Feedstock Recycling and Pyrolysis of Waste Plastics.pdf

Contents Contributors . . . . Series Preface  . . . . Preface . . . . . . . . About the Editors  . I

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xix xxiii xxv xxix

INTRODUCTION

1

1

Introduction to Feedstock Recycling of Plastics . . . . . . . . . . . . .  A. Buekens

3

Abbreviations 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Nomenclature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Pyrolysis of Plastics and Rubber . . . . . . . . . . . . . . . . . . . . 3.1 Survey of Previous Work  . . . . . . . . . . . . . . . . . . . . . 3.2 Products from Polymers . . . . . . . . . . . . . . . . . . . . . . 3.3 Hetero-atoms and Side Products . . . . . . . . . . . . . . . . 3.4 Fundamentals . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.5 Value of the Resulting Products . . . . . . . . . . . . . . . . . 4 Feedstock Recycling  . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.1 Survey  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2 Problems with Hetero-atoms  . . . . . . . . . . . . . . . . . . . 4.3 Collection Systems  . . . . . . . . . . . . . . . . . . . . . . . . . 4.4 Logistics of Supply . . . . . . . . . . . . . . . . . . . . . . . . . 5 Some Feasible Processes . . . . . . . . . . . . . . . . . . . . . . . . . 5.1 Pilot and Industrial Plant Operation . . . . . . . . . . . . . . 5.2 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Waste management  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.1 Principles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.2 Plastics Waste . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.3 Rubber Waste . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.4 Plastics Pyrolysis as a Waste Management Option . . . . 7 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3 3 4 6 7 8 15 18 20 22 22 23 24 25 27 27 32 32 32 33 35 35 39 40

vi

II

 

CONTENTS

CATALYTIC CRACKING 2

Acid-Catalyzed Cracking of Polyolefins: Primary Reaction Mechanisms  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

43

45

 Robert L. White

3

1 2 3 4

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Polyethylene Cracking . . . . . . . . . . . . . . . . . . . . . . . . . . . Polystyrene Cracking . . . . . . . . . . . . . . . . . . . . . . . . . . . Hydrocracking Processes . . . . . . . . . . . . . . . . . . . . . . . . . 4.1 PE-PtHZSM-5  . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2 PE-PtHY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.3 PE-PtHMCM-41 . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

45 46 54 60 60 63 63 67 67

Catalytic Upgrading of Plastic Wastes . . . . . . . . . . . . . . . . . . .

73

 J. Aguado, D. P. Serrano and J. M. Escola 1

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.1 Catalytic versus Thermal Cracking . . . . . . . . . . . . . . . 1.2 Plastics Susceptible to Upgrading by Catalytic Cracking 1.3 Products Derived from the Catalytic Cracking . . . . . . . 2 Catalytic Systems  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1 Homogeneous Catalysts  . . . . . . . . . . . . . . . . . . . . . . 2.2 Heterogeneous Catalysts . . . . . . . . . . . . . . . . . . . . . 3 Reactors  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.1 Batch/Semi-batch Reactors  . . . . . . . . . . . . . . . . . . . . 3.2 Fixed-bed Reactors  . . . . . . . . . . . . . . . . . . . . . . . . . 3.3 Fluidized-bed Reactors . . . . . . . . . . . . . . . . . . . . . . 3.4 Spouted-bed Reactors . . . . . . . . . . . . . . . . . . . . . . . 3.5 Screw Kiln Reactors  . . . . . . . . . . . . . . . . . . . . . . . . 4 Influence of the Main Operation Variables  . . . . . . . . . . . . . . 4.1 Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2 Catalyst Amount . . . . . . . . . . . . . . . . . . . . . . . . . . 4.3 Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.4 Plastics Waste Composition . . . . . . . . . . . . . . . . . . . 5 Processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.1 Direct Catalytic Cracking . . . . . . . . . . . . . . . . . . . . . 5.2 Thermal Degradation and Subsequent Catalytic Upgrading 6 Related Technologies: Coprocessing  . . . . . . . . . . . . . . . . . . 6.1 Coal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.2 Petroleum Cuts . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.3 Solvents  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Concluding Remarks  . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

73 74 77 78 79 79 79 85 86 86 88 90 91 92 93 94 95 95 96 97 99 101 101 102 103 103 104

vii

CONTENTS

4

Thermal and Catalytic Conversion of Polyolefins . . . . . . . . . . .

111

 Jerzy Walendziewski 1 2 3 4 5

5

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . General Scheme of Waste Polyolefin Processing  . . . . . . . . . . Waste Plastics Suitable for Cracking and Pyrolysis . . . . . . . . Mechanism of Cracking Processes  . . . . . . . . . . . . . . . . . . . Waste Plastics Processing . . . . . . . . . . . . . . . . . . . . . . . . . 5.1 Catalytic and Thermal Cracking Processes: Typical Products  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.2 Coprocessing of Waste Plastics with Other Raw Materials 6 Reactor Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Pilot Plants and Commercial Plants . . . . . . . . . . . . . . . . . . 8 Economic Aspects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

111 112 113 113 115 115 119 120 122 124 125

Thermal and Catalytic Degradation of Waste HDPE . . . . . . . . .

129

Kyong-Hwan Lee

6

1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Theory of Plastics Pyrolysis  . . . . . . . . . . . . . . . . . . . . . . . 3 Process Flow Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Total Mass Balance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Effect of Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Effect of Catalyst  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Various Catalysts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Effect of Addition of Other Thermoplastics  . . . . . . . . . . . . . 9 Fractional Distillation of Products . . . . . . . . . . . . . . . . . . . 10 Properties of Liquid Product  . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

129 130 133 136 137 141 144 149 153 155 158

Development of a Process for the Continuous Conversion of  Waste Plastics Mixtures to Fuel . . . . . . . . . . . . . . . . . . . . . . .

161

Takao Masuda and Teruoki Tago 1 2

3

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Recovery of Heavy Oil from Waste Plastic . . . . . . . . . . . . . 2.1 Degradation of Various Plastics  . . . . . . . . . . . . . . . . . 2.2 Catalytic Cracking of Waste Plastics Without Residue . . 2.3 Continuous Degradation of Waste Plastics Mixtures for the Recovery of Heavy Oil  . . . . . . . . . . . . . . . . . . . . Upgrading of Waste-plastics-derived Heavy Oil Over Catalysts 3.1 Catalytic Cracking of Heavy Oil over Solid-acid Catalysts 3.2 Production of High-quality Gasoline over REY Zeolites  . 3.3 Kinetics of the Catalytic Cracking of Heavy Oil over REY Zeolites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.4 Usage of Steam as a Carrier Gas  . . . . . . . . . . . . . . . .

