Tire Incineration — Solutions

TOPICS WITHIN THIS PAGE
Reuse
Rub­ber­ized Asphalt Con­crete
Devul­can­iza­tion
Monofills
Source Reduc­tion and Improve­ment of Con­tent
Foot­notes

Not only is tire incin­er­a­tion dan­ger­ous, it is also unnec­es­sary. There are a num­ber of much bet­ter solu­tions to the tire waste crisis.

Reuse and Recycling

Tires and tire mate­r­i­al can often be reused. One method of reuse is tire re-tread­ing.¹ Since about 60% of the tire mate­r­i­al is in the cas­ing, re-tread­ing can make a sig­nif­i­cant impact. A qual­i­ty car tire can be re-tread­ed about three times, and larg­er vehi­cles can be re-tread­ed as many as 12 times. Unfor­tu­nate­ly only 10% of cars and light trucks are re-tread­ed. If this were to change, the result would be a major reduc­tion in tire waste.

Tires can also be uti­lized for an almost unlim­it­ed range of cre­ative uses includ­ing auto parts, sound bar­ri­ers, and rail­road ties, just to name a few. They should not be con­sid­ered safe for use in play­grounds, how­ev­er. See safehealthyplayingfields.org and the Tire­less and Non-Tox­ic Play­grounds and Fields Face­book page for infor­ma­tion on why tires should not be used in playgrounds.

Fur­ther resources on the haz­ards of ground-up rub­ber tires in play­grounds, ath­let­ic fields, or gar­den mulch can be found at Envi­ron­ment & Human Health, Inc. (Yale tox­i­col­o­gists), No Tox­ic Turf, Turf Grass Forum, and SynTurf.org.

A good place to look for ideas on tire reuse is the “Recy­cling” page of Mon­tanans Against Tox­ic Burn­ing (the source of the above sta­tis­tics).² The Rub­ber Man­u­fac­tur­ers Asso­ci­a­tion’s report on Scrap Tire Mar­kets is anoth­er great source of infor­ma­tion on mar­kets oth­er than TDF burn­ing.³

As with all waste man­age­ment solu­tions, source reduc­tion and reuse are the high­est goals. How­ev­er, it’s also nec­es­sary to recy­cle as much as pos­si­ble, with­out “down­cy­cling” the mate­r­i­al to a low­er use that can no longer be made back into the same prod­uct. Actu­al recy­cling of scrap tires is very rare, but recy­cling tech­nol­o­gy is advanc­ing and becom­ing more of an option. For details, read the report on “Increas­ing the Recy­cled Con­tent in New Tires” pub­lished in May 2004 for the state of Cal­i­for­nia.⁴

The Cana­di­an province of Nova Sco­tia has banned land­fill­ing and incin­er­a­tion of tires in 1996. Nova Sco­tia has a strong tire recy­cling pro­gram. In Kemp­town, a com­pa­ny named Atlantic Recy­cled Rub­ber Inc. uses a patent­ed cryo­genic process to freeze scrap tires, remove fibers and met­al wire, and pro­duce crumb rub­ber sort­ed into dif­fer­ent mesh sizes to be recy­cled into var­i­ous rub­ber products.

Rubberized Asphalt Concrete

Rub­ber­ized Asphalt Con­crete (RAC) is a “down­cy­cling” use of scrap tires that could dras­ti­cal­ly reduce this waste stream. RAC is cre­at­ed by a process in which tires are shred­ded and ground into dust, then mixed with tra­di­tion­al asphalt. The result is a high qual­i­ty con­crete that can be used to pave roads. RAC is already in use in Cal­i­for­nia, Ari­zona, Flori­da, and around the world. Accord­ing to Joyce Eden of West Val­ley Cit­i­zens Air Watch, “Most if not all of the used tires could be used in RAC. RAC is bet­ter, longer last­ing, uses only 2” ver­sus 4″ of mate­r­i­al to make the road cov­er, is qui­eter and…the tires on the cars and trucks last longer because the sur­face is more giv­ing.” ⁵ The Cal­i­for­nia Inte­grat­ed Waste Man­age­ment Board not­ed in 1992 that “Rub­ber­ized asphalt has the poten­tial to use all the scrap tires in the State in the future.” ⁶

