Steps to maximise value at deconstruction Wwo
Design for reuse after deconstruction Design for recycling after deconstruction Roof structures support the roof sections of the building envelope which is dealt with in 3.4 . They are designed generally to carry imposed loads due to snow and wind, as well as loads arising from the need to have access to roof level for maintenance. They may also need to carry plant and equipment. Roof structures are generally of four kinds a truss or framework structure that supports a cladding of some kind, eg...
Why Plastics Need to be Sorted
We have already seen that thermosets cannot be reprocessed in the same manner as thermoplastics, because they do not re-melt. Therefore separation is needed of thermosets and thermoplastics. But what about thermoplastics do they need to be separated from each other Can we simply just mix all the plastics together and reprocess them Well, if we could do this, plastics recycling would certainly be much easier. In some cases it may be possible to simply mix and reprocess but generally the...
Ground Rubber Tire Composite Behavior
Although the use of ground rubber tire GRT as a filler in polymer blends is a potentially attractive approach, it is fraught with a number of difficulties. Generally, when the large GRT particles are added to either thermoplastic or thermoset matrices there is a large drop in mechanical properties, even at relatively low filler loadings.6'7 Given that the approach here is to use the GRT as a low cost additive, and that there are a number of other materials competing in this regard, overcoming...
Irradiation time days Fig Variation of k and power with time for the inert
one quarter of the inert matrix pins in the outer blanket of the reactor are removed these pins have been in the reactor for a period of 7 x 293 2050 days from the reactor. Such a scheme will ensure that the standard pins are in the reactor for 878 days whereas the inert matrix pins are in the reactor for the required 2050 days. It is not a requirement that the outer blanket should contain the sub-critical inert matrix based pins. Depending on the neutron distribution, this array of...
Recoverable Materials In The Motor Vehicle
Discarded vehicles yield ferrous metals, aluminium, copper, lead, and zinc. However, as currently processed by shredding, they also generate a valueless fraction, containing the non-metallic detritus of seats, carpets, tyres, and other components. The historical position of steel in the automotive scrap industry emerges from data for the composite car described in the pioneering work of Dean and Sterner. The recovered steel, even when contaminated with the residual copper in the car, would have...
Degradable Plastics
Since plastics can comprise up to 40 bulk of all the waste in landfill, another waste management strategy is to speed up their chemical breakdown once they enter the waste stream 5 . This is not recycling, simply an attempt to limit environmental damage. Plastic litter that is dropped will thereby harmlessly degrade in the natural environment. It makes good sense. In this chapter it has been shown that stabilisers can protect plastics from environmental damage. However, one solution to the...
Other Methods of Recycling and Waste Disposal Options
In Chapter 1, chemical recycling and energy recovery were introduced as alternatives to mechanical recycling. We have seen how plastics can be reprocessed if they are pure streams, if they can be sorted, or if suitable blends can be obtained. We have also seen potential applications for mixed plastics where the quality of the final product is reduced, but the inherent properties of all plastics such as rot-resistance can be utilised. An example of this is in wood replacement applications....
Transfer Moulding
This process combines elements of injection moulding and compression moulding. It is similar to injection moulding in that a fixed weight of material is transferred into a mould. Transfer moulding was originally developed from compression moulding, to allow production of more complex parts incorporating holes, recesses or inserts 2 . The result was a process whereby the mould was closed first and the moulding material then transferred by a compressive action into the cavity. A number of...
Energy Recovery
Energy recovery can be defined as incineration to recover inherent energy. Given that polymers are made from oil, it is not surprising that they are quite good fuel sources when they are burnt. The amount of energy that can be recovered depends on the calorific value of the material. Literature values tend to give an average calorific value of mixed plastic waste as 35 MJ kg. When compared to paper 16 MJ kg and organic waste 3 MJ kg , it can be seen that plastics give a relatively high energy...