161 162 162 165 168 172 172 175 180 183

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CONTENTS

4

7

Continuous Production of Fuels from Waste Plastics  . . . . . . . 4.1 Continuous Production of Fuels . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

188 188 190

Catalytic Degradation of Plastic Waste to Fuel over Microporous Materials  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

193

George Manos 1 2 3 4 5 6

8

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Operation Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Zeolites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Polymer-to-catalyst Ratio  . . . . . . . . . . . . . . . . . . . . . . . . . Initial Degradation Mechanism . . . . . . . . . . . . . . . . . . . . . Product Distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.1 Conversion, Liquid Yield, Coke Content  . . . . . . . . . . . 6.2 Characterization of Gaseous/Liquid Products . . . . . . . . 6.3 Boiling Point Distribution of Liquid Fraction  . . . . . . . . 7 Concluding Remarks  . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

193 194 195 196 199 201 202 203 203 204 206

Liquefaction of Municipal Waste Plastics over Acidic and Nonacidic Catalysts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

209

 Jale Yanik and Tamer Karayildirim 1 2

9

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Catalytic Liquefaction of MWP  . . . . . . . . . . . . . . . . . . . . . 2.1 Liquid Phase Contact . . . . . . . . . . . . . . . . . . . . . . . 2.2 Thermal Cracking plus Catalytic Upgrading . . . . . . . . . 2.3 Co-processing of MWP  . . . . . . . . . . . . . . . . . . . . . . 3 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

209 210 210 211 216 221 221

Kinetic Model of the Chemical and Catalytic Recycling of Waste Polyethylene into Fuels . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

225

 Norbert Miskolczi 1 2

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Reaction Kinetics of Degradation . . . . . . . . . . . . . . . . . . . 2.1 Reaction Mechanism  . . . . . . . . . . . . . . . . . . . . . . . . 3 Catalysts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.1 Monofunctional Catalysts  . . . . . . . . . . . . . . . . . . . . . 3.2 Bifunctional Catalysts . . . . . . . . . . . . . . . . . . . . . . . 3.3 Solid Alkalis  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

225 226 228 239 239 241 243 244

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CONTENTS

III

QUALITY OF FUELS 10

Production of Gaseous and Liquid Fuels by Pyrolysis and Gasification of Plastics: Technological Approach . . . . . . . . . . . .

249

251

C. Gis`ele Jung and Andr´  e Fontana 1 2

11

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Literature Review on Plastics Carbonization . . . . . . . . . . . . 2.1 Polyethylene (PE) . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2 Polypropylene (PP)  . . . . . . . . . . . . . . . . . . . . . . . . . 2.3 Polystyrene (PS) . . . . . . . . . . . . . . . . . . . . . . . . . . 2.4 Polyvinyl Chloride (PVC) . . . . . . . . . . . . . . . . . . . . 2.5 Polyethylene Terephthalate (PET) . . . . . . . . . . . . . . . 2.6 Plastic Mixtures  . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Technological Approach . . . . . . . . . . . . . . . . . . . . . . . . . 3.1 Predictive Carbonization Model . . . . . . . . . . . . . . . . . 3.2 Scale-up  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.3 Pyrolysis Technologies . . . . . . . . . . . . . . . . . . . . . . 3.4 Gasification Technologies  . . . . . . . . . . . . . . . . . . . . . 3.5 Fuel Valorization . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

251 254 255 258 262 264 266 267 271 271 272 272 275 278 280

Yield and Composition of Gases and Oils/Waxes from the Feedstock Recycling of Waste Plastic . . . . . . . . . . . . . . . . . . . .

285

Paul T. Williams 1 2

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Feedstock Recycling of Plastics . . . . . . . . . . . . . . . . . . . . . 2.1 Product Yield . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2 Gas Composition . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3 Oil/Wax Composition from the Feedstock Recycling of  Single Plastics  . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Composition of Liquid Fuels Derived from the Pyrolysis of  Plastics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

285 288 288 292 295 309 309

315

 Marianne Blazs´  o 1 2 3

4

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Experimental Methods  . . . . . . . . . . . . . . . . . . . . . . . . . . . Chemical Composition of Pyrolysis Liquids . . . . . . . . . . . . . 3.1 Relation of Major Oil Characteristics and Chemical Features of Component Compounds  . . . . . . . . . . . . . . 3.2 Thermal Decomposition Reactions of Polymers . . . . . . Pyrolysis Products of Packaging Waste Plastics . . . . . . . . . . 4.1 Polyolefins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

315 316 317 317 318 321 322

x

 

13

CONTENTS

4.2 Vinyl Polymers . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.3 Polyesters  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Pyrolysis Products of Automotive Waste Plastics . . . . . . . . . 5.1 Styrene Copolymers . . . . . . . . . . . . . . . . . . . . . . . . 5.2 Rubber Plastics . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.3 Polyamides  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.4 Polyurethanes (PU)  . . . . . . . . . . . . . . . . . . . . . . . . . 6 Pyrolysis Products of Electronic Waste Plastics . . . . . . . . . . 6.1 Polycarbonate . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.2 Epoxy Resin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.3 Phenol– Formaldehyde Resin . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

326 329 329 329 331 333 335 337 338 339 340 341

Production of Premium Oil Products from Waste Plastic by Pyrolysis and Hydroprocessing  . . . . . . . . . . . . . . . . . . . . . . . .

