Scrap tyre

The most obvious advantage to using tyres as a fuel source is the partial alleviation of many of the environmental problems associated with traditional disposal of scrap tyres in stockpiles and landfills. The eradication of tyre piles and landfill waste will reduce many of the risks to human health linked to the buildup of tyre waste. The removal of outdoor tyre stockpiles provides great aesthetic benefits as well. 

O. Senneca, P. Salatino and R. Chirone, A fast heating-rate thermogravimetric study of the pyrolysis of scrap tyres. Fuel, 78, 1575-1581 (1999). 

J. A. Conesa, 1. Martin-Gullon, R. Font and J. Jauhiainen, Complete study of the pyrolysis and gasification of scrap tyres in a pilot plant reactor. Environ. Sci. Tech-nol, 38, 3189-3194 (2004). 

W. Kaminsky and H. Sinn, Pyrolysis of plastic wastes and scrap tyres using a fluidised bed process.In J. L. Jones and S. B. Radding(eds) Thermal Conversion of Solid Wastes and Biomass.ACS Syposium Series 130, American Chemical Society, Washington,D.C (1980). 

Fluidized sand beds are surprisingly insensitive to the unit size of the feed material. Pieces of scrap tires up to a weight of 2.7 kg each were fed and quantitatively pyrolyzed. These results offer the perspective for a pyrolysis process for scrap tyres without prior size reduction. Most pyrolysis processes use feed crushed to a 200-20 nun size which involves considerable expense [9], Successful pyrolysis experiments in an indirectly heated rotary kiln have been conducted by Kobe Steel [3]. 

H. W. Schnecko, Pyrolysis of used tires, Chem. Ing. Techn., 48, 443-447 (1976). W. Kaminsky, Pyrolysis of plastic waste and scrap tyres in a fluid bed reactor. Resource Recovery Conserv., 5, 205-216 (1980). 

Considerable attention has been paid over the last few years to the use of microwave pyrolysis for the processing of scrap tyres. Approximately 2.5 million tonnes in North America, 2.0 million tonnes in the European Union and 0.5 million tonnes in Japan, of scrap tyres are discarded per year. As much as 50% of this waste is landfilled which is clearly causing an increasing unsustainable and unacceptable situation. Other recycling... 

S. Galvagno et al. Pyrolysis process for the treatment of scrap tyres preliminary experimental results, Waste Management, 22, 917-923 (2002). 

D. Y. C. Leung and C. L. Wang, Kinetic study of scrap tyre pyrolysis and combustion, Journal of Analytical and Applied Pyrolysis, 45, 153-169 (1998). 

P. T. Williams and A. J. Brindle, Fluidised bed pyrolysis and catalytic pyrolysis of scrap tyres. Environmental Technology, 24, 921-929 (2003). 

About 180.000 t/a. of scrap tyres remain to be processed, for instance by pyrolysis. In comparison the amount of plastic waste is about 1.4.lo6 t/a which is significantly higher. The main part (about l.l lO t/a) is mixed up with household waste ( 7), and therefore only a few hundred thousand tons are easily available from the producing and processing industries. 

At the University of Hamburg we have been developing a fluidized bed process for the pyrolysis of plastic waste and scrap tyres since 1970. We used three stages of up-scaling - 0.1 kg/h ... 

Products of fluidized bed pyrolysis of plastic waste and scrap tyres (wt-%)... 

In cooperation with the Hamburg company C.R.Eckelmann and promoted by the Federal Ministry of Research and Technology a pilot plant fluid bed reactor for a 1.5 to 2.5 t/d throughput of scrap tyres... 

As a result of our work, the firm C.R. Eckelmann are planning to build a commercial plant with a capacity of 6.000 to 10.000 t/a of unshredded scrap tyres and hydrocarbon-containing waste. 

Pyrolysis can be used for the thermal decomposition of waste materials that are predominantly organic in nature, e.g. scrap tyres, scrap cables, waste plastics, shredder wastes, and acid sludge. Rotary kilns are particularly suitable as universally applicable pyrolysis units for continuous operation. Highly aromatic pyrolysis oils for use as chemical raw materials are obtained at reactor temperatures of about 700 °G. Such pyrolysis oils could form the basis for the production of aromatics such as benzene, naphthalene, and their homologues, thermoplastic hydrocarbon resins and precursors of industrial carbon, when the proven processes for the refining of coal tar and crude benzene are applied. 

COMPONENTS l%] Scrap tyres Waste plastics Shredder wastes Scrap cables Aci d tar... 

The disposal of scrap tyres is currently an important environmental problem, as most used tyres are dumped in landfills. In some cases, accumulations of used tyres have accidentally caught fire, causing the release of toxic substances into the atmosphere. The generation of scrap tyres has been estimated to be of the order of 1.5 million tonnes per year in the European Union, 2.5 million tonnes per year in North America and 0.5 million tonnes per year in Japan.8... 

Williams P. 2001. Pyrolysis turns scrap tyres into oil and gas. Ind. Environ. Manag. 12(6) 24. 

Sept. 2001. Chemicals from pyrolysed scrap tyres. Specialty Chem. 21(7) 6. 

In 1975, Nickerson and Faber reported that scrap tyre mesh after fermentation by fungal strains was physically and chemically different from the starting material [39] the particle size was smaller, the material was hydrophilic, and a marked increase in oxygen content was observed. They specrilated that the transformations, during fermentation of passenger tire mesh, naade the product useful as a soil conditioner, since it had ion exchange capacity. 

R. H. Snyder, Scrap Tyres Disposal and Reuse, Society of Automotive Engineers, Inc., Warrendale, PA, 1998. 

Aguado, R. Olazar, M. Velez, D. Arabiourrutia, M. Bilbao, J. Kinetics of scrap tyre pyrolysis under fast heating conditions. J. Anal. Appl. Pyrol. 2005, 73, 290-298. 

Comparative LCA of two options for scrap tyre treatment material recycling versus TDF combustion [3]... 

Economic advantages of using ultra-fine scrap tyre rubber in virgin and recycled rubber and plastic compounds a comprehensive LCA [4]... 

Scrap Tyre Use/Disposal Study - 1996 Update, Scrap Tyre Management Council, Washington, DC, USA, April 1997. 

In Europe, the major tyre manufacturers have formed Producer Responsibility bodies to collect and recycle their scrap tyres and they fund this process with an up-front charge on their customers invoices [16]. This charge then fimds a national free recovery network, but there are difficulties, because not all tyres and tyre brands are included in these programmes. 

A group at Jiangsu Polytechnic University [17,18] have used a twin-screw extruder to continuously devulcanise scrap tyre rubber and have studied the influence that screw speed and process temperature have on the degree of devulcanisation and the physical properties of the material once it had been revulcanised. A scanning electron microscope (SEM) was also used to study the morphology of the DR... 

A standard production thermo-mechanical reclaiming machine , designated MRR-031, has been developed by Elast-Tekhologii LLC in Russia [20,21]. This machine is capable of reclaiming rubber from scrap tyres and GRG based on SBR, polyisoprene, EPDM and butyl rubber. The reclaimed rubber has been incorporated back into new rubber compounds at a replacement level of up to 90% of virgin rubber polymer. The physical properties that are reported for various... 

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