5th International Conference on

Sustainable Solid Waste Management

Speaker: Ki-Bum Park

Univ. of Seoul

1

230257

279 288 299 311 322

61 65 59 59 57 59 58

2005 2007 2011 2012 2013 2014 2015

World Europe

PS;

6,9

PET,

7,1PUR,

7,5

PVC,

10,1

HDPE;

12,1LDPE,

17,3

PP,

19,1

Others;

19,9

3

4

Pyrolysis

reactor:

Pyrolysis reactors:• Melting vessel stirred tank

• Shaft, tube reactor

• Rotary kiln, extruder

• Moving bed

• Fluidized bed

Gas

OilChar

Pyrolysis targets:• Production of oils for energy source

• Production of chemicals

BTX-aromatics

Wax

5

High Cl content in oil Not acceptable in petrochemical industries

Acceptable level: < 10 ppm

Generation of chlorinated compounds during PVC thermal degradation:

Ex: HCl

Problems caused by chlorinated compounds

• Corrosion of pyrolysis process lines and equipments

• Generation of dioxins in combustion of pyrolysis oil

6

Hamburg ProcessPCDD and PCDF concentration in the Pyrolysis oil

of mixed plastics with a PVC content of 13,7 % at 735 ºC.

(values in ng/g) (N.D.: Not detectable)

Results: As HCl Can be removed by water or alkaline solutions

Detection

Limit

Low

Boiling

High

Boiling

∑ TCDD 0.02 N.D. N.D.

2,3,7,8-TCDD 0.05 N.D. N.D.

∑ PeCDD 0.05 N.D. N.D.

∑ HxCDD 0.05 N.D. N.D.

∑ HpCDD 0.10 N.D. N.D.

OCDD 0.10 N.D. N.D.

∑ TCDF 0.02 N.D. N.D.

2,3,7,8-TCDF 0.02 N.D. N.D.

∑ PeCDF 0.03 N.D. N.D.

∑ HxCDF 0.03 N.D. N.D.

∑ HpCDF 0.10 N.D. N.D.

OCDF 0.10 N.D. N.D.

7

1. Application of catalysts and additives

• Fe- and Ca-based catalysts (Polymer

Degradation and Stability 87 (2005) 225-

230)

• Calcium carbonate carbon composite

(Ca-C) (J. Anal. Appl. Pyrolysis 72 (2004)

27–33)

• Ca-based additives such as CaO (J. Anal.

Appl. Pyrolysis 51 (1999) 127–134)

2. Preliminary study using stepwise

pyrolysis (Fuel Processing Technology

92 (2011) 253–260)

• Not effective enough

• Catalyst deactivation

• Only conceptual

approaches: (Not

implementable in

industries)

8

9

Proximate analysisa (wt. %) Ultimate analysis (wt. %)

Volatile matter 98.10 ± 0.26 Carbon 62.44 ± 0.25

Fixed carbon 1.84 ± 0.26 Hydrogen 8.00 ± 0.03

Ash 0.06 ± 0.01 Nitrogen 0.16 ± 0.01

Oxygen 8.75 ± 0.21

Sulfur N.D.

LHV (MJ/kg) 23.22 ± 0.44 Chlorine 20.60

N.D.: Not Detected

Proximate analysisa: ASTM D3172 method, moisture free base

10

Temperature (oC)

200 400 600 800

0

6

12

18

24

30

Nor

mal

ized

mas

s to

inita

il m

ass (

wt.%

)

0

20

40

60

80

100

20 oC/min

10 oC/min

5 oC/min

Der

ivat

ive

wei

ght c

hang

e (%

)

11

Plasticizer (i.e. phthalate)

release peakChlorine release peak

Polyene degradation peak

Two-step pyrolysis:

• 1st pyrolysis at 300-450 ℃• 2nd pyrolysis at 600-700 ℃ using the residue from the 1st pyrolysis 12

Sample conditions

Material: soft PVC

Sample amount per experiment: 200 g

Feed material size: 3-4 mm

Fixed bed reactor conditions

Fluidizing gas: nitrogen

Flow rate: 5 ℓ/min

Run 1 Run 2 Run 3 Run 4 Run 5 Run 6

1 Step

Heating rate (oC/min) 10 10 10 10

Residue from 1st

step (400 oC)Temperature (oC) 300 350 400 450

Holding time (h) 3 3 3 3

2 Step

Heating rate (oC/min) 10 10

Temperature (oC) 600 700

Holding time (h) 2 2

13

2,26

0,61 0,66

7,34 7,61

6,14

0

2

4

6

8

350 400 450

Cl co

ncentr

ation (

wt.

%)

Temperature (℃)

Residue Oil+wax

14

58,64

24,6418,25 13

27,90

38,51 48,2449,02

13,46

36,85 33,51 37,98

0

20

40

60

80

100

300 350 400 450

Pro

du

ct yie

ld (

wt.

%)

Temperature (℃)

Residue Oil+wax Product gas

Virgin PVC: 20.60

15

Virgin PVC

Oil Residue Product gas

Pyrolysis oilChar+gas

Cl:100

17.73 0.53 81.73

0.220.31

1st

step

2nd

step

48,45 50,57

28,8632,01

22,6917,43

0

20

40

60

80

100

600 700

Pro

du

ct yie

ld (

wt.

%)

Temperature (℃)

Char Condensated oil Product gas

Characteristics:

• Auger & fluidized bed reactors connected in series

• Auger pyrolyzer: slow or intermediate pyrolysis, removal of HCl

• Fluidized bed pyrolyzer: fast pyrolysis, high yield of oil

PP 61.5

PE 36

PVC 2.5

(wt. %)Feed material

Quenching system

Char

separate

system

N2 jacket

16

17

Auger reactor

Fluidized reactor

Cyclone

Hot filter

Quenching

system

Auger

quenching system

18

19

Reactor type Products Experiment

Auger reactor

: ~300 oC

Gases 17.80

Oil+wax 6.22

Residues 5.00

Fluidized bed reactor

: ~ 700 oC

Gases (sum) 46.59

Hydrogen 0.24

Methane 14.29

Ethane 3.61

Ethene 18.56

Propene 6.26

Butenes 1.24

1,3-butadiene 1.58

Oils (sum) 20.76

Aliphatics (sum) 0.02

Cyclooctatetraene 0.01

Other aliphatics 0.01

Aromatics (sum) 19.55

Mono aromatics (sum) 9.12

Benzene 0.06

Toluene 0.91

Ethylbenzene 0.21

o-Xylene 0.18

Styrene 2.14

Other mono aromatics 5.62

Poly aromatics (sum) 10.86

Naphthalene 4.02

Other poly aromatic compounds 5.33

Unknowns 1.19

Char 3.64

Chlorine concentration in

pyrolysis oil

: 8.07 ppm

Petrochemical industries

chlorine standard

: 10 ppm

20

In TGA, chlorine as HCl was released at 280-400 °C

In the two-step pyrolysis using batch reactor,

• Pyrolysis oil from the 2nd step conducted at 700 °C contained only

0.5 wt.% of chlorine

In the two-stage pyrolysis of mixed plastic which contained 2.5 wt. % PVC,

chlorine content in oil from fluidized bed reactor was below 10 ppm (8.07 ppm)

Pyrolysis oil from fluidized bed reactor of two-stage pyrolysis process was

mainly composed of aromatic hydrocarbons (over 94 wt. %)

Yields of ethene and propene was ~25 wt. %

Resource Recycle lab.

THE UNIVERSITY OF SEOUL5th International Conference onSustainable Solid Waste Management