Co-principal Investig~tors Robert Pfeffer, Ph.D
Transcription
Co-principal Investig~tors Robert Pfeffer, Ph.D
EVALUATION AND TEST PROGRAM OF A 50-TON PER "WASTE CONVERTER" Investig~tors Co-principal Robert Pfeffer, Ph.D, GabrieliTardos, Ph.D and Alberto LaCava, ~h.D. for the United states Department of Energy Office of Inventors Support Division under Contract DE-FGOl-82-CE-15126 F. J., Ramos Technical Director i 2148 Nw 17th Street Pompano Beach, FL 33069 Phone' (305) 950-0222 (BOO) 932-9652 Fax ;(305) 960-1050 :;;) ,~, TABLE OF CONTENTS ABSTRACT EXECUTIVE SECTION A 1. 2. 3. 4. 5. 6. 7. B. SECTION B 1. 2. 3. 4. 5. SECTION C 1. 2. 3. 4. 5. 6. 7. B. 9. 10. SECTION D 1. 2. 3. 4. 5. ........... ·....... SUMMARY • . . . .-. . . iii iv ·........................ Introduction • • • • • • • • • • • • • • • • Background • • • . • . • • • • • • • • • . • Professional Consultants • • • • • • • • Process Description • • • • • • • • • • • • • Air Pollution Testing • • • • • • • • • • Air Emission Standards • • • • • • • • • • • Dioxin and Furan Emission Standards • • • • • Universal Emission Standards • • • • • • • • ·................. • • • • • • • • . .• .• .• .• Description of the Facility and Equipment Measuring Equipment • • • • • • • • • • • Computerized Data Acquisition System •• Process Control in the Plant • • • • Software Development • • • • • • • • • • • • • • • • • • • • ........ ·............ Introduction . • • • . • . . • • • • • . • • . • Scarifier • • • • • • • • • • • • • • • • • • Dryer . . . . . . . .. . . . . . . . . . . Char Ram . . • Stack Damper Haste Converter ..... • . • • • • . • . • • • • • • • • • • • • • • ............... . Temperature Monitoring • • • • • • • • • • • • • Pyro Burner . • . . Burner History and Re-Design • • • • • • • • Conclusions • • • • •• • • • 0 • • • • • • • • • • A-4 A-4 A-4 A-5 B-1 B-1 B-2 B-B B-10 B-12 C-l C-1 C-1 C-2 C-3 C-3 C-4 C-4 C-5 C-5 C-6 D-l Introduction . • • . • • . . • . • • . • . . D-1 Operational Characteristics of the Plant • • • • D-1 A SIMULATION MODEL OF THE PLANT • •• • • • D-13 MATERIAL AND ENERGY BALANCES AT THE DESIGN CONDITIONS • • • • • • • • • • • • • • ',. ~ -. • .. 0-13 MATERIAL AND ENERGY BALANCES UNDER ENVIRONMENTAL TEST CONDITIONS • • • • 0-14 ... SECTION E · . . . . . . . . . . . . . . . . . . . . . . . . 1. MUNICIPAL SOLID WASTE AND SOLID RESIDUE. .. 2. 3. 4. A-I A-I A-I A-I A-I STACK EMISSIONS • • •• •• • • • • • • • • • • • • • • EMISSION CONTROL CONCLUSION • • • • • •• • • APPENDIX 1 PLANT SIMULATION RESULTS TABLE 1 - DESIGN CONDITIONS TABLE 2 - ENVIRONMENTAL TEST, ACTUAL CONDITIONS ... E-l E-l E-13 E-22 E-25 Numbers A-1 B-1 B-2 B-3 D-l D-2 D-3 D-4 D-5 D-6 D-7 D-8 E-1 E-2 E-3 List of Figures schematic of the Process. schematic Representation of the waste Converter unit at Testing site. Instrumentation and Process Control Diagram. Schematic of Data Acquisition system. Flowsheet of the waste Converter Plant. Effeciency of Volatiles Conversion in the waste converter. ',,',.' '!", , Municipal waste ,Moisture 'Effedt on Theoretical Energy productionpr~ lb., of wet waste. Ste~ ;Eriergy VS ,Feeprat;.e Htfficiency Depends on Feedrate . ' 1 " , Total Energy VS Feedr'ate" Efficiency Depends on Feedrate. , Boiler Exbess Air Depended upon Feedrate. Steam Production"of Moisture'., ComparisoI):, Plant Simulation with Actual Results. Typical Coinpos'itiori, of>~SW. Volumeariki weight Reduction of MSW. Hydro,...Sonic Scrubber. A-3 B-4 B-5 B-9 D-2 D-4 D-6 D-8 D-9 D-ll D-12 D-15 E-2 E-7 E-24 ltfumber lB-1 D-1 D-2 ))-3 ))-4 E-1 E-2 E-3 I~-4 E-5 E-6 E:-7 E:-8 E-9 E:-10 E-11 E-12 E-13 Key to Temperature and Pressure Numbering System, Figure B-2. Conversion to Gas. Conversion to Energy. Steam Rate VS MSW Feedrate. Comparison, Simulation VS Measured Emissions. MSW Proximate Analysis. MSW Ultimate Analysis. MSW Hazardous Characteristics Analysis. Char Proximate Analysis. Char Ultimate Analysis. Char Hazardous Characteristics Analysis. MSW Volume and Weight Reduction. Heavy Metal Concentration. Air Pollution Testing Results - Uncontrolled Emissions. New Jersey Emission Guidelines for New Resource Recovery Facilities. Air Pollution Testing Results, Uncontrolled Emissions. Uncontrolled Heavy Metal Emissions. Comparison of Waste Converter Controlled Emissions. B-6 D-3 D-5 D-12 D-14 E-3 E-3 E-4 E-8 E-8 E-9 E-10 E-10 E-14 E-16 E-17 E-20 E-26 ABSTRACT This overall project was begun in 1978 under the Non-Nuclear Energy Act of 1974. Under the Act, a request for evaluation of an energy-related invention, now known as The Waste Converter, was made to the U.S. Department of Commerce, National Bureau of Standards (NBS), Office of Energy Related Inventions (OERI). The National Bureau of Standards/Department of Energy (DOE), Energy Related Invention Evaluation Program, Undertook the evaluation,. The operating experience of the OERI shows that of, some 10,000 inventions submitted for evaluation about 2, percent were recommended to the DOE for support. In 1979, thi,s particular invention, was recommended by NBS to DOE for support to identify the precise n'ature of the energy savings to 'be made if the invention were" utilized., In 1982, the Inventors'Support ,Division of DOE granted, assist.ance: awa'rd No. DE-FG01-82CE15126' for extensive testing and evaluation of. a 50-ton, per 4~Y:,waste,.converter. t' , " The results of tMfinal: testing' ~nd evaluation set forth hereinafter indicates that the invention has the ability to provide substantial energy savings in an environmentally safe manner, utilizing municipal solid waste as its sole sourCe of fuel. The technology, ary distillation, should be able t,Q'convert a wide variety of potentially hazardous waste products into useable energy without polluting the atmosphere. These include garbage, pharmaceutical waste, printers, inks, paper, plastics, solvents, agricultural waste and Other organic material. iii EXECUTIVE SUMMARY In the past, energy recovery from municipal solid waste (MSW) has been viewed as a large-scale enterprise suitable for application only to large amounts of waste processed per day. The present study, commenced in 1982 and partially funded by the Department of Energy Contract No. DEFGOl-82CE15126, reports on the process evaluation of a patented 50-ton per day modular resource recovery invention known as a Waste Converter. It has been clearly demonstrated that the waste converter is a viable commercial means of disposing of MSW and recovering energy at the same time. PROFESSIONAL CONSULTANTS The testing of the waste converter was supervised by Professors Robert Pfeffer, Gabriel Tardos;and Alberto LaCava, of the Department of Chemical Engineering, ~he City College of The City University of New York, who were consultants to the project. The protocol for the testing of chemical emissions from the waste converter was formulated in accordance with currently existing regulations of the U.s. Environmental Prot,ection (NJDEP). OBJECTIVES The basic objectives of the project were first set forth by the U.S. Department of Commerce, National ~ureau of Standards in a 1979 recommendation to the DOE for support of the invention: (i) To gather complete cost dflta, efficiency ratings and other information throuighout a significant test period. (ii) To have such data accepted as authoritative, generating such data under the guidance of respected persons in the academic world. (iii) Finally, to release this authoritive data to the public, to accelerate utilization of this process in designing energy recovery systems." The scientific and economic objectives of this s·tudy· were to evaluate the invention's capacity for converting municipal solid waste into useable energy and also: (iv) To obtain a significant reduction in volume and weight of the MSW 1Ilsed as fuel. (v) To obtain a maximum conversion of MSW into energy with minimum air and water: pollution. iv To evaluate the economic potential in marketing the recovered resources. (vi) Upon completion of the evaluation of The Waste Converter the basic objectives of an environmentally sound waste disposa~ system and its related resource recovery capabilities were successfully demonstrated. WEIGHT AND VOLUME REDUCTION , The tested "MSW' consisted' of over 50 percent biomass. When subjected to .the destructive distillation process, at temperatures of about 10000F,the biomass is reduced by over 90 percent volume and by ove,r75 percent in weight. !'< CARBON ;ii ,,' i'i cltARm:sIbuE I. The biontass' is' 'converted in the oxygen-free atmosphere of the waste ponverter to' gaseous compounds and into a carbon char solid residue • Th.e:i'pr6cessed ch~:tis free of living organism. Glass, metal and '~r.tt pre's'enb in the char are sterilized by the heating process. Due to tl}e chemical reactions taking place during the destruct~:ve distillation 0:1; MSW, heavy metals -.., such as lead and other,e,lie~~pt:s .lik~ chlorine' -- have a tendency to be absorbed or encapsul.J&t:~Ki dQrttalninantsresist leaching when the char is exposed to waletlti. 'il:[rrh:i,s ••.. f~!~tu:te .' is!:ponsidered' to be a most favorable envirdIliY!~~~~ilil!:,Cipa~IIa:~t~!r:i,'St~¢ ~.; dhemical analysis of. these residues detected no il;iben,zpdio:xins' or dibenzofurans. . 'i AIR \1"-',-::I;i':"'I;:,' I "i < EMlsstONS' The most significant air emission finding made during the testing of the waste converter uncontrolled emissions was that llQ dibenzodioxins or .dibenzofurans were detected during the processing of unsorted municipal solid waste. The waste converter if equipped wi th a Hyd~o-Sonic scrubber can be guaranteed to meet or exceed all existing federal' EPA and state air emission standards. L ,, ,, , I I! , ! RESOURCE RECOVERY POTENTIAL Steam • When the waste converter produced gas was combusted in a standard water tube boiler, energy recovery in the form of superheated steam averaged about 2.5 pounds of steam per pound of MSW processed. This net energy yield resulted after efficiency losses in the burner and boiler and energy; requirements to sustain the process were taken into .account. The Energy Tax Act of 1978 requires that electricity produced by steam generated from MSW be purchased by Public utility Companies thereby automatically assuring a market. v Ferrous metal • • • After completion of the process, ferrous metal was found to be relatively clean and unmelted. It is recommended that ferrous metal be recovered after processing, only if economically warranted or necessary to meet specific resource recovery requirements; otherwise it should be magnetically removed from the waste stream prior to the drying process and deposited in a landfill. At present there is no market for unclean scrap. Carbon Char • • • EP toxicity tests performed on the carbon char residue after reducing the char to ash showed increased leaching of heavy metals; for example, l'ead by 244 percent. Carbon use as an absorbent predates Roman civil~zation and can be utilized in pollution control. Tests of the adsorbent qualities of the carbon manufactured by the waste convert~r should be undertaken to determine if this carbon has industria~ application which would give it a substantial economic value. Oni the other hand, if burned this char could add 20 percent to the tbtal energy output of the system. Glass and Non-Ferrous Metal • • • These materials do not slag during the heating process in the wast~ converter, however, the pulverized condition of the glass and the: minute quantities of nonferrous metal found in the residue makes the recovery of the materials mechanically or economically u:nfeasible. CONCLUSION The results of the environmental, energy and resource recovery studies have clearly demonstrated that a significant reduction in volume and weight of the MSW used as feedstock is achieved and that the process produces a significant amount of useful energy. Conversion of MSW to energy with minimum air, ground and water pollution should apply to almost any loc.jl.tion where a facility of this type is contemplated. It must be t,aken into consideration, however, that there may be unique local ,factors, such as extreme climatic conditions or lack of energy users that could influence the economic viability and subsequent ~plementation of similar projects at certain locations. vi "t'<;lt11 ': ,, ; .. •• l l .. i • i t SECTION A SECTION A FORWARD 1. Introduction The subject of the testing program was a 50-ton per day waste converter. This converter produces a volatile gas product ( sui table as a boiler fuel) and carbon char residue via the destructive distillation of municipal solid waste (MSW). Actual testing was performed on a demonstration unit located at Marcal Paper Mills, Inc. in Elmwood Park, New Jersey. 2• Background Testing of the waste converter was s~pported in part by the Department of Energy Contract No. DE-FGOl-82CEI5126, under which an evaluation of the technology was begun in September 1982. Initial efforts focussed on specifying and implementing the complete instrumentation and ~ontrol of t~e system schematically shown in Figure A-I. An instrumentation and process control diagram in presented in Figure B-2 and 'rable B-l. With this operating conditions and with many! different machinery modifications in order to optimize the process. Upon completion of this phase of the program, environmental! testing of the waste converter was performed by an independent tEi!sting laboratory. This testing encompassed the sampling of the !