Polyolefin Reaction Engineering E-Book

Joao B. P. Soares

• Herausgeber: Wiley-VCH
• Kategorie: Wissenschaft und neue Technologien
• Sprache: Englisch

Seitenzahl: 504

Veröffentlichungsjahr: 2013

Beschreibung

Monomers composed of carbon and hydrogen atoms are the simple building blocks that make up polyolefins - molecules which are extremely
useful and which have an extraordinary range of properties and applications. How these monomer molecules are connected in the polymer chain defines the molecular architecture of polyolefins.

Written by two world-renowned authors pooling their experience from industry and academia, this book adopts a unique engineering approach
using elegant mathematical modeling techniques to relate polymerization conditions, reactor and catalyst type to polyolefin properties.
Readers thus learn how to design and optimize polymerization conditions to produce polyolefins with a given microstructure, and how different
types of reactors and processes are used to create the different products.

Aimed at polymer chemists, plastics technologists, process engineers,the plastics industry, chemical engineers, materials scientists, and company libraries.

Leseprobe

Table of Contents

Related Titles

Title Page

Copyright

Dedication

Acknowledgments

Preface

Nomenclature

Acronyms

Symbols

Greek Letters

Superscripts and Subscripts

Chapter 1: Introduction to Polyolefins

1.1 Introduction

1.2 Polyethylene Resins

1.3 Polypropylene Resins

Further Reading

Chapter 2: Polyolefin Microstructural Characterization

2.1 Introduction

2.2 Molecular Weight Distribution

2.3 Chemical Composition Distribution

2.4 Cross-Fractionation Techniques

2.5 Long-Chain Branching

Further Reading

Chapter 3: Polymerization Catalysis and Mechanism

3.1 Introduction

3.2 Catalyst Types

3.3 Supporting Single-Site Catalysts

3.4 Polymerization Mechanism with Coordination Catalysts

Further Reading

Chapter 4: Polyolefin Reactors and Processes

4.1 Introduction

4.2 Reactor Configurations and Design

4.3 Olefin Polymerization Processes

4.4 Conclusion

References

Further Reading

Chapter 5: Polymerization Kinetics

5.1 Introduction

5.2 Fundamental Model for Polymerization Kinetics

5.3 Nonstandard Polymerization Kinetics Models

5.4 Vapor-Liquid-Solid Equilibrium Considerations

Further Reading

Chapter 6: Polyolefin Microstructural Modeling

6.1 Introduction

6.2 Instantaneous Distributions

6.3 Monte Carlo Simulation

Further Reading

Chapter 7: Particle Growth and Single Particle Modeling

7.1 Introduction

7.2 Particle Fragmentation and Growth

7.3 Single Particle Models

7.4 Limitations of the PFM/MGM Approach: Particle Morphology

References

Further Reading

Chapter 8: Developing Models for Industrial Reactors

8.1 Introduction

References

Further Reading

Index

Epilogue

Isayev, A. I. (ed.)

Encyclopedia of Polymer Blends

Volume 2: Processing

Series: Encyclopedia of Polymer Blends 2011

ISBN: 978-3-527-31930-5

Isayev, A. I. (ed.)

Encyclopedia of Polymer Blends

Volume 1: Fundamentals

Series: Encyclopedia of Polymer Blends 2010

ISBN: 978-3-527-31929-9

Xanthos, M. (ed.)

Functional Fillers for Plastics

Second, Updated and Enlarged Edition

2010

ISBN: 978-3-527-32361-6

Elias, H.-G.

Macromolecules

Series: Macromolecules (Volumes 1–4)

2009

ISBN: 978-3-527-31171-2

Matyjaszewski, K., Gnanou, Y., Leibler, L. (eds.)

Macromolecular Engineering

Precise Synthesis, Materials Properties, Applications

2007

ISBN: 978-3-527-31446-1

Meyer, T., Keurentjes, J. (eds.)

Handbook of Polymer Reaction Engineering

2005

ISBN: 978-3-527-31014-2

Severn, J. R., Chadwick, J. C. (eds.)

Tailor-Made Polymers

Via Immobilization of Alpha-Olefin Polymerization Catalysts

2008

ISBN: 978-527-31782-0

Asua, J. (ed.)

