Converting plasric waste into automobile suitable diesel fuel through pyrolysis process.

1. PRODUCTION, CHARACTERIZATION
AND FUEL PROPERTIES OF
ALTERNATIVE DIESEL FUEL FROM
PYROLYSIS OF WASTE PLASTIC
GROCERY BAGS

2. PLASTIC WASTE : A TIME BOMB TICKING FOR
INDIA
Source : Status report on municipal solid waste management by CPCB
Source : The Hindu , dated: April 4, 2013

3. PLASTICS : DEFINITION
 Plastics are a generic group of synthetic or natural materials, composed of high-molecular
chains whose sole or major element is carbon.
 A plastic material is (Society of Plastics Industry) any one of a large group of materials
consisting wholly or in part of combinations of carbon with oxygen, hydrogen, nitrogen, and
other organic or inorganic elements which, while solid in the finished state, at some stage in its
manufacture is made liquid, and thus capable of being formed into various shapes, most usually
through the application, either singly or together, of heat and pressure.’

4. PLASTICS : CLASSIFICATION

5. PYROLYSIS : DEFINITION
 Pyrolysis, also termed thermolysis (Greek : pur = fire; thermos = warm; luo = loosen), is a
process of chemical and thermal decomposition, generally leading to smaller molecules.
 It differs from combustion in that it occurs in the absence of air and therefore no
oxidation takes place.

6. PYROLYSIS OF PLASTICS AND RUBBER
 In its simplest definition pyrolysis is the degradation of polymers at high temperatures under
non oxidative conditions to yield valuable products (e.g. fuels and oils).
 Pyrolysis can be conducted at various temperature levels, reaction times, pressures, and in the
presence or absence of reactive gases or liquids, and of catalysts.
 Plastic pyrolysis proceeds at low ( < 400⁰C ), medium (400⁰C - 600⁰C) or high temperature (
>600⁰C).
 The pressure is generally atmospheric. Sub atmospheric operation, whether using vacuum or
diluents, e.g. steam, may be selected if the most desirable products are thermally un-stable, e.g.
easily re-polymerizing, as in the pyrolysis of rubber or styrenics.

7. PYROLYSIS : ADVANTAGES OVER ALTERNATE
PLASTIC TREATMENT PROCESSES
 It can deal with plastic waste which is otherwise difficult to recycle and it creates reusable
products with unlimited market acceptance.
As feedstock recycling and pyrolysis is not incineration there are no toxic or environmentally
harmful emissions.
The major advantage of the pyrolysis technology is its ability to handle unsorted, unwashed
plastic. This means that heavily contaminated plastics such as mulch film (which sometimes
contains as much as 20% adherent dirt/soil) can be processed without difficulty.

8. COMMERCIAL
PYROLYSIS PROCESSES
FOR WASTE PLASTICS.

9. PLASTICS SUITABLE FOR TREATMENT
CLASSIFICATION OF POLYETHYLENE
1. HIGH DENSITY POLYETHYLENE (HDPE)
2. MEDIUM DENSITY POLYETHYLENE (MDPE)
3. LOW DENSITY POLYETHYLENE (LDPE)

10. Source : Feedstock Recycling and Pyrolysis of Waste Plastics: Converting Waste Plastics into Diesel and Other Fuels Edited by
J. Scheirs and W. Kaminsky 2006 John Wiley & Sons, Ltd ISBN: 0-470-02152-7

11. STRUCTURE OF THE SYSTEM

12. COMMERCIAL PLASTIC PYROLYSIS
PROCESSES
1. THERMOFUEL PROCESS
2. SMUDA PROCESS
3. POLYMER-ENGINEERING PROCESS (CATALYTIC DEPOLYMERIZATION)
4. ROYCO PROCESS
5. REENTECH PROCESS
6. HITACHI PROCESS
7. CHIYODA PROCESS
8. BLOWDEC PROCESS
9. CONRAD PROCESS

13. THERMOFUEL PROCESS
 In the Thermofuel process, plastic waste is first converted to the molten state and then
‘cracked’ in a stainless steel chamber at temperatures in the range 350–425⁰C under inert gas
(i.e. nitrogen).
 The hot pyrolytic gases are condensed in a specially designed two-stage condenser system to
yield a hydrocarbon distillate comprising straight- and branched-chain aliphatic, cyclic aliphatics
and aromatic hydrocarbons.
The resulting mixture is essentially equivalent to regular diesel.

