Thermocatalytic Recycling Of Plastics

There are several physical and chemical methods to investigate the degradation of polymers, from methods without change of physical and chemical properties of polymers to degradation processes for the recovery of monomers. The initiation of degradation may be considerably different heat (thermal degradation), heat and catalyst (thermocatalytic degradation), oxygen (oxidative degradation), heat and oxygen (thermo-oxidative degradation), radiation (photochemical degradation), radiation and oxygen...

Introduction

Pyrolysis and cracking of waste polyolefins (plastics) can be categorized as the tertiary mode of recycling. Application of this type of recycling is reasonable especially in case of polyolefins when their further using in primary recycling (conversion into products similar in nature to the original product) and secondary recycling (conversion into products of different shape for less demanding products) is impossible. Pyrolysis and cracking are considered as alternative methods of the final...

Ethical and Political considerations

In principle, it makes no sense to collect waste streams separately, unless suitable outlets are secured for such flows. This seems the case for soiled and mixed plastic packaging wastes, since these cannot be reprocessed to any better materials than those that substitute low-grade wood and since the option of feedstock recycling is operating at a huge economic loss. Moreover, no serious health, toxicity, or safety problems become apparent in case of less strict collection requirements....

Aspect of Fluids Mechanics

As their name implies, plastics are easily deformable and once molten they may be heated not only externally, but also internally, by dissipating friction or dielectric heat. Once the pyrolysis temperature is attained, the melt viscosity starts decreasing rapidly and rising pyrolysis vapour bubbles agitate the mix. Many properties of plastics can be derived using methods used and developed by Van Krevelen 13 . The pyrolyzing plastic's rheology is poorly-documented, however, since the evolution...

Ch ch ch ch

Intramolecular hydrogen transfer reactions -CH2-CH2-CH2-CH2-CH2-CH2-CH2 -ch2-ch2- ch2-ch2-ch2-ch2-ch2- (D) Cyclization and aromatization Generally the concentration of iso-paraffins and olefins increased with decreasing temperature because the increase in further degradation of branched hydrocarbons is greater, than that of non-branched with increasing temperature. A similar phenomenon could be observed in the case of catalysts possessing a weak hydrogenation property accompanied by...

Concluding Remarks

Catalytic cracking and conversion of plastics wastes is currently a field of intense research and open to innovative technologies to be discovered and applied. Significant advances have been carried out in recent years, with several commercial plants being already in operation based on the use of catalytic cracking for the plastic waste conversion into valuable products. However, there is still room for further developments. In this regard, the following fields of research can be foreseen in...

Environmental Aspects

Little has appeared on the environmental effects of waste plastics pyrolysis. Conceptually, the topic can be subdivided in those environmental aspects related to collection, transportation of feed materials Sorting of plastics is often manual and can cause allergic and health problems. Remarkably, plastic waste is not without a smell, and air extracted from storage and handling is thermally deodorized, e.g. at the Ube Industries gasification plant. Part of the pyrolysis products can be regarded...

Heteroatoms And Side Products

A major problem in pyrolysis is in the rather unpredictable specifications of both feedstock, if it is a mix of plastics, and products. Especially the presence of halogens has been considered problematic, both because of product quality and operating problems, such as corrosion by HCl, especially in the presence of water vapour clogging by CaCl2, a problem that once plagued the plant at Ebenhausen, based on the Hamburg University pyrolysis process.

Influence Of The Main Operation Variables

Both the activity and selectivity of the catalysts heavily depend on the following reaction variables Henceforth, their respective effect over the catalytic cracking of plastics is described Temperature is likely the most important variable affecting the catalytic cracking of plastics. Reaction temperatures are usually in the range 300-450 C. In general, a temperature increase leads towards a parallel activity enhancement of the catalysts. Nevertheless, it must be taken into account that at...

Initial Degradation Mechanism

TGA is an excellent technique for a fast evaluation of the polymer degradation. However it does not reveal anything about solid state reactions taking place during degradation. TGA experiments showed that in the absence of catalyst, HDPE was decomposed very rapidly at around 773 K, without any weight loss at lower temperatures, indicating that no volatile products were formed until then. TGA experiments were not conclusive on the existence of any solid state reaction that would have changed the...

