This document outlines an experimental study on recycling plastic waste through pyrolysis. It discusses sources of plastic waste, different recycling methods, and the hydrocarbon cracking mechanism involved in pyrolysis. Thermogravimetric analysis was conducted on polyethylene and polypropylene samples at various heating rates and temperatures to analyze degradation. Pyrolysis experiments were carried out in a reactor, and the liquid products were analyzed through aniline point and ASTM distillation tests. The results show that pyrolysis can produce useful gaseous, liquid and solid products from plastic waste and help address environmental issues.

2. OUTLINE
• SCOPE OF THE PROJECT
• INTRODUCTION
• SOURCES OF PLASTIC WASTE
• DIFFERENT METHOD OF PLASTIC WASTE
RECYCLING
• HYDROCARBON CRACKING MECHANISM
• THERMOGAVIMETRIC ANALYSIS
• EXPERIMENTAL PROCEDURE
• EXPERIMENTAL RESULTS
• CONCLUSION
• ACKNOWLEDGEMENT

3. SCOPE OF THE PROJECT
IN THIS SCENARIO OUR PROJECT AIMS TO
SOLVE THE TWIN PROBLEM OF ENVIRONMENT
POLLUTION DUE TO PLASTIC WASTE AND THE
NEED FOR AN ALTERNATIVE FUEL SOURCE .

4. INTRODUCTION
PLASTIC ARE NON DEGRADABLE POLYMERS OF
MOSTLY CONTAINING CARBON, HYDROGEN AND
FEW OTHERS ELEMENTS SUCH AS
CHLORINE , NITROGEN ETC
DUE TO ITS NON-BIODEGRADABLE NATURE ,THE
PLASTIC WASTE CONTRIBUTES SIGNIFICANTLY TO
THE PROBLEM OF MUNICIPAL WASTE
MANAGEMENT

5. SOURCES OF PLASTIC WASTE
1. Municipal plastic waste.
2. Industrial plastic waste

6. DIFFERENT METHODS OF PLASTIC WASTE
RECYCLING
Land filling
Mechanical recycling
Biological recycling
Thermal recycling/incineration
Chemical recycling
Depolymerisation
Partial oxidation
Cracking / pyrolysis

7. THE HYDROCARBON CRACKING
MECHANISM
1.Mechanism of thermal degradation-
(1)END-CHAIN SCISSION OR UNZIPPING,
(2) RANDOM-CHAIN SCISSION/FRAGMENTATION,
(3) CHAINSTRIPPING/ELIMINATION OF SIDE CHAIN,
(4) CROSS-LINKING.
2. Mechanism of catalytic degradation-
(1) IONIC MECHANISM
(2) FREE RADICAL MECHANISM

8. THERMOGAVIMETRIC ANALYSIS
APPARATUS

9. WHAT IS THERMOGAVIMETRIC
ANALYSIS?
 Thermogravimetric Analysis (TGA) measures
weight changes in a material as a function of
temperature (or time) under a controlled atmosphere.
Its principal uses include measurement of a material's
thermal stability and composition.
Thermogravimetric Analysis instruments are
routinely used in all phases of research, quality control
and production operations. TA Instruments offers the
Discovery TGA, Q500, Q50, and simultaneous DSC /
TGA (Q600) to meet the various needs of the
researcher, quality control analyst and academic
instructor.

10. THERMOGRAVIMETRIC ANALYSIS
 ISOTHERMAL CONDITION-
- Thermogravimetric studies were carried out in an inert
atmosphere of nitrogen, using an instrument of Perkin
Elmer make, with polypropylene and polyethylene as raw
material for pyrolysis at four different temperatures of 350,
400, 425 and 450oC. The loss in weight per unit time was
obtained.
 NON ISOTHERMAL CONDITION
 Thermogravimetric studies were carried out in an inert
atmosphere of nitrogen, using an instrument of Perkin
Elmer make, with polypropylene and polyethylene at
heating rates of 5, 10 and 20oC/min, and at the rates of 5
and 10oC/min respectively.

11. TGA plot for polyethylene with the heating rate of 5
oC per min

12. TGA plot for polyethylene with the heating rate of 10 oC
/min

13. TGA plot for polypropylene with the heating rate of 5 oC
/min

14. TGA plot for polypropylene with the heating rate of 10
oC /min

15. TGA plot for polypropylene with the heating rate of
20°C/min

16. TGA plot for polyethylene at
350°C

17. TGA plot for polyethylene at 400°C

18. TGA plot for polyethylene at
425°C

19. TGA plot for polyethylene at
450°C

20. TGA plot for polypropylene at 350°C

21. TGA plot for polypropylene at
400°C

22. TGA plot for polypropylene at
425°C

23. TGA plot for polypropylene at
450°C

24. EXPERIMENTAL PROCEDURE
 PYROLYSIS-
 Larger carbon molecules are break into smaller molecules.
 In the reactor-
 Thermocouple is used to measure high temperature .
 The top of the reactor outlet is connected with the condenser where the
vapour is condensed.
 Process-
Take waste plastics of some kind [ldpe, hdpe] inside the reactor.
Start the heater for heating the reactor and measure the temperature .
When the temperature reaches 150oc the vapour start to come down to
the Condenser.
The heating is continued for about 11/2 hours till the vapour stop
collecting.
After 1 or 11/2 hrs the plastics were decomposed.
Finally the fuel from condensed vapour is collected .

25. PRODUCT ANALYSIS
 ASTM DISTILLATION
 DETERMINATION OF ANILINE POINT

26. EXPERIMENTAL RESULT OF ANILINE
POINT
Sample
no.
Raw materials Liquid
fraction
obtained up
to 120oc
Liquid
fraction
obtained up
to 120oc to
200oc
Liquid
fraction
obtained at
200oC to
260oC
1 Waste polyethylene
with catalyst
36 45 65
2 Waste Polyethylene
without catalyst
41 54 80
3 Polypropylene (used
milk pouch) without
catalyst
45 53 71
4 Polypropylene
(used milk pouch)
with catalyst
43 51 75

27. EXPERIMENTAL RESULT FOR ASTM
DISTILLATION USING 50 ml SAMPLE
Temperature
(⁰C)
Waste
polyethylene
with catalyst
(ml)
Waste
polyethylene
without
catalyst
(ml)
Polypropylen
e (used milk
pouch)
without
catalyst
(ml)
Polypropylen
e (used milk
pouch) with
catalyst
(ml)
<120 8 6 6.5 6
120-200 15 15 15 14
200-260 15 19 17.5 22
>260 12 10 10 8

28. CONCLUSION
 The average activation energies obtained with a half order
rate for pyrolysis of polyethylene and polypropylene, are
found to fit the experimental data close enough to
conclude applicability of the assumed reaction model. For
different polymer samples the activation energies are found
to vary, which is acceptable.
 Pyrolysis of waste plastics provides gaseous, liquid and
solid products. All the products are useful. So, eliminating
hazardous raw materials from the mixtures we can
definitely obtain something of value by pyrolysis of
polymeric wastes.

29. ACKNOWLEDGEMENT
 We are thankful to our guide Dr. Paramartha Mukhopadhyay,
Department of Chemical Engineering, University of Calcutta.
 We also thank our library staff for supplying us with necessary books.

30. THANK YOU