SCRAP TIRE PYROLYSIS

Scrap tire pyrolysis, 22 466-467 Scrap tire regulations, 22 462 Scrap tire utilization projects, goal of, 22 478... 

Nippon Zeon estimated that the break-even cost of its tire pyrolysis pilot plant was 0.25 per tire (29,30). One study indicates that pyrolysis of tires and other polymers should be considered as a means for disposing of scrap within environmental constraints. A plant processing 81,000 t/yr of scrap could be profitable, based on sales of reclaimed products (31). 

B. L. SchuJman and P. A. White, "Pyrolysis of Scrap Tires Using the Tosco-11 Process— Progress Report," ACS Symposium Series No. 76, American Chemical Society, Washington, D.C., 1978. 

Pyrolysis of scrap tires was studied by several mbber, oil, and carbon black industries [14]. Pyrolysis, also known as thermal cracking is a process in which polymer molecules are heated in partial or total absence of air, until they fragment into several smaller, dissimilar, random-sized molecules of alcohols, hydrocarbons, and others. The pyrolysis temperature used is in the range of 500°C-700°C. Moreover, maintenance of partial vacuum during pyrolysis in reactors lowered the economy of the process. Several patents were issued for the pyrolysis of worn out tires to yield cmde oil, monomers, and carbon black in economic ways [15-18]. The major drawback of chemical recycling is that the value of the output is normally low and the mixed oils, gases, and carbon black obtained by pyrolysis cannot compete with similar products from natural oil. Pyrolyzing plant produces toxic wastewater as a by-product of the operation [19]. 

Pyrolysis - [MANGANESE COMPOUNDS] (Vol 15) -in batteries [BATTERIES - PRIMARY CELLS] (Vol 3) -of benzene [BENZENE] (Vol 4) -of esters [ESTERS, ORGANIC] (Vol 9) -of lignite [LIGNITE AND BROWN COAL] (Vol 15) -of scrap tires [RECYCLING - RUBBER] (Vol 21)... 

The U.S. Environmental Protection Agency s Office of Solid Waste recently produced a report entitled "Markets for Scrap Tires", which summarizes the barriers to development of TDF markets for dedicated tire-to-energy facilities, other utility facilities, the cement industry, the pulp and paper industry, and pyrolysis facilities. Table 1-4 summarizes the reported barriers. 

The only raw material required for most tire pyrolysis processes is scrap tires. Some processors purchase and use whole tires, while others chip whole tires into two inch pieces, or purchase the tires already chipped. Conrad uses a local tire chipper to shred whole tires to a 2-inch size, wire-in, for their use. The tire chipper, who works on Conrad property, receives a tipping fee for collecting the tires, and provides the TDF to Conrad free of charge. 

If markets for char cannot be developed, the char becomes a major solid waste problem. Analysis of char from the pyrolysis of scrap tires does not indicate a problem with hazardous materials.4 However if it must be disposed of in a landfill, the char should be collected in plastic bags and shipped and disposed of in steel drums to prevent additional fugitive emissions during transportation and disposal. 

In 1983, the U.S. Department of Energy evaluated the economic viability of tire pyrolysis and published its findings in a report entitled Scrap Tires A Resource and Technology Evaluation of Tire Pyrolysis and Other Selected Alternative Technologies.2 Their "Economic Results" stated in part ... 

Dodds, J., W.F. Domenico, D.R. Evans, W. Fish, P.L. Lassahnn, and W.J. Toth. SCRAP TIRES A Resource and Technology Evaluation of Tire Pyrolysis and Other Selected Alternate Technologies. U.S Department of Energy. November, 1983. 

Schulman, B.L., P.A. White. Pyrolysis of Scrap Tires Using the Tosco II Process. American Chemical Society 0-8418-0434 9/78/47-076-274. September, 1978. 

The book is presented in two parts. Part I covers the problems associated with scrap tires and identifies existing and potential source reduction and utilization methods that may be effective in solving the tire problem. Barriers to increased utilization and options for removing the barriers are identified and evaluated. Part II provides information on the use of whole, scrap tires and tire-derived-fuel (TDF) as combustion fuel, and on the pyrolysis of scrap tires. The use of whole tires and TDF as a primary fuel is discussed for dedicated tire-to-energy facilities. The use of whole tires and TDF as a supplemental fuel is discussed for cement manufacturing plants, electric utilities, pulp and paper mills, and other industrial processes. The focus of Part II is on the impact of burning whole tires and TDF on air emissions. The information in the book is from the following documents ... 

He is currently supervising a group of 15 students and scientists in the field of pyrolysis of plastic waste in a fluidized bed process and a group in the field of metal-locene/methylaluminoxane chemistry. His past experience includes the development of pilot plants for the feedstock recycling of plastic wastes and scrap tires, and discovering highly active metallocene catalysts for the polymerization of olefins. He has published more than 300 papers and books and holds 20 patents. He has organized several international symposia in the field of pyrolysis and olefin polymerization. 

H. Sinn and W. Kaminsky Pyrolysis of Plastic Waste and Scrap Tires Using a Fluidized-Bed Process. Abstr. Pap. Am. Chem. Soc., 94 (1979). 

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]. 

Figure 17.5 Scheme of the pilot plant for the pyrolysis of whole scrap tires. 1 steel wall with fireproof walling 2 fluidized bed 3 tiltable grate 4 radiation fire tubes, two layers, third layer inlet tubes for fluidizing gas 5 nozzles to remove sand and metal 6,8, and 9 flanges for observation and repairs 7 gas-tight lock 10 shaft for steel cord... 

H. Sinn, W. Kaminsky and J. fanning. Plastic waste and scrap tires into chemical raw materials, especially by pyrolysis, Angew. Chem. Int. Ed. Engl., 15, 660-672 (1976). 

W. Kaminsky and H. Sinn, Pyrolysis of plastic waste and scrap tires using a fluidized bed process, ACS Symposium Series, 130, 423-439 (1980). 

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