Microwave Pyrolysis of Plastic Waste by E Khaghani U of Aukland
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Transcript of Microwave Pyrolysis of Plastic Waste by E Khaghani U of Aukland
MICROWAVE PYROLYSIS OF PLASTIC WASTES FOR PRODUCTION OF FUEL AND OTHER CHEMICALS
Department of Chemical and Materials Engineering 1
Elham Khaghani Professor M. M. Farid
Professor A. Williamson
Presentation outline 2
Introduction Research objectives Pyrolysis background
Thermal pyrolysis Microwave pyrolysis
Experimental thermal pyrolysis setup Results and discussions Proposed microwave induced pyrolysis setup Conclusions Future work
Research objectives Introduction 3
Comprehensive literature review Conducting thermal pyrolysis experiments Developing the ASTMS method Analysing the products using GC/FID Designing the microwave heating system
Presentation outline 4
Introduction Research objectives Pyrolysis background
Thermal pyrolysis Microwave pyrolysis
Experimental thermal pyrolysis setup Results and discussions Proposed microwave induced pyrolysis setup Conclusions Future work
Introduction 5
Definition of pyrolysis: Pyrolysis can be described as the thermal decomposition of organic components in an oxygen-free atmosphere to yield char, oil and gas
Key parameters in pyrolysis reaction reactor type pyrolysis temperature heating rate pyrolysis time operating pressure chemical composition of resins
Introduction 6
Types of pyrolysis Pyrolysis Hea,ng rate Residence
,me Temperature (°C)
Reac,on environment
Pressure (bar)
Major product
Carboniza,on Very slow Hrs‐days 400 Combus4on 1 Charcoal
Conven,onal 10‐100 °C/min
10s‐10min <600 Primary /Secondary
1 Gas, Liquid, Char
Fast/Flash Up to 1000°C/s
<1s <600 Primary /Secondary
1 Liquid
>700 Primary 1 Gas Ultra Very high <0.5s 1000 Primary 1 Gas Vacuum Medium 2‐30s 400 Primary <0.1 Liquid
Introduction 7
• Candidates for pyrolysis
55%
15%
11%
9%
3% 7%
Fraction %
PE PP PVC PS Expanded PS ( fast food packagin) Others
Industrial process for pyrolysis Introduction 8
Fuji fixed-bed pyrolysis process Hamburg university process VEBA pyrolysis process BASF process BP recycling plant
Fuji fixed-bed pyrolysis process Introduction 9
Zeolite – based ZSM-5 catalysts
Maximum capacity 5000
tonne/year plastic wastes
80% oil
60% gasoline
20%
kerosene
20% diesel 15% gas
Hamburg university process Introduction 10
Maximum capacity 50 kg/h
25-45% gas 30-50% liquid
VEBA pyrolysis process
11
Synthetic oil produced by rotary kiln reactor at 650°C
VCC Veba Combi Cracking LPH Liquid Phase hydrogenation GPH gas Phase hydrogenation
Maximum capacity 40000 tonne/year
80% high quality liquid products
10%methane-butane gas and further
10%hydrogenation residues
BASF process Introduction 12
Maximum capacity 150000 tonne/year
20-30% gas 60-70% liquid
BP recycling plant Introduction 13
• Nominal capacity 50 kg/h • 80%efficiency in converting plastic wastes into petrochemical • The gas contains high content of ethylene and propylene
Why thermal pyrolysis? Introduction 14
Limited supply of natural resources (crude oil and gas) Fluctuation of high price and availability of crude Decreasing toxic air emissions and reducing greenhouse gases Recycle some of the stored energy within the waste plastics Diminishing imports of crude oil
Sample Calorific value (MJ kg-1)
Polyethylene 46.50
Polypropylene 46.50
Polystyrene 41.90
Kerosene 46.50
Gas Oil 45.20
Heavy Oil 42.50
Pyrolysis products Introduction 15
