Preface

VI Contents

**Part 2 Recycling of Tires, Pharmaceutical** 

Chapter 8 **Recycling of Scrap Tires 195**  Ahmet Turer

Uladzimir Kalitko

Chapter 10 **Study on the Feasibility** 

Chapter 12 **Reuse of Waste Shells**

Yu-Chu Peng

Chapter 14 **Possible Uses of Steelmaking** 

**Packaging and Hardwood Kraft Pulp 193** 

Chapter 9 **Waste Tire Pyrolysis Recycling with Steaming: Heat-Mass Balances & Engineering Solutions for By-Products Quality 213** 

**of Hazardous Waste Recycling:** 

Chapter 11 **Recycling of the Hardwood Kraft Pulp 265**  Jarmila Geffertová and Anton Geffert

**Part 3 Potential Uses of Recycled Wastes 299**

**as a SO2/NOx Removal Sorbent 301**

Kyung-Seun Yoo and Byung-Hyun Shon

**Slag in Agriculture: An Overview 335** Teresa Annunziata Branca and Valentina Colla

Gity Mir Mohamad Sadeghi and Mahsa Sayaf

**Composting Process and Soil Amendment 391** 

Chapter 15 **From PET Waste to Novel Polyurethanes 357**

Hafedh Rigane and Khaled Medhioub

Chapter 13 **Carbon Steel Slag as Cementitious** 

Chapter 16 **Valorization of Organic Wastes by** 

Jong-Hyeon Jung, Jae-Jeong Lee, Gang-Woo Lee,

**Material for Self-Consolidating Concrete 323** 

Vincenzo Gente and Floriana La Marca

**The Case of Pharmaceutical Packaging 237**

If the 20th century could be characterized by the rapid increase in the production and consumption of materials that helped improving the standards of living, then the 21st certainly has many elements to qualify as the century of recycling. Since the duration of life of a number of wastes is very small (roughly 40% have duration of life smaller than one month), there is a vast waste stream that reaches each year to the final recipients creating a serious environmental problem. The presently most common practice of handling such waste streams is to incinerate them with energy recovery or to use them for land-filling. Disposing of the waste to landfill is becoming undesirable due to legislation pressures, rising costs and the poor biodegradability of commonly used materials. Therefore, recycling seems to be the best solution. The major driving force in today's recycling project is not only to re-use the materials but also to produce secondary value-added products, reducing the consumption of natural resources and the amount of energy needed, while lowering CO2 emissions in the environment.

The word re-cycling comes from the Greek word '*κύκλος*' meaning cycle and is usually used to denote the involvement of materials in a continuous cycle from 'cradle' (resources) to 'grave' (disposal of waste) and back to 'cradle' (re-formation of resources).

The purpose of this book is to present the state-of-the-art for the recycling methods of several materials, including polymers, as well as to propose potential uses of the recycled products. It targets professionals, recycling companies, as well as researchers, academics and graduate students in the fields of waste management and polymer recycling in addition to chemical engineering, mechanical engineering, chemistry and physics.

This book comprises 16 chapters that have been prepared from the contribution of 50 co-authors from almost all around the world. There are contributions from Europe (Belarus, Czech Republic, Greece, Italy, Romania, Slovakia), Asia (Iran, Republic of Korea, Saudi Arabia, Taiwan, Turkey), America (Mexico) and Africa (Tunisia). The book chapters have been organized loosely in three subtopics. The first consisting of 7 chapters deals with a very 'hot' subject both from academic and industrial point of view, that of polymer recycling. The second, including 4 chapters, refers to the recycling of specific large-scale wastes, such as tires, pharmaceutical packaging and

#### XII Preface

hardwood kraft pulp. In the final, counting 5 chapters, possible uses of recycled materials are proposed. A brief description of each chapter follows.

Preface XI

*Chapter 7. Pyrolysis of waste polystyrene and high-density polyethylene* 

*Chapter 8. Recycling of scrap tires*

*Solutions for By-Products Quality* 

with steaming.

presented in detail.

*packaging* 

using for structural engineering applications.

waste processing and set-up of size reduction operations.

*Chapter 12. Reuse of waste shells as a SO2/NOx removal sorbent* 

experimented and the preparation method of sorbents was investigated.

*Chapter 13. Carbon steel slag as cementitious material for self-consolidating concrete* 

*Chapter 11. Recycling of the hardwood kraft pulp*

**C. Potential uses of recycled wastes** 

In this chapter, the product distribution obtained from pyrolysis of polystyrene and high-density polyethylene, as well as of their mixtures, is investigated. Moreover, the potential use of pyrolysis in the recycling of municipal plastic wastes is illustrated.

