Gasification Kinetics of Coal and Biomass
Estefania AlbaMerced RamirezJoshua Felton
Outline1. Objective2. Introduction/Background3. Methodology4. Results5. Conclusion
Objective1. The goal of this research
project is to study the effect of blending biomass with coal on the gasification reactivity.
Gasification of coal and biomass can increase efficiency and reduce carbon dioxide emissions.
IntroductionWorld Primary Energy Production by Source 1990, 2006. (Quadrillion Btu)
BackgroundBiomassCoal
ADVANTAGES•Enormous world stock•High energy density•Relatively low cost•No seasonal limitations
DRAWBACKS•Environmentally harmful compounds (S, N,CO2)•Low H/C ratio•Non renewable source
ADVANTAGES•Economic way to dispose waste•Content less pollutants•Carbon neutral •High H2 contentDRAWBACKS•Low energy density•Seasonal limitation•Poor reliability in supply•High moisture content
Background
Gasification is an endothermic reaction between a carbonaceous fuel and a gas in a reactor where the oxygen supply is limited (partial oxidation).
Combustion is an exothermic reaction between a fuel and an oxidizer.
Fuel + oxygen (limited) + Steam/CO2 →hydrogen + carbon monoxide + (some water and carbon dioxide + light
hydrocarbons )
Fuel+ oxygen →heat + water+ carbon dioxide
Methodology
Biomass has a fibrous structure which makes it hard to grind
Hammer mill
Coal is easier to grind due to Coalification
Ball mill or Bar/rod mill
Coal: Bituminous coal (Pittsburgh #8)
Milled to: < 140 mesh(<105 μm)Biomass: Switchgrass
Milled to:60-120 mesh (250-125 μm)120-200 mesh (125-74 μm) < 200 mesh (< 74 μm)
MethodologyProximate analysis determines the percentage composition of moisture, volatile matter, fixed carbon and ash
MethodologyUltimate analysis determines the elemental
composition
MethodologyDrop Tube Furnace
Feeder
Collection Probe
Furnace
Methodology
Sample Biomass: 60-120 mesh Coal: < 140 mesh
Blend ratio (Energy basis)
Method1. Moisture 107℃ in N2 (Flow rate100 ml/min)
2. Volatile 950 ℃ in N2 (Flow rate100 ml/min)
3. Char 950 ℃ in CO2 (Flow rate100 ml/min)
The Thermo Gravimetric Analyzer is used to determine the rate of reaction
Coal % Biomass %100 070 3040 600 100
Results
Calorific Value Btu/lb kJ/kgSwitchgrass, <200 6996.8
16274.5
Switchgrass, 120x200 7294.3
16966.6
Switchgrass, 60x120 7307.7
16997.7
Coal < 140 8836.520553.
9
Proximate Analysis Moist % Vol % FC % Ash %
Switchgrass, <200 9.1 67.2 12.7 10.9
Switchgrass, 120x200 9.5 72.9 12.8 4.8
Switchgrass, 60x120 9.9 73.9 12.5 3.7
Coal <140 10.0 39.9 41.3 8.9
Ultimate analysis dry ash free basis
C % H% N % S % O %Switchgrass, <200 50.5 7.6 1.8 0.7 39.5Switchgrass, 120x200 49.4 6.7 1.5 0.7 41.7Switchgrass, 60x120 47.6 6.9 1.1 0.6 39.8
Coal <140 74.2 5.4 1.0 1.2 18.2
Results
ConclusionA blend of 60% biomass and 40% coal: reacts faster than other blends
Use of biomass in thermochemical processes can
increase efficiency reduce CO2 emission reduce emission of other environmentally harmful
compounds
AcknowledgementsEberly College of Science Daniel J. LarsonCollege of Earth and Mineral
SciencesWilliam E. EasterlingDr. Sarma PisupatiAime Hilaire TchapdaBrandon EmigJody MarkleyDerek JamesUBMS Staff
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