( 1) MSW feedstock, (2) produced volatile gas (fuel), (3) char res~due and (4) stack flue gases. u.s. 3. Professional Consultants The overall program was supervised by Prof. Robert Pfeffer, Gabriel Taros and Albert LaCava of the Department of Chemical Engineering. The City College of the City University of New York, who were the consultants to the project. Actual testing of the environmental discharges was conducted· by Princeton Testing Laboratory of Princeton, New Jersey, A New Jiersey-approved chemical testing laboratory. 4. Process Description The waste converter is a continuous ~elf-sustaining process utilizing a combination of patented devices which convert 50-tons per day of biomass waste into the heat equivalent of about 3,000 gallons of fuel oil in the form of hot' off-gases, which are partially used to heat the system; the r~maining gas is used as fuel in a separate steam boiler. The process, Figure A-I, is based on the principal of destructive or dry distillation and produces a A-I volatile gas and carbon residue; no liquid fuel of residue is generated. The processed MSW is reduced by about 90 percent in volume and about 75 percent in weight. Shredded MSW is fed into a rotary drying unit, which utilizes process waste heat, to remove excess moisture. After drying, the MSW is transferred directly into the waste converter using hydraulic ram. The waste converter unit is an oxygen-free slowly rotating retort maintained at a tempElrature somewhat above 1000 degrees Fahrenheit. Within the waste converter, the conversion of organic materials, ~swel1as'thegeneration of gas, takes place. This gaseous product is then 'c:ombusted in situ in a standard (Babcock wilcox) water tube steam boiler to produce 225 psi superheated steam at 435°F. The "key to this technology is the waste converter. The high temperature and 'the absence of oxygen in the retort permit no dire,~t incineration, or b~rning of the MSW to occur. Furthermore, t,hese • pa~ameters,allow .for the generation of volatile gas that can '_ ,I "', '. be "urt,il,ized ,as ,'a bOl.ler ,fueL As a result, the waste converter p.F9dpcersuse,fulenex:;gyfrom muniqipal solid waste, while minimizing ~~e,jI'0Hut~~m, F~rCl~lems,i1orinally associated with mass-burning l.~c~p,e:r::p.~ors ., 1_ ,,', ' ' , A-2 ----------~~-------------.hi. -~------- _. ,~I,__- ·oa __ . • •_ ..-- '---~- .. ~ .~~'::':-·"il . .; SCHEMATIC OF PROCESS BOILER SHREDDER 0w .A ~~ J!:}i.' ~ '1m ((\\ MAGNETIC Yw~ SEPARP..TION o " 0, , , 1 PRODUCED GAS r---7 DRYER ... !to MUNICIPAL SOLID WASTE ,..!---L-,--' I w ---<7 ~I"ASTE CONVERTER ",' , ~~II. .' ~ ~Q~ j GAS TURBINE I • RAM 1 ,I .r I STEAM, TUR BINE ,',t, WET REFUSE ,,*ETAL BINI7 'GENERATOR ~ '-', : PRODUCED I GAS .J. l (115 ... useD TO SUSTAIN PROCeSS) "Tl C> C ::rJ \ CHAR BIN ' / o 0 m >I ... 5. Air Pollution Testing Environmental testing was -conducted on waste conversion. Technology's demonstration unit at Elmwood Park, New Jersey. The tests were performed while using municipal (residential-commercial) solid waste from the Monmouth County Recl8.lllation Center, Tinton Falls, New Jersey. Air pollution stack testing was carried out in accordance with methods and procedures established by the U.S. Environmental Protection Agency (EPA) and the New Jersey Department of Environmental Protection (DEP). All samples were taken from a common stack venting the drying unit, distillator unit and the boiler. This stack had no pollution-'contrpl equipment installed for the removal of, air contaminants. . 6. Air 'Emission Standards Under current air pollution regulations pertaining to Prevention of Significant Deterioration (PSD) and Nonattainment Area New Source Review (NRS), specific numerical emission standards are not defined for a new source. Each proposed new facility must propose emission. standards that reflect Best Available Control Technology (BACT) (for PSD) and/or Lowest Achievable Emission Rate (for NSR) for the equipment to be installed. The environmental regulatory agency: reviews the proposed emission standards and, on a case-by-case b$.sis, determines whether or not the degree of control is sufficient to protect human health and the environment. 7. Dioxin and Fhran Emission Standards Dioxin and furan emissions from municipal garbage incinerators have only recently become an issue because only recently has the technology been developed to measure these emissions in minute quantities. Dr. Barry Commoner l , Director of the Center for the Biology of Natural Systems, Queens College, states that dioxin is a chemical compound which is created when lignin is burned with chlorine. The prime contributors of chlorine to household waste are products mad¢ of polyvinyl chloride while wood and paper are the principal contributors of lignin. The debate over dioxin emissions is complicated by the fact that, as of this data, there is no univers.ally accepted standard for what), if anything, is a safe level of exposure. lThe New York Times, December 5, 1984, Metropolitan Section, p.3. A-4 During testing of the waste converter, no dibenzodioxins or dibenzofurans were detected in t.he stack flue gases emitted from tbe destructive or dry distillation of municipal solid waste. S" Universal Emission standards It is important to note that at present there are no universal emission standards specifically defined for new resource-recovery facilities. A-S SECTION B SECTION B THE RESEARCH & DEVELOPMENT FACILITY 1. Description of the Facility and Equipment The test facility was housed within a 45' x 50' x 36' clear span steel pre-fabricated building. The building was erected on a 8-inch steel reinforced concrete slab. An overview of the facility is pictured in Figure B-l. Included in Figure B-1 are Detail I-A and Details 1 to 9, which correspond to the equipment described below. Municipal solid waste (MSW) feed~tock used during the test period was provided by Monmouth County 'Reclamation Center (MCRe). all MSW was shredded at MCRC, loaded in a standard 40' transfer t:railer and then trucked to the test site, a distance of 128 miles round trip. The shredded MSW was then 'unloaded from the transfer t:railer to a Keith Walking Floor (Detajil 1): live-bottom storage container of approximately the same dimension as the transfer t.railer. The Keith Walking Floor, suppll~ed by Keith Mfg., Co., was modified with a computerized electronic strain gauge scale system, (Detail 1A). The floor allowed the weighing of refuse and a.utomatically regulated the feed to the waste converter. The Keith Walking Floor was an ideal metering device in this application. The test facility was capable of shredding incoming waste to a uniform size. The rotary shear-type shredder (Detail 2), supplied by Eidal International, was fbund to be ideal for this application. The slow-speed shredder is specifically designed to reduce dust and eliminate the possibility of explosions that are associated with hammer mills. Since its inception in 1972, a period of some 13 years, there has not been one reported incident of an explosion involving a rotary shear shredder. The shredder was located over the Keith Walking Floor. The shredder was fed by a modified Heil hydraulic lifting system. Objects such as engine blocks, hot water tanks and tree stumps had to be separated from the waste stream before shredding. Experience indicates that a c.ommercially available Grizzly hydraulic lifting device, manufactured by Crane Equipment Mfg., Inp., should be incorporated in the system to replace the experimenta~ hydraulic lifting system. The Scarifier (Detail 3) was design'ed and constructed on site and was installed at the discharge end 6f the Walking Floor. The sc::arifier, in conjunction with the computerized Walking Floor, off loads shredded waste at an automatid,ally pre-set rate ranging from 10 pounds per minute to 100 pounds!per minute. As the waste is discharged from the. Wal~ing Floor. pnto a feed conveyor, it passes through a magnet~c f~eld (Deta~l 4) removing the ferrous metals. The waste is then transported ~o the rotary dryer. B-1 The FioKi Dryer (Detail 5) has one major moving component: a rotating steel tube 35 feet in length, and 6 feet in diameter enclosed in an insulated steel oven. The dryer is installed above the distillator. The discharge from the dryer passes directly into the feed ram of the distillator firebox is used in the drying process. The Waste Converter (Detail 6) is similar in design and construction to the dryer. The major component of the converter is a, steel retort tube 32 feet in length and 4 feet in diameter. This tube! is also enclosed in an insulated oven. As the feed ram (Detail 7) forces the waste into the retort of the converter, the waste, is cpmpressed into a semi-solid plug , thereby creating an air-tight seal. ", After, the ~aste hasbeE!m forced into the retort by ther atn sY:Ftem, destrut:ti:v~',or dry distillation begins to take place in ,the ' ox~gen~free ::', atmosphere.' The waste, continues to d~compbsea~ itmovesslo..tly through toe rotating retort to the dlii;t:ha!tge"eridofithe system. ','!,." , ," d , ,.' , I I 'j , .\,' , ' : :i, ', 'i _ ;:. ': ' ,; -: ;: ;1 .; , G'a's produced by the ,dry distil1~t:;ionoftH~ organic materials of the amount , requilied to sust,ain the converter , i s draWI'loffand is immediately burne~La~ ':Ii~ue;l'iih 'c;tspecJially' cOlnstruc,ted ' gas" burner (Detail 8). ~his9~S't:'~nilb~' bU'rnedl;hy itself Or fited int:6njunctionwith other fuels tl:ilInthe': e\rent,lii6'f':~ ,hbiler:p;hu:tti,own oran,overprodu¢tion of gas, the gas isauto~aticaliy flared. th~':MSW , i n excess tempet:atil1~elof,th!e "waste in , ~; ," :1;1 Ylt,: ~. ,:j." Ii: '_I _ '-', :1 ... ':i! :_' ';' , ~fiteffuost;'9fthei,volati!Le\$>roducts have been extracted from the b;jliP'IIlf~s'(MpW) , ·thEH remaining\char residue is removed from the wastei\l~qpy~:ttJrl~yi'ia, hYdfau.tililici:::ra:m (,Detail 9).; At this point, the drigil:l!elil,' ,)jlL~m~~i,? :i,('HSr/F t&at :llwa:sl$ubjected to the dry distillation proc~~!~ ~a!~ilpeeni'l~etlu~~dlllinil:,'8~).l«l~lbyover 90 percent and in weight by ,ovW4'ltt",15111:[perfl¢n,lt,+'i'lli-rhelii:rtel~!f~e~~ei:~,ime in the waste conve.rter is cib, o~t,ljl,lliW'5,' , ,'~,ti,'n, u,::~~,'I, ~'":i,!i~ndi!',I !ie" ,'X!,!I.I~, ,Q, ,',:, I:i, I~, i,'.~, :I"l i,',i.rt,L,~'e, '~S.W,' and ~esul tant, resl.due. to tefll',pe,:',ti!!~,!t,,ultil,, ~~',', JJ,bi!"I~:lI!, ll±e,S$r',:dO,',:,f,' lH10,'O"IO,f,)EI,irll\',i",' , T;Hl., s extended exposure, to hl.gh tempe~~lt:iiu:llt:el~i' [;nllil~d, ox'YJIS'~n':'lfF~el!lfa~m.oSlphere, converts the volatiles qf. i1i~~!iI'i~ "~~S~i!ll!fidll!!FJii$!i 1~~(fii!~~~:il'~l~ a:id~esidue of char. The char is freellll#>iif 'II, in(iilIIP~~~~f~I#~ .1:II!ii~~~I,4:):,S 1!!Ii~ound in the residue such as gliassWII!I~~,'i!~~~li!ijriiJ#I!~ea~~th!li~,~erril:ized in the heating process • . ' 2:.; ,'t,l1!li!j!i:,. ,. ': :::-:: ,: ~i [l~; \ ,: '::' I:,., ;1 ~~a!s;uri:ngJ",flq1!ilji:iPmerit:: ';: !11i!~'i '.I!li::! (::ili:l; ,_ 1 i, 'Ii! The instrumentation and process control of the 50-ton per day waste converter was carefully designed and installed during the test period. AS:chematic diagram of the plant showing the location of the,. thermocouples, presshre transducers, pitot tubes, orifice meters,!, dampers lanit p~elltnat:i:c actuators is given in Figure B-2 and Table:!a-l. 'Theinstrl.'hnent.ation and control of the boiler was instaiJ;iledisepara!~efY tiy :ltheCleaverBro~ks Corporation. A total of 35 CntIOmeI"'Al.ume~\EhermcilcolipleS t 19 Vall.dyne pressure transducers, 15 ori.fice p]:at·es and 3 pitot tubes were installed and connected to a Burr Brown industrial-type front end computer interface which was B-2 located near the operator control panel of the plant. The Foxboro actuators were pneumatically operated and had the capability, by using current to pressure transmitters, to be computer controlled. B-3 FIGURE; ELECTRH ".t· RO"'A a: o ~ z > o u ,, ,I I I I \r-----~~~~~~1r~~L---------------------~~~~~~~~~~~~~ II: o oQ I Q I I ~ I .. KEITH WALKING FLOOR I I 0: I W , OETAIlI., I > o ,I H"o-.l!\'" ROTARY SHEAR SHREJ)OER ( OETAIL 2' I , ,I .. " J = ==:::c::== J ,. ..•. /' = ... .. ~ SCHEMATIC REPRESENTATIONS OF THE CONVERTER UNIT AT TESTING SITE W~STE B-4 j, I; 'OltIlORO PNEUMATIC ACTUATOR 1m QDI{fUlfruIIru lID I I OAI'lCd~1 !'LATE f I I I I I DRYER r 15 BAROMETRIC DAMPER oi>~.IIOIIO PNEva.. hC n ·\'OltIlORO.)1I 1 PIIEUMATIC,._ _- ' L... ,..., tD I In ACTUATOR I I LAB. I je 1~~~1~'L..1-l E1 ;;;;;'Lqn' I I: I, LINE TO ANALyTIcAL ;',", ACTUATOR I I I I CONVERTER .