How­ev­er there are cur­rent­ly some seri­ous polit­i­cal obsta­cles to wide­spread RAC use. The cement indus­try is gen­er­al­ly opposed to RAC because it is more dif­fi­cult to apply than tra­di­tion­al con­crete and it is less prof­itable because it lasts longer. There are also some legit­i­mate health con­cerns: There is evi­dence that RAC may pose an occu­pa­tion­al haz­ard to work­ers apply­ing it. Addi­tion­al­ly, a study per­formed in 1995 by aller­gy spe­cial­ists indi­cat­ed that dust from RAC could poten­tial­ly cause seri­ous aller­gic reac­tions in motorists who are aller­gic to latex.⁷

Still, the ben­e­fits of RAC are entic­ing. Below is an excerpt from the tran­script of a Date­line NBC sto­ry on RAC.⁸

MORRISON: (Voiceover) George Way is an engi­neer with the Ari­zona Depart­ment of Trans­porta­tion. He showed us this test road. On one side, a stretch of con­ven­tion­al asphalt four inch­es thick. On the oth­er, just two inch­es of rub­ber­ized asphalt. The dif­fer­ence was strik­ing. Take a look at the rub­ber­ized asphalt. Even after sev­en years of wear and tear it’s still near­ly as good as new.

(Way and Mor­ri­son talk­ing; road)

Mr. GEORGE WAY: Vir­tu­al­ly no crack in it at all, in this sec­tion, and that’s been down sev­en years.

MORRISON: By gol­ly, it’s amazing.

Mr. WAY: It is. It’s darn amaz­ing. It’s pret­ty impressive.

MORRISON: (Voiceover) As for the oth­er stretch of road with four inch­es of reg­u­lar asphalt, the con­stant stream of traf­fic has tak­en a heavy toll.

(Cracked road)

Mr. WAY: (Voiceover) That sec­tion actu­al­ly start­ed to crack up the first year, and it’s got­ten pro­gres­sive­ly worse every year. 

As this excerpt demon­strates, RAC is an impres­sive and valu­able use of tire waste, despite its cur­rent prob­lems. For this rea­son, envi­ron­men­tal sci­en­tists like Dr. Sey­mour I. Schwartz advo­cate the use of RAC. While rec­og­niz­ing that “There are also occu­pa­tion­al health con­cerns aris­ing from RAC use…[which] should be exam­ined more ful­ly to estab­lish if the rub­ber addi­tive is capa­ble of caus­ing seri­ous health prob­lems”, Schwartz insists that “Man­dat­ing RAC use is a pol­i­cy option for real­iz­ing its poten­tial for recy­cling mil­lions of tires per year.…” Schwartz rec­om­mends that gov­ern­ment agen­cies “offer grants for RAC research that study meth­ods for enhanc­ing the gran­u­lat­ed rubber’s effec­tive­ness as an asphalt mod­i­fi­er, and the health effects on work­ers paving roads. Offer oth­er grants to train paving con­trac­tors and work­ers in appro­pri­ate appli­ca­tion meth­ods, and to pro­vide an incen­tive to local gov­ern­ments to use RAC.” ⁹

Devulcanization

Pos­si­bly the sin­gle most promis­ing solu­tion to waste tires is devul­can­iza­tion, a process by which cured rub­ber can be bro­ken down and recy­cled. Recent inno­va­tions in this field have opened up a whole new realm of pos­si­bil­i­ty for gen­uine tire recycling.

Vul­can­iza­tion is the process by which rub­ber is com­bined with oth­er ingre­di­ents, heat­ed, and hard­ened in order to ren­der it into a state where it can be made into prod­ucts like boots, hoses, rain­coats, and tires. It used to be thought that the vul­can­iza­tion process was irre­versible. Accord­ing to Ron Kovalak, a “mas­ter chem­i­cal tech­ni­cian” for Goodyear, “Ear­li­er meth­ods devul­can­ized by using every­thing from microwaves, cryo­genic process­es, pyrol­y­sis, ultra­son­ic waves, alka­li met­als to organ­ic sol­vents, which typ­i­cal­ly yield­ed 1 to 2 per­cent recov­ery.” ¹⁰

That has changed. Goodyear has recent­ly invent­ed a new devul­can­iza­tion process that can recov­er 80% of the rub­ber from waste tires, which can then be revul­can­ized and made into new prod­ucts (includ­ing tires).

