The document summarizes a presentation about converting biomass to steam using gasification. It discusses the environmental challenges of producing 360,000 pounds per hour of steam from varied biomass fuels to meet stringent emissions requirements. A dual wet electrostatic precipitator (WESP) technology was proposed to control multiple pollutants such as particulate matter, acid gases, sulfur and nitrogen compounds, and mercury. Test results showed the WESP system could meet emissions limits after additional NOx controls. The system was ultimately approved by state permitting.

1. Biomass to Steam: The
Environmental Challenge
Presented April 18th, 2012
BBI International Biomass
Conference

2. Overview
• Making Green Power Via Gasification
• The Environmental Challenge
• Technical Approach
• Results / Lessons Learned

3. The Project Objective
• Produce 360,000 lb/hr of 850 psig
steam
• 60 MW worth of Electricity
• Over the Fence line Agreement with
Chemical Plant to Take 90% of Energy
Generated

4. Why Gasification?
•Demand for low cost energy from alternative sources
increasing
• Woody biomass
• Agricultural byproducts
• Refuse derived fuel
• Spent tires
• Carpet fibers
• Automotive shredder residue
•Reduced burden on landfills
• Creating energy while reducing waste

5. The Environmental Challenge?
– Projected Environmental Permitting in State of
Michigan Required Emissions to Be Equivalent to
a Similar Sized Natural Gas Facility
– Challenge of Varied Fuel Needs Versus Absolute
Requirements of Stack Emissions on TPY Basis

6. Multi-Pollutants
• Alternative energy sources
pose potential pollution
problems
– Particulate Matter
– Acid Gas/Mist (HCl, H2SO4)
– SOx
– NOx
– Mercury (Hg)
– Metals

7. Particulate Matter
• What is Particulate
Matter?
» Mixture of air-borne
particles and liquid
droplets composed of
acids, water, organic
chemicals, and metals
» PM10, PM2.5

8. HCl
• HCl gas produced from fuels that may
contain Chloride:
» Solid waste (MSW, RDF)
» Plastics
• Hydrochloric Acid formed in the
presence of liquid water
• Environmental / Health Hazards
» Corrosive

9. SOX
• Sulfur Dioxide (SO2) & Sulfur Trioxide (SO3)
» SO3 Forms Sulfuric Acid (H2SO4) aerosol with moisture
• Generated as a result of combustion of fuels that contains
Sulfur
» Solid waste (MSW, RDF) O
S O
» Tires
» Cardboard O
» Plastics H H
• Environmental / Health Hazards O
» Acid Rain S S
O
O O O

10. NOX
• Nitric Oxide (NO) & Nitrogen Dioxide (NO2)
• Produced during combustion at high temperatures
» Nitrogen in air
» Small amounts of nitrogen in biomass fuels
• Environmental / Health Hazards
» Forms acid rain
» Creates smog
» Depletes the ozone layer
N
O
O O N

11. Mercury (Hg)
• Mercury exists in different forms:
» Elemental Mercury (Hg, Hg0, Hg2+) – vapor phase, reactive
» Mercuric Oxide (HgO) – solid particulate
» Mercuric Chloride (HgCl2) – vapor, water soluble
• Generated from solid waste incineration
• Environmental / Health Hazards
» Toxic

12. Technology Alternatives
Dry Fabric Dry Wet
Scrubber Filter ESP Scrubber
Acid Gas
Acid Mist*
Hg
Moisture
PM2.5
Metals
*Acid mist refers to condensed aerosols (< 1micron) which include HCl and H2SO4.

13. Single System Approach

14. Dual Field Wet ESP Approach
1. Quench
2. Spray Tower
3. Downflow WESP
4. Acid Scrubber
5. Upflow WESP
6. Outlet

15. Basic WESP Operation

16. WESP-2F Technology
• Inlet quench duct
– High efficiency syngas saturation
– Concurrent, full cone design
– Large particulate scrubbed

17. WESP-2F Technology
• Spray Tower Pre-Scrubber
– Acid gas HCl, H2S adsorption
– Counter-current spray design
– Integrated mist elimination

18. WESP-2F Technology
• Ultra-Fine Atomizing Spray System
– Add sub-micron water droplets to syngas
– Continuous WESP wash
– Operator / maintenance
access

19. WESP-2F Technology
• WESP Field #1
– PM/PM10/PM2.5 and acid gas removal
– Downflow design

20. WESP-2F Technology
• Horizontal Acid Gas Scrubber
– Horizontal flow design

21. WESP-2F Technology
• WESP Field #2
– PM/PM10/PM2.5 and fine acid particle removal
– Upflow demisting design

22. WESP-2F Technology
• Control / Pump Skid
– Dual pumps for uptime guarantee
– Pre-pipe / pre-wired for easy install
– Single interface for complete
system control

23. Results
• System Permitted for NOx
Reduction Via Selective
Catalytic Reduction Followed
by WESP
• Liquid Blowdown to Be
Evaporated and Discharged as
Solids with Gasifier Bottom
Solids
• Permit Approved by State of MI
in late Dec, 2011.
–WESP-2F Test Unit at Gasifier Location

24. Conclusion
Bradley L. Ginger
Engineering Product Manager
EISENMANN Corporation
p: 815.356.2633
e: bradley.ginger@eisenmann.com