~ rUA t3511 IIAM FEED£II .T35C !.J/ HAND OPERATED DAMPER FO.IlOAO !'NEUMATIC ACTUATOR / SOLENOIO VALVE \!: 'ii' il $lAIIToUP GAS Llkf ORlnCE "LATE fLOWMfT£R OXYGEN ANALYZER LEGEND or:l STEAM PRESSURE -B BOILER PRESSURE T~'HSOUCER THERMOCOU"U -{) "MEUWATIC ACTIVATOR n- I"TO T TUIII! r1 ORI'ICE "LA fE , [mo'I'~ ~,., I• ',> ~)Hl? .,11 ~ INSTRUMENT ATION AND PROCESS CONTROL DIAGRAM O~"PER / <] o SENSOR (LOAD CElLI STREAM HUMBER' 'TI &::> c m :0 CD I I\) TABLE B-1 KEY TO TEMPERATURE AND PRESSURE NUMBERING SYSTEM TEMPERATURES Pyro Gas feed line into boiler Gases exiting retort fire box Gases exiting dryer Dryer bypass duct Gases from inside dryer Gases from dryer fire box Boiler exhaust Flarestack temperature located above the roof Steam from boiler Flarestack located below roof level Converter retort tube interior temperature Converter tube skin temperature Tempei'ature of material feeding into dryer Convei'ter fire box temperatures PRESSURE TRANSDUCER P I 'O-P 14 PIS P 16 P 17 -P 24 " P 28 P 33 PI P2 P3 P 26 P 2S P 27 Gases entering dryer, orifice plate pressure drop Drrer bypass, orifice plate Gases from dryer interior, orifice plate flowmeter Gases exiting dryer, orifice plate flowmeters Boiler s.teampressure Natural 'gas flowmet.er, orifice plate A:j;,r intake, flow topyro gas burner in retort fire box, pitot tube pyro gas flow into retort fire box, pitot tube aq~ler pyre!> gas flow, pitot tube Boiler exhaust gasiflow, pitot tube Dryer exha~s~ gases and bypass gases, pitot tube Flifirestack, [located! above the roofline, pitot tube B-6 The Burr Brown front end computer communicated with a LabTech 70, microcomputer (Laboratory Technologies Inc.) which was installed in an elevated trailer that overlooked the plant. This trailer served as a combination of instrument and control room and office for the personnel involved in the testing project. The LabTech computer has 380Kbytes of memory, a 10 MB Winchester hard disc, a floppy disc. back-up and the necessary software for Real Time Multi-tasking operation (IRMX - 86 operating system). The computer was also equipped with an AIDS Viewpoint terminal, an Epson MX-80 dot-matrix pdjnter and a Hayes smart modem to allow telephone communication to and from another computer or terminal. The entire computer syst~m as described above was carefully selected by the consultants iat the time as the best and most cost-effective system available to handle the multi-tasking required to properly evaluate and control the operation of the plant. ' In addition to the computer systiem, a number of analytical instruments were installed for analyzinig the produced gas and stack gases. A 1/2" line from the stack to the instrument room was installed. This line was heated usingl an electric strip to 150°C and was insulated to pH·Tent condens~tion of HCL using an HCL analyzer, and for partie" lates, aftejr cooling and removing of water, by using a ,<oyco l<:·del 2~7 co~nter. The cooled stack gas could also be aL; lyzed ,ising gas !chromatographs which were specifically purchased for this task. One of the chromatographs was a GC-Orsat analyzer and was used for measuring N2 , H2 , CO, and CH 4 ; the other was a hydrocarbon ahalyzer and was used for hydrocarbons up to C70 • The measurement of S02 and NOx was to be performed by an outs~de laboratory. The gas produced by the dry distillation process could be analyzed by first separating out any co~densible liquid using a dry ice trap and then sending the non-bondensible gas to a gas chromatograph. The liquid condensed in. the dry ice trap could then be recovered with a sol vent and analyz'ed by chemical means. The combination of the gas and liquid anal~sis could then be used to assess the composition and heat content ,of the gas and vapors which are produced by the waste converter before it was sent to the boiler. This information, together with the rate of flow of produced gas, was used to determine the efficiency of the process. The amount of feedstock at a per-mlnute rate of processing by 1:he waste converter was digitally displaiyed automatically using the LabTech 70 Computer. The Walking Flooriwhich discharges the waste onto the feed conveyor was equipped with four load cells. These load cells are connected to an amplifi~r, transducer and then to , B-7 the digital readout. The signal from the load cells was also sent directly to the Burr Brown front end and continuously transmitted to the LabTech 70 Computer. The installation of the aforementioned equipment and measurement devices involved many hours of skilled labor. Much of this equipment was installed after the system had been constructed and was operational. Portions ·of the converter's duct work had to be dismantled, re-designedand re,...assetnbled in order to accommodate tJbiei,on-goinginstallation of ,the measurement equipment. The,retrofitting and" field "install'ation, 9f this equipment resulted in educatingbothen~in~~rs; an~ :te,s:ting ,personnel. in the practical dperation'iofthe tel?t': ,f~qiHty. 3,!'comp~~erized'Data Aci~U:isi.t:.iohsyst':,em < • ", ,"'!', ; ,,',,'! The data acquisition and control of the plant was also based upon the LabTech70 measurement and control computer a.nd a Burr Brown MCS100A-116 'data acquisit;ion. and control front end. The sensor~J f;,~ansd/.1cers ,'and a!?:tuator~ of the Waste ,Converter Plant are shoWDi:i.'n :F~9ure:~,-3.!' i.', ,i: ,iI' ", ' 1:_! ':1 , : I, \ 'I B-8 .1, . -- -r------------------------I I LAB TECH I 'TI C) c :n m CD ,.I "- The installation of the instrumentation and sensors was described in Section B, "Measuring Equipment." An overview of the position of the sensors in the plant is given in Figure B-2 and Table B-1. After installation of the measuring devices, an important task was the calibration of the sensors. This was performed for all thermocouples, pressure transducers and load cells in the plant. The calibration data was incorporated into calibration subprograms resident in the LabTech 70 Computer. Some of the sensors were recalibrated frequently (load cells and pressure transducers ) since they exhibit zero drift and some variation in the calibration constants. All calibration programs were written in FORTRAN, to provide automatic conversion of the signals received by the front end compu,!::erinto the desired engineering units. Further description of the data: acqui~ition software is given in the section "Software Development~" Data obtained.du!I."ing experimental runs of thewasteconV'eiter plant were printed and a backup of the data was sayed on floppy diskettes. 4. I I I t ~ Proces!S Contro.l in the Plant Data obtained during the preliminary testing period suggested that the following factors were important in regulating the overall effectiveness of the waste converter plant: I. Pressure Control in the Waste Converter: The pressure in the waste converter had to be maintained very close to atmospheric pressure, and slightly positive •. This prevented entry of air into the retort chamber. Pressure fluctuations were monitored and controlled to insure smooth operation of the boiler burning system. To attain control Objective 1, the pressure was measured with a t:r:ansducer ,.PT3 , (see Figure B-2) and the barometric damper on stream 27 (same figure) was opened or closed to allow for pressure equalization. In the case of excess pressure, the damper opened :to allow some of the fuel gas to flare in the main stack, thereby equalizing the pressure. The control loop was implemented in a program that operated on a one-second cycle, using a PID (Proportional Integral Derivative) numerical algorithm. However, since the barometric damper presents a highly non-linear response to output position, an adaptive control algorithm was implemented, which was able to correct for the nonlinearities of the device. As a result the gain of the PID controller was modified as a function of the valve opening, in that the response of the feedback loop was always tuned according to the Ziegler-Nichols criteria. The control loop had a manual override, in case of equipmeIlt failure. B-IO -'}'~>f~;';~*~~~'~t{;-~;$i~t;{~J~~_ ~i~i~10;rf-"'4\1:},!/~j~<\~~~~~'~k'i ~:i>::J II. Moisture Control of the Feedstock: The waste converter plant uses waste heat to' eliminate moisture present in the municipal waste. The transfer -of heat and the subsequent vaporization of the moisture takes place in the dryer. The control objectives for maximum effectiveness of operation of the overall plant are to permit the maximum transfer of waste heat so that the municipal waste is as dry as possible. The amount of heat being transferred has to be controlled. Control Objective II was implemented insuring that the temperature sensed by thermocouple T16 was always lower than the ignition temperature of waste. When. that pre-set value was reached, pneumatic actuators closed the dampers in streams 10, 11, 12, 13 and 14 (preventing the admission of hot waste gas to the dryer) and opening the damper on stream 15, to bypass the hot gases directly to the main stack A proportiona~ controller algorithm was used in this loop, with a scanning frequency of fifteen seconds. III. Feedrate Control: The feedrate should be fairly cClnstant. This improves operation of' the solids manipulation equipment such as the dryer and the ram ihjectors. This results in minimizing swings in the produced gas flQ~ rate. The efficiency of the magnetic metal separator unit is also improved, and in turn reduced possible blockage in the solids handling equipment. Control Objective III was implemented from a calculated value of the feedrate, received from the walking floor load cells and cClrrected by calibration. The algorithm controlled the average feedrate by modifying the Keith Walking Floor hydraulic movement. This control system was based upon a reading cycle of one second averaged through fifteen seconds, to avoid excessive fluctuation of the controls of the walking floor. IV. Temperature Control of the Retort: The optimal operating temperature of the retort has two considerations. On one hand, extremely high temperatures shorten the life of the retort tube and enables the melting of glass, thereby creating slag. On the other hand, it is desirable to operate at a temperature as high as po>ssible, to increase the yield of volatile gases from the feedstock. An optimal temperature is maintained to serve both considerations so that plant efficiency is Jr,aximized. Once this temperature is established, the objective of the control system is to maintain this pre-set value. Control Objective IV was implemented by using the signal from thermocouples T35A and T34 and a pneumatic actuator installed on Stream 1. The actuator modifies the flow of air admitted to the converter heating furnace. The design of the pyro burner was based upon a Venturi feeding of the fuel gas driven by the air flow and B-ll pressure, the actuator on Stream 1 controlled the flow of fuel gas to the combustion chamber. A proportional integral numerical algorithm was used in this control loop, on a scanning cycle of fifteen seconds • 5. . Software Development During the testing program, a variety of computer programs and subroutines necessary for data acquisition and control of the waste converter plant were written. These routines were integrated into a final data acquisition and dontrol program, structured ill the .. following manner: PROGRAM NAME FUNCTION MAIN Initialization creation of all tasks and assignment of priorities. TASK 1 Schedules and keeps the timing of "TASK 4." TASK 2 Schedules and keeps the timing of "TASK 5. " TASK 3 Schedules and deeps the timing of "TASK 6. " TASK 4 1 Sec. cycle fast task. Controls retort pressure, measures weight and feedrate, measures steam flow and production, measures natural gas flow and amount used. TASK 5 15 Sec. medium speed task. Performs data acquisition over all sensors. Controls retort temperature, dryer temperature and municipal waste feedrate. Performs units conversion using calibration subroutines. TASK 6 10 Min. printing and reporting task. This task organizes and prints a reports on the status of the plant. The report gives the values measured in the plant to the terminal and printer. Also saves a data acquisition file on floppy diskettes. B-12 The above tasks use a series subroutines that were prepared to communicate with the Burr Brown front end. A description of the routines follow: a. Program Name: TASK 5 This program is the foundation for the complete data analysis and control system used at the test facility. In conjunction with the sub-programs to be described below, "Task 5" communicates with the Burr Brown front end computer, giving the commands for the Burr Brown to read the output of the entire network of instrumentation. It then. reads these values into the LabTech 70 memory, converting the machine code into appropriate scientific units (degrees fahrenheit, millivolts, etc.) and makes them available either as a printed hard copy of as terminal screen output. b. Program Sub-routine: Communic'ate This sub-routine handles the entire communication task between the LabTech 70 main computer and the Burr Brown front end. The main program calls "Communicate" giving j,t a character string line that represents the