Kinetics and Mechanism ofPyrolysis

The study of kinetics and mechanism of pyrolysis is of considerable scientific interest, with regard to the thermal behaviour of organic molecules, the precise constitution of molecules or copolymers, including irregularities, such as structural defects and incorporation of initiator molecules and radical scavengers, used to control the MW. Some important results from the team of Professor Bockhorn (Cycleplast project) 6 are shown in Table 1.8. The kinetic parameters given are derived from the...

Liquid vs Gas Phase Operation

It is somewhat difficult to visualize plastics as a liquid. The viscosity of a plastic melt markedly decreases as the temperature is raised to levels at which pyrolysis becomes rapid for all resins, i.e. 450 C. Several means may be used to bridge the gap between feed temperature, generally room temperature, and reactor temperatures, namely melting, plasticizing and possibly pyrolysing the feed in an extruder-feeder dissolving the cold feed into hot liquid, serving as thermal flywheel and...

Mass Balances Processing Margins

It is essential to determine the yield of each major product rather precisely and at different values of the various operating parameters, mainly temperature, residence time, and pressure. Many studies are incompletely documented, considering only gas or liquid phase products, without mention of residues or mass balances. Moreover, in practice the product yield of pyrolysis is reduced by losses inherent to consecutive purification. Inevitable losses occur further during storage, transfer, and...

O p

If rearrangement of (7) results in chain unsaturation and intramolecular ring protonation, volatile indenes ultimately result. If intermolecular ring protonation occurs, macro cation (1) would likely be formed. Figure 2.7(b) shows that benzene can be obtained by PS catalytic cracking at temperatures as low as 130 C. The fact that the temperature at which volatile decomposition products were detected from PS-catalyst samples was dependent on the catalyst acidity suggests that the rate-limiting...

Operation Modes

In the following a brief selective overview, rather a personal account, is presented, in order to highlight variations in polymer catalytic pyrolysis scheme regarding modes of operations and reactor types. Prompted by the oil crises of the mid 1970s and early 1980s, the first research projects trying to convert plastic waste to fuel go back to the second half of the 1980s 2,3 . It was logical to extend earlier work on thermal noncatalytic conversion of plastic waste 4 , as its products needed...

Pyrolysis Of Plastics And Rubber

Pyrolysis, also termed thermolysis (Greek pur fire thermos warm luo loosen), is a process of chemical and thermal decomposition, generally leading to smaller molecules. Semantically, the term thermolysis is more appropriate than pyrolysis, since fire implies the presence of oxygen and hence of reactive and oxygen-bearing intermediates. In most pyrolysis processes, however, air is excluded, for reasons of safety, product quality, and yield. Pyrolysis can be conducted at various temperature...

Useful Publications

APME (Association of Plastics Manufacturers Europe, today Plastics Europe), with member companies given in 29 has classified plastic waste in a series of categories and monitors their origin and recycling, according to their field of application. Several early publications are still of interest, to compare past and present. A recent book on plastics recycling is Scheirs 38 . A few sites of interest are also Community Recycling, a comprehensive guide to setting up, maintaining or expanding a...

Feedstock Recycling and Pyrolysis of Waste Plastics

Converting Waste Plastics into Diesel and Other Fuels Copyright 2006 John Wiley & Sons Ltd, The Atrium, Southern Gate, Chichester, Email (for orders and customer service enquiries) cs-books wiley.co.uk Visit our Home Page on www.wiley.com All Rights Reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, scanning or otherwise, except under the terms of the Copyright,...

Reactor Types and Processes Table

Professor Fontana and Dr Jung classified all major gasification routes and pyrolysis processes, studying their mass and energy balances as well as operating conditions refer 2nd ISFR Ostend 9 , predicting the behaviour of mixed plastics during pyrolysis and gasification, in order to assess the production of valuable substitution fuels. Their model was validated by laboratory-scale experiments and the quality of the resulting substitution fuels evaluated, to choose the best thermal process for...

Zeolites

The decomposition of a polymer chain, being a hydrocarbon cracking reaction, is catalysed by acidic catalysts. The main category of solid cracking catalysts, as well as the more widely used in industry, are zeolites, as they constitute the main ingredient of catalysts used in the FCC process in refineries. Zeolites are crystalline aluminosilicates with a well-defined microporous structure with cages and channels of dimensions comparable to the size of common simple organic molecules. Zeolites...

