LlTljih

8

9

9

H

G u

S

S

2

S

o 2

to bO

Cfl o

Figure 1-1. Trace metal levels in whole waste tires compared to bituminous coal.5

NOTE: Tick narka Indicate Matured wait* tire netal concentration«. Bar ahous the range In trace aetal concentration« Matured In bltinlnou« coal.

come from existing piles, in which the tires are often old and very dirty. TDF must be purchased from a tire-shredder, or shredded on-site using purchased or leased equipment.

Energy required to produce smaller sizes of rubber pieces increases exponentially.7 For example, about 40 Btu's are required to produce one pound of 6-inch TDF, while 750 Btu's are required to produce a pound of 1-inch TDF.7 From a general cost perspective, 2-inch TDF, wire-in TDF, can cost as little as $20/ton, whereas crumb rubber (wire-free, from 20-30 mesh) averages $160/ton.7 Capital costs, of course, vary according to capacity. A shredder that can chip 100 tires/hr into 2-inch TDF costs about $50,000? larger machines (1000 tires/hr capacity) can cost $500,000.7

Haulers may be paid from $0.35 to $5.00 to dispose of whole tires.1 In general', the cost to landfill whole tires is double the cost to landfill mixed munic oal solid waste. The rate charged for landfilling whole tires depends on the quantity of tires being landfilled and the region of the country. For small quantities, landfill fees range from $2 to $5 per truck tire.1 One survey in Illinois found that, in 1990, Chicago-area landfills charged an average of $2.98 to landfill each passenger tire.7 For large quantities, tipping fees range from $35 to $100 per ton for whole tires. In some instances, a landfill's bad experience with whole scrap tires have led to a ban on the tires.

Shredding companies charge from $19 to $75 per ton to form TDF.1 Many States and municipalities allow landfilling of shredded tires, but not whole tires. In States where landfill space is at a premium, and tire tipping fees are high, landfilling shredded tires can result in a considerable savings over disposing of the tires whole.1

One TDF supplier has found that pulp and paper mills are the most profitable (i.e., purchase the most expensive type of TDF) type of customer, followed by cement plants and utility boilers.8 Pulp and paper mills pay a higher price for TDF for several reasons. First, the pulp and paper mills demand a higher quality of shredded tire? that is, tires that are clean and have all the metal removed.8 Second, they do not have the fuel-buying power that a utility might have; thus, tires provide a proportionally larger economic incentive for them.8 One pulp and paper mill was paying approximately $39 and $43/ton for TDF in 1990 and in part of 1991, respectively.9

Cement manufacture is a power-intensive process, which allows cement companies to buy fuel in bulk and obtain the fuel at a somewhat lower price. Also, kiln feed mechanisms are easily modified, to accept alternate fuels. Further, because temperatures in a kiln reach 2700*F, kilns can burn poorer quality coal than pulp and paper mills or even utilities, and can easily tolerate a wide variety of waste products.10 In addition, kilns can accommodate the lower priced TDF (wire-in TDF and even whole tires). These factors make the economics of supplying TDF to cement manufacturers less favorable than for pulp and paper mills.10 One cement manufacturer is paying approximately $30/ton for TDF.11

Utilities have the least economic incentive to use tires.8 Often, power plants that use TDF only substitute up to 5 percent of their total energy requirements with TDF. Utilities must buy better quality coal (i.e., higher heat value and lower ash) than cement plants, but have significant bulk fuel-buying power. They are not usually interested in TDF unless the price is $1 per million Btu's (MMBtu's) ($30—$31 per ton) or less.8 The use of petroleum coke has recently been increasing in the utility industry, partially in response to the reduced demand for coke in the depressed steel industry.10 Coke often costs from $0.50 to $0.75/MMBtu ($14 to $21 per ton), which is difficult for TDF to match in many regions.10

Regional economics of TDF are paramount. Electric Power Research Institute (EPRI) created a computer model of TDF use in a cyclone-fired boiler. The model included an economic analysis of alternative fuel firings to account for the fact that, if boiler efficiency decreases, the company would need to purchase power to replace power lost by the boiler derating.12 These costs are called "busbar power costs".12 Even considering the decrease in the net heat rate caused by TDF use, the model found that TDF provided overall savings in levelized busbar power costs relative to 100 percent coal-firing.12

1.2.3 Air Pollution Emissions Issues

The principal concern when using tires for fuel is the effect on emissions. Pollutants of particular concern include criteria pollutants, particulates, metals, and unburned organics.