345

S.J. Miller ,  N. Shah and G.P. Huffman 1 2 3 4 5 6 7

Background  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Conversion of Waste Plastics to Transportation Fuels . . . . . . Direct Liquefaction and Co-processing of Waste Plastic  . . . . . Pyrolysis and Hydroprocessing . . . . . . . . . . . . . . . . . . . . . Feasibility Study . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Conversion of Waste Plastic to Lubricating Base Oil  . . . . . . . Lubricating Base Oils from Fischer– Tropsch Wax and Waste Plastic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 One-gallon-per-day Pilot Plant . . . . . . . . . . . . . . . . . . . . . 8.1 Hydroprocessing . . . . . . . . . . . . . . . . . . . . . . . . . . 8.2 Pyrolysis Pilot Plant Results for Various Feedstocks . . . 9 Summary and Conclusions  . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

The Conversion of Waste Plastics/Petroleum Residue Mixtures to Transportation Fuels  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

345 346 346 347 350 351 351 354 355 355 358 360

363

 Mohammad Farhat Ali and Mohammad Nahid Siddiqui 1 2 3 4 5

6 7

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The Characteristics and Chemical Structure of Plastics . . . . . The Characteristics and Chemical Properties of Petroleum Residue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Technologies for Petroleum Residue Upgrading . . . . . . . . . . Technologies for Tertiary Recycling of Mixed Plastic Waste (MPW) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.1 Feedstock Recycling of MPW with Low PVC Content . Coprocessing for Fuel from Mixed Plastic Waste . . . . . . . . . Pyrolysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.1 Reactor Types Used for Pyrolysis . . . . . . . . . . . . . . . 7.2 Chemical Products of Pyrolysis  . . . . . . . . . . . . . . . . .

363 364 365 365 366 367 369 374 375 375

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CONTENTS

8 Environmental Impacts of Recycling of Waste Plastics . . . . . 9 Economic Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . IV

REACTOR TYPES 15

Overview of Commercial Pyrolysis Processes for Waste Plastics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

376 376 378 378 381

383

 John Scheirs 1

2

3

4

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.1 Advantages of Pyrolysis . . . . . . . . . . . . . . . . . . . . . 1.2 Thermal Cracking . . . . . . . . . . . . . . . . . . . . . . . . . . 1.3 Catalytic Cracking . . . . . . . . . . . . . . . . . . . . . . . . . Feedstock Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1 Polyethylene (PE) . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2 Polypropylene (PP)  . . . . . . . . . . . . . . . . . . . . . . . . . 2.3 Polystyrene (PS) Pyrolysis  . . . . . . . . . . . . . . . . . . . . 2.4 PET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.5 PVC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.6 Halogenated Polymers  . . . . . . . . . . . . . . . . . . . . . . . 2.7 Plastic Feedstock Specification . . . . . . . . . . . . . . . . . Operational Considerations  . . . . . . . . . . . . . . . . . . . . . . . . 3.1 Preventing Coking . . . . . . . . . . . . . . . . . . . . . . . . . 3.2 Preventing Corrosion . . . . . . . . . . . . . . . . . . . . . . . . 3.3 Tank/Kettle Reactors  . . . . . . . . . . . . . . . . . . . . . . . . 3.4 Reflux . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.5 Problems with Batch Pyrolysis . . . . . . . . . . . . . . . . . 3.6 Continuous Systems . . . . . . . . . . . . . . . . . . . . . . . . 3.7 Fluidized-bed Processes  . . . . . . . . . . . . . . . . . . . . . . 3.8 Fluid-bed Coking  . . . . . . . . . . . . . . . . . . . . . . . . . . 3.9 Fluid Catalytic Cracking (FCC)  . . . . . . . . . . . . . . . . . 3.10 Catalytic Cracking . . . . . . . . . . . . . . . . . . . . . . . . . Engineering Design Aspects  . . . . . . . . . . . . . . . . . . . . . . . 4.1 Pyrolysis Chamber Design  . . . . . . . . . . . . . . . . . . . . 4.2 Pyrolysis Vessel Construction . . . . . . . . . . . . . . . . . . 4.3 Agitator Speed  . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.4 Burner Characteristics  . . . . . . . . . . . . . . . . . . . . . . . 4.5 Inert Purge Gas . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.6 Distillation Columns  . . . . . . . . . . . . . . . . . . . . . . . . 4.7 Centrifuge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.8 Scrubber  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.9 Dechlorination  . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.10 Hydrotreating . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.11 Catalytic Dewaxing and Isomerization Dewaxing . . . . .

383 385 385 386 386 387 387 388 389 390 391 391 392 392 393 393 393 393 394 394 394 394 394 395 395 396 396 396 396 397 397 397 397 397 398

xii

 

CONTENTS

5

16

Quality of the Output Fuels . . . . . . . . . . . . . . . . . . . . . . . 5.1 Unsaturation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.2 Carbon Residue in the Fuel . . . . . . . . . . . . . . . . . . . 5.3 Low-temperature Properties . . . . . . . . . . . . . . . . . . . 5.4 Fuel Instability . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.5 Diesel Additives  . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.6 Storage Stability of Plastic-derived Diesel Fuel . . . . . . 5.7 Characteristics of the Solid Residue  . . . . . . . . . . . . . . 5.8 Gaseous Emissions  . . . . . . . . . . . . . . . . . . . . . . . . . 6 Catalytic Cracking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.1 Catalyst Activity and Selectivity . . . . . . . . . . . . . . . . 6.2 Layered Clay Catalysts . . . . . . . . . . . . . . . . . . . . . . 6.3 External Catalysts  . . . . . . . . . . . . . . . . . . . . . . . . . . 6.4 PS Catalytic Cracking  . . . . . . . . . . . . . . . . . . . . . . . 6.5 Catalytic Dechlorination . . . . . . . . . . . . . . . . . . . . . 7 Commercial Plastic Pyrolysis Processes . . . . . . . . . . . . . . . 7.1 Thermofuel™ Process . . . . . . . . . . . . . . . . . . . . . . . 7.2 Smuda Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.3 Polymer-Engineering Process (Catalytic Depolymerization) . . . . . . . . . . . . . . . . . . . . . . . . . 7.4 Royco Process  . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.5 Reentech Process . . . . . . . . . . . . . . . . . . . . . . . . . . 7.6 Hitachi Process . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.7 Chiyoda Process  . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.8 Blowdec Process . . . . . . . . . . . . . . . . . . . . . . . . . . 7.9 Conrad Process . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.10 Other Processes with Separate Catalyst Beds  . . . . . . . . 8 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

399 399 399 399 400 401 401 403 403 404 404 405 406 406 407 407 407 414

Fluidized Bed Pyrolysis of Plastic Wastes . . . . . . . . . . . . . . . . .

