to described above can be used to
transport solid (shredded) plastics to a feeder 201 and into
reactor 27.
[0026] The feeder 201 can be any transport mechanism for shuttling
the plastics, but in one embodiment is a channel comprising a
screw-type feeder. The feeder 201 transports the nitrogen-laden
plastics into the reactor 27. The feeder can have a hollow-flight
screw. Coolant, such as water, is sent through the screw as well as
through an air jacket around the feeder 201. The purpose of both of
these is to maintain the plastic feed at a temperature below its
melting point so that it can be transported into the reactor as a
solid, thus reducing gumming residue.
[0027] A nitrogen source can be connected to the feeder 201 for
supplying nitrogen to a sealed intermediate space between the
feeder and the reactor. The nitrogen is used to displace oxygen so
as to minimize the amount of oxygen entering the process, thus
reducing the yield of undesirable CO2 end product. A slide gate
(not shown) at the entry of the intermediate space opens and allows
the plastics to enter therein. At the same time, the nitrogen
source supplies nitrogen into the intermediate space. The plastics
becomes packed in the intermediate space and filed with nitrogen.
Once the plastics have been exposed and saturated with the
nitrogen, a door on the opposite end of the intermediate space
opens, and the nitrogenated plastics exit the intermediate space
and enter the reactor.
[0028] The reactor 27 is a vessel, ideally large enough to handle
large quantities of plastics, such as about 2000-5000 lbs of raw
plastics, for efficient flowthrough of the feedstock through to
processing. Ideally, the reactor 27 can have a length of about 22
feet to about 100 feet, typically 22 feet to about 40 feet, more
typically 18 feet. Longer reactors may be desired to increase the
interior volume, throughput and efficiency. The diameter of the
reactor 27 is typically between about 3-10 feet, or about 6
feet.
[0029] The feed rate to the reactor can be controlled to maintain
an efficient use of heat in the reactor 27, the rate of fuel being
produced, temperature and pressure of gasses in reactor 27, and
temperature of gasses downstream, for example. As one example, the
feed rate can be controlled such that material is fed into the
reactor until the reactor cools to below a target temperature, or
within a target temperature range, such as at or below 360.degree.
C. A thermocouple (not shown) can be added to a side of the reactor
27 to indicate the amount of liquid in the reactor; with more
liquid present, the temperature is generally lower, and the
addition of plastics to the reactor can be reduced. The addition or
reduction of plastics can be controlled through manual or automatic
means, such as through a computer-based algorithm or the like.
[0030] The reactor 27 can be made of any suitable material, but
ideally iron as a major component. In one embodiment, the reactor
has a shell 23 comprising 99.5% iron and up to 0.5% manganese.
Chromium oxide formed by the reaction protects the iron from
rusting. While a stainless steel reactor may be used, it can be
damaged by various impurities (such as halides, for example) in the
plastics, requiring it to be replaced more frequently and adding to
the expense of the operation.
[0031] The reactor 27 is effectively a gradient system comprising
different zones therein. The reactor receives the plastics from the
feeder 201 (as raw feedstock 22 or molten plastic from the
premelter 2, if such is used, via pipe 20). The reactor 27 can be
of the rotary type which is rotated during pyrolysis of the
plastics so that its internal surfaces are hot enough to vapourize
the liquid/solid plastics, forming hydrocarbon vapour and carbon
black. A catalyst can be mixed with the liquid or hard plastic in
the reactor 27 to facilitate selective cracking of hydrocarbons. A
catalyst may be selected according to the desired fuel to be
generated from the overall process. For example, catalysts such as
aluminum oxide or calcium hydroxide can be added to facilitate the
removal of halogens, such as chlorine. In other embodiments, a
Group VIII metal can be added to the reaction mixture. This can
facilitate a reaction whereby water is broken down, carbon
monoxide, unsaturated hydrocarbons, and hydrogen gas react to form
saturated hydrocarbons and carbon dioxide. H2 gas is particularly
beneficial for effecting hydrogen saturation of the fuel
downstream. This reduces the need for more costly additives, such
as in current methods which require an external H2 source and a
platinum catalyst under high pressure (300 psi), to facilitate
hydrogen saturation. Within the reactor 27 is a reaction zone 202
where the liquid and solids are vapourized, producing a hydrocarbon
stream, and solid residue. The vapourized hydrocarbons are cracked
to molecules having carbon chains ranging from CI to about C49 or
C50. Higher length carbon chains are cracked until they are within
the lower range. The solid residue comprises primarily carbon
black. The reactor operates in a range of about 340 to 445.degree.
C., ideally about 350 to 425.degree. C., or about 400.degree. C.
The heat required for this temperature can be obtained with a
furnace which uses hydrogen gas, methane and ethane as fuel.
