Production of Biomass Fuel for Resource Recovery: Trash Recycling in Dade County, Florida

Transcription

1 Prductin f Bimass Fuel fr Resurce Recvery: Trash Recycling in Dade Cunty, Flrida Paul J. Mauriell, AICP and Kathie G. Brks, AICP Department f Slid Waste Management N.W. 53rd Street Suite 201 Miami, Flrida ABSTRACT Dade Cunty, Flrida has been in the frefrnt f resurces recvery frm municipal slid waste since the early 1980's. The Cunty cmpleted its 3,000 tns per day (six days per week) refuse derived fuel waste-t-energy facility in The Resurces Recvery facility is perated under a lng-term agreement with Mntenay-Dade, Ltd. The trash prcessing capability f this facility was upgraded in 1997 t prcess 860 tns per day (six days per week) f trash int a bimass fuel which is used ff-site t prduce electrical energy. Under current Flrida law, facilities like trash-t-fuel that prduce alternative clean-burning fuels fr the prductin f energy may receive credit fr up t ne-half f the state's 30 percent waste reductin gal. Intrductin Prir t waste diversin prblems, and the U. S. Supreme Curt decisin invalidating waste flw cntrl by lcal gvernment, Dade Cunty, Flrida was preparing t expand its 3,000 tns per day refuse derived fuel waste-t-energy facility by 50 percent. Industrial revenue bnds in the amunt f $190 millin were sld in 1990 t finance the expansin, and t retrfit the facility with a new air quality cntrl system t meet federal maximum available cntrl technlgy standards. Lcalized ppsitin t the expansin resulted in frmatin f a Citizens Task Frce Fr Slid Waste Management in This grup, appinted by the Bard f Cunty Cmmissiners, was charged with evaluating the need fr additinal waste dispsal capacity and the apprpriateness f the planned expansin t fulfill that need. The Task Frce was staffed by a cnsultant team, hired by the Cunty t prepare its master plan fr slid waste management, and members f the Cunty's slid waste management department. After tw years, thirty meetings, and cuntless hurs f staff time, the Task Frce agreed that additinal waste dispsal capacity was needed and that the expansin f the Resurces Recvery facility was the apprpriate technlgy. The Bard f Cunty Cmmissiners, hwever, was nt cnvinced and asked the cnsultant t cntinue t evaluate ther technlgies. At apprximately the same time, Mntenay-Dade, Ltd. was apprached by Okeelanta Crpratin, a central Flrida sugar prducer, regarding Mntenay's ability t prvide bimass fuel fr an electric pwer plant Okeelanta was planning. The Trash-t-Fuel (TTF) alternative was brn. TTF had several advantages ver expansin f waste-t-energy capacity at the Resurces Recvery facility. The prcess was less cstly than n-site cmbustin, ff-site cmbustin was mre attractive t residents in the vicinity f the facility, and in 1993 the Cunty was successful in its effrt t have the state legislature amend the state's Slid Waste Management Act t allw clean-burning fuels, used fr the prductin f energy, t cunt tward achievement f the state's 30 percent waste reductin gal fr cunties. Althugh waste diversin prblems and assciated financial impacts were threatening t derail the TTF prject, the Cunty and Mntenay were able t mutually agree n mdificatins t their peratins and 127