435

418 422 423 427 429 429 430 431 431 431

Umberto Arena and Maria Laura Mastellone 1

2

3

4

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.1 Fluidized-bed Technology for Waste Thermal Treatments: The Key Role of Hydrodynamics . . . . . . . . . . . . . . . 1.2 From Plastic Waste to Feedstocks and Energy by Means of Fluidized-bed Pyrolysis . . . . . . . . . . . . . . . . . . . . Different Stages in the Fluidized-bed Pyrolysis of a Plastic Waste 2.1 An Overview of Physical and Chemical Phenomena . . . 2.2 The Polymer Degradation Process  . . . . . . . . . . . . . . . Operability Range of Fluidized-bed Pyrolysers  . . . . . . . . . . . 3.1 The Phenomenology of Bed Defluidization . . . . . . . . . 3.2 Predictive Defluidization Models and Operability Maps . The Effect of the Main Process Variables on the Yield and Composition of Pyrolysis Products . . . . . . . . . . . . . . . . . . .

435 435 437 444 444 452 453 453 454 456

 

CONTENTS

17

xiii

4.1 Fluidized-bed Pyrolysis of Monopolymeric Waste  . . . . . 4.2 Fluidized-bed Pyrolysis of Multipolymeric Waste . . . . . 4.3 Fluidized-bed Pyrolysis of Other Polymeric Wastes  . . . . 5 Operating Experience with Industrial Fluidized-bed Pyrolysers 5.1 The BP Chemicals Polymer Cracking Process . . . . . . . 5.2 The Akzo Process . . . . . . . . . . . . . . . . . . . . . . . . . 5.3 The Ebara TwinRec Process  . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

462 464 466 467 467 468 469 471

The Hamburg Fluidized-bed Pyrolysis Process to Recycle Polymer Wastes and Tires . . . . . . . . . . . . . . . . . . . . . . . . . . .

475

Walter Kaminsky

18

1 2

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Pilot Plant Description . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1 Pyrolysis of Whole Tires . . . . . . . . . . . . . . . . . . . . . 3 Pyrolysis Product Composition . . . . . . . . . . . . . . . . . . . . . 3.1 Industrial Pilot Plants . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

475 476 480 482 488 490

Liquefaction of PVC Mixed Plastics . . . . . . . . . . . . . . . . . . . .

493

Thallada Bhaskar and Yusaku Sakata 1 2

3

4

5

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Experimental and Analytical Methods . . . . . . . . . . . . . . . . 2.1 Preparation of Iron and Calcium Composites  . . . . . . . . 2.2 Experimental Procedure  . . . . . . . . . . . . . . . . . . . . . . 2.3 Analysis procedure  . . . . . . . . . . . . . . . . . . . . . . . . . 2.4 HCl Adsorption Capacity  . . . . . . . . . . . . . . . . . . . . . Fundamental Studies on the Decomposition of PVC . . . . . . . 3.1 Product Distribution and Mechanism of PVC Decomposition . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.2 Degradation of PVC – Polymer Mixtures . . . . . . . . . . Liquefaction with Commingled Plastics and Dechlorination . . 4.1 Pyrolysis of PE, PP or PS with PVC . . . . . . . . . . . . . 4.2 Thermal Degradation of PP/PVC by Solid Acid Catalysts and Dechlorination with Iron Oxides . . . . . . . . . . . . . 4.3 Thermal Degradation of PE Mixed with PET  . . . . . . . . 4.4 Laboratory Evaluation of Various Carbon Composites as HCl Sorbents  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.5 Liquefaction of PVC Mixed Plastics and Dechlorination with Ca-C  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.6 Liquefaction of PP/PE/PS/PVC with HIPS-Br and Dehalogenation with Ca-C  . . . . . . . . . . . . . . . . . . . . 4.7 Liquefaction of Real Municipal Waste Plastics  . . . . . . . Pilot Plant Scale Studies for the Liquefaction of PVC Mixed Plastics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

493 496 496 496 497 498 498 498 501 502 502 505 508 509 514 518 521 523

xiv

 

19

CONTENTS

6 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

525 525

Liquid Fuel from Plastic Wastes Using Extrusion– Rotary Kiln Reactors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

531

Sam Behzadi and Mohammed Farid 

20

1 2

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Pyrolysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1 Industrial-scale Pyrolysis Processes . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

531 532 533 547

Rotary Kiln Pyrolysis of Polymers Containing Heteroatoms . . . .

549

 Andreas Hornung and Helmut Seifert  1 2

21

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Technical Variations . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1 Conrad Process . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2 Double Rotary Kiln Pyrolysis  . . . . . . . . . . . . . . . . . . 2.3 Pyrolysis of Tires: Faulkner System  . . . . . . . . . . . . . . 2.4 VTA Pyrolysis: A Rotary Kiln for the Treatment of  Petrochemical Residues and Hydrocarbon Residues  . . . . 3 State of the Art of Rotary Kiln Technology  . . . . . . . . . . . . . 3.1 Haloclean Gas-tight Rotary Kiln . . . . . . . . . . . . . . . . 4 Rotary Kiln Principles  . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Treatment of Thermoplastics: PVC . . . . . . . . . . . . . . . . . . 6 Pyrolysis of Mono Fractions: Polymethylmethacrylate PMMA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Treatment of Shredder Light Fractions/Shredder Residues . . . 8 Treatment of Electronic Scrap . . . . . . . . . . . . . . . . . . . . . . 8.1 The European Dimension  . . . . . . . . . . . . . . . . . . . . . 8.2 The Pyrocom Rotary Kiln . . . . . . . . . . . . . . . . . . . . 8.3 The Haloclean Rotary Kiln Process . . . . . . . . . . . . . . 9 Dehalogenation of Pyrolysis Oils  . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

549 549 550 550 550

Microwave Pyrolysis of Plastic Wastes . . . . . . . . . . . . . . . . . . .

569

551 551 552 553 553 556 557 557 558 558 559 562 564

C. Ludlow-Palafox and H.A. Chase 1 2

3

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Background  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1 Microwave Heating . . . . . . . . . . . . . . . . . . . . . . . . 2.2 Microwave Pyrolysis  . . . . . . . . . . . . . . . . . . . . . . . . Microwave Pyrolysis of Plastics in the Scientific Literature . . 3.1 Microwave Pyrolysis Equipment . . . . . . . . . . . . . . . . 3.2 Results from the Microwave Pyrolysis of Plastics  . . . . . 3.3 Microwave Effect in Microwave Pyrolysis . . . . . . . . .