Recovery Of Heavy Oil From Waste Plastic

Polyester Resin Reactor Drawings

The waste plastics generated from households are in the form of plastic mixtures among such mixtures, the amount of PET generated as a household waste has rapidly increased as the production of PET bottles has increased. PET is formed by the ester bonding of terephthalic acid and ethylene glycol. When PET is heated above 380 C, pyrolysis suddenly starts, yielding oxygen-containing hydrocarbons and a significant amount of carbonaceous residue 17-19 . Accordingly, in order to develop a recycling...

Theory Of Plastics Pyrolysis

The decomposition of plastics can be considered as depolymerization of polymer into low-molecular product. The general reaction mechanism for the thermal degradation is described with the following steps, and also shown in Figure 5.1. Initiation may occur at random or end-chain positions. Depropagation is the release of olefinic monomeric fragments from primary radicals. Hydrogen chain transfer reaction, which may occur as intermolecular or intramolecular processes, leads to the formation of...

Logistics Of Supply

A naphtha cracker producing ethylene has a typical yearly capacity of 500000 tonnes of ethylene, necessitating about 1.2 Mtonnes of naphtha feedstock Polymerization to resins is conducted with a somewhat lower capacity, but still at the same order of magnitude, say 150000 tonnes. Engineering plastics are produced at lower capacity, but this lower rank is still far superior to the capacity of the largest feedstock recycling units conceived to date The problem...

Product Distribution

The original polymer mass in the presence of a catalyst is generally converted into volatile products while a residue is left unconverted. This residue consists of a polymer solid residue of genuinely unconverted plastic, although usually not of the same composition and molar mass distribution as the original, and coke formed on the catalyst surface. From these two residue components, the first one can be eliminated by changing the reaction conditions most obviously by increasing the polymer...

Product Specifications

Distinction should be made between monomers, specific petrochemicals, and more or less typical oil fractions, produced by mixed plastics pyrolysis. Potential pyrolysis products from polyolefins are naphtha, kerosene, or gas-oil. These are blends of numerous different Table 1.6 Typical naphtha specifications and testing methods 18 Table 1.6 Typical naphtha specifications and testing methods 18 hydrocarbons, but they still need to satisfy some common commercial specifications. Off-specification...

Japanese Initiatives and Processes

Both the Ministry of International Trade and Industry MITI and the Plastics Waste Management Institute PWMI have been very active in promoting plastics recycling from early in the seventies. In Tokyo, plastics and metals were considered as waste, unfit for incineration and separately collected 1973 and treated in a Nippon Steel shaft furnace. Early Japanese systems, e.g. from Japan Steel Works, Japan Gasoline Co., Kawasaki H. I. Co., Mitsui Shipbuilding amp Engineering Co., Mitsubishi H. I....

Survey Of Previous Work

Most work on plastics pyrolysis has been academic and directed at the analysis of polymers, their molecular structures and thermal stability, at the study of pyrolysis products, e.g. fire research, or at feedstock recycling at a laboratory or pilot scale. An early survey was given by Madorsky 4 . Given the large number of possible purposes, or different resins, additives, and operating conditions, the field is as wide as the sky Since the introduction of modern instruments ca 1962 the thermal...

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...

Various Catalysts

The thermal degradation of waste HDPE can be improved by using suitable catalysts in order to obtain valuable products. However, this method suffers from several drawbacks. The catalysts are deactivated by the deposition of carbonaceous residues and Cl, N compounds present in the raw waste stream. Furthermore, the inorganic material contained in the waste plastics tends to remain with the catalysts, which hinders their reuse. These reasons necessitate a relatively high purity of waste plastics,...

Catalytic Liquefaction Of

In these studies were solid acids amorphous silica-alumina, zeolites, zeolite-based FCC catalysts, MCM mesoporous materials and super acidic zirconia, etc. . Besides acidic catalysts, a few studies have been performed with activated carbon and nonacidic mesoporous silica catalyst FSM 11-15 . Acidic cracking catalysts are very useful for direct liquefaction of PE and PP. The catalytic effect of acidic catalysts in plastic pyrolysis has been explained by a carbonium ion theory. The catalytic...