2 management agreement that take int accunt unstable waste flws t the facility. The new agreement, dated September 1, 1996, requires the Cunty t deliver all the garbage available in the Cunty's slid waste management system, up t 936,000 tns, but n less than 572,000 tns. The Cunty must als deliver a minimum f 400,000 tns f trash fr TTF and n-site cmbustin, the n-site prtin f which may be displaced by garbage (130,000 tns). The result is an verall annual minimum waste delivery requirement f 972,000 tns and a maximum f 1,206,000 tns depending n waste flw (refer t figure 1). Mrever, t assist with the financial impacts f the lss f revenue prducing waste tnnage, the revised agreement prvided fr a reduced fee f apprximately $5 per tn fr 234,000 tns f the 936,000 tns t be cmbusted n-site, thereby reducing verall facility csts by mre than $1 millin per year. The TTF Prcess The TTF prcess was cnstructed at a cst f apprximately $26 millin and is currently in start-up mde. Under the Cunty's peratins and management agreement with Mntenay, the peratr guarantees that TTF will prcess 270,000 tns per year f trash (862 tns per day, six days per week). The TTF prcessing fee t the Cunty is $22.41 per tn, plus an additinal fee f $1.36 per tn fr the resulting prcessed fuel that qualifies fr recycling credit under state law. When debt service cst and transprtatin f rejects and residue fr TTF are factred in, the ttal cst per tn is apprximately $38. The primary cmpnents f the prcess are a trash srting flr where reject and nn-prcessable materials are remved frm the trash stream, a material strage pit (existing), hppers, cnveyrs, shredders, ferrus metal separatin, material sizing trmmels, material strage bunkers, lad-ut area, and utbund scale. The bimass fuel material prduced must cntain n mre than 3 percent versize material (ver 5 inches in diameter) in rder t meet custmer specificatins. TTF utputs include bimass fuel 50 percent, fines 30 percent (dirt, grit and stnes), rejects 17.6 percent (nn-bimass materials srted frm the incming trash stream), and ferrus metals 2.4 percent (refer t figure 2). The fuel is hauled ut by Okeelanta at its sle cst, and n payment is made t Okeelanta fr taking the fuel. The fines are categrized as primary (lamy dirt material) and secndary (stnes). The primary fines will be supplied t a third party fr plant nursery use. The Cunty is respnsible t accept up t 10 percent f the ttal incming TTF material as primary r secndary fines annually (27,000 tns). This material may be used as landfill cver by the Cunty. Dispsitin f fines abve the 10 percent fines guarantee is the respnsibility f Mntenay. A special unmanned scale was cnstructed t weigh-ut the fuel and fines. The Cunty is respnsible fr dispsal f up t 17.6 percent f the ttal incming TTF material as rejects annually (47,520 tns). Dispsitin f rejects abve the 17.6 percent rejects guarantee is the respnsibility f Mntenay. Ferrus metals recvered frm the TTF prcess are transferred t the Resurces Recvery ferrus bunker fr further prcessing by Namc Internatinal Crpratin, an n-site third party metals prcessing cmpany under cntract with Mntenay. Cnclusins Dade Cunty was successful in negtiating unique waste delivery guarantees and financial enhancements t ensure that this innvative expansin f its Resurces Recvery facility wuld prceed withut WFC. Withut reinstatement f lcal gvernment waste flw cntrl (WFC) authrity by the federal gvernment, hwever, the frmatin f public/private partnerships t develp facilities similar t Dade's TTF prcess elsewhere in the State f Flrida, r elsewhere in the natin is unlikely. In Suth Flrida, the ptential fr develpment f such facilities is reduced further by the abundance f lw cst waste dispsal alternatives, primarily landfills. 128

3 References 1. Official Flrida Statutes Published by the State f Flrida, Tallahassee. 2. Third Amended and Restated Operatins and Management Agreement by and between Metrplitan Dade CuntY,1<lrida and Mntenay-Dade, Ltd., September 1, 1996; Reslutin number R Nn-Exclusive Agreement Between Metrplitan Dade Cunty, Flrida and Waste Management Inc. f Flrida fr Prvisin f Municipal Slid Waste Dispsal Services, Octber 27,

4 DADE COUNTY, FLORIDA RESOURCES RECOVERY FACILITY GARBAGE AND TRASH COMMffMENTS September 1, 1996 Frm: September 1, 1996 After: RTIAPCD** ii'\9 N? R 1t@9 M!NmHm?;gOO T&tiJ'!::/. \.. Yi\ r.;. TraShM II i :.1 Ttal 972,000 w MAXIMUM WASTE DELIVERY AMOUNTS If garbage is available fr delivery, Cunty must deliver up t - 936,000 ARTGT- 270,000 Maximum Waste Delivery Amunt- 1,206,000 *AOSWGT - AnnuaLOn-site Waste Guaranteed Tnnage **RTIAPCD - Recyclable Trash Imprvements Actual Perfrmance Cmpletin Date ***ARTGT - Annual Recyclable Trash Guaranteed Tnnage (Figure 1)

5 .. DADE COUNTY, FLORIDA TRASH-TO-FUEL PROCESS en Q Z :::J 0 :::c J Z - en 100 z J- 2.4 % 17.6% 30.0% 50.0% TRASH INPUT [((CG' 'err'," 1 OUTPUTS BIOM ASS FUEL (135K) fi1 FINES (81K) (Figure 2) D REJECTS (48K) mj FERROUS METALS (6K)