14. Source : Feedstock Recycling and Pyrolysis of Waste
Plastics: Converting Waste Plastics into Diesel and
Other Fuels Edited by
J. Scheirs and W. Kaminsky 2006 John Wiley & Sons,
Ltd ISBN: 0-470-02152-7

16. SMUDA PROCESS
 The Smuda pyrolysis process developed by Dr Heinrich W. Smuda is a continuous process
where the mixed plastic feedstock is fed from an extruder into a stirred and heated pyrolysis
chamber
 The extruder acts as an airlock to exclude oxygen and also to preheat and melt the polymer,
so less energy input is required in the main chamber.
 The pyrolysis vessel operates at a constant level of 60% and the headspace is purged with
nitrogen gas. A layered silicate catalyst (5–10% by vol) is added to the plastic melt to give a
catalytic cracking reaction.
 The fuel from the Smuda process is both transportation-grade diesel (85%) and gasoline (15%).

17. Photograph of Smuda stirred-tank reactor (left) and bottom of distillation column (right).
(Copyright. Scheirs)

18. CHARACTERIZATION
AND PROPERTIES OF
ALTERNATE DIESEL FUEL

19. PRODUCTION OF TEST FUEL
 Thermochemical conversion of plastic grocery bags (HDPE) to oils were conducted using a pyrolysis
batch reactor in triplicate.
Pyrolysis was performed in a Be-h desktop plastic to oil system containing a 2 L reactor and oil
collection system using approximately 500 g of plastic grocery bags each time.
 The pyrolysis reactor has two heating zones (upper and lower); the upper and lower temperatures
were set to 420 and 440 °C, respectively. Once the reactor reached the set temperatures, a reaction
time of 2 h was employed from that point on.
Vapors produced as a result of pyrolysis were condensed over water as plastic crude oil (PCO). The
upper oil layer was separated and weighed. The reactor lid was opened once the temperature was
below 50 °C to remove the remaining residual solid material and weighed separately.
The PCO thus obtained after pyrolysis of waste plastic grocery bags was distilled into four fractions
(b190; 190–290; 290–340; and 340+°C equivalent of motor gasoline (MG), diesel#1 (PPEH-L), diesel
#2 (PPEH-H) and VGO respectively.

21. CHEMICAL CHARACTERIZATION OF
PLASTIC OIL FRACTIONS

22. 1. Gas chromatography–mass
spectroscopy (GC–MS)
An Agilent DB-35MS column (30 m × 0.320 mm; 0.25μmfilm thickness) was used with a helium flow
rate of 0.509 mL/min. The temperature program began with a hold at 30 °C for 10 min followed by an
increase at 1 °C/min to 195 °C, then 35 °C/min to 330 °C, which was held for 1 min. The injector and
column transfer line heater were both set to 340 °C. The detector inlet and MS quadropole
temperatures were 220 and 150 °C, respectively. The injection volume was 1μL.
RESULTS :-
 The principal constituents in PPEH-L and PPEH-H were quantified by GC–MS, as depicted by a
representative chromatogram.
 In agreement with the NMR results, both samples were comprised of a series of saturated and
unsaturated hydrocarbons.
The test demonstrated that both fuels were composed of a mixture of hydrocarbons. However,
PPEH-H contained heavier constituents GC–MS results further revealed that PPEH-L contained 43.6%
(peak area) of compounds containing one or more double bonds (olefins), while PPEH-H contained
28.2% of such olefin peaks.

