Carbon Neutral Energy from Waste Gasification Presented by Allen Medearis and Trip Dacus April 14, 2010 University of Tennessee at Chattanooga

Outline Gasification UTC Natural Gas Replacement Design -Background -Material and Energy Balance -Cost Analysis -Conclusions Garbage Gasification Design -Basis -ChemCAD -Material Balance -Power Production -Economic Analysis -Conclusion

Gasification Extracting Energy From Organic Materials Converts Carbonaceous Materials Into Carbon Monoxide and Hydrogen Uses High Temperatures (>700°C) and Controlled Oxygen Content Result is Syngas

Replacing UTC’s Natural Gas Usage Use Wood and Paper Gasify to Make Fuel to Use in Furnaces Replace UTC’s Natural Gas Usage +20% with Syngas Assumptions -Wood and Paper Are Viewed as Cellulose - Syngas Can Be Sufficiently Burned to Power the Furnaces

UTC CO 2 Footprint

Process Flow Diagram

Material and Energy Balance Results Replacing 120% of Natural Gas Usage Material Composition of Feed - 70% Cellulose - 20% Water - 10 % Ash Feed Stream: 22.7 Tons/Day of Wood and Paper Exit Stream: 17 Tons/Day of Syngas

Cost Analysis Capital Costs -Grinder $60,000 -Cleaner $350,000 -Gasifier $330,000 Lang Factor (3.63) Labor Cost $300,000/year Annual Power Cost $10,000/year

Cost Analysis (cont’d) Total Capital Cost: $2.7 Million Time to Payoff: 3.6 Years Total Savings Per Year: $770,000

Conclusions About UTC Design Great Way for University to Save Money Fast Payoff Reduces Carbon Footprint of University Recommend University Fund Further Research

Outline Gasification UTC Natural Gas Replacement Design -Background -Material and Energy Balances -Cost Analysis -Conclusions Garbage Gasification Design -Basis -ChemCAD -Material Balance -Power Production -Economic Analysis -Conclusion

Introduction Gasify Chattanooga Waste for Production of Syngas Burn Syngas in Combined Cycle Gas Turbine for Power Production

Basis - Assumptions 4.4 lbs of trash per person per day Chattanooga population - 300,000 Use existing trash collection infrastructure

Basis Chattanooga Trash Output – 660 tons/day of trash MaterialFormulaPercentageTons/Day PaperC 6 H 10 O 5 63%420 PET PlasticC 10 O 8 H 4 20%130 WaterH2OH2O7%45 Ash -10%65

Plant Design Schematic Air Waste Filter Gasifier Grinder Combustion Turbine Exhaust Power Ash/Slag Power Steam Turbine Condenser

Material Balance RPM Gasifier System Waste, 660 tons/day Air, 3100 tons/day CO tons/day H 2 O 690 tons/day Ash/Slag 65 tons/day

Power Generation Power (MW) Combustion Turbine71 Steam Turbine3 Total74 Cooling Utility13

Capital Cost Analysis Capital Cost of the Plant = $27M per year

Capital Cost Analysis C TM – Capital cost of the plant C p,i – Purchased cost for major equipment units F Lang – Lang Factor (3.63 for solid-fluid processing) Total Capital Cost = $120 M

Economic Analysis Income (per year) CHANGE  74MW sold at $0.05 per kW·hr = $31M Expenses (per year)  10% of electricity for plant usage = $3M  10 employees at $100,000 per year = $1M Net Income = $27M per year

Cash Flow Diagram 4 ¼ Years to pay off capital investment

Recommendation Based on this design, we recommend that the city should fund a detailed design study

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