Particulate emissions may increase if combustion is not complete. As seen in Tables 1-2 and 1-3, sulfur emissions may decrease if the tires or TDF replace higher sulfur coal, but may increase if tires or TDF replace wood waste containing little sulfur. NOx emissions, likewise, may increase or decrease based on the relative nitrogen content of the fuel. Also, NOx emissions may increase if additional excess air enters the combustion system to facilitate the feed of the tires or TDF.

Heavy metal content varies in tires and TDF relative to coal as shown in Figure l-l. In particular, zinc, which is added to tires during rubber compounding to control the rate of vulcanization, has the potential to increase from an emissions standpoint.13

Organics, especially polynuclear aromatic hydrocarbons, were measured at a number of facilities. Dioxin and furan formation are also of concern because of their toxic nature.

The two main process units burning TDF and tires are kilns and boilers. Kilns are usually controlled by electrostatic precipitators (ESP's) or fabric filters. Boilers are usually controlled by venturi scrubbers or ESP's, although some are uncontrolled.

A recent EPA report characterized the emissions from the simulated open burning of scrap tires under experimental conditions.14 The report identified several pollutants of potentially significant health concern from uncontrolled scrap tire fires, including benzo(a)pyrene, benzene, lead, zinc, and numerous aromatic organic compounds.14 Environmental concerns identified by the report included leaching of metals present in the ash to groundwater systems and localized problems resulting from high S02 emissions.

1.3 MARKETS FOR TIRES AS FUEL

Applications that can burn whole tires include a few cement kilns, large dedicated tires-for-fuel boilers, and some experimental applications in utility boilers. Applications that can use TDF include most cement kilns, many thermal decomposition units, boilers at pulp and paper plants, utility plants, and other industrial facilities.

As described in more detail in subsequent chapters, the desirability of tires or TDF varies among each industry. Often that advantage is regionally specific, because the incremental benefit of tires is tied to regionally comparative fuel prices.

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.

1.4 STATE WASTE TIRE DISPOSAL PROGRAMS

As of January 1991, 33 States had laws or regulations pertaining to disposal of waste tires. Other States introduced waste tire measures in their respective 1991 State legislatures. Nine States remain with no legislation passed or pending.15

Table 1-5 shows the status of waste tire disposal laws for States with laws, and summarizes some features of the measures.15 Table 1-6 lists States with laws or regulations proposed and those with no planned laws or regulations. Many States have provided funding for reasons such as developing scrap tire recycling industries and administering disposal programs. Funds also are dedicated to increasing tire or TDF market incentives by methods such as allowing price preferences when purchasing recycled and recyclable goods, or to give priority status to businesses proposing to expand use of tire derived material. Table 1-5 also lists which regulations cover storage, processing, or transportation of tires.15

Of the 33 States with either laws or regulations in place, over half (18) include market incentives for tire use, such as a monetary rebate, grant, loan, or funds for testing.

Table 1-4. Market Barriers to TDF Use

Industry

Econoaic Barriers

Non-econoaic barriers

Dadteatad Tire-to-

Coat of air pollution équipant.

1. Siting.

Power Industry

1. Lou utility buy-back retes for electricity in aany ragfan* of the U.S.

Low tipping fee in aany regions.

1. Siting.

1. Handling and feeding capital costs.

2. Lou cost of alternóte fuels.

3. Expense and dountiae in enviroraental peraitting process.

Oelay in environmental peraitting procedures.

Pulp and Paper Mills 1. Wire-free TDF is expensive.

