1. A method of sustainable plastic pyrolysis comprising following steps: j) Collecting the plastic scrap not limiting to High Density Polyethylene (HDPE), Low Density Polyethylene (LDPE) and Polypropylene(PP); k) Shredding the plastic scrap (HDPE/LDPE/PP) into smaller pieces; l) Feeding the shredded plastic into the reactor preheated to 400-600 oC with self pyrolytic oil as catalyst; m) Thermal depolymerization of the broken plastic pieces in the reactor heated to 400-600 oC in the absence of oxygen at high temperature and 2kg/cm2pressure thereby converting long chain hydrocarbons into short chain hydrocarbons in the form of vapors; n) Obtaining short chain hydrocarbons in the form of vapors comprising a liquid fraction and a gaseous fraction; o) Passing the Vapors through the condenser, condenser being surrounded with the water helps in cooling the vapors through heat exchanging between vapors and the water; p) Separating the gaseous fraction from the liquid fraction by passing the vapors through the separator wherein liquid fraction in the form of oil is settled below in the separator and the gaseous fraction stays above the liquid oil; q) Collecting the liquid (oil) settled below in the separator in separate container to be used further as a catalyst in the process and as a Product; r) Passing the collected gasthrough water in the tank and then stored in the cylinder for further use as a fuel;

2. The method of sustainable plastic pyrolysis as claimed in claim 1 wherein thermal pyrolysis takes place without using any external catalyst;

3. The method of sustainable plastic pyrolysis as claimed in claim 1 wherein the self-output of the process i.e. plastic oil is used as catalyst;

4. The method of sustainable plastic pyrolysis as claimed in claim 1 wherein the output percentage of the oil is very high;

5. The method of sustainable plastic pyrolysis as claimed in claim 1 wherein energy consumption is very less in the process;

6. The method of sustainable plastic pyrolysis as claimed in claim 1 wherein the said plastic waste are recycled and transformed to high energy gas, fuel oils and carbon black.

7. The method of sustainable plastic pyrolysis as claimed in claim 1 wherein the source of plastic scraps are either HDPE or LDPE or PP but not limiting to them;

8. The method of sustainable plastic pyrolysis as claimed in claim 1 wherein the thermal pyrolysis occurs in the reactor at a temperature 400-600 oC.

9. The method of sustainable plastic pyrolysis substantially as herein before described with reference to the above examples.