569 570 570 572 575 575 577 581

CONTENTS

xv

4

Microwave Pyrolysis in the Commercial Literature  . . . . . . . . 4.1 Patents History and Comparison with Scientific Literature 4.2 Companies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

582 582 585 586 587

Continuous Thermal Process for Cracking Polyolefin Wastes to Produce Hydrocarbons . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

595

22

 Jean Dispons 1 2 3 4 5 6 23

Background  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The Two Principal Phases of Polyolefin Waste Cracking . . . . Thermal Valorization of Polyolefin Wastes . . . . . . . . . . . . . Continuous Feeding of the Cracking Reactors . . . . . . . . . . . Heating Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Waste Plastic Pyrolysis in Free-Fall Reactors . . . . . . . . . . . . . .

595 596 597 598 598 599 605

 Ali Y. Bilges¨  u, M. Cetin ¸ Ko¸cak, and Ali Karaduman 1 2 3 4

Pyrolysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Previous Pyrolysis Work  . . . . . . . . . . . . . . . . . . . . . . . . . Design Aspects of FFR to be Used in Pyrolysis  . . . . . . . . . . A Free-Fall Reactor System for Flash Pyrolysis . . . . . . . . . . 4.1 Set-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2 Experimental Procedure  . . . . . . . . . . . . . . . . . . . . . . 5 Plastic Waste Recycling  . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Results from Ateklab Free-Fall Reactor . . . . . . . . . . . . . . . 6.1 LDPE Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.1 Polystyrene Results  . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . V

605 605 609 610 610 611 612 613 613 617 621

MONOMER RECOVERY

625

24

627

Monomer Recovery of Plastic Waste in a Fluidized Bed Process .

Walter Kaminsky 1 2 3

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Fluidized-bed Process . . . . . . . . . . . . . . . . . . . . . . . . . . . Pyrolysis of PMMA . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.1 Pure PMMA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.2 Filled PMMA . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Pyrolysis of Polystyrene . . . . . . . . . . . . . . . . . . . . . . . . . 5 Pyrolysis of PTFE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

627 628 629 629 631 635 635 638 638

xvi

 

25

CONTENTS

Feedstock Recycling of PET  . . . . . . . . . . . . . . . . . . . . . . . . . .

641

Toshiaki Yoshioka and Guido Grause 1 2 3

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Physical Recycling (Mechanical Recycling)  . . . . . . . . . . . . . Solvolysis (Chemolysis) . . . . . . . . . . . . . . . . . . . . . . . . . . 3.1 Glycolysis  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.2 Methanolysis  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.3 Hydrolysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.4 Other Processes . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Pyrolysis and Other Hot Processes  . . . . . . . . . . . . . . . . . . . 4.1 Decomposition Mechanism of PET . . . . . . . . . . . . . . 4.2 Pyrolysis Processes  . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . VI

ASIAN DEVELOPMENTS 26

The Liquefaction of Plastic Containers and Packaging in Japan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

641 643 643 644 644 647 649 649 650 653 659 663

665

 A. Okuwaki, T. Yoshioka, M. Asai, H. Tachibana, K. Wakai, K. Tada 1

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.1 Brief History of Plastics Liquefaction in Japan  . . . . . . . 1.2 The Law for Promotion of Sorted Collection and Recycling of Containers and Packaging . . . . . . . . . . . 1.3 Feedstock Recycling of Plastic Containers and Packaging  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Niigata Waste Plastic Liquefaction Process . . . . . . . . . . . . . 2.1 Plant Outline  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2 Process Description . . . . . . . . . . . . . . . . . . . . . . . . 2.3 Quality of Waste Plastics  . . . . . . . . . . . . . . . . . . . . . 2.4 Properties of Outputs . . . . . . . . . . . . . . . . . . . . . . . 2.5 Material Balance and Consumption Figures  . . . . . . . . . 2.6 Heat Balance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.7 Application of the Outputs  . . . . . . . . . . . . . . . . . . . . 2.8 Environmental Measurement . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Sapporo Waste Plastics Liquefaction Process  . . . . . . . . . . . . 3.1 Plant Outline  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.2 Process Description . . . . . . . . . . . . . . . . . . . . . . . . 3.3 Quality of Waste Plastics  . . . . . . . . . . . . . . . . . . . . . 3.4 Properties of Outputs . . . . . . . . . . . . . . . . . . . . . . . 3.5 Material Balance and Consumption Figures  . . . . . . . . . 3.6 Heat Balance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.7 Application of the Outputs  . . . . . . . . . . . . . . . . . . . .

665 665 666 667 670 670 670 671 673 673 675 675 676 678 678 678 678 680 682 684 687 688 691

 

CONTENTS

27

xvii

3.8 Environmental Aspects . . . . . . . . . . . . . . . . . . . . . . 3.9 Characteristics of the Plant  . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Mikasa Waste Plastic Liquefaction Plant  . . . . . . . . . . . . . . . 4.1 Plant Outline  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2 Process Description . . . . . . . . . . . . . . . . . . . . . . . . 4.3 Quality and Application of Reclaimed Oil  . . . . . . . . . . 4.4 Material Balance . . . . . . . . . . . . . . . . . . . . . . . . . . 4.5 High Energy Collection  . . . . . . . . . . . . . . . . . . . . . . 4.6 Characteristics of the Plant  . . . . . . . . . . . . . . . . . . . . 4.7 Application of the System . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 The Scope of Liquefaction in Japan  . . . . . . . . . . . . . . . . . . 5.1 Present Status of Feedstock Recycling . . . . . . . . . . . . 5.2 Scope for Liquefaction . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

692 693 695 695 695 695 698 698 700 700 702 702 702 702 706 708

Process and Equipment for Conversions of Waste Plastics into Fuels  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