Polymer Reaction Engineering

2007

ISBN: 978-4051-4442-1

The Authors

Prof. Dr. João B. P. Soares

University of Waterloo

Department of Chemical Engineering

University Avenue West 200

Waterloo, ON N2L 3G1

Canada

Prof. Dr. Timothy F. L. McKenna

C2P2 UMR 5265

ESCPE Lyon, Bat 308F

43 Blvd du 11 Novembre 1918

69616 Villeurbanne Cedex

France

All books published by Wiley-VCH are carefully produced. Nevertheless, authors, editors, and publisher do not warrant the information contained in these books, including this book, to be free of errors. Readers are advised to keep in mind that statements, data, illustrations, procedural details or other items may inadvertently be inaccurate.

Library of Congress Card No.: applied for

British Library Cataloguing-in-Publication Data

A catalogue record for this book is available from the British Library.

Bibliographic information published by the Deutsche Nationalbibliothek

The Deutsche Nationalbibliothek lists this publication in the Deutsche Nationalbibliografie; detailed bibliographic data are available on the Internet at <http://dnb.d-nb.de>.

© 2012 Wiley-VCH Verlag & Co. KGaA, Boschstr. 12, 69469 Weinheim, Germany

All rights reserved (including those of translation into other languages). No part of this book may be reproduced in any form — by photoprinting, microfilm, or any other means — nor transmitted or translated into a machine language without written permission from the publishers. Registered names, trademarks, etc. used in this book, even when not specifically marked as such, are not to be considered unprotected by law.

Print ISBN: 978-3-527-31710-3

ePDF ISBN: 978-3-527-64697-5

ePub ISBN: 978-3-527-64696-8

mobi ISBN: 978-3-527-64695-1

oBook ISBN: 978-3-527-64694-4

To our wives, Maria Soares and SalimaBoutti-McKenna, for their love, dedication, and patience while we wrote this book, not to mention the interminably long hours we spent discussing polyolefins in their presence. This book belongs to both of you, but you don't need to read it – you have heard all about it already.

João Soares and Timothy McKenna

Acknowledgments

Personally I'm always ready to learn, although I do not always like being taught.

Sir Winston Churchill (1874–1965)

Several of the concepts covered in this book arose from our daily interactions with students and colleagues in academia and industry. They are too many to be named individually here, but we would like to express our sincere gratitude to their outstanding contributions that are summarized in this work. We did like being thought by all of you.

First, we would like to thank our former mentors, who trusted and guided us when we were starting our careers, and kept encouraging us throughout these years. Their mentoring, support, and friendship are greatly appreciated.

This book could not have been written without the dedication of our graduate students, post-doctoral fellows, and research assistants, who toiled day after day in our laboratories to propose and test hypotheses, challenge us with unexpected new results, and in the process advance our understanding of polyolefin reaction engineering. Several of their results are interspersed throughout this book and constitute main contributions to the field of olefin polymerization science and engineering. We are very thankful to their hard work, perseverance, and confidence in us as their supervisors.

We would also like to thank our academic and industrial collaborators who over the years helped us better understand olefin polymerization and polyolefin characterization, often kindly allowing us to use their laboratory facilities (for free!) to complement the work done in our institutions. We are indeed indebted to these extraordinary colleagues and look forward to continue working with them in the future.

Finally, we would like to thank the polyolefin companies all over the world that have hired us as consultants and instructors of our industrial short course on Polyolefin Reaction Engineering. This book is a result, in large part, from the stimulating discussions we had with the scientists and engineers who took these courses. If it is true, as said by Scott Adams, the creator of the comic strip Dilbert, that “Give a man a fish, and you'll feed him for a day. Teach a man to fish, and he'll buy a funny hat. Talk to a hungry man about fish, and you're a consultant”, then we hope that talking to the course participants over these years has at least stimulated them to look deeper into the vast sea of polyolefin reaction engineering.

Preface

It is the mark of an instructed mind to rest satisfied with the degree of precision which the nature of the subject permits and not to seek exactness where only an approximation of the truth is possible.

Aristotle (384–322 BC)

The art of being wise is the art of knowing what to overlook.

William James (1842–1910)

The manufacture of polyolefins with coordination catalysts has been a leading force in the synthetic plastic industry since the early 1960s. Owing to the constant developments in catalysis, polymerization processes, and polyolefin characterization instruments, it continues to be a vibrant area of research and development today.