Acknowledgements
The Environmental Protection Authority gratefully acknowledges the information and advice received from the following Australian Paper Manufacturers, Spearwood Councils and Shires of Western Australia Federated Municipal and Shire Council Employees Union of Australia WA Division Keep Australia Beautiful Council WA Waste Management Authority of New South Wales School of Environmental and Life Sciences, Murdoch University Dr Goen Ho
The environmental impacts of plastics and plastics recycling
The rapid growth of plastics production is reflected in the growth of plastic waste as a proportion of total Municipal Solid Waste MSW . This can be seen in Table 3.3, which gives figures for the United States. Table 3.3. Proportion of plastic in MSW Table 3.3. Proportion of plastic in MSW The difference in the plastic component of European waste in the early 1990s is shown below in Table 3.4, with figures ranging from 6 UK to 11.5 Ireland . Table 3.4. Proportion of plastics in MSW by weight...
Byproducts
The major product of pyrolysis is either a monomer PMMA, PS , or a series of fuel fractions. By-products of plastics pyrolysis are related to the presence of Heteroatoms oxygen in the resin or the pyrolysis atmosphere leads to the formation of water and oxygenated products chlorine leaves pyrolysis units mainly as an irritating and corrosive hydrogen chloride gas. Normally, no chlorine gas is formed, due to the strongly reducing conditions. Bromine, under similar conditions, is somewhat easier...
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...
Competition between domestic and foreign firms
DSD does not discriminate against foreign suppliers in so far as they can obtain a Green Dot on their packaging. However, in practice the quota for refillables could be barrier as imported packages are more likely to be one-way. The deposit refund will only be appropriate for domestic firms. So a refillable quota could limit imports. A tax on oneway containers would lead to increased supply of domestic returnables and tend to leave the amount imported unchanged, so there would be no problem as...
Recovery Of Heavy Oil From Waste Plastic
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
Plastic resins are bulk commodities. 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....
Rheology
Rheology is the study of deformation and flow. Consider the following examples of flow 1. Squeezing toothpaste through a tube, 2. Tipping honey from a spoon, and The toothpaste, honey and water all have different viscosities. The toothpaste is the most viscous, the water the least. Viscosity means the resistance to flow. In viscous flow, a material continues to deform as long as a stress is applied. To put it more simply, in the case of the toothpaste tube, the toothpaste is squeezed out only...
Case Study Packaging
Recycling rates vary greatly across Europe, due to different legislative and environmental measures adopted by member states. The country at the forefront of implementing plastics recycling schemes is Germany. Packaging waste concepts introduced in Germany in June 1991 have provided much valuable data for the rest of the EU. The target set was 64 to be recycled by July 1995, based on a system of collection, sorting and recycling technology. The high environmental awareness present in the German...
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...
Air Conditioning Refrigeration Contractors
Airport Hts. Drive 36 Paddy DobbinDr. Avalon Steamatic Ltd. Baker's Refrigeration amp Heating Bennett's Refrigeration amp Air Conditioning Black amp McDonald Cimco Refrigeration C amp J Sheet Metal Keep Cool Refrigeration amp Air Conditioning Limited Kool - Rite Refrigeration 9 Mullock Provincial Refrigeration Ltd. 23 Rhodora Whitten Agencies Limited 28 Eastview Cr 726 - 0220 753 - 3377 738 - 2988 747 - 1406 754 - 6180 726 - 7997 726 - 6300 576 - 2130 364 - 3498 364 - 3506 726 - 7761
full cycle
In general, humans build great edifices and nature eventually destroys them. We humans should take solace, then, in the fact that nature sees fit to destroy not just our great works but its own as well. The great recycling plants that are molecular clouds are ultimately limited, and then destroyed, by their own success. Supernovae and other powerful stellar winds push material around, and the en- ergetic photons from hot young stars eat away at gas that could have extended those stars'...
Implement harmonised standards for retreads crumb rubber and TDF
Safety should of course not be compromised just to reduce the problem of waste tyres, but studies have shown that retreads can be just as safe as new tyres and the retread industry even claims they are of a higher quality than the budget tyres from Asia and Russia. The main problem then is to convince the public of this fact. One way to do this is the introduction of clearly communicated safety standards for retreaded tyres that should be very similar to standards for new tyres. The UNECE...
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 Mwp
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...