Hydrogen Methane Ethane Ethene Propane Propene Butane Butene CO CO2 HCL HDPE 0.12 1.9 2.21 6.08 1.31 4.56 0.22 0.36 0 0 0.00 LDPE 0.05 1.14 1.67 4.00 1.33 4.00 0.32 2.00 0 0 0.00 PS 0.04 0.53 0.08 0.26 0.02 0.05 0.00 0.06 0 0 0.00 PP 0.05 0.93 1.45 3.52 1.00 3.53 0.23 1.29 0 0 0.00 PET 0.31 0.71 0.03 1.41 0.13 0.09 0.00 0.00 13.29 22.71 0.00 PVC 0.12 0.77 0.47 0.15 0.24 0.19 0.11 0.15 0 0 52.93
• Gas products
• Oil/wax products (C6-C60)
• Solid products: the major element is carbon
HDPE, LDPE and PP : mainly saturated alkane and alkene group liquids PVC :combination of alkane, alkene and aromatic compounds PS : aromatic compound generated from benzene ring PET : aldehydes, ketones, carboxylic acids, alcohols and aromatic compounds
PE PP PS PVC PET
Why microwave pyrolysis ? Introduction 16
MW technology is environmentally friendly (is produced from electricity) Volumetric heating leads to produce uniform
microstructure materials The high heating rate Quick respond to changes in process parameters The nature of microwave heating is also much more
efficient compared to resistance heating
Microwave pyrolysis Introduction 17
Interaction of electromagnetic radiation with
materials
Reflection Conductor
Transmission Insulation
Absorption Dielectrics
18
Types of cavities
Single mode Multimode
Microwave pyrolysis Introduction
Dielectric theory
19
D=f (Temperature, ion concentration, ion size, dielectric constant, microwave frequency, viscosity of reacting medium)
Microwave pyrolysis Introduction
Microwave pyrolysis Introduction 20
Dielectric mechanisms
Microwave pyrolysis Introduction 21
Electromagnetic wave propagation (Reflected and transmitted signals)
Microwave pyrolysis Introduction
22
Available technologies Semi batch reactor Ludlow Palafox et al. (2001)
Continues conveyor belt type reactor Charles L.Emery (1993)
Continues screw type reactor (under design) Petter Heyerdahl and Geoffrey Gilpin
Continues type reactor James S. Klepfer (1999)
Schematic drawing of the microwave-induced pyrolysis of HDPE
Ludlow Palafox et al. (2001) 23
Schematic drawing of the microwave-induced pyrolysis
Charles L.Emery (1993) 24
Schematic diagram of the microwave-assisted pyrolysis system under design P. Heyerdahl and G. Gilpin (Norwegian Uni.)
25
Schematic diagram of the microwave pyrolysis of organic waste materials James S. Klepfer (1999)
26
Presentation outline 27
Introduction Research objectives Pyrolysis background
Thermal pyrolysis Microwave pyrolysis
Experimental thermal pyrolysis setup Results and discussions Proposed microwave induced pyrolysis setup Conclusions Future work
Thermal pyrolysis setup 28
Presentation outline 29
Introduction Research objectives Pyrolysis background
Thermal pyrolysis Microwave pyrolysis
Experimental thermal pyrolysis setup Results and discussions Proposed microwave induced pyrolysis setup Conclusions Future work
Results of thermal pyrolysis 30
Effect of temperature 500°C 525°C 575°C
PLASTIC Oil/wax Gas Residue Oil/wax Gas Residue Oil/wax Gas Residue HDPE 74.04 25.96 0 73.30 26.7 0 73.20 26.8 0 LDPE 73.92 26.08 0 72.74 27.26 0 69.62 30.38 0 PP 77.30 22.70 0 77.20 22.80 0 75.76 24.24 0
Product analysis
Shimadzu GC 2010 with FID FORTEHT-5 column
(25 m×0.22mm×0.10um) 0.1gr sample dissolved in 5 ml
carbon disulfide Internal standard: C15 and C23 Standard mixture: D2887 (C6-
C44) 1 µl injected into column Oven temperature:
start: 80°C followed by ramp 15°C/min to 160°C ,then ramp 30°C/min to 380°C (15 min)
FID temperature: 400°C Helium used as carrier gas
31
Gas Chromatograph –Flame Ionisation Detector (GC/FID)
Pyrolytic oil/wax composition of HDPE at 500°C
32
GC/FID chromatogram
Diene
Alkene
Alkane
Carbon number distribution for the pyrolysis of HDPE 33
0
0.02
0.04
0.06
0.08