25. 2. Simulated distillation by GC–FID
 The boiling point distribution of PCO fractions was obtained by performing simulated
distillations.
 The analysis was performed on 1% (w/w) sample solutions in dichloromethane using an HP
5890 Series II FID gas chromatograph equipped with a temperature programmed vaporizer
injector.
RESULT :-
 The boiling point distribution of PCO fractions was obtained using high temperature GC–FID.
.As boiling point and MW distribution of PCO were similar to petroleum fractions and
contained negligible heteroatom content, therefore, it is speculated that these PCOs will be
compatible with petroleum crude oil for refining in a conventional refinery.

27. (contd.)

28. Simulated distillation of a plastic crude and its four
fractions.

29. 3. Size exclusion chromatography (SEC)
analysis
 Molecular weight (MW) distributions were determined by SEC.
 SEC analysis was carried out on a on a Waters (Milford, MA) Styragel HR1 SEC column (7.8 mm
× 300 mm), Waters 2414 RI detector, and THF as mobile phase (1.0 mL/min).
 The resulting chromatographic data was processed using Matlab software to provide the
weight-average MW (Mw) and polydispersity index (PDI).
RESULTS :-
Comparison to the MW obtained for ULSD (Mw of 131 with max MW of 299 g/mol) revealed
greater similarity to PPEH-L than PPEH-H. For most of the PCO fractions polydispersity index (PDI)
ranged between 1.33 and 1.65, thus indicating a narrow distribution of MWs for these fractions
compared to the ULSD exhibiting a higher PDI (2.08).

31. 4. NMR and FT-IR spectroscopy
 Chemical functionality information was obtained by analyzing the fractions using Fourier-
Transform infrared (FT-IR) and nuclear magnetic resonance (NMR) spectroscopies.
Samples were dissolved in CDCl3(Cambridge Isotope Laboratories, Andover, MA) and all
spectra were acquired at 26.9 °C. Chemical shifts (δ) are reported as parts per million (ppm)
from tetramethylsilane based on the lock solvent.

32. RESULTS :-
Compositional analysis by NMR spectroscopy revealed the presence of aromatic, olefinic and
paraffinic protons in PPEH-L and PPEH-H
Aromatics comprised 1.0 and 0.6% of the overall proton content of PPEH-L and PPEH-H,
respectively.
Unsaturated protons (aliphatic olefins) constituted 5.4% and 2.6% of PPEH-L and PPEH-H,
respectively.
The remainder of the content of PPEH-L (94.0%) and PPEH-H (96.8%) was composed of aliphatic
saturated hydrocarbons.
No oxygenated species such as carboxylic acids, aldehydes, ketones, ethers, or alcohols were
detected by either 1H or 13C NMR spectroscopies.

34. Properties of PPEH and comparison to
ULSD
 PPEH-L showed excellent cloud point and pour point values. There was significant
improvement over the conventional ULSD.
 PPEH-H, with its greater content of higher-melting longer-chain paraffinic constituents
relative to PPEH-L and ULSD, provided CP (4.7 °C), CFPP (3.7 °C) and PP (4.0 °C). The 1:1 PPEH-
L/H blend, representative of summer grade ULSD, yielded cold flow properties (CP−5.9 °C,
CFPP−6.0 °C, and PP −8.3 °C) intermediate to those of the neat materials.
 The plastic derivative fuels were found to have reduced stability. The presence of unsaturated
constituents was speculated as the reason for the reduced stabilities of PPEH-L and PPEH-H
versus ULSD.

36. CONCLUSIONS
 Pyrolysis of HDPE waste plastic grocery bags followed by distillation resulted in a major liquid
hydrocarbon product (PPEH-L).
 Also obtained was a heavier boiling fraction (290–340 °C) equivalent of diesel#2 from
distillation of the crude pyrolysis product, PPEH-H.
 ThermoFuel is a truly sustainable waste solution, diverting plastic waste from landfills,
utilizing the embodied energy content of plastics and producing a highly usable
commodity that is more environmentally friendly than any conventional distillate.
 The result of this process is claimed to be a virtually nonpolluting, (100%) synthetic
fuel that does not require engine modification for maximum efficiency.