709

 Alka Zadgaonkar  1 2

3

4

5

6

7

8

9

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Pyrolysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.1 Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2 Plastics Suitable for Pyrolysis  . . . . . . . . . . . . . . . . . . Pyrolysis: Mode of Operation and Apparatus  . . . . . . . . . . . . 3.1 Batch Pyrolysis . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.2 Types of Pyrolyzers . . . . . . . . . . . . . . . . . . . . . . . . Pyrolysis: Thermal Cracking/Noncatalytic Cracking . . . . . . . 4.1 Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2 Process Mechanism . . . . . . . . . . . . . . . . . . . . . . . . 4.3 Degradation of Polymers . . . . . . . . . . . . . . . . . . . . . Pyrolysis Catalyst  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.1 Role and Effect of Catalyst . . . . . . . . . . . . . . . . . . . 5.2 Properties of Catalyst . . . . . . . . . . . . . . . . . . . . . . . Pyrolysis: Output Characteristics  . . . . . . . . . . . . . . . . . . . . 6.1 Effect of Temperature on Pyrolysis Products . . . . . . . . 6.2 By-products of Pyrolysis . . . . . . . . . . . . . . . . . . . . . Pyrolysis of Heteroatom Polymers  . . . . . . . . . . . . . . . . . . . 7.1 Pyrolysis of PVC  . . . . . . . . . . . . . . . . . . . . . . . . . . 7.2 Pyrolysis of ABS  . . . . . . . . . . . . . . . . . . . . . . . . . . Refinement of Pyrolysis Output Products . . . . . . . . . . . . . . 8.1 Removal of Unsaturation and Olefinic Products . . . . . . 8.2 Various Examples of Pyrolysis . . . . . . . . . . . . . . . . . 8.3 Comparison of Pyrolysis of PE and PP  . . . . . . . . . . . . Recently Developed Innovative Technologies  . . . . . . . . . . . .

709 709 709 710 710 710 711 712 712 713 713 715 715 716 719 719 719 720 720 721 721 721 722 724 724

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9.1 9.2

28

CONTENTS

Thermofuel of Waste Plastic by Ozmotech . . . . . . . . . Conversion of Waste Plastics to Fuels: Zadgaonkar’s Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

724

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

724 728

Converting Waste Plastics into Liquid Fuel by Pyrolysis: Developments in China . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

729

Yuan Xingzhong 1

Progress in Converting Waste Plastics into Liquid Fuel by Pyrolysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Theory of Plastics Pyrolysis  . . . . . . . . . . . . . . . . . . . . . . . 2.1 Mass Balance for the Pyrolysis Process . . . . . . . . . . . 2.2 Energy Balance for the Pyrolysis Process . . . . . . . . . . 2.3 Mechanism of Plastics Pyrolysis . . . . . . . . . . . . . . . . 2.4 Methods for Plastics Pyrolysis . . . . . . . . . . . . . . . . . 3 Process of Plastics Pyrolysis  . . . . . . . . . . . . . . . . . . . . . . . 3.1 Veba Process  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.2 BP Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.3 Fuji Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.4 BASF Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.5 Hamburg University Process  . . . . . . . . . . . . . . . . . . . 3.6 Hunan University Process . . . . . . . . . . . . . . . . . . . . 3.7 United Carbon Process . . . . . . . . . . . . . . . . . . . . . . 3.8 Likun Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.9 Other Processes . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Main Factors in Plastics Pyrolysis  . . . . . . . . . . . . . . . . . . . 4.1 Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2 Catalyst . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Pyrolysis of PVC  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Catalytic Reforming of Cracked Gas . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

729 730 730 732 734 735 738 738 738 741 741 741 742 743 743 744 744 744 746 747 748 750 757

Contributors Jos´e Aguado, Rey Juan Carlos University, ESCET, c/Tulip´an s/n, 28933 M´ostoles, Spain Mohammad Farhat Ali, Department of Chemistry, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia Umberto Arena, Department of Environmental Sciences, University of Naples II, Via Vivaldi 43, 81100 Caserta, Italy Masao Asai, Rekisei Kouyu Co. Ltd, Niigata Plastic Liquefaction Center, 3-1 Heiwa, Niigata, Japan Sam Behzadi, Department of Chemical and Materials Engineering, The University of Auckland, Private Bag 92019, Auckland, New Zealand

Thallada Bhaskar, Yusaku Sakata Laboratory, Department of Applied Chemistry, Faculty of Engineering, Okayama University, 3-1-1 Tsushima Naka, 700–8530 Okayama, Japan Ali Y. Bilges¨u, Chemical Engineering Department, Engineering Faculty, Ankara University, Tando an 06100 Ankara, LK, Turkey M. Blazs´o, Institute of Materials and Environmental Chemistry, Chemical Research Center Hungarian Academy of Sciences, Pf. 17, H-1525 Budapest, Pusztaszeri u´t 58–67, H-1025 Budapest, Hungary Alfons Buekens, Vrije Universiteit Brussel (V.U.B.), Domstraat 7, 1602 Vlezenbeek, Belgium H.A. Chase, Department of Chemical Engineering, University of Cambridge, New Museums Site,

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CONTRIBUTORS

Pembroke Street, Cambridge CB2 3RA, UK

P.O. Box 3640, 76021 Karlsruhe, Germany

Jean Dispons, Chemical Engineering Adviser France

G.P. Huffman, University of Kentucky, Consortium for Fossil Fuel Science, 107 Whalen Building, 533 S. Limestone St, Lexington, KY 40506-0043, USA

J.M. Escola, Rey Juan Carlos University, ESCET, c/Tulip´an s/n, 28933 M´ostoles, Spain Mohammed Farid, Department of Chemical and Materials Engineering The University of Auckland, Private Bag 92019, Auckland, New Zealand

C. Gis`ele Jung, Chercheur de l’Universit´e, Universit´e Libre de Bruxelles, Solvay Business School – Centre Emile Bernheim, Service de Chimie Industrielle, 50, Av.F.D.Roosevelt, CP165/63, 1050 Bruxelles, Belgium

Andr´e Fontana, Universit´e Libre de Bruxelles, Solvay Business School – Centre Emile Bernheim, 50, Av. F.D. Roosevelt, CP 145/1, 1050 Brussel, Belgium

Walter Kaminsky, Institute for Technical and Macromolecular Chemistry, University of Hamburg, Bundesstr. 45, 20146 Hamburg, Germany