A comprehensive review of the methods proposed for recycling of scrap tires is presented in this chapter. After a brief history on the production technology of tires, the recycling methods are introduced, including thermo-chemical degradation (pyrolysis), burning for energy recovery, as well as mechanical re-processing and re-

*Chapter 9. Waste Tire Pyrolysis Recycling With Steaming: Heat-Mass Balance & Engineering*

This chapter presents detailed material and energy balances as well as engineering solutions for by-product quality concerning the recycling of waste tires using pyrolysis

*Chapter 10. Study on the feasibility of hazardous waste recycling: the case of pharmaceutical* 

This chapter is focused on a feasibility study for the management of packaging waste from a pharmaceutical plant, considering waste material characterization, tests on

This chapter focuses on the recycling process of hardwood kraft pulp fibers. Dimensional, optical and mechanical characteristics of the recycled fibers are

In this chapter, the feasibility of using waste oyster shells as a sorbent for removal of both sulfur and nitrogen oxides, at the same time, from exhaust gases, is illustrated. In addition, the calcination and hydration reaction of waste oyster shells were

**B. Recycling of tires, pharmaceutical packaging and hardwood kraft pulp** 

#### **A. Polymer recycling**

#### *Chapter 1. Recent advances in the chemical recycling of polymers*

This chapter provides a critical review on the methods proposed and/or applied, during mainly the last decade, on the recycling of widely used polymers, including polypropylene (PP), polystyrene (PS), low density polyethylene (LDPE), high density polyethylene (HDPE), poly(vinyl chloride) (PVC), polycarbonate (PC), poly(methyl methacrylate) (PMMA) and nylon. The state-of-the-art of the chemical and thermochemical recycling methods of these polymers is illustrated.

#### *Chapter 2. Recent Developments in the Chemical recycling of PET*

In this chapter, methods for the chemical recycling of poly(ethylene terephthalate) PET are reviewed. Special emphasis is put on glycolytic depolymerization, one of the oldest, simplest and less capital-investment requiring processes. Supercritical, catalytic and microwave-assisted depolymerization processes are also discussed.

#### *Chapter 3. Overview on Mechanical recycling of post consumed PET bottles by chain extension*

This chapter presents an overview on the structural upgrading of post-consumer PET by macromolecular chain extensions at reprocessing (reactive processing). This is a very efficient method for enhancing the properties of mechanically recycled PET.

*Chapter 4. Poly(bisphenol A carbonate) recycling: High pressure hydrolysis can be a convenient way.* 

In this chapter, hydrolysis of PC with sub-critical liquid water under high pressure is investigated as a means of recovering the monomer, bisphenol-A. Both pure PC and DVD wastes were used. A concerted path de-polymerization mechanism is proposed and the process kinetics is characterized and compared with lab-scale experimental data.

#### *Chapter 5. Degradation of plasticized poly(vinyl butyral) during re-processing*

This chapter focuses on the possibility and conditions for optimal re-processing of plasticized poly(vinyl butyral) (PVB). The scope is to determine degradation of PVB sheet at different kneading conditions and to estimate the influence of temperature, air oxygen content and mechanical stress on the course of the degradation process.

#### *Chapter 6. Materials and methods for the chemical catalytic cracking of plastic waste*

Thermo-chemical methods for the recycling of plastic wastes are discussed in this chapter. In particular the effect of several catalysts on the pyrolysis of polyethylene is examined in detail.

#### *Chapter 7. Pyrolysis of waste polystyrene and high-density polyethylene*

In this chapter, the product distribution obtained from pyrolysis of polystyrene and high-density polyethylene, as well as of their mixtures, is investigated. Moreover, the potential use of pyrolysis in the recycling of municipal plastic wastes is illustrated.

#### **B. Recycling of tires, pharmaceutical packaging and hardwood kraft pulp**

#### *Chapter 8. Recycling of scrap tires*

X Preface

**A. Polymer recycling** 

*convenient way.*

examined in detail.

hardwood kraft pulp. In the final, counting 5 chapters, possible uses of recycled

This chapter provides a critical review on the methods proposed and/or applied, during mainly the last decade, on the recycling of widely used polymers, including polypropylene (PP), polystyrene (PS), low density polyethylene (LDPE), high density polyethylene (HDPE), poly(vinyl chloride) (PVC), polycarbonate (PC), poly(methyl methacrylate) (PMMA) and nylon. The state-of-the-art of the chemical and thermo-

In this chapter, methods for the chemical recycling of poly(ethylene terephthalate) PET are reviewed. Special emphasis is put on glycolytic depolymerization, one of the oldest, simplest and less capital-investment requiring processes. Supercritical, catalytic

*Chapter 3. Overview on Mechanical recycling of post consumed PET bottles by chain extension* 

This chapter presents an overview on the structural upgrading of post-consumer PET by macromolecular chain extensions at reprocessing (reactive processing). This is a very efficient method for enhancing the properties of mechanically recycled PET.