Polymertocatalyst Ratio

Tga Graphs

An important aspect in a future catalytic process for degradation of plastic waste is the amount of catalyst used in such a process. In a batch system, which is the most broadly used so far to test the performance of various catalytic systems, the amount of catalyst is characterized by the polymer-to catalyst mass ratio. Results from initial experiments carried out on a TGA equipment Figure 7.1 9 using high-density polyethylene HDPE as raw material at different polymer to catalyst mass ratios...

Properties Of Liquid Product [

Distillation Graph Diesel Fuel

The need for various grades of the product oils separated in the distillation tower is evident. In order to keep the various grades on a uniform basis, the authorities in each country have standardized on a few grades by the properties of the oil produced. It is necessary to compare reliable properties of the oil produced, as a comparison with those of commercial gasoline, kerosene and diesel. It is essential to determine the physical measurements such as those listed for a variety of the oils,...

Effect Of Addition Of Other Thermoplastics

Lee et al. 29 reported the effect of PS addition in the catalytic degradation of waste HDPE and PS mixture using spent FCC catalyst at 400 C. Figure 5.14 shows the cumulative amount distributions of liquid products as a function of reaction time for the catalytic degradation of waste HDPE and PS mixture in different proportions. The increase of PS content in HDPE and PS mixture showed much high initial degradation rate and high Figure 5.14 Cumulative amount distributions of liquid products for...

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...

Waste Plastics Suitable For Cracking And Pyrolysis

Cracking and pyrolysis are the suitable processes for the tertiary recycling of additive polymers such as polyolefins, mainly polyethylene PE , polypropylene PP , polybutadi-ene PBD and polystyrene PS . Small admixtures of other plastics, such polyethylene terephthalate PET , polyvinyl chloride PVC , less than two 2 , are admissible yet not desirable. Taking into account the total share of polyolefins in plastics production 70 wt including PS they are the highest environmental problem. Their...

Decomposition Modes

As a rule, the pyrolysis of plastics follows complex routes that cannot be described by one or more chemical reactions, but only and still rather imperfectly by either empirical formulas featuring fractional stoichiometric coefficients or comprehensive systems of elementary reactions, i.e. reactions that really proceed as written. Moreover, the composition and structure of these reaction systems may vary with details of molecular structure, such as chain irregularities, incorporation of...

Fractional Distillation Of Products

Flow Diagram Fractional Distillation

Reactor effluent that is composed of oils with various boiling temperatures is fed into the base of the fractional distillation tower where it is fractionated into selected product streams. Various product streams in the distillation tower are fractionated from Figure 5.18 Flow diagram of distillation tower Figure 5.18 Flow diagram of distillation tower reactor effluent due to their different boiling temperatures. The control variables are the temperature gradient in distillation tower,...

Upgrading Of Wasteplasticsderived Heavy Oil Over Catalysts

In the series described thus far, it was found that the degradation of waste plastics proceeds efficiently by both thermal pyrolysis and hydrolysis in a steam atmosphere. A wax and carbonaceous residue produced by the hydrolysis of PET are decomposed by reaction with steam over an FeOOH catalyst, the activity of which remains stable in a steam atmosphere. However, the liquid product from generated from the process mentioned above contains a large amount of heavy oil, as shown in Figure 6.10....

Related Technologies Coprocessing

In addition to the above-mentioned catalytic processes, there are some other related technologies wherein the catalytic cracking of plastic wastes is combined with the coprocessing of other substances, mainly coal and petroleum feedstocks lube oil, LCO, VGO or even a solvent. Hereafter, these technologies are explained more in detail. Coprocessing of plastics with coal in order to convert both of them into fuels is another promising option deeply studied by different authors 105-109 . The...

References

Gulyurtulu and I. Cabrita, Pyrolysis of plastic waste 2. Effect of catalyst on product yield, Journal of Analytical and Applied Pyrolysis, 51, 57-71 1999 . 2. N. Miskolczi, L. Bartha, Gy Deak, B. Jover and D. Kallo, Kinetic model of the chemical recycling of waste polyethylene into fuels, Process Safety and Environmental Protection, 82, 223-229 2004 . 3. J. -S. Kim, W. -Y. Lee., S. -B. Lee, S. -B. Kim and K. -J. Choi, Degradation of polystyrene waste over base promoted...