Guido Grause, Laboratory for Chemical Process Engineering, Materials Process Engineering, Division of Materials Science and Engineering, Graduate School of Engineering, Hokkaido University, N13 W8 Kita-ku, Sapporo 060–8628, Japan

Ali Karaduman, Ankara University, Engineering Faculty, Chemical Engineering Department, Tando an 06100 Ankara, LK, Turkey

Andreas Hornung, Forschungszentrum Karlsruhe GmbH, Institut f u¨ r Technische Chemie, Thermische Abfallbehandlung – ITC-TAB, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen,

Kyong-Hwan Lee, Clean Energy Research Department, Korea Institute of Energy Research (KIER), 71-2 Jang dong, Yusong ku, Daejeon 305–343, Korea

Cetin ¸ Ko¸cak  Ankara University, Engineering Faculty, Chemical Engineering Department, Tando an 06100 Ankara, Turkey

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CONTRIBUTORS

Carlos Ludlow-Palafox, Department of Chemical Engineering, University of Cambridge, New Museums Site, Pembroke Street, Cambridge CB2 3RA, UK George Manos, Department of Chemical Engineering, University College London, Torrington Place, London WC1E 7JE, UK Maria Laura Mastellone, Department of Environmental Sciences, University of Naples II, Via Vivaldi 43, 81100 Caserta, Italy Takao Masuda, Laboratory for Chemical Process Engineering, Materials Process Engineering, Division of Materials Science and Engineering, Graduate School of Engineering, Hokkaido University, N13 W8 Kita-ku, Sapporo 060–8628, Japan S.J. Miller, Chevron Texaco, 100 Chevron Way, Richmond, CA 94802, USA Norbert Miskolczi, University of Veszpr´em, Department of Hydrocarbon and Coal Processing, Egyetem u. 10, Veszprem, H-8200, Hungary Akitsugu Okuwaki, Tohoku University,

31-9 Hagurodai, Taihaku-ku, Sendai 982-0817, Japan Yusaku Sakata, Department of Applied Chemistry, Faculty of Engineering, Okayama University, 700–8530 Okayama, Japan John Scheirs, ExcelPlas Polymer Technology, PO Box 2080, Edithvale, VIC 3196, Australia Helmut Seifert, ITC-TAB, Forschungszentrum Karlsruhe Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany D.P. Serrano, Rey Juan Carlos University, ESCET, c/Tulip´an s/n, M´ostoles, Spain N. Shah, University of Kentucky, Consortium for Fossil Fuel Liquefaction, 107 Whalen Building, 533 S. Limestone st, Lexington, KY 40506–0043, USA Mohammad Nahid Siddiqui, Department of Chemistry, King Fahd University of Petroleum and Minerals, KFUPM, Dhahran 31261, Saudi Arabia

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Hideaki Tachibana, 2879-52 Kikuma, Ichihara, Chiba 290-0007, Japan Kazuhiko Tada, Kubota Corporation, 3-1-3 Muromachi, Nihonbashi, Chuo-ku, Tokyo 103–8310, Japan Teruoki Tago, Division of Materials Science and Engineering, Graduate School of Engineering, Hokkaido University, N13 W8 Kita-Ku, Sapporo 060–8628, Japan Keiji Wakai, Sapporo Plastics Recycling Co. Ltd, 45– 57 Nakanuma-chou, Higashi-Ku, Sapporo 007–0890, Japan Jerzy Walendziewski, Institute of Chemistry and Technology of  Petroleum and Coal, Technical University of Wroclaw, ul. Gda´nska 7/9, 50–344 Wroclaw, Poland Robert L. White, Department of Chemistry and Biochemistry, University of Oklahoma, Norman, OK 73019, USA

CONTRIBUTORS

Paul T. Williams, Energy and Resources Research Institute, Houldsworth Building, The University of Leeds, Leeds LS2 9JT, UK Yuan Xingzhong, Department of Environmental Science and Engineering, Hunan University, Changsha, Hunan Province, 410082, P.R. China Jale Yanik, Ege University, Faculty of Science, Chemistry Department, 35100 Bornova/Izmir, Turkey Toshiaki Yoshioka, Graduate School of Environmental Studies, Tohoku University, Aramaki Aza Aoba 6-6-07, Aoba-ku, Sendai 980–8579, Japan Alka Zadgaonkar, Department of Applied Chemistry, G.H. Raisoni College of Engineering, 9 Buty Layout, RPTS Road, Laxmi Nagar, Nagpur 440016, India

Series Preface The Wiley Series in Polymer Science aims to cover topics in polymer science where significant advances have been made over the past decade. Key features of the series will be developing areas and new frontiers in polymer science and technology. Emerging fields with strong growth potential for the twenty-first century such as nanotechnology, photopolymers, electro-optic polymers will be covered. Additionally, those polymer classes in which important new members have appeared in recent years will be revisited to provide a comprehensive update. Written by foremost experts in the field from industry and academia, these books have particular emphasis on structure–property relationships of polymers and manufacturing technologies as well as their practical and novel applications. The aim of each book in the series is to provide readers with an in-depth treatment of the state-of-the-art in that field of polymer technology. Collectively, the series will provide a definitive library of  the latest advances in the major polymer families as well as significant new fields of  development in polymer science. This approach will lead to a better understanding and improve the cross-fertilization of  ideas between scientists and engineers of many disciplines. The series will be of interest to all polymer scientists and engineers, providing excellent up-to-date coverage of diverse topics in polymer science, and thus will serve as an invaluable ongoing reference collection for any technical library. John Scheirs June 1997