command for the fro~t end computer. Through the ; sub-routines that follow, "Communicate" identifies the communication port, sends the command anp receives the reply; the reply being either data or a command ;ceceived confirmation. This reply is then returned to the main program. c. Program Sub-routine: SPWRIT "SPWRIT" is called by "Communicate," given the communication port identification code and the command which is now in integer fo.rm. It reads the status of the port and sends the command integer when the port status is ready. See program listing comments for details. d. Program Sub-routine: SPREAD "SPREAD" is called by "Communicate" and given a port identification number. It reads the data in the port after checking for a "port ready" status. See program listing comments for details. e. Program Sub-routine: SPINIT "SPINIT" initiates the communication port for data transmission as described in the comments on the program itself" See program listing comments for details. B-13 f. Program Sub-routine: SETBAUD "SETBAUD" is called by the main program at start-up, to define the communication rate between the LabTech 70 and the Burr Brown front end. See program listing comments for details. g. Program Sub-routine: HEXA-CONV "HEXA-CONV" is called by the main program when a hexadecimal string must be converted into decimal values. It reads each loc,ation in the string, identifying- it as one of the hexadecimal characters with ,values of ,0 to 15 in decimal. The decimal value is assigned to a variable lid" which then.multiplies the appropriate power of 16 represented by the location within the string of the original hexadecimal, character. This value is added to the decimal base conversion of the'original hexadecimal string. These subroutines were, complemented by calibration routines which implement the calibration curves "and equations to calculate flowrates from pressure drops in orifice plates andpitot tubes. " L I- r " \i -I Ii,I" 11 l--J I'1: I' B-14 • SECTION C SECTION C RESEARCH & DEVELOPMENT ACHIEVEMENTS 1. Introduction The R&D facility occupied 2,250 square feet and was design rated to process 50 TPD of "as received " MSWi the daily disposal rate required to service a population of about 25,000. In order to achieve the design feedrate, the following modifications were made. 2. Scarifier Monmouth County Reclamation Center (MCRC) was contracted with to provide feedstock for the test. All MSW, shredded at the MCRC, was loaded in a standard 40' transfer trailer and then trucked approximately 62 miles to the test site. At the test site the transfer trailer was positioned in front of a Keith Walking Floor storage container which was approximately the same dimension and elevation as the transfer trailer. The MSW was then pushed into the storage container via a hydraulic ram located within the transfer trailer. The MSW loading at Monmouth and the unloading at the site resulted in over compacting the feedstock. This compaction made it virtually impossible to meter the desired amount of feedstock onto the feed conveyor. Magnetically separating the ferrous metal from the overly compacted waste was found to be difficult and resulted in extracting an unacceptable amount of biomass from the waste stream. modification/design :I The scarifier, a device designed to evenly meter feedstock flow, was developed after several unsuccessful attempts. The final design of the scarifier was the product of on-site design testing and refinement, and in its present form can handle all types of waste up to any degree of compaction presented by handling. The device consists of two (2) 8 foot parallel shafts, an upper shaft mounted above the storage container at the discharge end and a lower shaft mounted over the feed conveyor. Each shaft has five sprockets driving five chains on which sickle blades are staggered along the face of each chain. The chains have the ability to rotate in either a clockwise or counter clockwise direction, thereby avoiding jams. By controlling the number of revolutions and direction of the scarifier in conjunction with the speed and direction of the live-bottom storage container, feed material can effectively be discharged from the container to the feed conveyor at an automatically pre-determined rate. C-l 3. Dryer Dryer Retort Feed and Seal The dryer has one major moving component: a steel retort tube 35 feet in length and 6 feet in diameter. As manufactured the dust seal at the feed end of the dryer retort was obtained by using a stationary flat plate open at the center, to allow wet feedstock to inter the dryer. As the tube rotated, ,the contact surface between "the plate and tube face was greased thereby creating a seal. With continued use of the dryer, sand, ,glass and other abrasive llIlaterials worked their way between the tube face and the plate. ~rhe integrity of the seal continually deteriorated and dry material sifted through the seal. As this material passed through the grease seal, drag increased on the rotating tube and caused the t.ube to stall. Modification/design The dryer feed end seal was re,designed during the test program. The stationary plate was welded along the circumference of the dryer tube, making the tube and! plate one rotating piece. Thin a 36-inch circular opening was cut !in the center of the plate. A feed chute was then manufactured to ftt the circular opening. A t:ough rubberized canvas seal was mount.ed in the clearance space between the feed chute and the rotating plate. By reducing the "contact area of the seal and eliminating the grease seal, the drag em the dryer tube was sUbstantially red~ced. The new seal was now located at the outside circumference of,the dryer tube; therefore, dry material could not sift through the! seal. Dryer Flights The dryer utilizes the waste heat from the converter firebox to eliminate unwanted moisture in the feedstock. The flue gas from the converter firebox heats the dryer oven. The heat is then transferred from the tube to the feedstock by surface contact. Initially biomass is never directly exposed to the hot exhaust gases. During the test period it was observed that the biomass had a tendency to slide along the bottom of the tube and not tumble. In some instances roping of the material occurred. Biomass that was in contact with the skin of the tube was found to be dry but dense chunks of material had moisture-laden centers that were thermally insulated by a dry biomass layer. Modification/design Three sets of lifting flights were installed inside the dryer tube. The first set was comprised of, six 90° flights. These f.lights were welded in a staggered manne',r throughout the first 1/3 of the tube at the feed end. The second set was comprised of six 135° flights. These flights were locat:ed at the midway point of C-2 the tube. The third set was comprised of six 180° flights. These flights were mounted in the last 1/3 of the tube at the discharge end. As the dryer tube rotated the flights would now lift and break up the biomass as it tumbled inside the tube. In addition to the installation of the lifting flights, exhaust waste heat at 200 0 P from the waste converter firebox was introduced into the center of the dryer tube from the discharge end. These modlfications resulted in reducing the molsture level of the feedstock to an accepta;ble level. 4. Char Ram Initially the char residue, dropped through a sealed transition hopper to a sealed auger conveyor. This auger then conveyed the hot residue to . storage bins for eventual disposal. The auger conveyor presented problems during long-term operation of the wasteconverte.r. Continuous operation of the auger created a poor seal ~t the discharge end of the retort tube. This allowed air to leak into the retort causil).g incineration of the char. Furthermore th~:'~ugercontin~aHy jammed as a result of .small metal Objects (can .topS! , I:Ipril),gs, nails,bol t,s); contained. in the ,residue. 1 1 ~ J : . .l.:.: ! 1;1 'iii!I_",':y. 'j To all1evia,te these problems, a hydraulic ram was fitted to the discharge transitiol). piece. The transition piece became the char hopper fO~I;t,hellrl~'~. ,The ram was designed to maintain a continuous materj,;al~~al~I~!thechar was rainmed out to the conveying system for dtisp~I~~l,r Ihl';l'lte ,ream . syst~m greatly reduced jainS due to the presence ot l.nerts,l.n:the char. 5. Stack Damper The stack damper is installed at the top of the discharge end of the converter retort. This damper controls the flow of aspiration stages. The first is located several feet above the damper. This allows for instant combustion of the produced gas as it leaves the waste converter. Initially the carbon steel damper was barometric and was assisted by a counter-weighed arm. The operator could also manually initiate various damper positions in accordance with .gas production • . Modification/design It was determined that the stack damper had to be redesigned to operate automatically. The new damper was fabricated from stainless steel plate swinging on heavy duty cast iron external bearings I allowing free operation at high temperatures. The damper was actuated pneumatically by a signal from the computer which calculated damper settings in accordance with gas production. Manual control (as an emergency override) was also maintained. C-3 6. Waste Convert.er Although the waste converter had an operating history, its opt.imum performance and efficiency was generally unknown. As data became available from the test program, it was soon apparent that the waste converter's performance could be enhanced by implementing design changes. Although the waste converter's retort tube had been previously used for five years, the other materials used in its manufacture were new. The purpose in; utilizing the used tube was to further test its useful life. Certain modifications were made for the purpose of being able to iattain an additional 24 months of continuous operation for the test project. Creating a good air seal arrangement on both ends of the retort was of prime importance. ' Modification/design The feedram seal was modified to eliminate air contamination of the retort atmosphere and to reduce th~ diameter of the seal to eliminate fines from sifting through th~ seal. The new design incorporated a 25" bronze spring loaded radial seal. The original seal was approximately 44" diameter carbon steel. The modification prc)ved to be superior. The discharge seal arrangement was modified to incorporate a floating bronze ring. In addition to the ring, sealing surfaces were machined to obtained true and concentric riding surfaces. Three feet of char flights were removed from the discharge end of the retort to minimize char turbulence'. Advancing spirals were installed at the feed end to propel incbming feedstock down the tube to reduce the back-washing effect of residue to the feed end seal. The drive assembly was modified to float with retort expansion. A torque bar was installed to minimize drive assembly vibration. 7. Temperature Monitoring Prior to the testing program the only temperatures that were monitored in the system were the firebox temperatures of the converter. These readings proved to be inadequate for measuring the actual temperature fluctuations of the interior retort atmosphere. Modification/design It was decided that a prima.ry sensor system was required to monitor the actual skin temperature of the tube. It consists of C-4 thermocouples mounted on the skin of the tube and two copper commutator rings mounted on the tube where the tube protruded from the firebox housing. As the tube and the rings rotate, thermocouple signals are picked up by a brush which rides the copper commutator ring. The skin temperature is read at three points on the tube: feed end, middle and discharge end. 8. Pyro Burner The pyre' burner provides the primary heat source for the distillation process. The pyro burner is self sustaining and utilizes gas produced by the' on"going process. The burner is located within the firebox of the waste converter. The burner was found to provide inadequate heat and had'to be re-designed during the tests • The. majorproblelq with the burner was uneven heat distribution 00 the retort tube surface .and failure of its carbon steel ?omponents t.o withstand the high temperatures ,associated with increased· feed; rat:~'s., .. . ,. , . After approximately 12 months the original pyro burner was completely scrapped in favor of a more efficient heat resistant stainless steel. Qurner. This replacement burner was of a new design and solvedbrlanyof the problems that were attributed to the failutet>f th~or!i!