Ideally, the fuel can be obtained downstream in the process of the
current invention. Typically, this combination of gases burns at
approximately 2,300.degree. F. The hot combustion gases are then
circulated through a spiral duct that runs around the outside of
the reactor. The spiral duct is typically a spiral refractory with
heat on end and exhaust on the other. The residence time of the
plastics in the reactor for any desired length of time, such as,
for example, between 10 minutes to 1 hour or more.
[0032] The liquefied plastic is moved at a slow rate until reaching
the end of reactor 27. Solids from the reactor 27 are removed by
lifters 29 and chutes 31 inside the reactor 27. Metal solids form a
bed in within reactor 27. Similar with the outlet 19 on the premelt
2, liquid passes through the outlet residue pipe 32 surrounded by a
sleeve pipe which collects vapour and sends it to through vapour
pipe 35 and preventing backflow of the vapour into the reactor 27,
while solid residue settles on the bottom of the channel and is
collected in a residue drum 34. The solid residue is discarded
using appropriate disposal means in accordance with local
regulations. Whereas larger metal solids and biomass are typically
removed from the feedstock in the premelter 2, finer solids are
removed from the reactor 27.
[0033] A cyclone 37 may also be used to remove any of the solid
residue from the reactor discharge. Hydrocarbon vapour flows out of
reactor 27 through pipe 35 to the cyclone 37. The cyclone 37
removes any entrained particulate matter from the vapour steam. The
particulate matter falls out through opening 36 into the residue
drum 34. Vapour from the cyclone 37 then heads to a catalyst tower
via a pipe 39. Ideally, a pipe having a 16 inch diameter (including
at the inlet end) can be used.
[0034] The solids-free vapours are then cracked, treated and
condensed in one or more catalyst towers, such as catalyst towers
T2 and T3, shown in FIG. 4. The catalyst towers are separation
vessels which, as a type of reactor, separate vapours into
petroleum products based on the boiling points of the hydrocarbon
constituents. Typically, the catalyst tower T2,T3 is about 20 feet
high having a diameter of about 3 feet, although any size as
appropriate can be used. Each catalyst tower T2,T3 consists of one,
two or more catalyst zones 40,41 separated by one or more weirs 45
to treat the hydrocarbons and facilitate selective hydrocarbon
cracking. Each catalyst tower T2,T3 produces and blends a petroleum
product within a particular specification. Petroleum products which
are out of specification are pumped either out of the catalyst
towers T2,T3 for further processing. For example, off-spec
petroleum products are collected in receptacle 44 and are sent by a
pump 210 back to the reactor 27. The off-spec petroleum can also be
collected and pumped via pump 211, condensed in condenser 212 and
added back to the tower at nozzle 42. Alternatively, these
hydrocarbons can be collected and taken out of the system for use
as fuel (such as furnace oil #4, #5 or heavy diesel, depending on
the operation). From further downstream catalyst towers, such as
T3, off-spec petroleum products are pumped back to catalyst tower
40 via pump P3 and pipe (400). The shunting of the different
petroleum products can also be performed automatically, such as
with automatic ball valves controlled by the system, for example.
The system open or closes the valve, depending on the amount of
movement of fuels, and any blending of the fuels, between the
towers to achieve the desired fuel product.
[0035] The temperatures of the catalyst towers vary T2,T3, and
generally decrease from upstream to downstream when multiple towers
are used. Heat from the hydrocarbon vapours maintains the interior
of the towers within a broad range. For example, the temperature in
T2 can be about 400.degree. C., while the temperature in T3 can be
up to 320.degree. C. This difference in temperatures permits
petroleum products of differing boiling points to precipitate from
the vapour. There is also an oil jacket around each tower (not
shown) which has hot oil circulating through it, which can also
maintain the temperature in each tower within a very narrow range.
No other external heat source is required to maintain the
temperature ranges within the catalyst towers, other than the heat
from the hydrocarbon vapours. Further, hydrocarbon vapours from a
downstream catalyst tower (such as T3) which are sent back to an
upstream catalyst tower (such as T2) can change and regulate the
temperature of the upstream tower, and vice versa.
[0036] The hydrocarbon vapours pass through the weirs 45 containing
a catalyst 43. These catalysts can include platinum, the catalysts
are composed predominantly of compounds such as a Group II, Group
VI and/or Group VIII XIII metal compound sulfides, oxides and
hydroxides, for example, molybdenum sulfide (MoS2), and a zeolite
depending on the fuel to be produced. Particularly preferred
zeolites are synthetic Y-type zeolite and ZSM-5. Hydrocarbon
vapours meeting specification pass through pipe 50, ideally
platinum plated and having a diameter of about 8 inches, at the top
of the reactor and proceed to the next catalyst tower or
hydrocarbon condensation system, depending on the desired products
to be obtained from the process. The platinum can act as a catalyst
to facilitate the saturation of unsaturated hydrocarbons before
leaving the catalyst towers to be condensed. Hydrogen and highly
reactive low boilers are in the stream to facilitate
saturation.