Preface This book covers thermal and catalytic pyrolysis processes that produce liquid fuels (or other useful chemicals) from waste plastics. The book provides a comprehensive overview of the main commercial plastics pyrolysis processes, the types of plastics that can be processed, the properties of the respective fuels produced and the key variables influencing the pyrolysis of plastics such as temperature, residence time, pressure and catalyst types. Only some 15–20% of all waste plastics can be effectively recycled by conventional mechanical recycling technologies (i.e. sort/grind/wash/extrusion). Beyond this level the plastics become increasingly commingled and contaminated with extraneous materials such as soil, dirt, aluminium foils, paper labels and food remnants. Pyrolysis is a tertiary or feedstock recycling technique capable of converting plastic waste into fuels, monomers, or other valuable materials by thermal and catalytic cracking processes. This method can be applied to transform both thermoplastics and thermosets in high-quality fuels and chemicals. Moreover it allows the treatment of mixed, unwashed plastic wastes. In its simplest definition pyrolysis is the degradation of polymers at high temperatures under nonoxidative conditions to yield valuable products (e.g. fuels and oils). Pyrolysis is also referred to as polymer cracking and its main advantages are that 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. Pyrolysis recycling of mixed plastics thus has great potential for heterogenous plastic waste that cannot be economically separated. This book provides an overview of the science and technology of pyrolysis of waste plastics. The book will describe the types of plastics that are suitable for pyrolysis recycling, the mechanism of pyrolytic degradation of various plastics, characterization of the pyrolysis products and details of commercially mature pyrolysis technologies. 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. Other normally hard to recycle plastics such as laminates of incompatible polymers, multilayer films or polymer mixtures can also be processed with ease,

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PREFACE

unlike in conventional plastic recycling techniques. In fact, most plastics can be processed directly, even if contaminated with dirt, aluminium laminates, printing inks, oil residues, etc. The production of gasoline, kerosene and diesel from waste plastics is an emerging technological solution to the vast amount of plastics that cannot be economically recovered by conventional mechanical recycling. Pyrolysis recycling of mixed waste plastics into generator and transportation fuels is seen by many as the answer for recovering value from unwashed, commingled plastics and achieving their desired diversion from landfill. Pyrolytic recycling of plastic wastes has already been achieved on commercial scale albeit to a limited extent. Nevertheless, the development and improvement of the pyrolysis plastics recycling technologies in recent years has great commercial potential. The development of bench-scale experiments carried out in laboratories to full-scale pyrolysis processes have now resulted in a number of  technically mature processes. Through the use of low-temperature vacuum pyrolysis and cracking catalysts, liquid fuels yield of up to 80% are possible with the resultant product resembling diesel fuel, kerosene, gasoline or other useful hydrocarbon liquids. There are now emerging a number of processes which will take post-consumer plastics and catalytically convert them into gasoline and low-sulfur diesel fuel. The diesel fuel meets or exceeds both European and Federal EPA standards for emissions and is designed specifically for the solid waste disposal industry that has significant investment in diesel-powered equipment. The types of plastic targeted as feedstock for this project have no commercial value and would otherwise be sent to landfill. High-temperature pyrolysis and cracking of waste thermoplastic polymers, such as polyethylene, polypropylene and polystyrene is an environmentally acceptable method of  recycling. These type of processes embrace both thermal pyrolysis and cracking, catalytic cracking and hydrocracking in the presence of hydrogen. Mainly polyethylene, polypropylene and polystyrene are used as the feedstock for pyrolysis since they have no heteroatom content and the liquid products are theoretically free of sulfur. The principal output products are gaseous and liquid hydrocarbon fractions that are remarkably similar to the refinery cracking products. Their chemical composition and properties strongly depend on the input feed composition, (i.e. proportion of polyethylene, polypropylene and polystyrene in the feedstock) and they can also be unstable due to their high reactive olefins content (especially from polyethylene and polystyrene cracking). The book also explores the application of various acidic catalysts, such as silica– alumina, zeolites (HY, HZSM-5, mordenite) or alkaline compounds such as zinc oxide. However, the main problem with catalytic cracking is that in the course of the cracking process all catalysts deactivate very quickly. Expensive zeolite catalysts increase the cost of waste plastics cracking process to the point where it becomes economically unacceptable since the catalyst becomes contained in coke residue and therefore cannot be recovered and regenerated. Effective engineering design of the cracking reactor for waste plastic processing is very important since the carbonaceous solid residue is one of the cracking products (levels up to 10% or more) and its continuous removal from the reactor is necessary to ensure profitable running. Stirred vessel reactors which have augers in the bases to facilitate continuous char removal are presented.

PREFACE

 

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This book is truely international in scope with contributing authors from Spain, Saudi Arabia, Italy, New Zealand, Japan, Turkey, Hungary, Poland, Belgium, France, Germany, Korea, UK, USA, India, China and Australia. John Scheirs Walter Kaminsky 8 August, 2005

About the Editors Dr John Scheirs is a polymer research specialist with an emphasis on plastic recycling and pyrolysis of waste plastics into fuels. He serves as a consultant for Ozmotech Australia and has worked on the development of their Thermofuel process which can convert unwashed mixed plastics into low-sulfur diesel transportation fuel. He has studied the pyrolysis of  HDPE, PP, PET and engineering plastics. John Scheirs is the author of the leading book on plastics recycling entitled   Polymer   Recycling: Science, Technology and Applications   published by John Wiley & Sons Ltd, Chichester in 1998. He is also a member of the editorial board of the international journal Polymer Degradation and Stabilization, Elsevier Scientific, Netherlands. John Scheirs is now the principal consultant with ExcelPlas Polymer Technology where he specializes in polymer recycling, polymer degradation, polymer processing and testing. Professor Walter Kaminsky   was born 1941 in Hamburg and studied chemistry at the University of Hamburg. His thesis was in the field of metallocene chemistry and his habilitation in the field of recycling of polymers by pyrolysis. Since 1979, he has occupied the role of Full Professor of Technical and Macromolecular Chemistry at the University of Hamburg. He is currently supervising a group of 15 students and scientists in the field of pyrolysis of plastic waste in a fluidized bed process and a group in the field of metallocene/methylaluminoxane chemistry. His past experience includes the development of  pilot plants for the feedstock recycling of plastic wastes and scrap tires, and discovering highly active metallocene catalysts for the polymerization of olefins. He has published more than 300 papers and books and holds 20 patents. He has organized several international symposia in the field of pyrolysis and olefin polymerization. In 1987 he received, together with Hansj o¨ rg Sinn, the European Research Prize for the development of the Hamburg process for pyrolysis of polymers. In 1997 he received the Carothers Award of the American Chemical Society (Delaware Section), and in the same year the Walter Ahlstr o¨ m Prize in Helsinki, Finland. Since 1998 he has been an Honorary Member of the Royal Society of Chemistry in London, and Honorary Professor of the Zhejiang University in China. In 1999 he received the Benjamin Franklin Medal for Chemistry, Philadelphia and in 2003 the Hermann Staudinger Prize of the German Chemical Society (GDCh).