Southern Company Biomass Co-firing Research Slide 2 Doug Boylan
& Steve Wilson Southern Company Bill Zemo Alabama Power Kathy
Russell Georgia Power Southern Company Participants Slide 3
Switchgrass Co-firing Sponsors and Participants Southern Company
Auburn University EPRI Southern Research Institute Wilson Farms
Sunbelt Expo U.S. DOE McBurney Slide 4 Plant Staff Gadsden and
Mitchell Slide 5 Co-milling - mix biomass with coal and introduce
into the furnace through the coal handling system Simple procedure
Reduced capital cost Reduced transport cost Considerable system
experience Direct injection - introduce ground biomass
pneumatically into the furnace through dedicated burners Higher
co-firing percentages Direct biomass control Biomass Co-firing
Technologies Slide 6 Co-Milling Switchgrass and Coal Coal does not
flow when mixed with low percentages of grass Slide 7 Pellet
Co-firing Potential Advantages Improved efficiency Reduced plant
capital Reduced transportation Reduced labor Reduced dust Slide 8
Cubing Setup - Switchgrass farm in Lincoln, AL Slide 9 Cubes
sensitive to Moisture Binder type and percentage Grass type and
rate Slide 10 Mitchell Cube Combustion One week of testing
completed Cubes handle and burn fairly well Serious bunker issues
Rat-holing Slide 11 Tub grinder Metering Bin Transport Fan 3 Levels
of coal at each corner Boiler Pneumatic Transport Lines Upper Grass
Burner Lower Grass Burner (not connected) Switchgrass Bales Upper
Grass Burner Switchgrass Co-firing Schematic Slide 12 Gadsden
Co-Firing Facilities Slide 13 Slide 14 (Full Load - 7% by heat
input) Switchgrass Co-firing and Boiler Efficiency Slide 15 Cement
and Ash Tests ASTM specifications exclude biomass ash with coal ash
for cement Conducted tests with University of Alabama in Birmingham
to evaluate effect of wood ash on cement properties Coordinating
efforts with ASTM Slide 16 SCR Catalyst Effects SCR (Selective
Catalytic Reduction) is NOx emission control device Catalyst is
affected by biomass ash Pilot study at Plant Gadsden with EPRI
Slide 17 Grass Co-Firing Energy Cost Present Slide 18 Grass
Co-Firing Energy Cost Future Slide 19 Conclusions 1.Direct
injection with grass was technical success 2.Co-firing reduced
emissions, but was a little less efficient 3.Cubes have problems
4.Grass co-firing cost predictions were about 2.6/kWh to 3.0/kWh
higher than coal power 5.Results suggest a subsidy will be required
to make grass co-firing viable for an RPS 6.Biomass cannot be
co-fired at some units for technical and cost reasons at this time
7.Research is on-going at Southern Company to address these issues
Slide 20 Questions?