The present invention relates to a method of conversion of
plastic waste into high quality hydrocarbon fuel oil and more
particularly a method of thermal depolymerization of scrap
plastic taken from industrial waste or domestic waste to
maximize oil yield and minimize the requirements of external
catalyst consumption, rather uses the self output product as a
catalyst to maximize the yield and minimize the energy
consumption for the process as it is endothermic reaction
process.
Background of the Invention:
The Phrase “plastics” comprises of materials that are framed or
made of various elements like as Polyethylene PE, polyproplene
PP and Polystyrene PS. Plastics are Polymer molecules, which are
made by the process of polymerization and possess the quality of
converting into any shape by the mechanism of notable quantity
of heat and Pressure or some other sources.By the physical
properties exhibited by them, Plastic materials can be divided
into thermoplastics and thermosetting plastic materials.
Thermoplastic materials possess the quality of converting into
any shape by the mechanism of notable quantity of heat and
Pressure and become solid materials or objects upon cooling the
material.
India makes around 9.46 million tonnes of waste plastic every
year; out of total quantity 40 percent of the Waste Plastic gets
unresolved [3]. The use of plastics is more in the field
ofpackaging, almost all of it is single-use, a new study has
claimed. “Universally if we observe, 8.3 billion tonnes of
plastic materials have been generated since 1950, about 60% of
Plastic materials had ended up in landfills or in the natural
environment.
The total amount of plastic waste is increasing every year.
However, most plastics cannot rapidly degrade in a landfill and
thus, become a major waste in garbage. Moreover, it is not
environmentally friendly to dispose plastic waste by
incineration, which leads to carbon dioxide and other greenhouse
gas emissions even though incineration can generate energy.
Moreover, incineration of plastics still has some drawbacks,
such as high capital and maintenance cost. An alternative method
to decompose plastic waste to generate energy and useful gaseous
products is gasification. However, a conventional gasification
method releases tars, heavy metals, halogens and alkaline
compounds etc., and causes environmental problems. Another
effort to utilize plastic waste, which seems to be promising, is
the pyrolysis of plastic waste, resulting in a mixture of
hydrocarbons of heavy oils and olefins.
Prior Art:
US Patent Application number US20200115635disclosesorganic
compound disposal method and system which is able to close the
loop of plastic waste products (organic compound material) and
itslifecycle and generate more valuable usable fuel products
such as flammable hydrocarbon gas and liquid fuels.
US Patent Application number US20170283707discloses a process
and apparatus for producing liquid fuel from residential and
industrial waste plastic, and inparticular, to a process and
apparatus for producing continuously high quality grade liquid
hydrocarbon fuel from residential and industrial wasteplastic by
thermal and catalytic decomposition in an indirectly heated
screw reactor.
The present invention is a sustainable method of plastic waste
depolymerization which will help in increasing the oil yield
from the plastic scrap industrial as well as domestic waste
through thermal pyrolysis without using any external catalyst,
rather the process uses self-output as a catalyst to speed up
the reaction process and giving more yield with less energy
consumption.
Objectives of the Invention:
The principal object of the present invention is to provide a
sustainable method of plastic depolymerization to enhance the
yield of industrial fuel with less energy consumption as it is
an endothermic reaction process.
Another objective of the present invention is to provide a
sustainable and viable decomposition method for waste plastic as
it is a headache to the world
Further another object of the invention is to develop a viable
solution for the disposal of mixed plastic as the other
recycling method are not applicable if the plastic are mixed.
Further another object of the invention is to develop a method
for final disposal of waste plastic
Further another object of the invention is to provide a method
of plastic depolymerization to yield oil without using any
external catalyst.
Further another object of the invention is to provide a method
of plastic depolymerization to yield oil which is more economic.
Significance of the Invention:
The main significance of the present invention is to provide a
method of plastic depolymerization which is ecofriendly.
Another significance of the present invention is to provide a
method of plastic depolymerization to yield oil without using
any external catalyst.
Another significance of the present invention is to provide a
method of plastic depolymerization that saves energy input and
reduces cost.
Summary of the Invention:
The present invention is related to a method of sustainable
plastic pyrolysis comprising following steps:
a) Collecting the plastic scrap not limiting to High
Density Polyethylene (HDPE), Low Density Polyethylene
(LDPE) and Polypropylene (PP);
b) Shredding the plastic scrap (HDPE/LDPE/PP) into smaller
pieces;
c) Feeding the shredded plastic into the reactor preheated
to 400-600 oC ;
d) Thermal depolymerization of the broken plastic pieces in
the reactor preheated to 400-600 oC in the absence of
oxygen at high temperature and 2kg/cm2 pressure thereby
converting long chain hydrocarbons into short chain
hydrocarbons in the form of vapors;
e) Obtaining short chain hydrocarbons in the form of vapors
comprising a liquid fraction and a gaseous fraction;
f) Passing the Vapors through the condenser, condenser being
surrounded with the water helps in cooling the vapors
through heat exchanging between vapors and the water;
g) Separating the gaseous fraction from the liquid fraction
by passing the vapors through the separator wherein
liquid fraction in the form of oil is settled below in
the separator and the gaseous fraction stays above in the
separator;
h) Collecting the liquid (oil) settled below in the
separator in separate container to be used further as a
catalyst in the process;
i) Passing the collected gas through water in the tank and
then stored in the cylinder for further use as a fuel;
Detailed Description of the Invention:
The terms "comprises", "comprising", or any other variations
thereof, are intended to cover a non-exclusive inclusion, such
that a method or method that comprises a list of steps does not
include only those steps but may include other steps not
expressly listed or inherent to such a method or method.
Similarly, one or more devices or sub-systems or elements or
structures or components preceded by "comprises... a" does not,
without more constraints, preclude the existence of other
devices, sub-systems, elements, structures, components,
additional devices, additional sub-systems, additional elements,
additional structures or additional components. Appearances of
the phrase “in an embodiment”, “in another embodiment” and
similar language throughout this specification may, but not
necessarily do, all refer to the same embodiment.
Unless otherwise defined, all technical and scientific terms
used herein have the same meaning as commonly understood by
those skilled in the art to which this invention belongs. The
system, methods, and examples provided herein are only
illustrative and not intended to be limiting.
The present invention is related to a method of thermal
pyrolysis.
Pyrolysis is a process of degradation of high molecular weight
polymeric plastic molecules (household and industrial plastic
waste) into lighter liquid and gaseous hydrocarbons (fuel) in
the absence of oxygen at very high temperature and pressure.
Pyrolysis can be done in three ways:-
1. Thermal pyrolysis: The pyrolysis process that is carried
out without use of any catalyst
2. Catalytic Pyrolysis: The pyrolysis process that is carried
out in the presence of catalyst.
3. Plasma Pyrolysis:
Source of the plastics that can be used in the present invention
may include:
A) HDPE (High Density Polyethylene); Forexample: Crinkly
shopping bags, freezer bags, milk bottles, bleach bottles,
buckets, rigid pipes and crates;
B) LDPE (Low Density Polyethylene);Forexample: Garbage bags,
squeeze bottles, black irrigation tubes, films and garbage
bags;
C) PP (Polypropylene); For example: Trays, potato bags,
drinking straws, containers, tubs, plastic garden settings,
baby baths and plastic boxes.
The present invention is the process of thermal pyrolysis that
does not use any catalyst rather the process uses the selfoutput i.e. oil that speed up the reaction process.
Figure 1 is the flowchart comprising steps involved in the
thermal pyrolysis in the present invention.
SEPARATING AND SHREDDING OF SCRAP STEP 2
STEP 1
THERMAL PYROLYSIS
STEP 6
STEP 4
IS A ALTERNATIVE FUEL ANDMAY BE USED
AS A CATALYST
STEP 7
SEPARATION OF THE LIQUID FRACTION AND GASEOUS FRACTION
LIQUID FRACTION IN THE
FORM OF OIL
GASEOUS FRACTION IN THE
FORM OF FUEL
COLLECTION IN THE OIL TANK COLLECTION IN THE CYLINDER
STEP 3
STEP 5 CONDENSING THE SHORTCHAIN HYDROCARBONS OBTAINED IN
VAPOR FORM
FEEDING INTO THE REACTOR WITH SELF PYROLYTIC OIL
MAY BE USED AS A FUEL FOR SELF
SUSTAINING SYSTEM
COLLECTION OF PLASTIC SCRAP
FIG: 1
According to figure 1, the method of sustainable plastic
ptrolysis comprises following steps:
STEP 1: Waste plastic scrap (HDPE/LDPE/PP) is collected from the
sources described herein above;
STEP 2: After collecting the plastic scrap, it is torninto
smaller pieceswith the help of shredder;
STEP 3: The shredded plastic is then feeded with self pyrolytic
oil into the reactor; reactor is being heated to 400-600
oC;
STEP 4: Thermal depolymerization of the shreddedplastic pieces
takes place in the reactor in the absence of oxygen at
high temperature and upto2kg/cm2 or above pressure and
convert long chain hydrocarbons present in the plastic
into short chain hydrocarbons;
After thermal depolymerization of the plastic, lighter
hydrocarbons are obtained in the form of vapors
comprising a liquid fraction and a gaseous fraction;
STEP 5: The Vapors obtained in above step are passed through the
condenser wherein heat exchange takes place between the
vapors and the water; Water is present outside the
condenser periphery. Heat exchange enables the vapors to
cool down;
STEP 6: Vapors are then passed through a separator wherein
gaseous fraction is separated from the liquid fraction.
Liquid fraction is settled below in the separator and
gaseous fraction stays above in the Seprator;
STEP 7: Liquid fraction now called as plastic oil which is a
alternative fuel is collected in the separate container
oil tankand can be used as a raw material along with the
scrap plastic in the present process of pyrolysis and
acts as a catalyst by speeding up the process;
The gaseous fraction collected in the separator is
passed through water in the collection tank and can be
stored in the cylinder for further use as a fuel in the
present process;
The present method of thermal pyrolysis produces high energy
gas, fuel oils and carbon black.
The present invention is designed and simulated with a capacity
of 15 kgoil per day of feed according to the process shown in
FIG. 1.
The following examples are intended to illustrate certain
embodiments of the present invention, but do not exemplify the
full scope of the invention.

