Eilhann Kwon. Department of Earth and Environmental Engineering (HKSM) Columbia University, New York, NY, 10027

Transcription

1 Investigation of Thermo-Gravimetric Analysis (TGA) on Waste Tires and hemical Analysis Including Light Hydrocarbon, Substituted Aromatics, and Polycyclic Aromatic Hydrocarbon (PAH) Eilhann Kwon Department of Earth and Environmental Engineering (HKSM) olumbia University, New York, NY, 10027

2 Presentation Outline Introduction & Background Experimental Setup Previous work Results onclusions & Future Work

3 Objectives haracterize the thermal degradation mechanisms of a waste tire in the combustion and pyrolysis process Identify by-products from the thermal degradation of a waste tire Investigate air pollutant generation mechanism from the combustion and pyrolysis process

4 Feasibility of Waste tires as fuel Heating Value of Fuels* Fuel Heating Value (Btu/lb) Peat 2,500-6,500 Wood 6,500 oal 8,000-14,500 Gasoline 20,400 Diesel 19,300 Tire 12,000-16,000 * Source: NIST hemistry WebBook 15,000 BTU 20lb lb 0.09quadrillion BTU / yr 12 million Barrel of Oil Assumption Avg. Wt. of a waste tire: 20lbs Experimental heating value of a waste tire: 15,000Btu/lb Waste Tire generation a year: 293million 6

5 Introduction Waste tire generation (293 million waste tires in U.S.) 1 waste tire / 1 person / 1 year Landfill/Stockpile 75% Void Volume Needs high cost of tipping fees Leads to extremely difficult conditions for quenching tire fires auses the piercing the landfilling cover Non-biodegradability Leachate Landfill Stockpiles Recycle Landfill Stockpiles Recycle ombustion Pyrolysis Utilization Alternatives (ombustion & Gasification/Pyrolysis) Source: EPA & Rubber Manufacturer Association

6 Overall Experimental Setup Heated tubing (280 o ) Micro-G & G/MS onst. Temperature Water circulation Mass Flow ontroller 80ml/min 20ml/min N 2 O 2 Air ertified gases (pure and mixtures)

7 Experimental onditions urrent conditions found in combustors Gasification/ pyrolysis (100% N 2 ) Air atmosphere (21% O 2, 79% N 2 ) Lean atmosphere (7% O 2, 93% N 2 ) Possible enhancements for higher efficiency Enriched atmosphere (30% O 2, 70% N 2 )

8 Properties of a Tire ross section of a tire Main constituents of rubber (Approximately 60%) * H 2 H 2 * * H 2 H 2 * H 3 H n H H n Natural Rubber (Poly-Isoprene) Butyl Rubber * H H H 2 H 2 H H H 2 H 2 H H 2 H 2 H H * n Styrene-Butadiene Rubber (SBR) 25 wt% of Styrene+75wt% of Butadiene

9 Previous Work Thermo-gram of SBR and IR in various atmospheres at 20 o /min heating rate Weight Loss Fraction, α[-] SBR Weight Loss Fraction, α[-] IR

10 Location of Epoxyethane in the Region of the Decomposition Plateau Marco J. astaldi and Eilhann Kwon, Beneficial Use of Waste Tires: An Integrated Gasification and ombustion Process Design via Thermo-Gravimetric Analysis (TGA) of Styrene-Butadiene Rubber (SBR) and Poly-Isoprene (IR), EES, In pressing, 2007

11 haracterization of Thermal Degradation of Tires % N 2 Atmosphere Weight Loss, [%] % O 2 & 97% N 2 Air Atmosphere 30% O 2 & 70% N 2 Volatilization + Oxidation Heating rate: 10 o /min Temperature, [ o ]

12 SEM/EDX Analysis 1000 o in N o in lean air 700 o in lean air 1000 o in lean air Temperature ( o ) Atmosphere Wt % S Wt% 25 o air 94.14% 2.6% 1000 o N % NA 500 o 7% O 2 & Bal. N % NA 700 o 7% O 2 & Bal. N % NA 1000 o 7% O 2 & Bal. N % NA

13 hromatograms from the thermal degradation of a Tire Toluene Ethylbenzene Styrene Limonene 1-methyl-4-(1-methylethyl)-benzene hromatogram from a Tire at 400 o in N 2 Atmosphere Styrene Limonene Isoprene hromatogram from SBR hromatogram from IR

14 oncentration Profiles of Styrene & Limonene Heating rate: 20 o /min

15 Proposed Limonene Formation Mechanism Equilibrium geometry based on Hartree-Fock approximations using the 3-21G method Modeling using SPARTAN, Wavefunction Inc. Limonene Isoprene hromatogram from IR in N 2 Atmosphere

16 Qualitative G/MS Results from a tire in Air Hydrocarbons hemical Species (M.W) hemical Species (M.W) Methane (16) 2-methyl-1-buten-3-yne (66) Acetylene (26) Octane (114) Ethane (30) 4-octene (112) Propane (44) n-dodecane (170) n-butane (58) Ethanol (46) But-1-ene (56) yclohexanol (112) 1,3-butadiene (54) 1-pentanol (88) Pentane (72) 1-cyclopropyl-ethanone (84) 1-pentene (70) Octanal (142) 1,4-pentadiene (68) Propanone (142) Hexane (86) Acetone (58) 1-Hexene (84) 2-Decanol (158) yclohexene (82) 1,3-Butadienal (68) 1,1-dimethyl-cyclopropane (72) 3-Butene-2-one (70) 3-methyl-2-pentene (84) Buanone (72) 2-methyl-1-pentene (84) Hexanol (102) 1-methyl-cyclopentene (82) 3-Methyl Butanol (88) 4-methyl-cyclopentene (82) Thiophene (84) yclopentene (68) Benzoic Acid (122) 2-pentyne (68) Benzaldehyde (106) Partial Oxidation Alcohol Aldehyde

17 oncentration Profiles of Phenol in Various Atmospheres

18 oncentrations of hemical Release from a TGA Unit with a Tire at heating rate 10 o /min in air

19 oncentration Profiles of Phenyl- 2-3 and Phenyl- 4 from a tire in 30% O 2 and Bal. N 2 Atmosphere Precursors to the formation of PAH Structure breakdown Gas phase addition of reactive intermediates

20 oncentration Profiles of Phenyl- 6 from a tire in 7% O 2 and Bal. N 2 Atmosphere Hexylbenzene 1,2,4-triethylbenzene 1,3,5-triethylbenzene

21 The Origin of Benzene Derivatives Main pathway to form benzene derivatives from SBR

22 The Origin of Benzene Derivatives From the thermal degradation of IR Diels-Alder Reaction From SBR backbone Diels-Alder Reaction

23 oncentration Profiles of Naphthalene with a Tire in Various Atmospheres H 3 H 3 H 3 H 3 H 3

24 oncentration Profiles of 2 and 3 ring at 10 o /min Heating Rate in Air Atmosphere

25 onclusions Volatilization and combustion was observed simultaneously when oxygen presented. The bond scission followed by hydrogenation was observed in monomer of main constituents of a tire The Hierarchical step for growing benzene derivatives by gas phase addition also observed. The oxidized benzene derivatives such as phenol reached up to 30PPMV in enhanced air atmosphere and the secondary oxidized chemical species derived from phenol such as benzaldehyde were observed. Oxidation is the feasible way to reduce the level of hazardous air pollutants including VOs and PAHs. The chemical analysis from different ratio between SBR and IR in various atmospheres should be carried out.

26 Future Work Determine and develop the higher efficiency and lower emission firing technology.

27 Acknowledgement Marco J. astaldi