Acknowledgements
Many people contributed to the Construction Materials Recycling Project. The project director gratefiilly acknowledges the contributions of the following people as well as other contributors not listed here. Greg Batch, 3M Facil. Eng. amp Real Es David Bergstrom, Eberhardt Commercial Real Estate David Boe, Waters amp Bonner, Inc. R. Bruce Cornwall, Bentz Thompson Rietow.lnc Tracy W. Donovan, Commonwealth Electric of MN Sunny Jo Emerson, Metropolitan Council Craig Gerkin, Materials Recovery Ltd....
ShortTerm Mechanical Testing
Experiments for measuring the effects of reprocessing have now been discussed. MFI as a method of monitoring degradation has already been mentioned, next the methods of mechanical evaluation will be considered namely tensile and impact properties. Tensile testing can be thought of as a stretching test. Tensile properties are a method used widely to analyse the short-term stress-strain response of a material. Computer controlled tensile test machines are commonly employed, allowing one simple...
Conclusion
The experience accumulated so far at the BN plant has demonstrated the commercial viability of MOX fabrication. The MIMAS process developed is suited for commercial use considering the particularity of the MOX fabrication technology and the variability of the plutonium as received from reprocessing. The same process has therefore been choosen by COGEMA for the MELOX plant in Marcoule and for CFCa in Cadarache. The irradiation of MIMAS MOX fuel in commercial reactors as well as experimental...
RESULTS AND DISCUSSION Processing
When mixed plastics waste is processed, one ofthe main problems is to find the best compromise between homogenization and degradation. In the waste material, there are polymers with different melting points and different thermal stability. Especially, PVC and PET are very difficult to process together, because the melting point of PET is over 250oC, and at this temperature PVC is easily decomposed forming HCl and chary residues. Therefore, the optimal processing Figure 1. The modulus and impact...
Polymertocatalyst Ratio
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...
Solvent Degradation By Photocatalytic Oxidation
Photocatalytic solvent oxidation had been demonstrated at the pilot scale in two recent field tests located at McClellan Air Force Base AFB in Sacramento, California and at the Fort Carson U. S. Army Installation in Colorado Springs, Colorado Watt et al., 1999 Magrini et al., 1998 . The objective of the tests was to determine the effectiveness of solar-powered photocatalytic oxidation PCO treatment units for destroying emissions of chlorinated organic compounds trichloroethylene and...
Mechanical behavior of HDPELDPE blends
The mechanical properties of blends of virgin HDPE and LDPE and plastic wastes are below those expected on the basis of an additive rule.22-29 In Figure 5 Figure 5. Polar representation of mechanical behavior of HDPE LDPE system containing either virgin polymers or composition from urban wastes. Figure 5. Polar representation of mechanical behavior of HDPE LDPE system containing either virgin polymers or composition from urban wastes. a polar representation was plotted showing the mechanical...
Quality of the raw materials
Virgin PET had an intrinsic viscosity of 0.78 dl g and was crystallized and solid state-polycondensed upgraded by the chemical manufacturer. PET reground flakes came from an unknown PET source. The flakes consisted of 100 PET before the reground bottle flakes went through a separation and clean-up process. The flakes were not regranulated since this step involves separate machinery and would add to the cost of the reground polymer material. The intrinsic viscosity was 0.03 to 0.05 dl g lower...
Mechanical Properties
The mechanical properties of all the investigated materials are reported in Figures 2-5 as a function of the mixed plastics waste concentration. The experimental results are reported in dimensionless form, i.e., the value relative to each blend is divided by the corresponding value of the unblended matrix. These latter values are reported in Table 2 for three matrices. As expected, all the mechanical properties, except for the elastic modulus, decay on increasing the MPW content. The extent of...
The lifecycle of tyres
The increased number of vehicles has led to a tremendous growth in the volume of used tyres. Over a billion tyres reach their end of life in the world each year Brown and Watson, 2002 of which about 200 000 000 arise in Europe and 290 000 000 in the United States RMA, 2003 . From 1998 to 2008 this is expected to change by 2 every year. Vast quantities of tyres are stocked piled in designated landfills or illegally dumped, since a small quantity is presently reused and recycled see www .rma.org...