~ibal burner. The net result of this redesign .wastheburne!r:~sabilityto distribute heat where required and thereby iricreas'e: tli!le feed rate of the waste converter. , 9. : ., Bur~er· , J -'j;," H!iJstdt¥, and Re-Design In the month of ,F.ebruary, 1983, attempts were made to operate the commercial gas burner system installed on ;the steam boiler. The packaged instrumentation system absolutely did not work in conjunction with the'burner. Malfunctions of this system caused: :1 1 1 1 Unpredicted shutdowns EXplosions Flame outs Pulsating over pressures Smoke Noxious odors Fire in the main gas line, and a reversal of air flow which almost caused a meltdown of the main stack. During the period from May, 1983, to August, 1983, numerous tests were made on the equipment as designed by the manufacturer and installed in accordance with specifications. One of the tests conducted was a combustion air flow test which proved the system would never work as designed. This test indicated that as greater volumes of combustion air were introduced into the burner chamber by the boiler forced draft fan, the air flow into the boiler C-5 " '" ,'' ' '-":; ;')~;,~~~:~~;:'~;,<,::~I~;i~J <It'_ ' ':1i::' ~;':,l\'~"i' 1 a.ctually reversed at a certain point and blew combustion air into the gasifier chamber of the retort. An error in basic instrumentation logic was discovered and was of such a magnitude that it precluded .the system from ever operating. Coupled with major mechanical design problems, which were discovered in the burner head, the decision was made to replace the faulty burner with an in-house burner operated properly. This problem delayed the overall project for considerable months before it was solved. 10. Conclusions As the project commenced the testing group relied upon initial surveys of equipment suppliers and manufactures which had indicated that "off the shelf" technology and equipment was readily available, to support the waste converter plant design. As the R & D advanced, it was soon apparent that because of the resultant produced gas and char, unique solutions were required. Therefore, costly modification or redesign of much of the "off the shelf" equipment supplied to the project had tp be made to meet project requirements. The non-homogeneous nature of the MSW and its deleterious effect on material handling ~nd flow control equipment WE!re typical of the factors that nece'ssitated the redesign or modification of much of the initial equipment supplied to support the system. C-6 • SECTION D SECTION D EXPERIMENTAL RESULTS AND DISCUSSION 1. Introduction A complete material and energy balance made on the plant will be presented in this section. The experimental information recorded was obtained from runs beginning in December 1982 through Noyember 7, 1984. On the last runs, a complete analysis of particulate and chemical emissions was performed under a joint effort between Princeton Testing Laboratory and the research team. The complete results of the analytical study and its environmental importance is set forth later in this report (See Appendix 2). The experimental runs were performed using Monmouth County (NJ) municipal solid waste. A complete elemental analysis of the waste is also presented in Appendix 2. Figure D-1 shows a flowsheet of the plant. The numbering, as it appears in Figure D-1 will be used in the following discussion to identify the flow of overall mass, components and energy in each of the streams. 2. Operational Characteristics of the ~lant The thermal decomposition of waste (dry distillation) in the absence of air can yield considerable amounts of gases. These gases, in the present process, are burneq immediately in a boiler to produce steam. At present the waste converter's design temperature is below 1200 o F. As a consequence, there will be some small amount of volatile matter remainidg in the waste. A good measure of the maximum conversion of volatiles in the waste is giyen by the ASTM "proximate" analysis method. This method uses a very high temperature to thermally deqompose the waste in an oxygen-free atmosphere. Conversion of vo~atiles, at the plant will be lower than the total "volatile contenjt" of the ASTM proximate analysis. The maximum yield of volatiles is dependent on ideal reaction conditions in the retort and thJ nature of the municipal waste that is being processed. D-1 ~'""',2';";' ·-;;:~7,;r.:".'..;;,.=;_~: __ ~;;;.~.::..;~. '.:r::;;;::~5::h:;Tft~::t~,:-.,'-;~,~~:J~. J!,W!<". ;:I.,.{ ", ",3l@:::~±;iI±K~~i1'!':""kglii&±5m"IJiiiiiiii!iWfi ""~------- :;;;:;;;;+ .._.........-.. & .. _ ..... _ ..._._-_ ...•...... FLOW SHEET OF THE WASTE CONVERTER PLANT TO CLEAN UP AIR FOR FLARE "') __ S14 R S17 ~ I I 82 01 . IV DRIED WASTE E ci I B B S1 S1 --~OC------- MUNICIPAL WASTE 84 PRODUCEO S7 GAS_._~ ~ S5 S6 G NATURAL WASTE GAS S.l.~ CONVERTERtl... l S 11 M FURNACE Kl S9 L CHAR AIR S13 H S10 J (START-UP] S14 t WASTE CONVERTER ;I F Z P S3 DRYER I • BOILER EXHAUST BYPASS STREAM TO FLARE (EMERGENCIES) DRYER STEAM tJ P · ....OCI--.:...----~ AIR FOR COMBUSTION o IH~T STEAM s 12 WATER "T1 C> C :0 m o ... I A series of test runs were performed to determine the effect of different operating conditions on the conversion of municipal waste to volatile gases. The runs involved varying the waste converter tube temperature and the feedrate of waste being put -through the reactor. The direct effect of waste converter temperature is shown in Figure D-2. The conversion is referred to 1the volatile content of the ASTM proximate analysis. The results indicate a linear dependency of the conversion with temperature in the range of interest (1000° to 1200° F)'. The varied feedrates did not significantly affect the conversion during the tests. At the retort design temperature of 1150 0 F, th~ conversion is more than 90 percent of the total amount of volatil~s available that could be obtained from the waste. Under ideal: conditions this is a very acceptable result for an industrial un~t. a. Conversion of Chemical Elements Present in the Waste , The chemical elements present .t,n the waste did convert following different selectivities. ThiJs means that some elements c:onverted to volatiles in a higher degree than others. The c:onversion of these elements in the' plant was calculated by performing an atomic balance on the "as~ received" municipal waste a.nd then on the residue char. This bala~ce was performed utilizing several samples of char exiting the distlillator at 11500 F. Typical results are presented in Table D-1. TABLE D-l COMPONENT Carbon Sulphur Chlorine Hydrogen Oxygen Nitrogen % CONVERSION TO GAS 71.8 69.6 13.0 97.9 100.0 70.6 STANDARD DEVIATION% 9.5 6.5 9.4 0.5 0.0 9.8 In Table D-1, the relatively high standard deviation is due to the heterogeneous nature of the municipal waste. Oxygen is completely converted at 1150 0 F and is accomplished within the given residence time that the waste is in the converter. Hydrogen is almost totally converted to volatiles. Nitrogen, carbon and sulphur convert to gases in about equal levels and average close to 70 percent; the remainder of these elements are found in the char. Only a small fraction of the chlorine is converted to gas, most of this element was found to be encapsulated in the carbon structure of the char residue. D-3 100 EFFICENCY OF VOLATILES CONVERSION IN THE WASTE CONVERTER ?f. z 0 95 c J)' 0:: UJ > tJ Z 0 0 "'" en I 90 UJ ..J - le( ..J 0 > 35 .: 00 tOoo 1050 1100 TEST RESULTS 1150 " 1200 C) C :0 CONVERTOR TEMPERATURE DEG. F m o I I'\) . lw.-..... _ .. ,.•••. ,........ . . .• --'~ ....... -.",~.~O:'.;.."".~...~~.+i~..:...:,.!,,~.}r':.,'(.r~~...... '" , .. .•..: ~ ................,'\.~\.;,~~- b. Conversion of the Energy in the Waste The amount of combustion energy or the heat of combustion contained in the "as received" waste that is transferred to the m.anufactured gas during the dry distillation process can be calculated by performing a complete hea~ of combustion balance of all the various streams entering and exiting the waste converter. This calculation was performed using samples exiting the waste converter at 11500 F which gave the result listed in Table D-2: TABLE D-2 STANDARD DEVIATION 5.5% ENERGY, GAS 83.68% c. Effect of Moisture on the Plant Operation The detrimental effect of moisture contained in the "as received" MSW was noticed early in the development of this project. It was determined that energy production of the plant dropped on days when the MSW was very wet. On occasion, in the Fall, waste could contain in excess of 50 percent moisture limiting energy production. The effects of moisture can be discqssed theoretically in ;the plot shown in Figure D-3. The theoretical energy ;available from 1 pound of waste has been plotted vs. the moisture content of the waste. The net energy produced is obtained by calculating the energy released when 1 pound of wet wa~te is processed and then deducting the total energy required to ~oth heat and vaporize the water content and to gasify the waste. '. Figure D-3 clearly shows that as moisture content goes up, net en~rgy drops and at about 75 percent moisture, the total energy relea~ed from the waste balances the total energy required for gasificati~m and water vaporization. At this point the plant produces zero net energy. In actual practice the limit of operability of the plant is lower than 75 percent. This is due to the energy overhead of the plant, that is tl:> say, the amount of energy required toi keep the plant running at its required operating temperatures; thiis also includes the heat It:>sses of the system. . D-5 t". ''? .ilf;;,:-J:~; . ~,:;."" -- .-:~:::2~':;:.""-; ~[~::,'U ~-;Z~"",~~l:~-,~2~-- -----=-c=-:::,~,,-_:_:_~ I_._ ............ .J't:. .. ........ - ... --.' ... ,------.~ ._--_._------- .. -.. ---- . MUNICIPAL WAStE M"OJSTURE EFFECT ON THEORETICAL . ENERGY PRODUCTION PER LB OF WETW ASTE 8000 70gg 6000 ~ Sggg ~ "- t:1 I ~ ::l ~ NET THEORE.TICAL ENERGY / 4090 ENERGY RELEASED (GROSS) / 3099 I UtAtT Of'~PE1'ABIUTY Of Pt.ANT I ~ 20BB w ffi 1BBB ENERGY REQU,RE[I ~ FOR DISTIllATION" " . 9 -lBBg :'2099 g 10 20 30 40 50 MOISTURE % 60 70 80 ." 90 109 G) c: m o :0 I Go) d. Efficiency of steam Energy Produced Versus Feed Rate The effects of varying the waste feedrate and showing its relationship to total steam production was studied experimentally in a separate set of test runs. Results obtained from these tests are presented in Figure 0-4. The curve shown on Figure 0-4 indicates that no appreciable steam energy is produced below a feed ra~e of 1100 lb/hr •• When this feed rate is exceeded, the energy production increases with increased feed rate, with a maximum value of approximately 2950 BTU/lb.. Identical results are shown in F[igure 0-5 which is a plot of net energy produced per hour versus the feed rate of wet municipal waste. Again we see that very little energy is produced unt~il an 1100 lb/hr. feed rate is reached and then the energy output continues to increase linearly. In order to explain the increase of plant efficiency with increased feed rate, two factors must b~ discussed. The first factor is what we call the "energy overheap." of the plant. This is the. amount of energy required to have all of the steams of the pla.nt heated to operating temperature. Energy must be used to heat the, plant, and to sustain the process even though this energy is exhausted in the hot flue gases or waste heat from the plant. The second factor is that the plant is ineffi¢ient when the feed rate drops below its design capacity. One example of such an inefficiency lies in the operation of the ,boiler. The boiler used in the tests has a design rating of 35 MMBTU/hr. and is designed to operate most efficiently in that range. The air-to-fuel ratio controller installed could not go below a certain minimum air flowrate to the combustion chamber of the hoiler. Excess air beiing fed to the boiler is shown in Figure 0-6 as a function of municipal waste. feed rate. It is obvious from the graph that the boiler energy efficiency is very poor at low feed rates and that efficiency increases as design capacities', are reached. Note also that these low efficiencies begin to appear only when the plant is operating below 50 percent capacity but, When operating at design conditions of 5000 lb/hr. feed rate ineffli.ciency does not appear. 0-7 .---;,~~ --:::---;_1T,C-·-··-;~·-· ~,~?~ --:'£,'-::;"~~",.;,.;;;;;E;;:~'- .. ~. _~--;,;.~~ _._.~ _ _ _ _ _._ _ _ _ _ _ _ __ STEAM ENERGY VS. FEEDRATE EFFICIENCY DEPENDS ON FEEDRATE 5300 4500 40G0 ~ 3500 "- ASYMPTOTIC ~ 30UO t:l I OJ . VALUE: 2,950 BTUIIB ~ 2500 • IX: W zw 2000 • 1500 A A • leg0 • A 500 0 .-----,------r-.-- 0 -I - - TEST RESULTS A TEST RESULTS B ----I----~.,------.., 500 1990 1500 2000 2500 3900 3500 4gg0 4500 5000 FEEDRATE LBtHR I .I -------------~ ....--..-..-;-~----~--- ." G> c :Il m . o I .- . ~ . ~ ".~;,' J: 0 '-w 9 8 '~;:~. 7 1',.':.,:.-.:, " ~ •.·~.r. J· .• "......." _ . ~ ,'. ".: )TOTiAL ENERG't!~V.s. FEEDRATE EFFiCiENCY DEPEi~6'S ON·FEEDRATE 12 11 19 0: i:' ;'-'~. =>C,) 1:J :E:c :Etc .. '0. '\DI~L;_ ~S;~ ,w,w .. Z,I-. w (/) ~ Z w- £, 0 5 ,4 . 3 '!Iii', 1 1 Z 2 1 o • TEST RESULTS A. .. TEST RESULTS B o 500 lOgO :'15g0'2gQg\",,~:l}25'CG,' 3003·' '3500 . .;'; .'. .. ". .' .... FEEDRWTB,itB'1HR ".,_·y";~::i~t~"'hf:' r.' . 4000 4500 5g00 -n G> c m o :0 ' I (fI ._-------------_._•.._. ---------- .. __ ._--------_.- -_.