Dr. Aavram I. Isayev of the Uni­ver­si­ty of Akron explains UA’s own patent­ed devul­can­iza­tion process:

“When tires and waste rub­bers are devul­can­ized, they can be reprocessed, shaped and revul­can­ized in much the same as vir­gin rub­ber. Our novel…technology is based on the use of high pow­er ultrasonics…The scope of mate­ri­als with this state-of-the-art tech­nol­o­gy includes all kinds of rub­bers such as GRT (Ground Rub­ber Tire), SBR, NR, Sil­i­cone rub­ber, EPDM, etc. and crosslinked ther­mo­plas­tics like crosslinked PE, EVA, etc. their blend sys­tems, and ther­mosets such as polyurethane, SMC, etc…This new tech­nol­o­gy will rev­o­lu­tion­ize the way rub­ber and crosslinked plas­tics are recy­cled.” ¹¹

Dr. Sey­mour I. Schwartz com­ments fur­ther on the impact that devul­can­iza­tion will have:

Eco­nom­i­cal­ly, the mar­ket poten­tial of devul­can­ized rub­ber should be strong because it is capa­ble of replac­ing vir­gin rub­ber and polypropy­lene in high-val­ue prod­ucts at a recy­cled con­tent of up to 40 per­cent. Thus, mar­kets will come to it – to the high qual­i­ty recy­cled rub­ber – rather than need­ing mar­ket devel­op­ment efforts to cre­ate or pro­mote end uses that often must be sub­si­dized. Nat­ur­al rub­ber imports and polypropy­lene pro­duc­tion are each mul­ti-bil­lion dol­lar com­po­nents of the U. S. econ­o­my, sug­gest­ing that the mar­ket poten­tial for sub­sti­tute devul­can­ized tire rub­ber prod­ucts is huge. Per­haps the most imme­di­ate uses for devul­can­ized rub­ber are in asphalt for­mu­la­tions and in pas­sen­ger tires.¹²

Devul­can­iza­tion is clear­ly prefer­able to tire incin­er­a­tion and may very like­ly be the key to solv­ing the waste tire cri­sis if the tech­nol­o­gy becomes prac­ti­cal for wide­spread use. Duro­plas, a cor­po­ra­tion in north­east­ern Mary­land, is already paving the way with new chem­i­cal devul­can­iza­tion tech­nol­o­gy that can use scrap SBR (the rub­ber used in tires).¹³

Monofills

Until devul­can­iza­tion and gen­uine recy­cling process­es are ful­ly devel­oped, a prac­ti­cal short-term alter­na­tive to tire incin­er­a­tion is the use of monofills. Monofills are dis­pos­al sites for shred­ded tires. They dif­fer from nor­mal land­fills because they only con­tain waste tires and can be retrieved at a lat­er date to be ground into Rub­ber­ized Asphalt Con­crete or can be devul­can­ized and recy­cled into new tires.

Accord­ing to the Cal­i­for­nia Inte­grat­ed Waste Man­age­ment Board, “Shred­ding reduces the vol­ume and elim­i­nates oth­er prob­lems asso­ci­at­ed with land­fill­ing and stor­age” and “…shred­ding and monofill­ing tires is a method to safe­ly store this valu­able resource…”. Dr. Schwartz adds that “Retriev­able stor­age pro­vides an essen­tial com­po­nent of a tran­si­tion­al strat­e­gy capa­ble of bridg­ing the gap between the present and a long-term future that fea­tures true recy­cling in an envi­ron­men­tal­ly sound man­ner.“⁹

Monofills are only a tem­po­rary solu­tion, but when com­bined with oth­er tech­nolo­gies like devul­can­iza­tion, they present a real and per­ma­nent alter­na­tive to tire incineration.

Source Reduction

Aside from the afore­men­tioned alter­na­tives, anoth­er impor­tant goal is source reduc­tion, that is curb­ing the quan­ti­ty of tires pro­duced and the tox­ic sub­stances with­in them.

Accord­ing to the West Val­ley Cit­i­zens’ “In 1999, Ford Wind­stars are using Miche­lin tires which use 5% recy­cled rub­ber. Miche­lin’s tests show that they could use 10% used tire rub­ber mate­r­i­al in new tires and get the same results — per­for­mance and last­ing time same as 100% new rub­ber mate­r­i­al. If all tire man­u­fac­tur­ers did this, this alone would reduce the amount of used tires by mil­lions of tires per year.“¹⁴

Dr. Schwartz sug­gests a strat­e­gy to make this hap­pen. Although his pro­pos­al is geared toward the state of Cal­i­for­nia, the same con­cept should apply any­where. To quote him at length:

Miche­lin and Yoka­hama already sell tires with a tread­wear rat­ing of 620, which trans­lates to approx­i­mate­ly 124,000 miles of expect­ed use, and Goodyear sells a tire with a rat­ing of 540 (approx­i­mate­ly 108,000 miles) so there is no ques­tion about the nec­es­sary tech­nol­o­gy being avail­able. The only ques­tion is how to get the largest num­ber of long-lived tires on vehi­cles as quick­ly as pos­si­ble. Edu­cat­ing con­sumers to buy long-lived replace­ment tires at a pre­mi­um price is the wrong answer. These tires must be installed on new cars as orig­i­nal equip­ment, so it will only be nec­es­sary to con­vince or require auto mak­ers to install them. The extra cost rel­a­tive to today’s orig­i­nal equip­ment tires is small, prob­a­bly less than $100 per car – a rel­a­tive­ly insignif­i­cant amount on the aver­age $20,000 price of a new car. Fur­ther­more, the buy­er does not see the cost of tires item­ized, so the extra cost will not be a fac­tor in the consumer’s deci­sion or cause a prob­lem for the auto mak­er. Dri­ving their new cars more than 100,000 miles on a sin­gle set of tires will be the best mar­ket­ing device to con­vince vehi­cle own­ers to buy long-lived replace­ment tires.

I believe that state law should man­date that all new cars sold in Cal­i­for­nia be equipped with tires that have a min­i­mum tread­wear rat­ing of 500 (equiv­a­lent to 100,000 miles of expect­ed wear). Sure­ly, if the [Cal­i­for­nia Inte­grat­ed Waste Man­age­ment] Board can make the case on pub­lic health grounds that it is nec­es­sary to burn 22 mil­lion tires per year as fuel, it can make the case that new pas­sen­ger vehi­cles be equipped with long-lived tires in order to reduce the neg­a­tive health impacts of both uncon­trolled fires and con­trolled burn­ing using TDF.¹²

List of Tire Burn­ing Facilities

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Foot­notes:

1. Tire Retread Infor­ma­tion Bureau. www.retread.org
2. “Tire Recy­cling,” Mon­tanans Against Tox­ic Burn­ing. www.notoxicburning.org/recycling.html
3. “U.S. Scrap Tire Mar­kets 2005,” Rub­ber Man­u­fac­tur­ers Asso­ci­a­tion, Nov 2006.
   https://www.rma.org/getfile.cfm?ID=894&type=publication (796 KB PDF file) [Local copy]
4. “Increas­ing the Recy­cled Con­tent in New Tires,” Cal­i­for­nia Inte­grat­ed Waste Man­age­ment Board, May 2004.
   www.ciwmb.ca.gov/Publications/Tires/62204001.pdf
5. Joyce Eden. Let­ter. www.portaec.net/local/tireburning/california_integrated_waste.thml.html
6. Cal­i­for­nia Inte­grat­ed Waste Man­age­ment Board. Annu­al Report. 1992.
7. P. Brock Williams et. al., “Latex aller­gen in res­pirable par­tic­u­late air pol­lu­tion.” JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY Vol. 95, No. 1, Part 1 (Jan­u­ary 1995), pgs. 88–96.
   Also see www.rachel.org/bulletin/bulletin.cfm?Issue_ID=686
8. Nation­al Broad­cast­ing Co. Inc. DATELINE NBC. (8:00 PM ET) Octo­ber 23, 1998. http://www.portaec.net/local/tireburning/used_tires.html
9. Dr. Sey­mour I. Schwartz. Let­ter to Cal­i­for­nia Inte­grat­ed Waste Man­age­ment Board. Jan­u­ary 21, 1998.
   www.portaec.net/local/tireburning/dr_schwartz.html [Local copy]
10. AOL News. “Goodyear Patents Process to Recov­er Rub­ber from Tires.” Wednes­day, Sep­tem­ber 8, 1999. www.energyjustice.org/files/tires/files/goodyeardevulc.html
11. “Dr. Isayev’s rub­ber and plas­tic recy­cling home” www3.uakron.edu/isayev/
12. Dr. Sey­mour I Schwartz, Let­ter to Cal­i­for­nia Inte­grat­ed Waste Man­age­ment Board. August 31, 1999. http://www.ejnet.org/files/tires/files/schwarts2ciwmb.pdf
13. Duro­plas. www.duroplas.com/technology.html
14. West Val­ley Cit­i­zens’ Air Watch, “Tire Derived Fuel Issues Sum­ma­ry.” March 1999. www.portaec.net/local/tireburning/tire_derived_fuel_issues_summary.html