We have been working in this area for over 15 years, always feeling that there was a need for a book that summarized the most important aspects of polyolefin reaction engineering. This book reflects our views on this important industry. It grew out of interactions with the polyolefin industry through consulting activities and short courses, where we first detected a clear need to summarize, in one single source, the most generally accepted theories in olefin polymerization kinetics, catalysis, particle growth, and polyolefin characterization.

As quoted from Aristotle above, we will rest satisfied with the degree of precision which the nature of the subject permits and hope that our readers agree with us that this is indeed the mark of an instructed mind. It was not our intention to perform an extensive scholarly review of the literature for each of the topics covered in this book. We felt that this approach would lead to a long and tedious text that would become quickly outdated; several excellent reviews summarizing the most recent findings on polyolefin manufacturing and characterization are published regularly and are more adequate for this purpose. Instead, we present our interpretation of the field of polyolefin reaction engineering. Since any selection process is always subjective, we may have left out some approaches considered to be relevant by others, but we tried to be as encompassing as possible, considering the limitations of a book of this type. We have also sparsely used references in the main body of the chapters but added reference sections at their end where we discussed some alternative theories, presented exceptions to the general approach followed in the chapters, and suggested additional readings. The reference sections are not meant to be exhaustive compilations of the literature but sources of supplemental readings and a door to the vast literature in the area. We hope this approach will make this book a pleasant reading and also provide the reader with additional sources of reference.

Chapter 1 introduces the field of polyolefins, with an overview on polyolefin types, catalyst systems, and reactor configurations. We also introduce our general philosophy of using mathematical models to link polymerization kinetics, mass and heat transfer processes at several length scales, and polymer microstructure characterization for a complete understanding of olefin polymerization processes.

We discuss polyolefin microstructure, as defined by their distributions of molecular weight, chemical composition, stereo- and regioregularity, and long-chain branching, in Chapter 2. It is not an overstatement to say that among all synthetic polymers, polyolefins are the ones where microstructure control is the most important concern. Polyolefin microstructure is a constant theme in all chapters of this book and is our best guide to understanding catalysis, kinetics, mass and heat transfer resistances, and reactor behavior.

Chapter 3 is dedicated to polymerization catalysis and mechanisms. The field of coordination catalysis is huge and, undoubtedly, the main driving force behind innovation in the polyolefin manufacturing industry; to give it proper treatment, a separate book would be necessary. Rather, we decided to focus on the most salient aspects of the several classes of olefin catalysts, their general behavior patterns and mechanisms, and how they can be related to polymerization kinetics and polyolefin microstructural properties.

The subject of Chapter 4, polymerization reactors, is particularly dear to us, polymer reactor engineers. In fact, polyolefin manufacturing is a “dream come true” for polymer reactor engineers because practically all possible configurations of chemical reactors can be encountered. A great deal of creativity went into reactor design, heat removal strategies, series and parallel reactor arrangements, and cost reduction schemes of polyolefin reactors. We start the chapter by discussing reactor configurations used in olefin polymerization and then continue with a description of the leading processes for polyethylene and polypropylene production.

Chapter 5 is the first chapter dedicated to the mathematical modeling of olefin polymerization. We start our derivations with what we like to call the fundamental model for olefin polymerization kinetics and develop, from basic principles, its most general expressions for the rates of catalyst activation, polymerization, and catalyst deactivation. The fundamental model, albeit widely used, does not account for several phenomena encountered in olefin polymerization; therefore, some alternative polymerization kinetic schemes are discussed at the end of this chapter.

In Chapter 6, we develop mathematical models to describe the microstructure of polyolefins. This is one of the core chapters of the book and helps connect polymerization kinetics, catalysis, and mass and heat transfer resistances to final polymer performance. We opted to keep the mathematical treatment as simple as possible, without compromising the most relevant aspects of this important subject.

Particle fragmentation and growth are covered in Chapter 7. These models are collectively called single particle models and can be subdivided into polymer growth models and morphology development models. The two most well-established particle growth models are the polymeric flow model and the multigrain model. These models are used to describe heat and mass transfer in the polymeric particle after fragmentation takes place. The fragmentation of the catalyst particles themselves (described with morphology development models) is much harder to model, and there is still no well-accepted quantitative model to tackle this important subject. We review the main modeling alternatives in this field.