[0037] Hydrocarbons are condensed from heavy to light, depending on
the desired petroleum product, and each requires its own
hydrocarbon condensing system stage. One or more heat exchangers
(C1-C4) are in fluid communication with the catalyst tower T2 (or,
if two or more catalyst towers are used, the one most downstream
T3), to receive vapours coming from the top of the catalyst
tower(s) and condense the vapours. The temperature in the heat
exchanger(s) is regulated by a hot oil system coiled around the
outside of the heat exchanger 212, which provides water, hot oil or
air cooling within a very narrow range to ensure the right
selection of products is obtained. The products are flows into and
is collected in pipe 53.
[0038] The petroleum product passes through a manometer 55 and is
further cooled (if required) by a 3-phase separator and heat
exchanger 56. The petroleum product may be treated in-line with
fuel additives required to bring the fuel in specification. The
additives are metered into the system through a pump 64 and flow to
the liquid petroleum product, which is blended in the pipe 53. Fuel
additives can be lubricity additives, antioxidants, and other
common industry fuel additives. An automation system controls the
pump 64 to ensure the proper ratio of fuel additive and fuel.
Petroleum product in the 3-phase separator 56 is cooled to room
temperature and sent to a centrifuge (401) and filtered by a simple
strainer and into a storage tank (402).
[0039] Multiple condensers and heat exchangers permit different
fuels to be precipitated out of the hydrocarbon vapour. The
temperature of the cooling system is set based on the hydrocarbon
product the condensation system is intended to condense, and based
on the temperature of the catalyst towers. For example the
temperature is set at 170.degree. C. to 180.degree. C. for diesel
or heating oil #2, 240.degree. C. for heating oil #6, and about
20.degree. C. for gasoline. At 230.degree. C., the fuel is fairly
light (i.e., a mixture of C5-C8 hydrocarbons depending on the
degree of blending of the fuels at higher temperatures. At
280.degree. C., 60-70% diesel and 30-40% gasoline is obtained,
whereas at 235.degree. C., the ratio is about 60-70%) gas and
10-15%) diesel. Beyond 280.degree. C., paraffin wax (C20-C40) is
obtained.
[0040] As shown best in FIG. 1, the selective condensation system
condenses diesel at approximately 170.degree. C. to 180.degree. C.,
the light naphtha (or gasoline) is condensed at 20.degree. C. The
remaining hydrocarbon low boilers pass through a fuel seal that
ensure oxygen cannot pass back through the process. The low boilers
(ethane, methane, butane, propane, and hydrogen) are compressed by
a compressor or blower and routed to the furnace to provide
fuel.
[0041] Residual vapours then pass through pipe 62 to a petroleum
water seal 63 within tank 64. The vapours from pipe 62 condenses
any water remaining in the vapour stream. This water condenses and
falls into the bottom of the tank 64. The vapour bubbles through
the water. The water acts as a seal to exclude oxygen from passing
back through the system. The remaining vapour consists of hydrogen
and hydrocarbons having low boiling points (such as methane,
ethane, butane, and propane).
[0042] Optionally, a pH meter may be connected to the bottom of the
tank 63 to monitor for any halides that got into (or through) the
system. The vapour is sent via pipe 65 drawn to an off-gas
compressor to pressurize the off-gas (to about 1000 psi) for use as
fuel for furnace burners, such as for heating the premelter 2
and/or the reactor 27, or for other uses, such as propane for
barbecue tank fuel. No thermal oxidizers, scrubbers, or filters are
required for the flue gas. Ambient air is mixed with syngas by the
burner 204 and burned to provide heat for the reactor 27. The flue
gas exhaust from the furnace indirectly heats both the premelter 2
and the reactor 27, and then is routed to a stack (404) via an
exhaust fan (403). Overall, solid waste plastic is converted to
approximately 86.7% liquid petroleum products, 1-5% residue, and 8%
syngas used to provide fuel for the furnace.
[0043] All publications, patents and patent applications mentioned
in this Specification are indicative of the level of skill of those
skilled in the art to which this invention pertains and are herein
incorporated by reference to the same extent as if each individual
publication, patent, or patent applications was specifically and
individually indicated to be incorporated by reference.
[0044] The invention being thus described, it will be obvious that
the same may be varied in many ways. Such variations are not to be
regarded as a departure from the spirit and scope of the invention,
and all such modifications as would be obvious to one skilled in
the art are intended to be included within the scope of the
following claims.
* * * * *