Recycling of waste demolition of IBM laboratories Winchester
IBM has a general recycling policy which seeks to reuse or recycle about 50 per cent of the non-hazardous waste produced by the company.6 When in 1993 the company decided to demolish an office block in the heart of an estate of computer laboratories at Hursley near Winchester, it decided to collapse the 1960s building subject to the following criteria as many building materials as possible to be recycled demolition to be safe for site users and those occupying adjoining buildings noise levels...
Properties Of Liquid Product [
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,...
Design Features
Large Flow Area Upper Tie -Plate - Low Pressure Drop - Optimized Hot to Cold Reactivity Swing - Optimized Void Reactivity Coefficient - Simplified Enrichment Distribution - Proven Design Hydraulic Mechanism for High Precision Control of Coolant Leakage between LTP and Channel Box The spacer, upper tie-plate UTP and lower tie-plate LTP play important roles for the thermal-hydraulic performance. The ring-type spacer provides a high critical power which has been demonstrated by testing 4 , The low...
Francesco P La Mantia
Dipartimento di Ingegneria Chimica dei Processi e dei Materiali, Universita di Palermo, Viale delle Scienze, 90128 Palermo, Italy Mechanical properties of secondary plastic materials obtained by recycling of post-consumer plastic containers for liquids are very poor. This is due to the incompatibility between component polymers PET, PVC, and PE and degradation of components during the heterogeneous reprocessing. The use of different classes of additives, such as stabilizers, inert fillers,...
Multimaterial haulers and processors
Organizations that transport and or process more than one construction waste material for recycling. Unless otherwise noted, organizations listed provide waste containers and do not accept deliveries. 1. Haulers, transfer stations, and MRFs that accept mixed loads of construction wastes and sort out three or more materials forrecycling Concrete, concrete block, and or asphalt Concrete, concrete block, and or asphalt Wood dimensional lumber and or pallets and crates. Wood dimensional lumber and...
Signalling and market segmentation
Other market characteristics may also inhibit the take-up of recycled plastics. For instance, market signalling may play a role.48 Similar processes occur with other goods and services where product quality or similar attributes may be unobservable. Thus high quality cars are sold from opulent showrooms, and inferences will be made about cars sold from more basic premises. This could be used as a means of price discrimination, where a manufacturer will separate customers into those with a high...
Comparison of the Composition of Granular Slag and Basalt Lava Rock
I Soua -Jtnqtuunq m Attlttw U tor BMOttftrtrwanung- fWritafai ot Fteidu Rscydtig W sta Report by Dp.-tng. H nul Piper, Nikdaui Sorg GmCH amp Co KG, Jan 26,1991 h N mtorg I Soua -Jtnqtuunq m Attlttw U tor BMOttftrtrwanung- fWritafai ot Fteidu Rscydtig W sta Report by Dp.-tng. H nul Piper, Nikdaui Sorg GmCH amp Co KG, Jan 26,1991 h N mtorg The thermal energy contained in the flue gas is used for generating steam at 400 C and 40 bar in the heat recovery steam generator. The steam is subsequently...
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...
Microstructural aspects of HDPELDPE blends
Figures 9 to 10 show micrographs of the microtomed sections from injection molded bars. The different microstructure of HDPE LDPE blends, having different compositions, are shown Figure 9 . In fact, these thin sections taken in the parallel flow direction inside the cavity of a mold and near the gate, show differences in Figure 13. Micrographs of 85 15 left and 15 85 right HDPE LDPE ratio with 1 LMWPE. Figure 13. Micrographs of 85 15 left and 15 85 right HDPE LDPE ratio with 1 LMWPE. Figure 14....
Solvent Recovery From Hazardous Wastes
Table 22.2.5. Cleaning performance of solvents Table 22.2.4. Properties of cycloparaffins as a cleaning solvent Table 22.2.4. Properties of cycloparaffins as a cleaning solvent Table 22.2.5. Cleaning performance of solvents The process was previously used for chlorine compounds represented by perchloroethylene and trichloroethyl-ene and for fluorine compounds used for cleaning of press stamped metal parts. However, these compounds are now prohibited for use and production by environmental...