Claims:
We Claim:
1. A method of sustainable plastic pyrolysis comprising
following steps:
j) Collecting the plastic scrap not limiting to High Density
Polyethylene (HDPE), Low Density Polyethylene (LDPE) and
Polypropylene(PP);
k) Shredding the plastic scrap (HDPE/LDPE/PP) into smaller
pieces;
l) Feeding the shredded plastic into the reactor preheated
to 400-600 oC with self pyrolytic oil as catalyst;
m) Thermal depolymerization of the broken plastic pieces in
the reactor heated to 400-600 oC in the absence of oxygen
at high temperature and 2kg/cm2pressure thereby
converting long chain hydrocarbons into short chain
hydrocarbons in the form of vapors;
n) Obtaining short chain hydrocarbons in the form of vapors
comprising a liquid fraction and a gaseous fraction;
o) Passing the Vapors through the condenser, condenser being
surrounded with the water helps in cooling the vapors
through heat exchanging between vapors and the water;
p) Separating the gaseous fraction from the liquid fraction
by passing the vapors through the separator wherein
liquid fraction in the form of oil is settled below in
the separator and the gaseous fraction stays above the
liquid oil;
q) Collecting the liquid (oil) settled below in the
separator in separate container to be used further as a
catalyst in the process and as a Product;
r) Passing the collected gasthrough water in the tank and
then stored in the cylinder for further use as a fuel;
2. The method of sustainable plastic pyrolysis as claimed in
claim 1 wherein thermal pyrolysis takes place without using
any external catalyst;
3. The method of sustainable plastic pyrolysis as claimed in
claim 1 wherein the self-output of the process i.e. plastic
oil is used as catalyst;
4. The method of sustainable plastic pyrolysis as claimed in
claim 1 wherein the output percentage of the oil is very
high;
5. The method of sustainable plastic pyrolysis as claimed in
claim 1 wherein energy consumption is very less in the
process;
6. The method of sustainable plastic pyrolysis as claimed in
claim 1 wherein the said plastic waste are recycled and
transformed to high energy gas, fuel oils and carbon black.
7. The method of sustainable plastic pyrolysis as claimed in
claim 1 wherein the source of plastic scraps are either
HDPE or LDPE or PP but not limiting to them;
8. The method of sustainable plastic pyrolysis as claimed in
claim 1 wherein the thermal pyrolysis occurs in the reactor
at a temperature 400-600 oC.
9. The method of sustainable plastic pyrolysis substantially
as herein before described with reference to the above
examples.