-------_ •.... e. Operational Characteristics of the Dryer Experiments were performed to analyze MSW for moisture content at the input and output ends of the dryer. Results indicated that the dryer is heat-transfer limit~d under design conditions and was removing between 130 and 210 pounds of water per hour. The product of the heat-transfer co.efficient and the area of the dryer was calculated from the experiment; The value of U x A is 933 BTU per degrees F for a heat exchange area (A) of 622 square feet, and an overall heat-transfer coefficient (U) of 1.5 BTU per hour, per degrees F, persquarefpdt. The dryer, under present design conditions, typically removes 10 percent. of the t'otal moisture from the MSW. 'The heat-trans:fe'r model. of the dryer was incorporated into the simulate~ IIIod~l of the plant ana calculations were made, to establish .steam prc;>dllctj,ohat varying moistures. Table D-3aad Figur~D-1 show the limit'ing effect of.moisture on total steam ener91 ,produced. \1.1' ,,_, ,.,' , '\ It is recommended that municipalities take precautions to reduce excessive moisture in the "as received" municipal waste 10 increase steam production. The plant· s drying capability can still be:;;;;improv~d. by better utilization of the waste heat streams., ' . I 0-10 BOILER EXCESS AIR DEPENDED UPON FEEDRATE SgG 45G 4gg .,p. ex: 3Sg « 309 I en en 250 I-' I-' () 2g9 t:1 w >< w • , q , ~q i ,j .": • TEST RESULTS 1 15Y " lOG I II ! sG 0 2000 2250 2500 FEEDRATE LB/HR \ 2750 3009 "TI c:> C ::0 m t:1 I ~ I r ~ TABLE 0-3 LB. STEAM/HR. MOISTURE IN MSW 'lrl 5 10 15 20 25 30 35 40 65 15855 14524 13192 11851 10504 9150 7792 e 17154 55 14552 13460 12352 11234 10106 8974 7835 6692 Z o 50 13253 12264 11261 10244 9225 8201 7173 6137 w 45 11946 11060 10166 9263 8356 7435 6508 5580 !<a: 35 9323 8646 7962 7270 6572 5868 5159 4446 25 6686 6200 5733 5245 4759 4270 3774 3276 >..: (/) I- o --- W W LL. il '\ I, :l'I IIt~ FIGURE 0-7 ·STEAM PRODUCTION I 2gBBB I. I, 18BBB II I ~ II~ ij " ~i R ),1 Ii t3 U i~ "I '1 fJ, n H f-" If'B 65 1609O . 14BOB 55 Cf) - 0: :J: 50 45 120BB < UJ 10BGO fCf) 8GOG CD ..J 60GB 40gB ~ ::~ -- 20GB 0 .... 0 5 10 15 2S 30 3S 40 MOISTURE OF MSW % D-12 i 3. A SIMULATION HODEL OF THE PLANT The operational characteristics of the plant previously described provided enough basic operating information about the waste converter to develop a computer simulation model of the plapt. Information concerning the material and energy balances .each of the streams of the plant were then calculated under various ope~rating condition (Refer to Figure 0-1: Flowsheet of the Plant). The key unit of equipment in the plaQt is the waste converter assumed to be operating at a fixed temperature of 1150 oF. Thi.s temperature was found in actual tests to be high enough to produce a high volatile conversion rate ~ and yet not stress the retort material which in turn extends th~ life of the equipment. Using this 1150 0 F temperature, conversion! energy of the volatiles andl the conversion of atomic species werEi assigned the values set forth in the previous section. The waliite converter furnace or firebox was assumed to completely oxidizE! all carbon atoms to CO 2 since the emission of CO and hydrocarbons was almost negligible in the testing of the plant. All sulphur present in the produced gas converted to 502 and 50 3 while all hydrogen atoms was converted to water (See Table 0-1 and 0-2). All bther coagulations were performed from the exact material and eneirgy balances. and~as The combustion chamber of the boiler was calculated using the Sallile assumptions as in the converter furnape above. Boiler exhaust gases were assumed to leave the boiler at ~60oF, a temperature that was consistently observed during expeirimental runs. Other calculations were based upon the exact material and energy balances. Using the above assumptions and, applying mass and energy balances in all splitters and mixers, the ',model was implemented as a template in a personal computer advanced spread sheet program. The iterations required in all recycle' loops were numerically unstable and required convergence algorithms to obtain the steady state value. Figure D-8 shows a set of actual e~perimental data of net energy produced in the form of steam compared with simulated results obtained for values of the excess air in the boiler calculated using the graph in Figure O-~. The fit between the experimental data and the simulated mddel is quite good and therefore, the model can be used to provide material and energy balances in the plant under different operating conditions. 4. MATERIAL AND ENERGY BALANCES AT THE DESIGN CONDITIONS Table 1 (Appendix 1) gives the materi?l and energy balances of the plant as set forth under design conditions: 65 tons of wet municipal waste/day (5416 Ib/hr), at 35 p~rcent moisture,. with 30 percent excess air in ;the boiler and waste converter combustion chambers. Steam production is predicted 'to be a minimum of 9149 D-13 lb/hr (refer to Figure D-1 for stream numbering information) and as moisture content is reduced steam production increases. 5. MATERIAL AND ENERGY BALANCES UNDER ENVIRONMENTAL TEST CONDITIONS Table 2 (Appendix 1) gives the material and energy balances in the plant utilizing the conditions found in the environmental tests performed on November 7, 1984~ Note that in the Table the energies are given in BTU/hr, masse's in lb/hr. The municipal waste was fed intothewasteC()nverte;t:at,a rate of 4000 lb/hr, and contained 28 percelltmoi;;tui',e. 'i " T:ne::,r~isul't!3. of emission tests and those calculated from .,the simula'tibn, pt6<;Jram are compared in Table D-4. TABLE D-4 SIMULATiON , MEASURED 20.00 lb/nr 20.00 lb/hr 4.12 Iblh,r , 3.50 lb/hr , Particulates ,, 'L 5.60 lb/:hr It 0.00 lb/~~ D-14 5.60 lb/hr ND COMPARISON PLANT SIMULATION WITH ACTUAL PLANT RESULTS 50g9 4500 i: 43BB In ~ a 35B0 ~ 30g0 ::J , tl ...... lJ1 ga: 2530 >- 2000 0.. (!) ~ 1500 w 10B3 / SIMULATION MODEL • TEST RESULTS 533 3 t533 1750 2030 2250 2500 FEEDRATE LB/HR .-.. . ----- -'.'- .. -.-.. 275g 3g00:!!C> §5 m o tl, I SECTlON E- t f I: 1 SECTION E ENVIRONMENTAL STUDY 1. MUNICIPAL SOLID WASTE AND SOLID RESIDUE a. Introduction On November 7, 1984, a series of environmental tests were conducted on waste converter uni t locat~d at Elmwood Park, New Jersey. b. Municipal Solid Waste About 25 percent (by weight) of all MSW in America is comprised of water, with the balance primarily consisting of paper, food scraps, metals, and glass containers. MSW has been sorted, packed, weighed, and analyzed for years.. Figure E-l shows the composition of a typical MSW. 2 During the environmental testing of t~e waste converter, seven samples were taken of the "as received" I1SW feedstock. The MSW, utilized in the testing, was obtained from the Monmouth County Reclamation Center, Tinton Falls, New Jersey and consisted of a residential-commercial type waste. As ~art of the testing, a pro:x:imate analysis, ultimate analysis, and hazardous characteristics analysis were conducted on the waste. The results of these analyses are presented in Tables E-l through E-3. Addi tional information regarding MSW testing can be found in Appendix 2. I 2 Carr ier Corp Contract to Syracuse ~niversity' s Professors Drucker and Heimburg, 1976. E-l FIGURE E-1 TYPICAL COMPOSITION OF MSW NON-BIOMASS PRODUCING . PORTION BIOMASS LEGEND ENERGY PRODUCING .7 ~ PAPER, GARBAGE, YARD WASTE 7 •• ~ LEATHER, RUBBER, Tt:XTI~ES. WOOD, PLASTICS NON-BIOMASS 2S ~ MOISTURE 'Hl.e1l'o GLASS. FERROUS META~ . . . NON-FERROUS METAL. _ _ _ OTHERS I 100 .. E-2 TABLE E-1 Moisture Ash volatiles Fixed Carbon MSW PROXIMATE ANALYSIS Percentage By Weight 29.80 19.87 44.79 5.54 100.00 Heating Value: As received Moisture free 4,874 BTU/lb 6,943 BTU/lb 6.7 lb/ft 3 Density: TABLE E-2 MSW ULTIMATE ANALYSIS Percentage By Weight 32.17 7.34 19.42 0.40 0.23 0.18 12.26 28.00 Carbon Hydrogen Oxygen Nitrogen Sulfur Chlorine Ash Moisture 100.00 Dibenzodioxins Dibenzofurans ND* ND* I *ND = not detected; detection limit is approximately 10 mg/kg E-3 TABLE E-3 MSW HAZARDOUS CHARACTERISTICS ANALYSIS Ignitability waste will not ignite "as is" because of its high moisture content (1) Corrosivity pH is between 2-12(2) Reactivity less than .0001 percent of sulfide(3) less than .0001 percent of cyanide(3) (1) Per 40CFR261.21 (2), waste characteristics of ignitability. does not exhibit hazardous (2) Per 4 OCFR2 61. 2 2 ( 1), waste characteristics of corrosivity. does not exhibit hazardous (3) Per 40CFR261.23 (5), waste characteristics of reactivity. does not exhibit hazardous c. Solid Residue 1) Conventional Incineration Residue Major water quality compliance problems are associated with most incineration, RFD-fired boiler plants, and mass burning processes. These problems stem from heavy metals contained in the bottom ash which in turn can contaminate water discharges. This wastewater condition requires treatment before discharge into a sanitary sewer system or a receiving water. Also water-saturated ash retrieved from the main quenching troughs of some incineration systems requires that toxicity tests be performed to ascertain the toxicity· of the ash before deposit in a landfill where harmful materials could leach out. If any ash residue is found to be toxic, then disposal falls under the guidelines set forth by the Resources Conservation and Recovery Act (RCRA), whereby the residue must be manifested (tracked) and disposed of in an approved hazardous waste disposal site. (2) Char and Solid Residue from the Waste Converter This section considers the environmental impact upon a landfill in disposing of ~aste converter char residue versus disposal of bottom ash and fly ash residue produced by conventional or mass-burn incinerators. The dry distillation of MSW yields a volatile gas and a solid residue. This residue (residual char) contains a mixture of' highly polymerized organic matter and inorganic components, intimately E-4 agreggated. This solid residue consists of 30 to 50 percent carbon, and constitutes 21 percent of tne total original mass of unsorted municipal waste fed to the converter. Due to high temperature treatment d~ring the dry distillation process (over 1000 0 F), the solid residue is completely sterilized. The process temperature and long residence times make the survival of bacteria and germs impossible. During testing of the waste converter unit, three separate char residue samples were taken during each of three runs. A part of the testing, the following were conducted: (1) proximate analysis giving percentage by weight of,moisture, ash, volatiles and carbon and also heating value and density; (2) ultimate analysis giving percentage by weight of ~lements, ash and moisture and also findings with reference to dio.xins and furans; and (3) hazardous characteristics analysis ~ndicating ignitability, corrosivity, reactivity and EP toxicity. The result of these analyses are presented in Tables E-4 through E-6. Additional information regarding the char residue testing can be found in Appendix 2. 3) Volume and Weight Reduction The treatment of municipal solid was',te Hi the waste converter has the overall effect of greatly reducing the "as received" volume of the biomass or organic matter as well as concentrating it in form. This reduction in volume takes place due to two factors: the major factor is the reduction of mass due to chemical conversion of biomass in the converter and another reduction factor is due to an increase in the density of the solid residue through densification such as, the crushing of glass Table E-7 illustrates these two components as 'they relate to volume reduction. This volume and weight relationship of MSW and char residue is graphically depicted in Figure E-2. d. ABSENCE OF DANGEROUS POLLUTANTS Laboratory analysis of the waste converters solid residue using EPA Method 25 (G.e./M.S. screen) failed to detect any traces of Dibenzodioxins or Dibenzofurans. 1) ehar Encapsulation of Leachable Materials During the dry distillation processing of f.fSW, the solid residue is exposed to high temperature and hot organic vapors as well as hot hydrocarbon gases. These conditions tend to form a layer of polymerized organic coke material on the surface of the various particles making up the solid residue. E-5 Upon completion of the distillation phase, the individual solid residue particles have been encapsulated by this polymeric coke layer preventing the free dispersion of dangerous pollutants into the environment. Asa consequence of this encapsulation process, it is difficult for such chemicals to leach out from the waste converters char residue.· The conventional incineration of MSW creates no such protective capsule and over time leaves the Chemicals exposed to the weathering action of water and oxygen .which can dissolve these pollutants and contaminate underground water. To. give credibility to the above explanation and set forth the environmental advantages connected with the char residue produced by <iry distillation of MSW over ordinary ash, an experiment was performed (See Appendix 2). In this experiment a test sample of solid char residue was taken from the. waste converter and divided in!to', two parts. One of these parts was incinerated and .the z;esuitant 'ash. was sUbjected to EP' toxicity tests using distilled :wa't!er~ . The unburned portion of 'solid char residue was treated 1,ilk:ew'ise. The leachate fr.ombot~ samples WaS analyz.ed for .the priio.