*Chapter 4. Poly(bisphenol A carbonate) recycling: High pressure hydrolysis can be a* 

In this chapter, hydrolysis of PC with sub-critical liquid water under high pressure is investigated as a means of recovering the monomer, bisphenol-A. Both pure PC and DVD wastes were used. A concerted path de-polymerization mechanism is proposed and the process kinetics is characterized and compared with lab-scale experimental data.

This chapter focuses on the possibility and conditions for optimal re-processing of plasticized poly(vinyl butyral) (PVB). The scope is to determine degradation of PVB sheet at different kneading conditions and to estimate the influence of temperature, air

Thermo-chemical methods for the recycling of plastic wastes are discussed in this chapter. In particular the effect of several catalysts on the pyrolysis of polyethylene is

oxygen content and mechanical stress on the course of the degradation process.

*Chapter 6. Materials and methods for the chemical catalytic cracking of plastic waste*

materials are proposed. A brief description of each chapter follows.

*Chapter 1. Recent advances in the chemical recycling of polymers* 

chemical recycling methods of these polymers is illustrated.

*Chapter 2. Recent Developments in the Chemical recycling of PET*

and microwave-assisted depolymerization processes are also discussed.

*Chapter 5. Degradation of plasticized poly(vinyl butyral) during re-processing*

A comprehensive review of the methods proposed for recycling of scrap tires is presented in this chapter. After a brief history on the production technology of tires, the recycling methods are introduced, including thermo-chemical degradation (pyrolysis), burning for energy recovery, as well as mechanical re-processing and reusing for structural engineering applications.

*Chapter 9. Waste Tire Pyrolysis Recycling With Steaming: Heat-Mass Balance & Engineering Solutions for By-Products Quality* 

This chapter presents detailed material and energy balances as well as engineering solutions for by-product quality concerning the recycling of waste tires using pyrolysis with steaming.

*Chapter 10. Study on the feasibility of hazardous waste recycling: the case of pharmaceutical packaging* 

This chapter is focused on a feasibility study for the management of packaging waste from a pharmaceutical plant, considering waste material characterization, tests on waste processing and set-up of size reduction operations.

#### *Chapter 11. Recycling of the hardwood kraft pulp*

This chapter focuses on the recycling process of hardwood kraft pulp fibers. Dimensional, optical and mechanical characteristics of the recycled fibers are presented in detail.

#### **C. Potential uses of recycled wastes**

#### *Chapter 12. Reuse of waste shells as a SO2/NOx removal sorbent*

In this chapter, the feasibility of using waste oyster shells as a sorbent for removal of both sulfur and nitrogen oxides, at the same time, from exhaust gases, is illustrated. In addition, the calcination and hydration reaction of waste oyster shells were experimented and the preparation method of sorbents was investigated.

*Chapter 13. Carbon steel slag as cementitious material for self-consolidating concrete* 

#### XIV Preface

This chapter focuses on the use of carbon steel slag as a pozzolanic material to partially replace Portland cement in the production of self-consolidating concrete (SCC). Results showed that the design and performance of all the concrete mixtures used were comparable to those of SCC and high performance concrete.

#### *Chapter 14. Possible uses of steelmaking slag in agriculture: an overview*

This chapter intends to review the state-of-the-art related to the use of steelmaking slag, mainly coming from the Basic Oxygen Furnace process, in agriculture. Aspects covered include its use as fertilizer, liming agent and amending material for soils.

#### *Chapter 15. From PET Waste to Novel Polyurethanes*

This chapter focuses on the synthesis of secondary useful products, such as polyurethanes, from the chemical recycling of PET wastes. Various chemical decomposition methods of PET are described emphasizing in aminolysis in the presence of ethanolamine. The main product was used as chain extender or ring opening agent to obtain new polyurethanes.

#### *Chapter 16. Valorisation of organic wastes by composting process and soil amendment*

Last but not least, this chapter assesses the suitability of an organic waste compost to supply some essential plant nutrients such as N, P, K, Fe, Mn, Zn and Cu, also to evaluate and compare the effect of manure and compost on soil chemical properties as well as to elucidate the effect of compost on crop productivity.