Value Of The Resulting Products

Some pyrolysis products have high value. These are mainly monomers, such as methyl-methacrylate, caprolactam the monomer of PA 6 , tetrafluorethylene, or styrene. Others are comparable to standard products with specifications of naphtha, kerosene, or gas-oil. Such fractions have a well-known market, as follows from Table 1.7. However, it is still questionable as to how far plastics pyrolysis can yield product fractions, according to current specifications without extensive post-pyrolysis...

Mechanism Of Cracking Processes

The main task of thermal and catalytic cracking is decomposition of large long hydrocarbon molecules into smaller ones. High-molecular feedstock, such as paraffin hydrocarbons and plastic chains produces lower molecular paraffins and a-olefins 5 R-CH2- CH2 x-CH2-CH3 R- CH2 m-CH3 CH3- CH2 -CH CH2 Cracking of primary products, olefins, give higher molecular hydrocarbons by polymerization or tar and coke CH2 CH2 CH3-CH CH2 CH3-CH2-CH2-CH CH2 R-CH2-CH CH2 R-CH2-CH CH2 tar, coke It is generally...

Contents

Contributors Series About the 1 Introduction to Feedstock Recycling of Plastics 3 2 Nomenclature 3 Pyrolysis of Plastics and 3.1 Survey of Previous 3.2 Products from 3.3 Hetero-atoms and Side 3.4 Fundamentals 3.5 Value of the Resulting 4 Feedstock 4.2 Problems with 4.3 Collection 4.4 Logistics of 5 Some Feasible 5.1 Pilot and Industrial Plant 6 Waste 6.2 Plastics 6.3 Rubber 6.4 Plastics Pyrolysis as a Waste Management Option 35 2 Acid-Catalyzed Cracking of Polyolefins Primary Reaction 2...

Catalysts

Monofunctional catalysts are catalysts having only the cracking property. Their structure may be crystalline or amorphous. Typical crystalline cracking catalysts are zeolites. Amorphous catalysts are alumina-silicate, magnesium-silicate, titanium-silicate, titanium-alumina-silicate, titanium-alumina, silica-alumina dispersed in alumina, alumina-borate and other oxides with acidic characteristic. Usually the acidity of catalysts and the C-C cracking function is increasing in the order Al2O3 lt...

Plasticswaste

Pre-consumer plastic wastes are generated during the manufacture of virgin plastics from raw materials oil, natural gas, salt, etc. and from the conversion of plastics into plastic products. The nature of waste arising in various processing methods is discussed in 14 . Such waste streams are soiled floor sweepings, skimmings from wastewater treatment, crusts from polymerization reactors , mixed laboratory testing , or off-specifications. Both production and conversion waste are easily...

Polystyrene Cracking

Radical depolymerization of neat PS samples produces large quantities of monomer styrene and chain-end backbiting yields substantial amounts of dimer and trimer. Polymer decomposition proceeds by entirely different processes when a catalyst is present. Repetitive injection GC MS was employed to investigate the primary reaction processes that occur when PS is cracked by silica-alumina, sulfated zirconia, and HZSM-5 74 . These catalysts exhibit a wide range of acidity, but only the HZSM-5...

Effect Of Temperature

In the thermal and catalytic degradation of waste thermoplastics, the product yields such as liquid, gas and solid products change depending on the degradation temperature. Walendziewski and Steininger 8 reported the thermal and catalytic degradation of polyethylene in the temperature range 370-450 C. In the case of thermal degradation of polyethylene, an increase in degradation temperature led to an increase of gas and liquid products, but a decrease of residue bp gt 360 C . However, according...

Products From Polymers Major Operating Conditions

The major factors of influence determining the product distribution resulting from plastics pyrolysis are summarized in Table 1.1. Chemical composition plays a dual role 1. Mass conservation dictates that the pyrolysis products, distributed over the three phases, gas, liquid, and solid, consist of the same elements as the raw materials and that their relative amounts are conserved. There is a redistribution of relevant elements during pyrolysis, with hydrogen and chlorine enriching the gas...

General Scheme Of Waste Polyolefin Processing

Hydrocarbon Waste

Similarly to crude oil cracking the products of the waste polyolefin cracking process are hydrocarbon fractions. According to the process conditions different shares of gas, gasoline, light and vacuum gas oil fractions as well as solid residue coke can be obtained. The unsaturated character of these products makes the further treatment, i.e. hydrorefining or application as the feed in cracking or hydrocracking processes, necessary. Light gaseous fractions can be used as the source of C2-C4...