~ity pollutants using. the RCRAmethod (Federal Register May 19, .. 19'80). There were no toxicdrganic pollutants found in the prior analysis of the solid char residue, therefore, both leachate tests indicated no. detectab~~ '.'1, amounts of endrin, 'lindane, methoxyclor, toxaphene, 2,4-D or 2,4,5-TP Silvex. The results of tqe i~est perfqrined to det ec1:.11e)k:tyY; metals found· in 'the leachate of . tl~e ,~mburIled solid ch~rresidue!'a.nd those. found in;theleachate of 1ip'~ "~sh oLtheincinerate<i soli!4:'icharresiJdue the results! ,given in r:p,!a:Pl~ E - S . " , . i E-6 VOLUME & WEiGHT REDUCTiON OF MSW 97" VOLUME REDUCTION 1:1:1 I '}/j ~ "')1 L~~-i .~ \1 Ej ',,9," ONE CUBIC FOOT 48 LBS. RESIDUE J I 34 CUBLIC FEET MSW 229 LBS. -c ." I Ii G> ::0 m r it: m I I\) f I ~ TABLE E-4 CHAR PROXIMATE ANALYSIS (Average of Three Samples) Percentage By weight 0.13 66.44 5.S4 27.60 Moistu~e Ash Volatiles Fixed Carbon 100.00 ~t , Heating Value: as-received moisture-free 3,799 BTU/lb 3,S04 BTU/lb Density with inerts 4S lb/ft 3 TABLE E-5 CHAR ULTIMATE ANALYSIS (Average of Three Samples) Percentage By Weight 39.S9 0.79 Carbon Hydrogen Oxygen Nitrogen Sulfur Chlorine Ash Moisture 0.52 0.31 O.BS 56.62 0.98 100.00 ND* ND* Dibenzo-p-dioxins Dibenzofurans *ND = not detected: detection limit is approximately 10 mg/kg E-S TABLE E-6 . CHAR HAZARDOUS CHARACTERISTICS ANALYSIS 19nitabili ty char will not readily ignite by open flame, by friction, nor by elevated temperatures(l) Corrosivity pH is between 2-12(2) Reactivity less than .0001 percent of sulfide (3) less than .0001 percent of cyanide(3) (1 ) ( 2 ) , waste Per 40CFR261.21 characteristics of ignitability. does not exhibit hazardous (2) Per 40CF.R261.22 (l) , waste characteristics of corrosivity. does not exhibit hazardous (3) Per 40CFR261.23 (5) , waste characteristics of reactivity. does not exhibit hazardous E-9 TABLE E-7 MSW VOLUME AND WEIGHT REDUCTION PRINCETON TESTS: 1 ft 3 MSW 1 lb MSW reduces to: 1 ft 3 Char and Residue = = 6.70 lb. .21 lb. residue 48.00 lb. THEREFORE: 1 ft 3 MSW at 6.7 lb. x .21 lb. . residue = .L.! lb. char and solid AND: 1 ft 3 Residue at 48 lb. 1. 4 lb. = 34.3 ft 3 MSW x 6.7 lb/ft 3 = AND: 229.8 lb When reducing 34.3 ft 3 of MSW weighing 229.8 lb. to ft 3 of residue weighing 48 lb. the results are: MSW Volume Reduction RATIO: 97 percent = 79 percent 34:1 MSW Weight reduction RATIO: = 5:1 TABLE E-8 Heavy Metal Concentration - mg/ Arsenic Barium Cadmium Chromium Lead Mercury Selenium Silver Leachate of Unburned Solid Char Residue Leachate of Burned Solid Char Residue ND 0.82 0.02 less than 0.02 (ND) 0.09 ND ND ND ND 1.10 0.08 0.04 0.31 ND ND ND E-IO % Increase of Heayy Metal + 0 + 34 +200 +400 +244 + 0 + 0 + 0 · The aIIlount of heavy metals leached from ash derived from the incinerated sample of solid char residue is much higher than that leached from the unburned sample of solid c.har residue. It is known that bottom ash, as well as the fly ash collected from electrostatic precipitators installed in conventional incinerators, are high in ~oncentrated heavy metals and must be continually monitored before deposit in a landfill. The encapsulation of heavy metals in the solid char residue could prove to be a very desirable environmental advantage that the waste converter would have over ash disposal pr9blems associated with conventional incineration. It would also appear that although a 20-percent increase in energy output of the waste converter could be obtained by burning the char residue in an incinerator, this procedure would not be the best use considering both air pollution caused by the incineration and the potential adverse long-range environmental impact of heavy metals on wat\er supply systems. 2) The retention of Chlorine in the Solid Char Residue Relating to Dioxin and Furan Emissions It is believed that chlorine contained in municipal solid waste plays a major role in the production of dioxin during incineration. 3 The chemical process requires that chlorine (probably as HCL) be present in the gas phase for dioxin to be formed. In the waste converter, most chlorine atoms do not evolve into the fuel gas, but remain chemically bbund to the solid char (refer to "Conversion of Chemical Elements Present in the Waste") • Polychlorinated dibenzodioxins (PCDDs) are a family of compounds consisting of two benzene rings! joined by two oxygen atoms and having from one to eight chlorine atoms attached around the rings. There are 75 chlorinated dioxids which differ in; the positions or number of chlorine atoms. The tet.rachlorinated dibenzodioxins (TCDDs) are the twenty-two different dioxins (isomers) having four chlorine atoms. The ilsomer known as 2,3,7,8TCDD has chlorine atoms at the locations nuttIDered 2,3,7 and 8. The polychlorinated dibenzofurans (PCDFs) are a/very similar family of compounds differing in that only one of :the bonds between the benzl~ne rings contained an oxygen atom. Tfue nomenclature for the chlorinated dibenzofurans is completely an~logous to that for the dibenzodioxins. ' ! 3"Emissions and Emission Control Incinerators," Battelle s Columbus Ohio 1981. I E-ll j in Modern ~aboratories, Municipal Columbus, In the dry distillation process, !lQ polychlorinated dibenzodioxins or dibenzofurans were detected in any of the solid or gaseous product streams. The success of the waste converter in not producing dioxin is primarily due to the careful regulation of the process temperature and the oxygen-free atmosphere of the converter, which prevents the burning of MSW in the presence of chlorine. e .POTENTIALUSE/RESEARCB FOR SOLID RESIDUE The solid residu.e .froDl·waste conversion contains about 50 percent c:arbon. Potentialutilizati9n' for this product has not beenacthrelY' pursued in this ,study • . ,!=onsideration for use as activ'ated carbon is. an,!area:,ltcha;t . wa;rrants early. consi,deration beca~s: its bElnefic:iaLu,ses ~s l.an';aDsorbent has significant potent~ail.. "" ' " ' . , f. CONCLUSIONS 1) A solid residue is left after dry distillation of municipal solid waste. It constitutes about 3 percent of the in~tial waste volume which would be higher that the volume of ash produced by complete incineration. Volume redu.ctionof "aiS received" MSW was 34:1.or 97 percent; a Weightii'reduction of '!as received" MSW was 5: 1 or 79 percePiL 2) The high temperature treatment of the waste and the longresidence times dill all bacteria and germs contained in the municipal waste • The solid residue leaves the waste convertericomplete1y., sterilized. 1!1 3) In the dry distillation process, solid particles are enc:apsulated with a layer of polymeric coke; this coke layer shields inorganic components, making them more difficult to dissolve when the residue is exposed to water, and;, oxy:gen. As a· ):"esul t, the waste converter' s ,sdlIJLd:ic:halrresidue will; yield a smaller fraction of heavy metaJl,~, that the; natllral leaching. of conventional in6l:Ltterator ai;h wheo':jE!xp6sed to, the elements • . 4) ! t j I,. ", Most c:hlorine atoms present in municipal ,?01i4 waste (mainl-y originating from plastics) remain in an inactive form and are 'retained or encapsulated within the solid char ):"esidue. This prevents the chlorine atoms from participating: in chemicial reactions where the formation of new compolfhds -- such as, dioxin -- could take place. This fact,:Ln ' turn, insures that stack gases, as ,well as the Isoliid clia:rresidue ,produced by the waste conv.erter, are:dlotxih,[f!i:iee. E-12 2. ,a. STACK EMISSIONS Introduction Air pollution stack testing was carried out in accordance with methods and procedures established by the u. S. Environmental Protection Agency (EPA) and the New Jersey Department of Environmental Protection (DEP). All samples were taken from a conunon stack serving the: drying unit, converter unit, and boiler. This stack had no pollution-control devices installed for the relllloval of air contaminants. Table E-9 summarizes the results of t.he air pollution testing_ Since during the tests no pollution contro.l devices were installed, the data presented is representative of the technology's uncontrolled n uncontrolled "potential" emissions. Furthermore, since the data was collected from a common stack, it includes all source emissions from the facility. Additional information regarding the air pollution testing can be found in Appendix 2. b. Emission Standards Under current air pollution regulations pertaining to Prevention of Significant Deterioration (PSD) and Nonattainment .Area New Source Review (NSR), specific numel..Lcal emission standards are not defined for a new source. Instead, each proposed new source must propose emission limits that reflect Best Available Control Technology (BACT) for PSD and/or Lowest Achievable Emission Rate (LAER) for NSR for the control of air contaminants. The appropriate environmental regulatory agency then reviews on a caseby-case basis the proposed emission standards and considering economic, energy and environmental impacts, determines whether or not the degree of control reflects BACT and/or LAER and is sufficient to protect human health and the environment. E-13 TABLE E-9 AIR POLLUTION TESTING RESULTS - UNCONTROLLED EMISSIONS waste Converter Emission Rate (lbs/ton.) Pollutant Particulate .. ! j ~1 "I I ! 50 2 50 3 HCL* CO NOx Volatile Organic Substances Condensable Non-condensable Fontl<3:ldeh yde Lead Beryllium Mercury Nickel Chromium Arsenic Cadmium Dibenzodioxins Oibenzofurans *Obtained by Material Balance. E-14 9.170 1. 840 8.400 0.480 0.881 2.660 0.163 0.121 .0004000 .0079200 .0000245 .0000214 .0006200 .0026400 .0001340 .0005630 none detected none detected Although no specific universal emission standards are available, some state air pollution regulatory agencies have developed general emissions guidelines for new resource-recovery facilities. These are used to assist the agencies in setting BACT and or LAER requirements. . Since the waste converter unit was located in New Jersey, that state' s emissions guidelines were considered. Table E-10 presents a summary of 'the emissions guidelines imposed by the State of New Jersey on new resourcerecovery facilities. . c. Uncontrolled Emissions Rather than to rely on any vendo:rs claim or guarantee concerning BACT, the tests performed ~n t~e waste converter were conducted to set forth the maxl.mum predictable adverse environmental impact that the general public could be exposed to if all control technology of the facility failed. Therefore, all emission tests were conducted with no; pollution control devices installed on the waste converter. These: test results were then compared to the uncontrolled emissions. data of a mass-burn incinerator 4 • In an attempt to set forth: this analysis in clear terms, the number of pounds of each p011ut;ant emitted by each ton of lnunicipal solid waste for each procedure was calculated and compared on a percentage basis (See Table !,E-11) • 1) Particulates One of the products of thermal decon:1position of MSW in the wast.e converter is a hot gas which contains vaporized tars, oils, wateir and suspended char. When this gas is burned, the vaporized tars and oils produce particulate. 4Source: "Air Pollution Control at Resource Recovery Facilities"; California Air Resources Board; 24 may 1984. E-15 'fABLE E-lO Pollutant Guideline Particulates .02 qr/dscf, 3-hour average during non-soot-blowin9 .03 qr/dscf, i-hour average during soot-blowing iOO ppmv, i-hour average or 70 percent reduction by weight 200 ppmv, 3-hour average 300 ppmv, i-hour average co ~oo VOS, as CB4 LAER, if emissions exceed 50 tons/year BeL ppmv, i-hour average 50 ppmv, i-hour average or 90 percent reduction by weight Note: All concentrations are based on dry standard flue gas, corrected t~ 7 percent 02. PPMV = parts per million in volume. E-16 TABLE E-ll AIR POLLUTION TESTING RESULTS - UNCONTROLLED EMISSIONS Incinera-tor* Emission Rate (lbs/ton) Waste Converter Emission Rate ( l:bs/ton) Percent Reduction in Pollutant-Generation of the Waste Converter pollutant Particulate S02 50.0 9:.17 82% 3.9 ~.84 53% not reported 5°3 BCL 8.40 7.7 0.48** 94% CO 7.7 C).881 89% NO x 4.4 2.66 41% Volatile Organic Substances Condensable Non-:-ondensable E'ormaldehyde 0.284 0.21 not reported not .reported Lead .370 Beryllium .00008 Mercury 0.163 22% 0.121 .0004 .007 98% .• 00002 69% .002 .00002 99% Nickel .010 .0006 94% Chromium .020 .002 87% Arsenic .005 .0001 97% Cadmium .040 .0005 99% Dibenzodioxins not reported none detected *** Dibenzofurans not reported none detected *** *Source: "Air Pollution Control at Resource Recovery Facilities"; California Air Resources Board; 24 May 1984. **Obtained by Material Balance. ***Traces of Dibenzodioxins and Dibe:l1zofurans have been identified in the emissions from a number of incinerators abroad and in the U.S.. Testing results showed that no Dibenzodioxins or Dibenzofurans were detected in the Waste Distillator- stack gases. A comparison of emissions data, Table E-11, shows uncontrolled particulates to be 50 lblton of MSW for. incineration versus 9.17 lblton of MSW dry distillation. This indicates that the waste converter generates about 82 percent less particulates versus typical mass-burn incinerator. 