This document describes the process of converting waste plastic into fuel through pyrolysis. Pyrolysis involves thermally degrading plastic in the absence of oxygen to produce solid, liquid, and gaseous fuels. The process uses a specially designed reactor heated to 350°C along with catalysts to cause the random depolymerization of plastics into fuel products. The machine used in pyrolysis consists of a reactor, catalytic cracker containing ZSM-5 zeolite catalyst, condenser to liquefy vapors, and nitrogen cylinder to provide an inert atmosphere. Converting waste plastic to fuel through pyrolysis solves disposal issues while producing valuable energy sources.
2. CONTENTS
What is waste to fuel
Technologies used
Pyrolysis
Principal of pyrolysis
Process of pyrolysis
Parts of pyrolysis machine
Advantages
3. WASTE TO FUEL
Waste-to-energy or energy-from-waste is the
process of generating energy in the form of
electricity ,heat or fuel from waste.
WtE is a form of energy recovery.
Most WtE processes produce energy directly
through combustion, or produce a combustible fuel
commodity, such as methane, methanol, ethanol or
synthetic fuels.
4. WTE PLANTS AROUND THE WORLD
Lee County Solid Waste
Resource Recovery
Facility, Fort Myers,
Florida, USA (1994)
Montgomery County
Resource Recovery
Facility in Dickerson,
Maryland, USA (1995)
Algonquin Power,
Brampton, Ontario, Canada
Burnaby Waste-to-Energy
Facility, Metro
Vancouver, Canada (1988
)
8. PRINCIPAL OF PYROLYSIS
All plastics are polymers mostly containing carbon and
hydrogen and few other elements like chlorine, nitrogen, etc.
When this long chain of polymers breaks at certain points, or
when lower molecular weight fractions are formed, this is
termed as degradation of polymers. This is reverse of
polymerization or de-polymerization.
If such breaking of long polymeric chain or scission of bonds
occurs randomly, it is called Random depolymerization. Here
the polymer degrades to lower molecular fragments.
In the process of conversion of waste plastics into fuels,
random depolymerization is carried out in a specially designed
reactor in the absence of oxygen and in the presence of coal
and certain catalytic additives. The maximum reaction
temperature is 350°C.
There is total conversion of waste plastics into value-added
fuel products.
9. PROCESS
The process consists of two steps:
i) Random de-polymerization
Under controlled reaction conditions, plastics materials
undergo random depolymerization and are converted into three
products:
a) Solid Fuel i.e., Coke
b) Liquid Fuel i.e., Combination of Gasoline, Kerosene,
Diesel and Lube Oil
c) Gaseous Fuel i.e., LPG range gas
ii) Fractional Distillation
Separation of various liquid fuels by virtue of the difference in
their boiling points.
One important factor of the quality of the liquid fuel is that the
sulphur content is less than 0.002ppm which is much lower
than the level found in regular fuel.
13. CATALYTIC CRACKER
Catalytic cracking is the breaking of large
hydrocarbon molecules into smaller and more
useful bits.
The cracker must be designed in such a way that
the vapour from the reactor must have maximum
surface contact with the catalyst.
The catalyst will act as a molecular sieve which
permits the passage of small molecules.
The hydrocarbon molecules are broken up in a
fairly random way to produce mixtures of smaller
hydrocarbons, some of which have carbon-carbon
double bonds.
14. CATALYST USED
ZSM-5, Zeolite Socony Mobil–5, is an
aluminosilicatezeolite belonging to the pentasil
family of zeolites.
Its chemical formula is NanAlnSi96–nO192·16H2O
(0<n<27).
ZSM-5 catalyst was first synthesized by Argauer
and Landolt in 1972.
Patented by Mobil Oil Company in 1975, it is widely
used in the petroleum industry as a heterogeneous
catalyst for hydrocarbonisomerization reactions.
16. CONDENSER
It is the part of machine which
condenses the vapours
coming out from the catalytic
cracker.
The condenser must
condense the very hot vapors
in an efficient manner to give
the condensate
Clogging in the condenser
must be prevented.
This can be achieved by
increasing the diameter of the
pipe.
In this machine, we are using
a spiral condenser to
increase the efficiency of
condensation
17. NITROGEN CYLINDER
cylinder is attached to the
reactor.
Used to provide inert
atmosphere in the reactor
by pumping nitrogen from
nitrogen cylinder.
Purpose: plastic feed
should not burn instead it
should melt at high
temperature inside the
reactor.
18. ADVANTAGES
Problem of disposal of waste plastic is solved.
Waste plastic is converted into high value fuels.
Environmental pollution is controlled.
Industrial and automobile fuel requirement shall be
fulfilled to some extent at lower price.
No pollutants are created during cracking of
plastics.
The crude oil and the gas can be used for
generation of electricity