Collectionsystems

Under pressure from legislation, in particular the Packaging and Packaging Waste Directive, 94 62 EC, recycling of packaging products has increased dramatically from 1995. In numerous E.U. countries, collection of waste plastics is part of the mandatory recycling, imposed by the Packaging Directive and National Laws deriving from it Table 1.9 . Eight countries recovered over half the waste plastics from packaging in 2000 the Netherlands, Switzerland, Denmark, Norway, Germany, Sweden, Austria...

Effect Of Catalyst

Pona Hydrocracking

Because the addition of catalyst in the pyrolysis process has many advantages, many researchers have looked for ways of improving light oil yield and oil quality from waste plastics. According to the catalyst addition in plastic pyrolysis, the degradation temperature for achieving a certain conversion is reduced drastically. Also, the increase of catalyst content in waste plastic further lowers the degradation temperature. In the liquid product from catalytic degradation, more products in the...

Catalytic Systems

Pillared Clay

Both homogeneous and heterogeneous systems have been used in the literature for studying the catalytic cracking of polymers. In general, heterogeneous catalysts are the preferred choice due to their easy separation and recovery from the reacting medium. Homogeneous catalysts used for polyolefin degradation have mostly been classical Lewis acids such as AlCl3, metal tetrachloroaluminates melts and more recently, new catalytic systems based on organic ionic liquids. Ivanova et al. 30 degraded...

Processes

Waste Plastic Olefins

Initially, processing of plastic wastes was proposed to be carried out directly through their incorporation into the streams of oil refineries, since their main components polyolefins present several advantages that convert them into a desired feedstock for the different refinery units. These plastics possess a high hydrogen carbon ratio around 2 with a low tendency to form coke due to its aliphatic composition, showing also a reduced metal content. However, it was obvious fairly soon that this...

Heat Balances

The major terms in the heat balance of a pyrolysis reactor are evaporating any moisture contained supplying sensible heat and latent melting heat to the plastics supplying heat of reaction to the plastics. Process heat requirements tend to be lower if the feed is stepwise heated, as in certain multistep or selective decomposition schemes of plastics mixtures, or in case the Table 1.7 Some commodity prices Financial Times, 3 August 2004 Table 1.7 Some commodity prices Financial Times, 3 August...

Principles

Waste management was once a down-to-earth technical problem, to be solved under thrifty, yet environmentally 'acceptable' and hygienic conditions and preferably performed by unskilled labour. Most waste was disposed of in landfills, except in densely populated regions, where volume reduction by incineration was a practical necessity. The recovery of heat, distributed in district heating systems or converted into electrical power was a means of cooling flue gases prior to their cleaning, but...

Pilot Plants And Commercial Plants

Thermal or catalytic cracking are the typical refinery processes and therefore BP Chemicals built a fluid cracking plant for waste plastics at the Grangemouth refinery in England 58-60 . This was a pilot plant of 100 kg h capacity for cracking of commingled waste plastics composed of 80 PE and PP, 15 wt of PS, 3 wt of PET and 2 of PVC. Sand was used as fluidizing agent and the process temperature was varied in the range 400-600 C, close to FCC temperature or higher, i.e. olefin pyrolysis....

Plastic Recycling Feedstock Pyrolyse

An analysis of Plastics Consumption and Recovery in Europe, 2001 amp 2002, Brussels, 2003. 2. R. C. Mordi, R. Fields and J. Dwyer Gasoline Range Chemicals From Zeolite-Catalyzed Thermal-Degradation of Polypropylene. J. Chem. Soc. Chem. Comm. 374 1992 . 3. R. C. Mordi, R. Fields and J. Dwyer Thermolysis of Low-Density Polyethylene Catalyzed by Zeolites J. Anal. Appl. Pyrol., 29, 45 1994 . 4. H. Sinn and W. Kaminsky Pyrolysis of Plastic Waste and Scrap Tires Using a...

Voluntary Commitment of the PVC Industry

In the frame of Vinyl 2010 26 the PVC Industry in the European Union made a number of voluntary commitments, regarding the control of emissions from VCM-producing plant, the phasing out of cadmium both already realized and lead-based stabilizers to be completed by 2015 and the voluntary recycling of 200 000 tonnes per year by 2010. Some projects allow for mechanical recycling Solvay's Vinyloop, at Ferrara , but feedstock recycling is also being considered 26 . In Japan, Nihon Kokan now merged...

