ECS_NB2

• Wet bottom (slagging T>Tmelt ash)
• Dry bottom ( >85% fly ash)
• Front Fired
• Tangental Fired

• Coal -> Crushed -> Screen -> Pulverized -> Burner -> Ash
• 0.3-0.4m <10mm <74micron air^

Gasoline, Oil, Anthracite, Bituminous, Lignite, Biomass

Lignite, High VOC Bituminous, Medium Bituminous

Anthracite, Bituminous, Oil

As both increase heat rate increases.

t/h(steam) = 0.75 MWth heat input

• 1) Fuel burns in fluidized suspension of inert particles.
• 2) Combustion zone is kept low by extracting heat directly from combustion zone.
• 3) Exceptionally high degree of heating.

Difference lies in how the gas and solids move around in the furnace.

• 1) Low emission of SO2 and NOx
• 2) Very fuel flexible
• 3) Easy to operate and stable
• 4) Lower maintenance
• 5) Cost less than PC for lignite fuels
• 6) Cost less than PC if FGD and SCR is required?

**Note FB has a higher N20 (GHG) emssion than PC.

• 1) Bubbling - Low Speed (1-2m/s), 10mm dp
• 2) Circulating - High speed (4.5-5.5m/s), 6mm dp

FB can burn any fuel that has energy sufficient to raise itself and combustion gas above its ignition temperature.

• 1) Large thermal inertia allows most fuels to be heated to ignition without losing too much heat from the boiler.
• 2) Mixing makes it possible to dissipate the released heat and fresh fuel particles around the bed for easy ignition.

• 1) Low combustion temp allows limestone to capture Sulfur in combustion zone.
• 2) Low temp and stagged air does not allow nitrogen to form NOx.

Gasoline, Oil, Anthracite, Bituminous, Lignite, Biomass

Lignite, High VOC Bituminous, Medium Bituminous

Anthracite, Bituminous, Oil

As both increase heat rate increases.

t/h(steam) = 0.75 MWth heat input

• 1) Fuel burns in fluidized suspension of inert particles.
• 2) Combustion zone is kept low by extracting heat directly from combustion zone.
• 3) Exceptionally high degree of heating.

• 1) CFD Loop of solids
• 2) Convection loop of gas

• 1) Preheat bed solids
• 2) Let T increase until > Tign
• 3) Extract heat
• Water tubes in bed
• Regulating air passing through bed
• 4) Ash either stays in bed or entrained as fly ash.

• 1) Avoid melting or agglomerating bed solids
• 2) Reduction of NOx
• 3) Allows for Sulfur removal.

• 1) A = Vgas/Uf
• 2) Hb = 0.4 - 1.5m (Hb = 0.7Uf - Gives residence time of 0.7s)
• 3) Dp ~ 0.75mm
• 4) Uf = 2.5Umf
• 5) Qgrate = 3.3*Uf|300k/excess air (1.2 = 20% excess) (Mw/m2)
• 6) About 2.908 MJ/kg heat is generated when 1kg of dry air is consumed.

• P>220.9 bar
• T>374.3 C

**Efficiency increases with both temperature and pressure.

• 1) High efficiency
• 2) Lower emissions
• 3) Lower cost
• i) Once through is simpler
• ii) No drum
• iii) Smaller diameter tubes

• 1) For CFB highest heat flux region is in the water heating section.
• 2) For PC highest heat flux is near water-steam transition region.
• 3) Highest heat flux is much higher than average in PC.
• 4) Much more uniform heat distribution

It increases in a logarithmic fashion.

• 1) Air blown - 0.5 heating value of O2 blown
• 2) Oxygen blown - Much better for CO2 capture as flue gas is only CO2 and H2O

• 1) Low emissions
• 2) High efficiency
• 3) Best for CO2 capture
• 4) Can produce H2

• 1) PC can meet current standards
• 2) IGCC financing costs are higher
• 3) No reward for risk taking
• 4) Bottle neck construction
• 5) More project planning

• Simple cycle (36.4%)
• Combined cycle (52.7%)
• Co generation cycle (85.1%)
• Combined cycle with Cogen (89.3%)

• 1) In-situ carbon capture (oxygen firing and chemical looping)
• 2) Gasification systems (e.g. IGGC)

• Futuregen
• Annouced by bush in 2003
• in 2007 Mattoon Township
• in 2009 funding was pulled

• 1) Independent of wind direction
• 2) Low rotational speed (Torque up, Power down)
• 3) Mechanical components are on ground level for easy access.
• 4) Expensive tower is not required.

• 0.5926
• Theoretical maximum efficiency

• 2 blades (5)
• 4 blades (3)

**Efficiency increase with number of blades but noise increase with tip speed ^5

• Hub height - Height to middle of props
• Blade
• Gearbox and generator - Found in hub
• Swept blade area
• tower

• Cut in 7-10mph
• Cut out 45-80mph
• Rate speed 25-35mph (where design power is found)

• 1) Spillway - Release water downstream that is not used to make energy
• 2) Penstock - Collects water from upstream leading it to turbine
• 3) Draft tube - Passage directly below turbine
• 4) Tailrace - Passage from draft tube downstream
• 5) Surge tank - Reservoir that vents sudden pressure build up if required.
• 6) Intake - Leads to the penstock
• 7) Reservoir - Upstream water source

• 1) Reaction (Static pressure changes)
• Converts both flow and kinetic energy
• Axial flow - Kaplan
• Radial or mixed flow - Francis
• 2) Impulse (Static pressure is constant)
• Converts only kinetic energy
• Tangental bucket flow - Pelton

• 1) Very low head
• 2) High volume flow

• Axial Flow 7-14
• Mixed flow (Francis) 3.5-7
• Centrifugal or radial flow (Francis) 1-3.5
• Impulse (Pelton) 0-1

• 1) Typically produce up to 100kw power
• 2) 2000MW installed in Canada
• 3) 40 in NS supplying 11% of provincial capacity

Material extraction, Material Production, Product manufacture, Distribution, Retail, Use, Disposal

**There is also transportation throughout

• 1) Goal and scope definition
• 2) Inventory analysis
• 3) Impact assessment

• 1) Product development and improvement. (Product comparison)
• 2) Strategic planning (Product assessment)
• 3) Public policy making
• 4) Marketing (Eco-Labeling)

• 1) Product comparison
• 2) Product assement
• 3) Eco-labeling

• CH4 - 25
• N2O - 298
• HFC - 124-12800
• PFC 7000-12000