Fuels For SchoolsFuels For SchoolsGeneral Air Quality ConsiderationsGeneral Air Quality Considerations

Diane R. Lorenzen, P.E.Montana Department of Environmental

QualityOctober 17, 2007

Air Quality TopicsAir Quality Topics• Emissions EstimatesEmissions Estimates

– Criteria Air PollutantsCriteria Air Pollutants– Hazardous Air Pollutants (HAPS)Hazardous Air Pollutants (HAPS)

• Is an Air Quality Permit Required?Is an Air Quality Permit Required?

• Ambient Air ImpactsAmbient Air Impacts

• Non-attainment AreasNon-attainment Areas

Criteria Air PollutantsCriteria Air PollutantsRegulated by Air Quality Standards

• Carbon Monoxide (CO)Carbon Monoxide (CO)• Nitrogen Dioxide (NONitrogen Dioxide (NO22))• Sulfur Dioxide (SOSulfur Dioxide (SO22))• Particulate Matter Particulate Matter << 10 10 µµm (PMm (PM1010))• Particulate Matter Particulate Matter << 2.5 2.5 µµm (PMm (PM2.52.5))• Ozone, regulated as Volatile Organic Ozone, regulated as Volatile Organic

Compounds (VOC)Compounds (VOC)• Lead (Pb) [also a HAP]Lead (Pb) [also a HAP]

5

Criteria Pollutant Emissions ComparisonCriteria Pollutant Emissions ComparisonPotential to Emit (PTE)

Tons of pollutant per year (tpy)19 MMBtu/hr boiler (heat input)

Pollu-Pollu-tanttant

Wood Wood

FuelFuelDistillateDistillate

Fuel OilFuel OilLP Gas LP Gas

(Propane)(Propane)Natural Natural

Gas Gas FuelFuel

Coal Coal

FuelFuel

PMPM1010 16.616.6 1.041.04 0.360.36 0.630.63 5858

PMPM2.52.5 1313 0.80.8 0.30.3 0.60.6 3131

NOxNOx 18.318.3 11.011.0 12.812.8 2.662.66 4242

SOSO22 2.082.08 4.354.35 <0.01<0.01 0.050.05 110110(unc)(unc)

COCO 11.711.7 3.073.07 2.922.92 7.007.00 4848

VOCVOC 1.411.41 0.440.44 0.460.46 0.460.46 5.75.7

FuelFuel 2 tons/hr2 tons/hr 140 gal/hr140 gal/hr 208 gal/hr208 gal/hr 19,000 19,000 scf/hrscf/hr

1 ton/hr1 ton/hr

Example HAP EmissionsExample HAP Emissions2 MMBtu/hr Wood-fired Boiler

HAPHAP Emission Factor Emission Factor (lb/MMBtu)(lb/MMBtu)(1)(1)

Emission Emission Rate (lb/hr)Rate (lb/hr)

Emission Rate Emission Rate (tpy)(tpy)

Hydrogen Chloride*Hydrogen Chloride* 1.9E-021.9E-02 0.0380.038 0.170.17

FormaldehydeFormaldehyde 4.4E-034.4E-03 0.0090.009 0.0380.038

BenzeneBenzene 4.2E-034.2E-03 0.0080.008 0.0370.037

AcroleinAcrolein 4.0E-034.0E-03 0.0080.008 0.0350.035

ManganeseManganese 1.6E-031.6E-03 0.0030.003 0.0140.014

ArsenicArsenic 2.2E-052.2E-05 4.4E-054.4E-05 0.00020.0002

(1) (1) Emission Factors from AP-42, Section 1.6, External Wood Emission Factors from AP-42, Section 1.6, External Wood CombustionCombustion

PMPM1010 Emissions Comparison Emissions Comparison

Wood BurnerWood BurnerBurner SizeBurner Size

Heat InputHeat Input

PMPM1010 Emission Emission Factor Factor

(lb/MMBtu)(lb/MMBtu)

PMPM1010 Emissions Emissions (tpy)(tpy)

Small Wood Small Wood StoveStove 18,000 Btu/hr18,000 Btu/hr 0.530.53 0.040.04

Pellet FurnacePellet Furnace 85,000 Btu/hr85,000 Btu/hr 0.320.32 0.120.12

Outdoor Outdoor FurnaceFurnace 500,000 Btu/hr500,000 Btu/hr 0.60.6 1.311.31

Typical FFS Typical FFS BoilerBoiler 2 MMBtu/hr2 MMBtu/hr 0.300.30 2.632.63

Large FFS BoilerLarge FFS Boiler 19 MMBtu/hr19 MMBtu/hr 0.200.20 16.616.6

Small Sawmill Small Sawmill BoilerBoiler 32 MMBtu/hr32 MMBtu/hr 0.300.30 42.042.0

Large Hog Fuel Large Hog Fuel BoilerBoiler 292 MMBtu/hr292 MMBtu/hr 0.024 0.024 30.730.7

Boiler Stack and BuildingsBoiler Stack and Buildings

Building Downwash

Ambient Air Quality Ambient Air Quality BoundaryBoundary

Industrial FacilityIndustrial Facility

School YardSchool Yard

Stack Height ConsiderationsStack Height Considerations• Minimize building downwash effectMinimize building downwash effect• Good Engineering Practice Stack Height Good Engineering Practice Stack Height

(GEP)(GEP)

>> 2.5 times adjacent building height 2.5 times adjacent building height

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

40.0

45.0

50.0

30 35 40 45 50 55 60 65 70

Boiler Stack Height (ft)

To

tal P

M2.

5 Im

pac

t (u

g/m

3)

Boiler at Full Load 24-hour PM2.5 NAAQS Background Conc.

GEP Stack Height = 69'

Sample Boiler Modeling Results

Non-Attainment AreasNon-Attainment Areas

Wood Smoke is a primary Wood Smoke is a primary contributor to PM2.5 impacts in contributor to PM2.5 impacts in

Montana’s mountain valleysMontana’s mountain valleys..

Locating a Project in a Locating a Project in a Non-attainment AreaNon-attainment Area

• Contact state and local regulatory authorities at the beginning of planning

• Consider the effects of NAA restrictions on boiler operation and project economics

Source: http://www.fuelsforschools.org

Source: http://www.fuelsforschools.org

Open Open Burning vs. Burning vs. Fuel BoilerFuel Boiler

Carbon Carbon DioxideDioxide

Source: http://www.fuelsforschools.org

Burning Seasons in Burning Seasons in MontanaMontana

Heating Season

Open Burning Prohibited

General Open Burning

Fall Regulated Burning

Fire Season

JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC

Montana DEQ Montana DEQ Air Quality ContactsAir Quality Contacts

• Air permitting, emissions estimation and stack height:

Deb Skibicki (406) 444-1472

• Non-attainment Area information:Bob Habeck (406) 444-7305