Carbon Neutral Energy from Waste Gasification

Carbon Neutral Energy from Waste GasificationPresented 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 Material Into

Carbon Monoxide and Hydrogen Uses High Temperatures (>700°C) and

Controlled Oxygen Content Result is Syngas (CO and H2)

GasifierWaste 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 CO2 Footprint

Process Flow Diagram

Material and Energy Balance ResultsReplacing 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

GasifierWaste Syngas Combined

Cycle Gas Turbine

Electricity

Basis - Assumptions

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

Basis - RepresentativeChattanooga Trash Output –

660 tons/day of trash

Material Formula Percentage Tons/Day

Paper C6H10O5 63% 420

PET Plastic C10O8H4 20% 130

Water H2O 7% 45

Ash - 10% 65

Plant Design Schematic

Air

Air

Waste

Filter

Gasifier

Grinder

Combustion Turbine

Exhaust

Power

Ash/Slag

Power

Steam TurbineCondenser

Material Balance

RPM Gasifier System

Waste,660 tons/day

Air,3080 tons/day

Non-Fossil CO2

980 tons/day

H2O340 tons/day

Ash/Slag70 tons/day

N2

2350 tons/day

Power Generation

Power (MW)

Combustion Turbine 71

Steam Turbine 3

Total 74

Cooling Utility 13

Capital Cost Analysis

Capital Cost of Equipment = $27M

Capital Cost Analysis

ipLangTM CFC ,

CTM – Capital cost of the plant

Cp,i – Purchased cost for major equipment units

FLang – Lang Factor (3.63 for solid-fluid processing)

Total Capital Cost = $120 M

Economic Analysis

Displaced Expenses74MW sold at $0.05 per kW·hr = $31M

Expenses 10% of electricity for plant usage = $3M10 employees at $100,000 per year = $1M

Net Income = $27M

Cash Flow Diagram

4 ¼ Years to pay off capital investment

-140

-120

-100

-80

-60

-40

-20

0

20

40

0 1 2 3 4 5 6

Years

$M

Recommendation

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

Thank you for listening!

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