2. Handling coats.

3. Low alternate fuel cost.

1. Wire in TDF can plug soae hog fuel boilers.

2. Wire can liait ash aarket.

3. Higher PM eaissions than for hog-fuel alone.

4. Use of new fuel often requires reopening of enviroraental peraits.

Pyrolysis Fecilitit

1. Capital and opereting coats.

2. High cost for upgrading char by-products.

1. Upgrading char needs to be coonerciaUy deaonatrated on a sustained basis.

Table 1-5. Waste Tire Disposal Laws in the U.S." January 1991

Stat* (»«ulatonr Coverege funding Source

Nirkit Incentivas landfill •estrlctlona

Air Emissions Delatad Ci

CO CI FL

LA ME

»l/tlra retail salas

».50/vehlcla tftla peralt fee»/tlre storage »It«»

St»te budgtt appropriation

».50/vehlcle title fee

M/vehlcle title transfer

grant»

grantt/loan»

grante grants grants grants fmd»/te»tlng bans who!» tire»

tiras i ban» Uiole and cut tires bans whole tires leport fro« Integrated Ueste Management find due 12/1/91 on <a»»ibU(ty of tire us» In cenent kiln», pulp and paper, and other operation».

Fmfir« S TDF tett burns In 1991; IL peys 90* of test cost (deference 7). Lou Interest loans to fuel uaera to retrofit or laprove equipment.

Finding S TDF te»t bums In 1991 paya 90X of te«t cost (deference 7). low Intereit loans to fuel users to retrofit or laprove equipment.

Watte tire abatement report recconend» u»a of TDF at the 3 Itsta Universities.

Table 1-5. (Concluded)

Funding Sourc•

Harket Incentive«

landfill Restrictions

Air Ealsslona (elated Cement»

OH OK

TN TX

VT WA

Ul wv

IX aalet tax on new tires town gradiated vehicle registration fee

Sl/tlre surcharge new tira sales

»1/tlre disposal ta> on new tira sales

S.50/tire tax on neu tire salea fmdi coLTity tira collection grants S.01/lb graduated tax per tira alia

S.SO/tlre disposal fea on new tira salas

Si/vehicle registration

SZ/tire per vehicle title fea

*20/ton finds/teatlng grants S20/ton tires suit be cut tires aust be cut tlrei auat be cut tlrea aust be cut tiras at be cut law bans tlraa as a source of fuel within State, within 30 »lie of any reservoir watershed, and bana tlra export outside Stat* as a fuel source.

Open burning banned except In areaa with population! under 5,000.

bana wholt tires bans wholt tire»

Several Stata siixldiied tests of TDF and lAol* tire«.

tires aust be cut Tires have been burned at < faculties In Ul.

Ss o

cr o

'!» Storage regulations P • Processor regulations N • Hauler regulations

Table 1-6. States Without Laws or Regulations for Waste Tire Disposal15

January 1991

Statut

Legislative Comiente

Air Emissions Related Comenta

AK AR HS NY

SC AL DE GA

NO PA

Proposed Proposed Proposed Propoted

Propoied None None None

None

None

None

None

None None

NY also ha« environmental conservation lau ulth «ectlon that regulate* tire transportation.

Solid uatt« aanageaent plan under development No iegUlatlon

1990 Conprehenalve Solid Uaite Management plan ha« no it«ted tire dltpotal requirement«.

Draft ttateulde «olid uaite management plan doe« not addre«« tire«.

Propoted bill to require State «olid uatt* planning encourage« general recycling.

Solid ua«te plan befor* legislature doe« not mention tire«.

1987 Recycling Act ha« tlr* recycling incentive«, but no rettrlctlon*.

No legltlatlon.

Tuo uaata tlr* bill* Introduced In last year«; neither retulted In leglctatlon. No plan* for 1992.

Honolulu County plans • «crap tlr* aanageattnt progra that uould provide for tlr* shreddlrv for sal* to Honolulu Pouer.

* S ■ Storage regulations P ■ Procestor regulations H ■ Hauler regulations

The law in one State, Rhode Island, bans tire burning as a source of fuel within the State and within 30 miles of reservoir watershed.15 Furthermore, it bans tires exported from the state to be burned as fuel.15 South Dakota regulations, on the other hand, permit open burning in areas with populations under 5000.15

1.5 METHODOLOGY

First, a literature search was conducted to gather information on pyrolysis and burning tires for fuel and to identify companies using tires or TDF in their process. Information was gathered on emissions, control techniques required, control technique effectiveness, and control equipment cost.