Finally, Chapter 8 is dedicated to macroscopic reactor modeling. This chapter is, in a way, the most conventional chapter from the chemical engineering point of view, since it involves well-known concepts of reactor residence time distribution, micromixing and macromixing, and reactor heat removal issues. The combination of macroscopic reactor models, single particle models, detailed polymerization kinetics, and polymer microstructural distributions, however, is very challenging and represents the ultimate goal of polyolefin reactor engineers.

Nomenclature

What's in a name? William Shakespeare (1564–1616)

Acronyms

CCD chemical composition distribution

CEF crystallization elution fractionation

CFC cross-fractionation

CGC constrained geometry catalyst

CLD chain length distribution

CRYSTAF crystallization analysis fractionation

CSLD comonomer sequence length distribution

CSTR continuous stirred tank reactor

CXRT computed X-ray tomography

DEAC diethyl aluminum chloride

DIBP di-iso-butylphthalate

DSC differential scanning calorimetry

EAO ethylaluminoxane

EB ethyl benzoate

EDX energy dispersive X-ray spectroscopy

EGMBE ethylene glycol monobutylether

ELSD evaporative light scattering detector

EPDM ethylene-propylene-diene monomer rubber

EPR ethylene–propylene rubber

FBR fluidized bed reactor

FFF field flow fractionation

FTIR Fourier-transform infrared

GPC gel permeation chromatography

HDPE high-density polyethylene

HMDS hexamethyldisilazine

HPLC high-performance liquid chromatography

HSBR horizontal stirred bed reactor

IR infrared

LALLS low-angle laser light scattering

LCB long-chain branch

LDPE low-density polyethylene

LLDPE linear low-density polyethylene

LS light scattering

MALLS multiangle laser light scattering

MAO methylaluminoxane

MDPE medium-density polyethylene

MFI melt flow index

MFR melt flow rate

MGM multigrain model

MI melt index

MWD molecular weight distribution

MZCR multizone circulating reactor

NMR nuclear magnetic resonance

NPTMS n-propyltrimethoxysilane

ODCB orthodichlorobenzene

PDI polydispersity index

PFM polymer flow model

PFR plug flow reactor

PP polypropylene

PSD particle size distribution

RND random number generated in the interval [0,1]

RTD residence time distribution

SCB short-chain branch

SEC size exclusion chromatography

SEM scanning electron microscopy

SLD sequence length distribution

SPM single particle model

tBAO t-butylaluminoxane

TCB tricholorobenzene

TEA triethyl aluminum

TEM transmission electron microscopy

TGIC temperature gradient interaction chromatography

TMA trimethyl aluminum

TOF turnover frequency

TREF temperature rising elution fractionation

UHMWPE ultrahigh-molecular weight polyethylene

ULDPE ultralow-density polyethylene

VLDPE very low-density polyethylene

VISC viscometer

VSBR vertical stirred bed reactor

Symbols

Greek Letters

Superscripts and Subscripts

Chapter 1

Introduction to Polyolefins

It is a near perfect molecule […].

Jim Pritchard, Phillips Petroleum Company

1.1 Introduction

Polyolefins are used in a wide variety of applications, including grocery bags, containers, toys, adhesives, home appliances, engineering plastics, automotive parts, medical applications, and prosthetic implants. They can be either amorphous or highly crystalline, and they behave as thermoplastics, thermoplastic elastomers, or thermosets.

Despite their usefulness, polyolefins are made of monomers composed of only carbon and hydrogen atoms. We are so used to these remarkable polymers that we do not stop and ask how materials made out of such simple units achieve this extraordinary range of properties and applications. The answer to this question lies in how the monomer molecules are connected in the polymer chain to define the molecular architecture of polyolefins. By simply manipulating how ethylene, propylene, and higher α-olefins are bound in the polymer chain, polyolefins with entirely new properties can be produced.

Polyolefins can be divided into two main types, polyethylene and polypropylene, which are subdivided into several grades for different applications, as discussed later in this chapter. Taking a somewhat simplistic view, three components are needed to make a polyolefin: monomer/comonomer, catalyst/initiator system, and polymerization reactor. We will start our discussion by taking a brief look at each of these three components.