Polyethylene Cracking

Gas Sampling Valve Gas Chromatography

Although a wide variety of catalysts have been employed to crack PE, zeolites have proven particularly effective. For example, Garforth et al. reported that activation energies a measured when PE was catalytically cracked by HZSM-5, HY, and MCM-41 were much lower than when no catalyst was present. 66 They concluded that HZSM-5 and HY have similar activities and that both of these zeolites were more effective than MCM-41. Manos and co-workers found that catalytic cracking of PE by HZSM-5 and HY...

Liquefaction of PVC Mixed Plastics

2 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 3 Fundamental Studies on the Decomposition of PVC 3.1 Product Distribution and Mechanism of PVC 3.2 Degradation of PVC - Polymer Mixtures 4 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...

Total Mass Balance

Waste Polymers Feedstock Recycling

Total mass balance is based on input and output amount in a simple process flow diagram, as shown in Figure 5.4. In this process, the optimization control condition is the maximum production of the oil product and the minimum production of the gas product and the sludge. Generally, the yields of gas and oil product are below 20 and above 70 respectively, based on 100 of feeding amount. Also, the sludge amount is much decreased to below 10 , which should be discharged in much smaller amounts, if...

Reactor Design

For acceptable efficiency waste polyolefin cracking process should be realized in continuous mode. For the same reason, as well as due to high coke and mineral residue yields, construction of reactor for waste plastics cracking has to enable continuous coke removal. The best solution is a fluidized-bed process, known in refineries as fluid catalytic cracking FCC in crude oil processing with cracking catalyst or fluid thermal cracking with coke or mineral grains as the fluidization medium 5 . In...

Hydrocracking Processes

The yield of unsaturated catalytic cracking products can be reduced by the addition of hydrogen to cracking atmospheres. Dufaud and Basset demonstrated this by employing a zirconium hydride Ziegler-Natta catalyst to crack PE in a hydrogen atmosphere 25 . Ding et al. studied the hydroconversion of PE with sulfided Ni and NiMo silica-alumina and compared these catalysts with HZSM-5 76 . They found that Ni silica-alumina produced higher quality liquid products i.e. more isoparaffins and fewer...

Resins and Products

A systematic study of both physical and chemical aspects in plastics pyrolysis was launched in the Cycleplast project 6 . Thermal degradation of commodity polymers, including kinetic factors and mechanism, were systematically investigated by Professor Bockhorn and collaborators, using thermogravimetry, linked with mass spectrometry, as well as closed loop laboratory-scale pyrolysis reactors. The resulting kinetic parameters are discussed further. Polyolefins, mainly PE and PP, the main...

Thermal Degradation And Subsequent Catalytic Upgrading

Flowsheet Polyethylene

This type of process is the preferred choice for treating plastic wastes containing a high proportion of components that may affect negatively the catalyst performance. The occurrence of a previous thermal step allows for the removal of many of these components previously to the catalytic treatment. Figure 3.17 illustrates the flow sheet of the process developed by the company Nippon Steel Corporation, being applied in Japan on a commercial scale 102 . The process may use as raw materials any...

Some Feasible Processes

A brief survey is given of a number of processes that have been used in Europe for plastics pyrolysis. At present, all of these projects have been mothballed. The most relevant initiatives are according to 15 1. Hamburg University Pyrolysis Process, high-temperature pyrolysis of mixed plastics, using a fluid bed reactor. Demonstration plant at Ebenhausen has not survived shakedown, due to various operating problems. 2. BASF low-temperature pyrolysis of mixed plastics, using a battery of stirred...

Hamburg University Ebenhausen

A plant operating according to the Hamburg University pyrolysis process was built at Ebenhausen, with a capacity of 5000 tonnes per year. The feasibility of converting poly-olefins by pyrolysis was successfully demonstrated, with yields from PE PP mixtures of typically 51 m m gas, 42 m m liquids and the balance unaccounted for. However, the gas to liquids ratio is very sensitive to pyrolysis temperature. Since gas and oil are the major pyrolysis products, economic viability crucially depends on...