2) Sulfur Dioxide Sulfur dioxide emissions from incineration are a function of . the amount of sulfur in the solid waste. An average municipal refuse has been found to contain approximately 0.12 percent sulfurs on an as-received basis. Not all of the sulfur in ithe refuse appears in, !the' flue gas as S02when the refuse is incinerated. Dependin<Jupon the type of incinerator and the form of the sulfur in thewas'te., betwee.n 40 and 80 percent of the sulfur is retained in the 'a:s~. 'ii The MSW used in the waste converter tests cont,iined .23 perc~ptsulfur, TaBle E-:-2, by weight on an asreceived basis. '. A comparison of emissions data shows uncontrolled sulfur dioxide emissions to be 3.9 lb/ton of MSW for incineration versus 1.84 lblton of MSW dry distillation. This indicates that the waste converter generates about 53 percent less sulfur dioxide versus a typical mass-burn incinerator. 3) " :-1 Nitrogen Oxides The emission of nitrogen oxides from combustion sources is due to either the conversion of nitrogen in the fuel to nitrogen oxides, or to the fixation of atmospheric nitrogen at high temperatures. Combustion techniques applicable to fossil fuelfires boilers either are generally not applicable to the massburning of MSW or tend to cause higher CO emissions and unacceptable boiler corrosion. MSW used in the waste converter tests contained .40 percent nitrogen by weight on an as-received basis. A comparison of the emissions data shows uncontrolled nitrogen oxides emissions to be 4.4 lblton of MSW for incineration versus 2.6 lb/tonof MSW for dry distillation. This indicates that the iwaste converter generates 41 percent less nitrogen oxides versus a typical mass~burn incinerator. '. S"Emissions and Emission Control in Modern Municipal Incinerators," Battelle's Columbus Laboratories, Columbus, Ohio 1981. E-18 4) Carbon Monoxide Carbon monoxide is a product of incomplete combustion and depends largely on the overfire air rat;io, the design of the overfire air jets and combustion temperatures. When volatile gases produced by the dry distillation process are combusted in a boiler, standard combustion techniques are applied to control carbon . monolxide • A comparison of emissions data sho~s uncontrolled carbon monoxide to be 7.7 lb/ton of MSW for inqineration versus ~B81 Ib/t,on of MSW for dry distillation. This indicates that the w,:;,ste converter generates 89 percent less ca~bon monoxide versus a typi.cal mass-burn incinerator. ' 5) Hydrocarbons Hydrocarbons appearing in the flue gas of an incinerator are products of incomplete combustion. They are mostly low-molecularweight hydrocarbons, aldehydes and organjjc acids with traces of high molecular-weight compounds. No municipal incinerator known uses any type of add-on control device: to reduce hydrocarbon emissions. When the volatile gases' produced by the dry distillation process are combusted in a boiler, standard combustion techniques are applied to control hydrocaz!bons. Comparison shows uncontrolled condensible hydrocarbons emissions to be .21 lb/ton of MSW for ibcineration versus .163 lb/ton of MSW for dry distillation. This indicates that the waste converter generates 22 percent less condensible hydrocarbons versus a typical mass-burn incinerator. 6) Hydrochloric Acid Flue gases from municipal inciner~tors normally contain hydrochloric acid as a by-product of the combustion of PVC, other chlorinated plastics and sodium chloride found in the waste Hydrochloric acid emissions are not regula:ted by the U.S. EPA, but mos1t states require the emissions to b~ reported and control regulations are under consideration in several states. , 7) Sulfuric Acid Mist Very little data is available on emissions of 503 mist from municipal incinerators. Sulfuric acid mist will be a vapor at high temperatures but, especially in the presence of moisture, will condense as an aerosol at lower temperatures. 8) Polychlorinated Biphenyls (PCBs) PCBs have been found in trace amounts in several municipal incinerator emissions. These materials probably result from E-19 incomplete destruction of traces of PCBs found in the waste feed. Since the manufacture and distribution of PCBs is now prohibited, the amounts found in the refuse should decline. 9) Heavy Metals In mass-burning facilities the amounts of volatile and nonvolatile metals emitted in the flue gases will depend upon the . efficiency of the particulate control system. According to studies, most "metals' with' ,the exception of mercury appear to concentrate ,ihthe . bottom ',aSlh . and ,fly ash of. cC:>Ilventional incinerationpnits. buring 'the clrY,distillatioh processing of MSW, the solid .residue is.exposedtoll,igh ,temperature and hot organic vapors as well as ,hothYdr~cill.rbon gas~s~, These conditions tend to form a layer of· polymerized orgflni'cco~emate:tial on the surface areas of all the .various par.ticies inclpdinc;J : metals making up the s,olid residu~. ,. UpoIl; coIllpletion ofth~ dry. dist:.i.Uation. phase, the i#di vid.~al:sldli~'resi,a:~~pa:!t~iclelsy,Qay~, iibeen '. eJ:}capsulated by this polymer:i:Jd,';pF>k~i'IJiay;~tJ!I':~~;#"!i!~~titirlg:::njth~'i(;ldi,sp~r~ion ,of' dangerous p o....,r+ '."1,',..tita.'.'D 1:.0., '.I.,.,.tfi.":~.', '.:ie..11."':. );!Jjb,.:.Me.' ~.'t.,L.'J!, '. lte. If~r;I,.)Ii!;O.' "'.ls.''.e.,ct,iort,c.' " '. ,ts, ,..'jli!in.'.' i ",~I,' " j ' h ' .. ,1." ' ,~, of t:h. is rep· o.rt 1'~'$~nd:~"i~f'~b~ri9'ercDti's:'P:6]ll;iU~antlsl~i;, ~jl:J:iq~r:i:suilation of., Leach~ble Materials ~'" II'd i ,'.' Ii I! ',' . ,: 'r" ,'fir ,', ,. ', , I, l. , : I 'I " '~: " ":, ,.• ',' , I ,I, '., I j ', ir~ble;E-12 i!lhows a cd~;ar1son for thetincontrolled heavy metal emissions from MSW i=ncin~:tation'versus dry dis,tillation of MSW. Emissions -~ Pollutant Lead Beryllium Mercury Nickel Chromium Arsenic Cadmium 10) Incinerator 6 Emission Rate (lbs/tonl .37000 .{)o008 .00200 .01000 .02000 .00500 .04000 Waste Converter Emission Rate ( lbsltonl .,0079200 ,,0000245 .0000.214 .,0006200 .0026400 ,'e 000134,0 .0005630 Percent Reduction of Pollutants Generation of the Waste Converter 98% 69% 99% 94% 87% 97% 99% Dioxins and Furans Traces of polychlorinated dibenzodioxins and dibenzofurans have been identified in the emissions from a number of municipal incinerators abroad and in the u.S. In 1981 in response to reports 6Source: "Air Pollution Control at Resource Recovery Facilities," California Air Resources Board, 24 May 1984. E-20 that dioxin compounds were found in emissions from facilities burning municipal wastes, the u.s. Environmental Protection Agency (EPA) issued a report, "Interim Evaluation of Health Risks Associated with Emissions of Tetrachlorinated Dioxin from Municipal Waste Resource Recovery Facilities" (USEPA, 1981a). The 1981 EPA calculation of excess lifetime cancer risk for total TCDD was 8.4 x 10-6 • The Tetrachlorinated dibenzodioxins (TCDDs) are the twenty-two different dioxins (isomers) having four chlorine atoms. In addition to icancer other potential health effects have been associated with the dioxin and furan compqunds. EPA made several assumptions in evaluating the health risks. In summary, these were (USEPA, 1981a): a) The carcinogenic properties and ,reproductive effects of all TCDDs are the same as that cif 2,3,7,8-TCDD. b) The PTMAX air dispersion model adequately represents the transport of the emissions to g~ound level. c) The composition of emission p:ttoducts found at ground level is identical to the composition (but not the concentration) found in the stabk. d) Seventy-five percent of the inhaled emission particles (to which the TCDDs are prefer~ntially and tenaciously bound) are retained in the body~ e) All the TCDDs that are retained in biologically available to the o~ganism. the body are I f) The population is exposed to th.e maximum annual average ground level concentration from the source for 24 hours a day throughout a 70-year life~ime. g) Humans are the comparable sen!:;itivity to the animals tested in the carcinogenic and reproductive effect testing, taking relative body suirface areas into account. I h) The excess lifetime cancer riskb are calculated for a 70 kilogram person who inhales 201 cubic meters of air per day (USEPA, 198Ib). . Since 1981, changes have occurred in/the chemical analysis of samples for chlorinated dioxins and furans and in the toxicological data which can be used to estimate th~ health risks of these chl3micals. ! Based upon the EPA's verification that potential health risks were associated with polychlorinated diberizodioxin and dibenzofuran emissions eminating from mass-burning g~rbage plants, the major interest of this testing was characterization of emissions from the E-21 ---_.__ ._-_._- - waste converter especially the organic compounds -- such as, dibenzodioxins and dibenzofurans. Testing results showed that no dibenzodioxins or dibenzofurans were detected in the waste converter's stack gases or in its solid residue. 3.. EMISSION CONTROL a. Complete Combustion The ability to employ known standard boiler combustion control techniques when firing the volatile gases produced by the dry conversion proces.s greatly reduces the source of emissions. This source reduction simplifies final flue-gas clean-up by a large percentage. b. Mechanical Device A supersonic scrubber manufactured by HydroSonic Systems (Figure E-3) has been selected as best available control technology and will be specified as original equipment to be installed with a waste converter system. HydroSonic Systems have been tested and will be installed in the U.S. Department of Energy's Defense Waste Processing Facility under construction at the Savannah River Plant in South Carolina. This proj ect is being managed by E.!. du Pont de Nemours and Company (du Pont), with Bechtel National, Inc. doing the o.etailed design. Selected as the best available control technology for cleaning off-gas from the vitrification of radioactive waste, HydroSonic Systems had six prototype devices in operation at the Vitrification pilot Plant being tested prior to selection as the air pollution control device for· the main project. HydroSonic Systems, manufactures a family of steam and compressed gas scrubbers and fan powered free-jet scrubbers capable of submicron particulate capture and toxic fume removal, such as HCL, SOx' and NOx ' in the same process. The gas cleaner is a wet scrubbing system employing a unique nozzle arrangement and mixing tube to create thorough mixing of the gas stream with water droplets for pollutant capture. Either a forced draft or induced draft fan provides the driving force for the system. Dirty gas is driven through a free-jet nozzle fitted with a water infection ring. Water is injected onto the driven gas stream. Turbulent mixing occurs as the free-jet expands, causing capture of particulate ranging from large to very fine sub-micron sizes. This mixing also provides an efficient means for simultaneous 'capture of gaseous pollutants when proper reagents are added to. the water. As the steam progresses through the mixing tube, part:iculate-e'ntrained droplets collide to form larger sizes for ease of separation. Agglomerated droplets containing pollutants are spun through cyclone sepprators, where the liquids drop out to drain. Scrubbed gases are vented to atmosphere. E-23 HYDRO-SONIC@SCRUBBER SCRUBBING LIQUID INJECTED _._TURBULENT MIXING OF GAS & ,LIQUID l,'l:j I N "'" ..... , .•• ", ~ e" GAS INLET ..... ;•... .- -, o' :' ".(" • .. . . . ,.... . ... . ..: "", _.••.•~ ..•...•: : .0,:- . .. .. '. _.;: '" ~~":... ~':. ,~.'; ;....... :~ .." ~Vp . .. • . • • • :::,::~, AGGLOMERATION .\.. ~ :. ' : . . •••• • ... ..... . .... .,- .....": ... I FREE-JET NOZZLE . . .. MIXING TUBE ." C> C lJ m m I (.J j/ 4• CONCLUSION Implementation of the above emission control technologies should guarantee that the waste converter's controlled emissions will be maintained at a level representative of Best Available Control Technology BACT. A comparison of these guaranteed controlled emissions for a commercial waste converter facility to be installed in the New Jersey emission guidelines as set down for new resource recovery facilities. E-25 TABLE E-13 COMPARISON OF WASTE CONVERTER CONTROLLED EMISSIONS VS. NEW JERSEY EMISSION GUIDELINES FOR NEW RESOURCE RECOVERY FACILITIES Pollutant Particulates S02 NO x ' as N0 2 CO VOS, as CB 4 BCL New Jersey Guideline .02 100 200 400 gr/dscf ppmv ppmv ppmv .019 gr/dscf 90 ppmV 200 ppmv 245 ppmv 140 ppmv 40 ppmv 50 ppmv 0.13 lbs/ton 0.74 lbs/ton 1.19 lbs/ton 0.88 lbs/ton 0.28 lbs/ton 0.19 lbs/ton Note: All concentrations are based on dry standard flue gas corrected to 7 percent O2 , PPMV = parts per million by volume. E-26