Second, information was gathered through contacts with EPA Regional, State, and local air pollution control agencies. Copies of emission test results were requested and analyzed to determine the effect of burning tires either as the sole fuel or as a supplemental fuel. Permit applications and permits were reviewed to determine the processes using tires, the control techniques used, the limits set, and the permit conditions under which the permits were approved. Trade associations provided information on companies burning tires, and other available information.

Third, site visits were planned to facilities burning tires or TDF. Six companies, one from each major industry group using tires for fuel or pyrolysis, were selected for site visits. The facilities visited included the following:

• An electrical generating plant using tires as its only source of fuel

• An electrical generating plant using tires to supplement their primary fuel

• A cement manufacturer using tires to supplement its primary fuel in a wet process cement kiln

• A cement manufacturer using tires to supplement its primary fuel in a dry process cement kiln

• A paper mill using tires to supplement their fuel in a waste heat boiler

• A pyrolysis plant thermally decomposing tires into products.

In addition, a facility that shredded whole tires into TDF was visited. At each site, information was collected on the processes using tires, modifications necessary to accommodate tire use, control equipment in use, effect of tire use on emissions, control equipment effectiveness, cost of process and control equipment changes, changes in personnel or resource needs, and benefits of tire use. Problems using tires, and tire supply issues, such as source, quality, and reliability, were also discussed.

1.6 REFERENCES

1. U.S. Environmental Protection Agency, Office of Solid Waste. Markets for Scrap Tires. EPA/530-SW-90-074B. September 1991.

2. Scrap Tire Management Council. Scrap Tire Use/Disposal Study. September 11, 1990. p. 1-4

3. Murphy, M.L. Fluidized Bed Combustion of Rubber Chips: Demonstration of the Technical and Environmental Feasibility. Enercrv Biomass Wastes. 11:371-380. 1988.

4. Jones, R.M., J.M. Kennedy, Jr., and N.L. Heberer. Supplementary Firing of Tire-Derived Fuel (TDF) in a Combination Fuel Boiler. TAPPI Journal. May 1990.

5. Pope, K.M. Tires to Energy in a Fluidized Bed Combustion System. Presented at EPRI Conference: Waste Tires as a Utility Fuel. San Jose, CA. January 28, 1991.

6. Wisconsin Power and Light. The Operational and Environmental Feasibility of utilizing Tires as a Supplemental Fuel in a Coal-Fired Utility Boiler Preliminary Report. State of Wisconsin. 1990 Waste Tire Management and Recovery Program.

7. Berger, C., Illinois Scrap Tire Management Study Summary. Illinois Department of Energy and Natural Resources. Presented at the EPRI Conference: Waste Tires as a Utility Fuel. San Jose, CA. January 28, 1991.

8. Memorandum from Clark, C., Pacific Environmental Services, Inc. (PES), to Michelitsch, D., EPA/ESD/CTC. October 2, 1991. Site Visit — Waste Recovery, Inc.

9. Memorandum from Clark, C., PES, to Michelitsch, D., EPA/ESD/CTC. October 2, 1991. Site Visit — Smurfit Newsprint Corp.

10. Schwartz, J.W., Jr. Engineering for Success in the TDF Market. Presented at the Recycling Research Institute's Scrap Tire Processing and Recycling Seminar, West Palm Beach, FL. April 27, 1989.

11. Memorandum from Clark, C., PES, to Michelitsch, D., EPA/ESD/CTC. October 28, 1991. Site Visit — Calaveras Cement Company.

12. McGowin, C.R. Alternate Fuel Co-Firing with Coal in Utility Boilers. Presented at the EPRI Conference: Waste Tires as a Utility Fuel. San Jose, CA. January 28, 1991.

13. Gaglia, N., R. Lundquist, R. Benfield, and J. Fair. Design of a 470,000 lb/hr Coal/Tire-Fired Circulating Fluidized Bed Boiler for United Development Group. Presented at EPRI Conference: Waste Fuels in Utility Boilers. San Jose, CA. January 28, 1991.

14. U.S. Environmental Protection Agency: ORD:AEERL:CRB. Characterization of Emissions from the Simulated Open Burning of Scrap Tires. EPA-600/2-89-054. October 1989.

15. Recycling Research Institute. Third Annual Legislative Update. The Scrap Tire News. Vol. 5, No. 1. January 1991.

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