SCALE UP DEVULCANIZATION OF RECYCLED TIRE RUBBER WITH SUPERCRITICAL COSCALE-UP DEVULCANIZATION OF RECYCLED TIRE RUBBER WITH SUPERCRITICAL CO2SCALE UP DEVULCANIZATION OF RECYCLED TIRE RUBBER WITH SUPERCRITICAL CO22

Costas Tzoganakis Mohammad Meysami and Shuihan ZhuCostas Tzoganakis, Mohammad Meysami and Shuihan ZhuCostas oga a s, o a ad eysa a d S u a uDepartment Of Chemical Engineering University of WaterlooDepartment Of Chemical Engineering, University of WaterlooDepartment Of Chemical Engineering, University of Waterloo

Waterloo Ontario CanadaWaterloo Ontario CanadaWaterloo, Ontario, Canada

S l     f  bb  d l i i   Background Scale up of rubber devulcanization  processBackground Scale up of rubber devulcanization  processg p f pD l i i f    bb   i h  CO i     d  i     i ll  f i dl   i   1 Specific energy consumption calculation Material Extruder/Screw Feeding rate Screw speed ScCo Rate Process•Devulcanization of waste rubber with scCO2 in an extruder is an environmentally friendly continuous process; 1. Specific energy consumption calculation Material Extruder/Screw  Feeding rate  Screw speed  ScCo2 Rate  Process evu ca at o o waste ubbe w t scCO2 a e t ude s a e v o e ta y e d y co t uous p ocess;M t i l   i i   f d l i d bb   ff    t   f th l ti   l i t (TPV)

p gy pfi ti (lb/h ) ( ) ( / i ) diti•Materials engineering of devulcanized rubbers offers new types of thermoplastic vulcanizates (TPV); configuration (lb/hr) (rpm) (gr/min) conditiong g yp p ( );

Lab scale de ulcani ation process of  rubber crumbs usin  a t in scre  e truder has been established Kw (applied) = Kw(motor rating)×(%torque)×(rpm g ( ) ( p ) (g )

•Lab‐scale devulcanization process of  rubber crumbs using a twin‐screw extruder has been established; Kw (applied) = Kw(motor rating)×(%torque)×(rpm p g•In scale up trial  volatiles generated during devulcanization can blast out of the exit of extruder  periodically

pp g q p10 h CR 50 / #2 50 111 N U t bl•In scale‐up trial, volatiles generated during devulcanization can blast out of the exit of extruder  periodically.

running/max rpm) 0 97 10 mesh CR 50mm / #2 50 111 No gas Unstablerunning/max rpm)×0.97 / g

Objectivesg p ) 97

30 h C 0 / 3 0 0 S blObjectivesS ifi  E   ti    K ( li d)/K     30 mesh CR 50mm / #3 10 40 5 StablejSpecific Energy consumption = Kw(applied)/Kg per  30 mesh CR 50mm / #3 0 40 5 StableSpecific Energy consumption   Kw(applied)/Kg per 

• To achieve a higher throughput of the devulcanized rubber for cost‐ reduction ; h 30 mesh CR 50mm / #3 10 50 5 StableTo achieve a higher throughput of the devulcanized rubber for cost‐ reduction ; hour 30 mesh CR 50mm / #3 10 50 5 Stable• To maintain the degree of devulcanization in the scale‐up devulcanization ; hourTo maintain the degree of devulcanization in the scale up devulcanization ;T i i h d fi d h i i d id h l il 2 Process variables and conditions 30 mesh CR 50mm / #3 20 50 5 Stable•To optimize the process and find out the processing window to avoid the volatile 2. Process variables and conditions 30 mesh CR 50mm / #3 20 50 5 StableTo optimize the process and find out the processing window to avoid the volatilebl ffblast‐off . 30 mesh CR 50mm / #3 20 100 No gas Unstable30 mesh CR 50mm / #3 20 100 No gas Unstable 

S C fi ti S S d F di R tD l i i

Screw  Configurations Screw Speed  Feeding Rate  30 mesh CR 50mm / #4 50 200 10 StableDevulcanizationg p

( )g

(lb/h )30 mesh CR 50mm / #4 50 200 10 StableDevulcanization (rpm) (lb/hr)

1 T i i CO i j i d d i i i ( p ) ( / )

S #1 50 20 30 mesh CR 50mm / #4 20 50 5 Stable1. Twin screw extrusion, CO2 injection, and data acquisition Screw #1 50 20 30 mesh CR 50mm / #4 20 50 5 Stable1. Twin screw extrusion, CO2 injection, and data acquisition S #2 100 50Screw #2 100 50

30 h CR 50 / #4 50 200 10 St blS #3 200 100

30 mesh CR 50mm / #4 50 200 10 StableScrew #3 200 100

S C 2 i j iC l l S #4 220

Sc Co2 injection system30 h CR 50 / #4 60 200 5 St blVal e Val e

Control Panel Screw #4 220j y

30 mesh CR 50mm / #4 60 200 5 StableValve ValveS #5

/Feeder Screw #5

h / blCO S #6 30 mesh CR 50mm / #4 100 50 5 StableCO250 rpm200 C

Screw #6 30 mesh CR 50mm / #4 100 50 5 Stable

S i PCylinder200 C

S #7Syringe Pumph l

Screw #7 10 mesh CR 50mm / #4 50 100 5 StableThermocouples 10 mesh CR 50mm / #4 50 100 5 Stable

b l ( fl )3 Process Stability (Pressure fluctuations)3. Process Stability (Pressure fluctuations)Gear 2000

box 1400boxExtruder PressureExtruder Pressure

Transducers Die 1800Transducers1200

1600

1000 1400

si si

ps p

50 i d (L i i I Nj)2 C fi i f p,

p p,

120050 mm twin screw extruder (Leistritz Inc. Nj)2. Configurations of screw 800m

p mp( j)

