Recycling waste tires

There are various ways to recycle waste tire rubber. The first approach consists of reducing the tire rubber into scrap rubber. Sometimes, before retreading old tires with new rubber, the part of the tire that needs extracting is converted into scrap. 

Recycling waste tire rubber is such large a problem that it could be covered only by a book entirely devoted to the subject. Eollowing the scope of the present book concerned with the cure of rubbers, only general considerations have been made by giving attention to applications employing, to some extent, the cure process. 

Sadaka, F., Campistron, I., Laguetre, A., Pilard, J.F. Telechelic oligomers obtained by metathetic degradation of both polyisoprene and styrene-butadiene rubbers. Appl. Recycl. Waste Tire Rubber 98, 736-742 (2013)... 

Waste tires are a significant health and environmental concern if they are not recycled or discarded properly. Over the years, recycling waste tires into civil engineering applications, especially into asphalt paving mixtures and Portland cement concrete, has been gaining more and more interest (54). 

Tires. As with MSW disposal, state and local communities have sought increased utiUty assistance in waste tire management. In the United States, scrap tires are generated at the rate of one tire per person per year, and only 20% are reused or recycled in some fashion. Stockpiles exceed 2 x 10 scrap tires (see Recycling, rubber). 

According to E.W.M.C. International Inc., the Emery microwave process has been used commercially to recycle rubber tires and process medical waste. Research and development is currently being conducted on the application of the technology to treat contaminated media. All information is from the vendor and has not been independently verified. 

About 242 million automotive, truck, and off-road tires are discarded in the United States each year. This is approximately equal to one waste tire per person per year. Additionally, there are 33.5 million tires that are retreaded and an estimated 10 million that are reused each year as second-hand tires. It is estimated that 7 percent of the discarded tires are currently being recycled into new products and 11 percent are converted to energy. Nearly 78 percent are being landfilled, stockpiled, or illegally dumped, with the remainder being exported. 

An integrated solution is needed to the waste tire problem. Both government and industry need to work together to develop markets for scrap tires and to ensure proper disposal of those tires that are not recycled and are not incinerated for their energy value. In the next two sections of this chapter, options for mitigating the scrap tire problem are discussed. 

Both the Federal government and states have sponsored research. Funding levels for Federal research on the waste tire problem have fluctuated widely over the past two decades. The Department of Energy (DOE) has also researched recycling of tires, incineration and pyrolysis. Pyrolysis in particular, received significant research funding in the 1970 s, but the economics as yet have not been favorable for this technology to be commercially established in the United States. 

Tire dealers need ready access to information on reputable or licensed haulers, recyclers, or disposers of waste tires. They also need information on companies that sell used tires and that retread tires. Information on the location of large tire piles is helpful to entrepreneurs seeking to process these tires for eventual recycling or energy recovery. 

Another means to aid recycling of tires and the utilization of tires as fuel is to expand the use of existing solid waste exchanges to include tires. Classified advertisements in magazines and newsletters can help those who have sources of... 

Tires, Rubber—Recycling. 2. Recycling (Waste, etc.)—United States. 3. Waste products as fuel—United States. I. United States. Office of Solid Waste. II. Clark, Charlotte. 

The market for scrap tires and the technology for recycling and/or pyrolyzing them are discussed in this book. The management of scrap tires has become a growing problem in recent years. Over 242 million scrap tires are generated each year in the United States. In addition, about 2 billion waste tires have accumulated in stockpiles or uncontrolled tire dumps across the country. Millions more are scattered in ravines, deserts, woods, and empty lots. 

Maridass B. and B.R. Gupta. 2003. Recycling of waste tire mbber powder. KGK Kautschuk Gummi Kunststoffe. 56 232-6. 

In search for a more economical process for recycling used tires, the ultrasonic devulcanization technology was further investigated to develop a feasible process to minimize the stockpiles of waste tires. This process induces the cleavage of the chemical networks through the combination of ultrasonic and chemical devulcanization (Kim et al., 2003). According to authors, the products from devulcanization of tires are carbon black and extended oil that can be used in many applications. A claim was also made that the technology can separate sulfur. 

Fig. 8 Waste volume and recycling of tires from used vehicles [25, 26]...

Recently, a novel continuous process has been developed for devulcanization of rubbers as a suitable way to recycle used tires and waste rubbers [83-119]. This technology is based on the use of high-power ultrasounds. The ultrasonic waves of certain levels, in the presence of pressure and heat, can quickly break up the three-dimensional network in crosslinked rubber. The process of ultrasonic devulcanization is very fast, simple, efficient, and solvent and chemical free. Devulcanization occurs at the order of a second and may... 

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