I want to express my sincere thanks to all the contributors who provided their expertise and enthusiasm to this project and InTech for making this work possible. I would like also to thank my family for their patience and the time deprived them during the preparation of my chapter and the book editing. Finally, I would like to dedicate this book to the memory of my mother Lilika Achilia who always was a source of inspiration.

> **Dimitris S. Achilias** Associate Professor, Department of Chemistry, Aristotle University of Thessaloniki Greece

**Part 1** 

**Recycling of Polymers** 

**Part 1** 

**Recycling of Polymers** 

XII Preface

This chapter focuses on the use of carbon steel slag as a pozzolanic material to partially replace Portland cement in the production of self-consolidating concrete (SCC). Results showed that the design and performance of all the concrete mixtures

This chapter intends to review the state-of-the-art related to the use of steelmaking slag, mainly coming from the Basic Oxygen Furnace process, in agriculture. Aspects covered include its use as fertilizer, liming agent and amending material for soils.

This chapter focuses on the synthesis of secondary useful products, such as polyurethanes, from the chemical recycling of PET wastes. Various chemical decomposition methods of PET are described emphasizing in aminolysis in the presence of ethanolamine. The main product was used as chain extender or ring

Last but not least, this chapter assesses the suitability of an organic waste compost to supply some essential plant nutrients such as N, P, K, Fe, Mn, Zn and Cu, also to evaluate and compare the effect of manure and compost on soil chemical properties as

I want to express my sincere thanks to all the contributors who provided their expertise and enthusiasm to this project and InTech for making this work possible. I would like also to thank my family for their patience and the time deprived them during the preparation of my chapter and the book editing. Finally, I would like to dedicate this book to the memory of my mother Lilika Achilia who always was a

**Dimitris S. Achilias**

Greece

Associate Professor, Department of Chemistry,

Aristotle University of Thessaloniki

*Chapter 16. Valorisation of organic wastes by composting process and soil amendment* 

well as to elucidate the effect of compost on crop productivity.

used were comparable to those of SCC and high performance concrete.

*Chapter 14. Possible uses of steelmaking slag in agriculture: an overview*

*Chapter 15. From PET Waste to Novel Polyurethanes* 

opening agent to obtain new polyurethanes.

source of inspiration.

**1** 

 *Greece* 

**Recent Advances in the** 

*Aristotle University of Thessaloniki, Thessaloniki* 

Dimitris S. Achilias et al.\*

**Chemical Recycling of Polymers** 

*Laboratory of Organic Chemical Technology, Department of Chemistry,* 

**(PP, PS, LDPE, HDPE, PVC, PC, Nylon, PMMA)** 

During last decades, the great population increase worldwide together with the need of people to adopt improved conditions of living led to a dramatical increase of the consumption of polymers (mainly plastics). The world's annual consumption of plastic materials has increased from around 5 million tones in the 1950s to nearly 100 million tones today. Since the duration of life of plastic wastes is very small (roughly 40% have duration of life smaller than one month), there is a vast waste stream that reaches each year to the final recipients creating a serious environmental problem. The presently most common practice of handling such waste streams is to incinerate them with energy recovery or to use them for land-filling. Disposing of the waste to landfill is becoming undesirable due to legislation pressures (waste to landfill must be reduced by 35% over the period from 1995 to 2020), rising costs and the poor biodegradability of commonly used polymers (Achilias et

The recycling of waste polymers can be carried out in many ways. Four main approaches have been proposed presented in Scheme 1 (Karayannidis and Achilias, 2007; Scheirs, 1998): 1. *Primary recycling* refers to the 'in-plant' recycling of the scrap material of controlled history. This process remains the most popular as it ensures simplicity and low cost, dealing however only with the recycling of clean uncontaminated single-type waste. 2. *Mechanical recycling (or secondary recycling)*. In this approach, the polymer is separated from its associated contaminants and it can be readily reprocessed into granules by conventional melt extrusion. Mechanical recycling includes the sorting and separation of the wastes, size reduction and melt filtration. The basic polymer is not altered during the process. The main disadvantage of this type of recycling is the deterioration of product properties in every cycle. This occurs because the molecular weight of the

Lefteris Andriotis, Ioannis A. Koutsidis, Dimitra A. Louka, Nikolaos P. Nianias, Panoraia Siafaka,

*Laboratory of Organic Chemical Technology, Department of Chemistry, Aristotle University of Thessaloniki,* 

al., 2009). Therefore, recycling seems to be the best solution.

**1. Introduction** 

 \*

*Thessaloniki, Greece* 

Ioannis Tsagkalias and Georgia Tsintzou