0.1
8 13 18 23 28 33 38 43
TIC
%
0
0.02
0.04
0.06
0.08
0.1
8 13 18 23 28 33 38 43 TI
C%
0
0.02
0.04
0.06
0.08
0.1
8 13 18 23 28 33 38 43
TIC
%
(a) 500 °C (b) 525 °C (c) 575 °C
*(c) 500 °C *(d) 600 °C *(e) 700 °C
*Obtained by Carlos Ludlow-Palafox and Howard A. Chase (2001)
0
0.02
0.04
0.06
0.08
0.1
8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44
TIC
%
Carbon Number
HDPE-500
HDPE-525
HDPE-575
Comparison of HDPE at 500°C, 525°C & 575°C 34
Comparison of LDPE at 500°C, 525°C, 575°C 35
0
0.02
0.04
0.06
0.08
0.1
0.12
8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44
TIC
%
Carbon Number
LDPE-500
LDPE-525
LDPE-575
Comparison of PP at 500°C, 525°C, 575°C 36
0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
0.16
8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44
TIC
%
Carbon Number
PP-500
PP-525
PP-575
Comparison of HDPE-LDPE-PP at 575 °C 37
0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44
TIC
%
Carbon Number
HDPE-575
LDPE-575
PP-575
Evolution of diene compounds (C10-C22) 38
0
0.01
0.02
0.03
0.04
0.05
0.06
10 11 13 15 17 20 22
Alk
adie
ne T
IC%
Carbon number
HDPE500
HDPE525
HDPE575
Evolution of alkene and alkane compounds 39
0
0.01
0.02
0.03
0.04
0.05
0.06
8 15 26 31 36 39 44
Alk
ene
TIC
%
Carbon number
HDPE500
HDPE525
HDPE575
0
0.01
0.02
0.03
0.04
0.05
10 20 29 36 41 A
lkan
e TI
C%
Carbon number
HDPE500
HDPE525
HDPE 575
Presentation outline 40
Introduction Research objectives Pyrolysis background
Thermal pyrolysis Microwave pyrolysis
Experimental thermal pyrolysis setup Results and discussions Proposed microwave induced pyrolysis setup Conclusions Future work
Proposed microwave induced pyrolysis setup 41
Schematic of the microwave pyrolysis of plastic apparatus: 1) Generator, 2) Isolator (Circulator + Dummy load), 3) Directional coupler, 4) 3-stub tuner, 5) Quartz reactor, 6) Nitrogen inlet, 7) Seal, 8) Bearing, 9) Gear transition, 10) Adjustable speed electrical machinery,11) Applicator (rotary kiln reactor), 12) Optical pyrometer, 13) Feed inlet, 14) Condenser, and 15) Product container.
Presentation outline 42
Introduction Research objectives Pyrolysis background
Thermal pyrolysis Microwave pyrolysis
Experimental thermal pyrolysis setup Results and discussions Proposed microwave induced pyrolysis setup Conclusions Future work
Conclusions 43
Thermal pyrolysis of polyolefines yielded mainly oil/wax The maximum yield of oil/waxes (500°C to 575°C)
77.3% for PP>74.04% for HDPE> 73.92% for LDPE The yield of oil/waxes decreased with the increase in temperature GC chromatogram shows a homologous series of triplets (diene,
alkene, alkane) The main chemical components of the oil/wax :
alkenes > alkanes > diene The maximum yields of diene were observed at 525°C and for
alkenes and alkanes were recorded at 500 °C.
Conclusions 44
The Maximum yields for carbon number distribution was C10 to C15 for HDPE and LDPE C8, C11, C15 and C16 for PP
Concentration of aliphatic species above C32 were greatly reduced The higher temperature favours of formation of higher yield of
heavier compounds between 500°C and 575°C The average quantitative ratio of
alkane: alkene: diene at 500°C 1:1.61: 0.36 for HDPE 1:1.54: 0.29 for LDPE
Future Work 45
Conduct microwave pyrolysis experiment using rotary kiln reactor Simulate the electromagnetic field distribution Mathematical modelling Examine the effect of processing parameters Characterise the oil/wax fraction using GC/FID Kinetic study to investigate the effect of microwave on reaction rate Convert batch process to continuous process Construct the pilot scale reactor
46
Thank you
Questions?