Reference Case - Fuel Input standard for pollutant X

Input-based standard 0.0200 lbs/MMBtu fuel

Reference boiler efficiency 75.0%

Equivalent Output-based standard 0.0267 lbs/MMBtu steam

CHP Example - Boiler with back pressure steam turbine

Boiler steam outout (high pressure) 160.77 MMBtu/hr

CHP generation 3,000 kW

CHP generation (conversion to Btu) 10.24 MMBtu/hr

Steam to Process (low pressure) 150.00 MMBtu/hr

Boiler efficiency 75.0%

Boiler fuel input 214.37 MMBtu/hr (Boiler steam output divided by boiler efficiency)

Annual operating hours 8,000

Annual boiler fuel use 1,714,931 MMBtu/yr

Total emissions of X - input 17.15 Tons/yr (based on total fuel used @ 0.02 lb/MMBtu)

A. What are the output-based emissions for various output measurements?

Output Measurement

Total Site 

Emissions, 

Tons/yr

 Boiler steam output (high pressure) 17.15

 Steam to process + CHP output @3412 Btu/kWh 17.15

 Steam to process + CHP output @10,000 HR 17.15

 Steam to process + CHP output @5,000 HR 17.15

Output Measurement

Total Site 

Emissions*, 

Tons/yr

 Boiler steam output (high pressure) 17.15

 Steam to process + CHP output @3412 Btu/kWh 17.09

 Steam to process + CHP output @10,000 HR 19.20

 Steam to process + CHP output @5,000 HR 17.60

* CHP output offsets emissions at central station

Allowable Fuel emissions 

rate based on 0.0267 

output limit, lb/MMBtu 

input

0.0200

Output-Based Emissions 

Rate, lbs/MMBtu output

0.0199

0.0224

0.0205

B. What is the equivalent input-based limit if output-based standard is applied to various 

ouput measurements?

0.0267

0.0268

0.0238

0.0260
Reference Case - Fuel Input standard for pollutant X

Input-based standard 0.0200 lbs/MMBtu fuel

Reference boiler efficiency 75.0%

Equivalent Output-based standard 0.0267 lbs/MMBtu steam

Power only boiler with CHP retrofit - Industrial Site (generally lower pressure boiler, lower power cycle efficiency)

Fuel input, MMBtu/hr 200.0 200.0 200.0 200.0 200.0 200.0

Boiler Efficiency, % 75% 75% 75% 75% 75% 75%

Boiler Steam Output, MMBtu/hr 150.0 150.0 150.0 150.0 150.0 150.0

Boiler Steam Temperature, F 950 950 950 950 950 950

Boiler Steam Pressure, Psi 1500 1500 1500 1500 1500 1500

Boiler Steam flow, lbs/hr 103,000 103,000 103,000 103,000 103,000 103,000

Steam Turbine Condensing Extraction Extraction Extraction Extraction Back Pressure

Power Generation, kW 11,932 11,625 11,318 11,012 8,865 5,615

Power Generation, MMBtu/hr 40.71 39.66 38.62 37.57 30.25 19.16

Steam to process, lbs/hr 0 5,000 10,000 15,000 50,000 103,000

Steam to process, MMBtu/hr 0.00 6.30 12.60 18.90 63.00 129.78

Total Efficiency, % 20.4% 23.0% 25.6% 28.2% 46.6% 74.5%

Operating Hours 8,000 8,000 8,000 8,000 8,000 8,000

Total Emissions, Tons/yr 16.0 16.0 16.0 16.0 16.0 16.0

Output-based emissions rate, lbs/MMBtu, Boiler steam out 0.0267 0.0267 0.0267 0.0267 0.0267 0.0267

Output-based emissions rate, lbs/MMBtu, Process steam and CHP @3412 Btu/kWh 0.0983 0.0870 0.0781 0.0708 0.0429 0.0269

Output-based emissions rate, lbs/MMBtu, Process steam and CHP @5000 0.0670 0.0621 0.0578 0.0541 0.0373 0.0253

Output-based emissions rate, lbs/MMBtu, Process steam and CHP @7500 0.0447 0.0428 0.0410 0.0394 0.0309 0.0233

Output-based emissions rate, lbs/MMBtu, Process steam and CHP @10000 0.0335 0.0326 0.0318 0.0310 0.0264 0.0215

Output-based emissions rate, lbs/MMBtu, Process steam and CHP @12500 0.0267 0.0263 0.0259 0.0255 0.0230 0.0200

Power only boiler with CHP retrofit - Small Scale Utility Boiler (higher pressure boiler with higher power cycle efficiency, although not at the 33 to 35% level of large subcritical steam cycles)

Fuel input, MMBtu/hr 200.0 200.0 200.0 200.0 200.0 200.0

Boiler Efficiency, % 75% 75% 75% 75% 75% 75%

Boiler Steam Output, MMBtu/hr 150.0 150.0 150.0 150.0 150.0 150.0

Boiler Steam Temperature, F 950 950 950 950 950 950

Boiler Steam Pressure, Psi 2400 2400 2400 2400 2400 2400

Boiler Steam flow, lbs/hr 105,000 105,000 105,000 105,000 105,000 105,000

Steam Turbine Condensing Extraction Extraction Extraction Extraction Back Pressure

Power Generation, kW 15,168 14,678 14,187 13,697 10,262 6,010

Power Generation, MMBtu/hr 51.75 50.08 48.41 46.73 35.01 20.51

Steam to process, lbs/hr 0 5,000 10,000 15,000 50,000 105,000

Steam to process, MMBtu/hr 0.00 6.30 12.60 18.90 63.00 128.63

Total Efficiency, % 25.9% 28.2% 30.5% 32.8% 49.0% 74.6%

Operating Hours 8,000 8,000 8,000 8,000 8,000 8,000

Total Emissions, Tons/yr 16.0 16.0 16.0 16.0 16.0 16.0

Output-based emissions rate, lbs/MMBtu, Process steam and CHP @3412 Btu/kWh 0.0267 0.0267 0.0267 0.0267 0.0267 0.0267

Output-based emissions rate, lbs/MMBtu, Process steam and CHP @3412 0.0773 0.0709 0.0656 0.0609 0.0408 0.0268

Output-based emissions rate, lbs/MMBtu, Process steam and CHP @5000 0.0527 0.0502 0.0479 0.0458 0.0350 0.0252

Output-based emissions rate, lbs/MMBtu, Process steam and CHP @7500 0.0352 0.0344 0.0336 0.0329 0.0286 0.0230

Output-based emissions rate, lbs/MMBtu, Process steam and CHP @10000 0.0264 0.0261 0.0259 0.0257 0.0242 0.0212

Output-based emissions rate, lbs/MMBtu, Process steam and CHP @12500 0.0211 0.0211 0.0211 0.0210 0.0209 0.0196
CHP - Boiler with back-pressure steam turbine

Fuel Input

214.37 MMBtu/hr High Pressure Steam

600 Psi

125,000 lbs/hr

160.77 MMBtu/hr

No CHP - Boiler direct to process

Fuel Input

200.00 MMBtu/hr

Boiler

75% eff

Boiler

75% eff
Low Pressure Steam to Process

150 Psi

125,000 lbs/hr

150.00 MMBtu/hr

Power

3,000 kW

10.24 MMBtu

Losses

0.54 MMBtu/hr

Low Pressure Steam to Process

150 Psi

125,000 lbs/hr

150.00 MMBtu/hr

Steam 

Turbine