Plastics Pyrolysis As A Waste Management Option Status in the EU

Almost since its foundation 1975 the Association of Plastics Manufacturers in Europe APME, Brussels has monitored plastics production, consumption and waste generation. Major sectors are packaging, building and construction, automotive, electrical and electronics E amp E , agriculture, and others e.g. furniture, houseware, toys, engineering . After a short e.g. packaging , medium e.g. toys or long lifetime e.g. building the plastic product reports to one of various waste streams, such as...

Reactors

Ldpe Reactor Internal

The low thermal conductivity of the molten polymers and their extremely high viscosity are the major problems for the catalytic cracking reactor design. The most widely used reactor systems have been Apart from these reactors, thermogravimetric techniques TG have been widely applied for the study of the thermal and catalytic cracking of several plastics over different acid solids, determining relative activity of the catalysts and kinetic parameters under both isothermal and dynamic conditions...

Waste Plastics Processing

5.1 CATALYTIC AND THERMAL CRACKING PROCESSES TYPICAL PRODUCTS The most exhaustive studies on waste plastics processing by cracking and pyrolysis methods were carried out at Hamburg University by Kaminsky and co-workers e.g. 1, 8 . As a result of these studies various variants of the process were worked up. They used different types of the feed compositions and process parameters, starting from the low-temperature coking and cracking parameters temperature lower than 500 C and liquid and wax...

Veba Oil Bottrop Germany

Liquid Phase Hydrogenation

From 1981 Veba Oil AG operated a coal-to-oil hydrogenation plant at Kohleol Anlage Bottrop KAB in Germany, using the Bergius Pier coal liquefaction technology to convert coal into naphtha and gas oil. In 1987 the plant was modified, applying Veba Combi Cracking VCC technology to convert crude oil vacuum distillation residues into synthetic crude. Since 1988 a share of the petroleum residue feedstock was substituted by chlorine-containing waste containing, e.g. PCBs . In 1992 1993 a...

BASF Ludwigshafen

The BASF feedstock recycling process was designed to handle mixed plastic waste, as supplied by the DSD Duales System Deutschland green dot packaging collection system. A large pilot plant, with a substantial capacity of 15000 tonne yr, was started up in Ludwigshafen in 1994. At that time DSD estimated the total volume of mixed packaging plastics available for feedstock recycling at around 750 000 ton yr. BASF offered to erect a full-scale industrial plant with a capacity of 300000 ton yr, but...

Problems With Heteroatoms

The major hetero-atoms appearing in polymers are oxygen, nitrogen, chlorine, bromine, fluorine. After plastics pyrolysis, these elements either appear as intermediate organic compounds still incorporating the hetero-element, or as stable inorganic compounds, i.e. water, ammonia and hydrogen cyanide, hydrogen chloride, hydrogen bromide and bromine, hydrogen fluoride. Most of these are hazardous and corrosive and require a careful selection of construction materials, as well as methods to...

BP Grangemouth

In the early 1990s BP Chemicals first tested technology for feedstock recycling, using a fluid bed cracking process. Research on a laboratory scale was followed 1994 by demonstration at a continuous pilot plant scale nominal 50 kg hr at BP's Grangemouth site, using mixed waste packaging plastics. The technology was further developed with some support from a Consortium of European companies Elf Atochem, EniChem, DSM, CREED and from APME. In 1998, BP Chemicals, VALPAK and Shanks amp McEwan, set...

Reaction Kinetics Of Degradation

Description of decomposition reactions during degradation of plastics is quite difficult, because they are very complex. Furthermore there are considerable differences between thermal degradation of waste plastics in the absence and presence of catalysts, but the type of the reactor or the amount of plastics is also important. Degradation in the presence of catalysts is called thermocatalytic degradation. Cracking experiments are done in batch reactors in 95 of cases 1-11 and within it the...

Rubberwaste

Rubber tyres are by far the most visible of rubber products. Identification is trivial and collection is well organized. Recycling and disposal, however, are less evident. A major route for tyres is their use as a supplemental fuel in cement kilns. Major compounds in tyres are styrene-butadiene rubber SBR , synthetic and natural polyisoprene rubber, steel cord, carbon black, zinc oxide, sulphur and vulcanization-controlling chemicals. Tyres can be retreaded, which is economic for large sizes...