2. Configurations of screw 800

Am Am

R bb b CO rpm

m, A m, A 1000 rpmRubber crumbs CO2

rpm

Ampm pm

rpm

Amp

600

Amp

PressureRp Rp Amp

Pressure

1 2 3 4 5 6 7 98 10600R R

8001 2 3 4 5 6 7 98 10

600400

400

2008* 8*

GF

GF

GF

GF

GF

GF

GF

GF

4* GF

GF

GF

GF

GF

GF

GF

GF

GF GGF

GF

GF 8 200*K *KFA FA FA FA FA FA FA FA

*KS

FA FA FA FA FA FA FAFA FA

GFAFA FA FA 8*S K

S1K

S1

A-2-

A-2-

A-2-

A-2-

A-2-

A-2-

A-2-

A-2-S1-

A-2-

A-2-

A-2-

A-2-

A-2-

A-2-

A-2-

A-2-

A-2-

A-2

A-2-

A-2

A-2

S1- 1-21-2-45

-45

-45

-45-45-45-45-30-2--30-30-20

-20

-20

-20

-20-20

-20

2-20

-20-20-20-2- 0 02-7.

2-7.

5-1

5-6

5-6

5-65-35-35-30-6-7.50-30-30-6

0-6

0-6

0-6

0-30-3

0-3

0-1

0-30-30-3 7.5 1 21 41 61 81 10

112

114

116

118

120

122

124

126

128

130

132

134

136

138

140

142

144

146

148

150

152

154

156

158

160

162

164

166

168

170

172

174

176

178

180

182

184

186

188

190

192

194

196

198

100

102

104

106

108

110

112

114

116

118

120

1 1 32 63 94 125

156

187

218

249

280

311

342

373

404

435

466

497

528

559

590

621

652

683

714

745

776

807

838

869

900

931

962

993

024

055

086

117

148

179

210

241

272

303

334

365

396

427

458

489

520

551

582

613

644

675

706

737.5 .5N20

60 60 60 30 30 30 60 5 30 30 60 60 60 60 3030 30 120

30 30 30L5 1 1 1 1 1 2 2 2 2 2 3 3 3 3 3 4 4 4 4 4 5 5 5 5 5 6 6 6 6 6 7 7 7 7 7 8 8 8 8 8 9 9 9 9 9 10 10 10 10 10 11 11 11 11 11 12

2 2 2 3 3 3 4 4 4 4 5 5 5 6 6 6 7 7 7 9 9 9 9 10 10 10 1 1 1 12 12 12 13 13 13 13 14 14 14 15 15 15 16 16 16 17 17N0 0L

Time (S) Time (S)Time (S) Time (S)

Stable Process U t bl PStable Process Unstable ProcessProcess condition:3 Devulcanization mechanism Process condition:Process condition:3. Devulcanization mechanism Process condition:Temperature: 220 oC Temperature: 220 oCpScrew Speed: 100 rpm

Temperature: 220 CS S d 100Screw Speed: 100 rpm Screw Speed: 100 rpm

Flow Rate: 50 lb/hr.p p

Flow Rate: 50 lb/hrFlow Rate: 50 lb/hr.S #6Crosslink

Flow Rate: 50 lb/hr.Screw #6Vulcanized rubber Crosslink Screw #4Screw #4

C l di  R kS Concluding RemarksSYConcluding Remarks

Y

Devulcanization of ground tire rubber crumbs under stress in the twin screw extruder with supercritical CO is aDevulcanization of ground tire rubber crumbs under stress in the twin screw extruder with supercritical CO2 is a g p 2 continuous cost effective and environmentally friendly process;continuous, cost-effective, and environmentally friendly process;, , y y p ;A bl hi h th h t f d l i d bb h b bt i d i th l d l i ti i t iA reasonably high throughput of devulcanized rubber has been obtained in the scale-up devulcanization process in a twin y g g p p p

t d hi h i t blTypical devulcanized samples : screw extruder, which is stable;Typical devulcanized samples : , ;Th l til t d d i t i b t ll d d fi ti f di t d th da) Samples of de lcani ed r bber in strand shape The volatiles generated during extrusion can be controlled and screw configuration, feeding rate and the screw speed are CO a) Samples of devulcanized rubber in strand shape g g g , g pth k t t t l th t bilit

CO2the key parameters to control the process stability.SY

b) Devulcanized rubber ribbons exiting the die; the key parameters to control the process stability.SYb) Devulcanized rubber ribbons exiting the die;

ACKNOWLEDGEMENTSc) Samples of devulcanized rubber in ribbon shape ACKNOWLEDGEMENTSc) Samples of devulcanized rubber in ribbon shape

IPR 20

08