Example Calculations 2012 Emissions Inventory Workshop 1
2 For most emission sources the following equation is used: E = (Q*EF*(1-ER/100)) Where E = Calculated emissions in tons per year (tpy) Q = Activity rate (process rate) EF = Emission factor-Determined by the Methods of Calculation (e.g., AP42, Mfg Data). For combustion emissions, the sulfur percent and/or the ash content of the fuel will affect the emission factor ER = Overall Control Efficiency (Overall Emission Reduction efficiency), %. This is the combination of the capture efficiency and the control/destruction/removal efficiency. To calculate, multiply the capture efficiency by the control/destruction/removal efficiency and divide by 100
2012 Emissions Inventory Workshop 3
4 Process: Stone Quarrying - Primary Crushing SCC: or Annual Rate: tons of Limestone Permit Factor:PM10 – lb/ton of rock
717,600 tons lbs of PM year tons of rock 1 ton= lbs 1 ton 2000 lbs year 2000 lbs Stone Quarrying - Primary Crushing Process RateEmission Factor 2012 Emissions Inventory Workshop 5 = PM10 TPY
2012 Emissions Inventory Workshop 6 Process:4-cycle rich burn engine SCC: Factor:12 grams NOx/hp-hr from 500 hp engine Hours/Year:8760
2012 Emissions Inventory Workshop 10 Factor:PM2.5 – 9.500E-3 lb/mmBtu Fuel Input Annual Rate:45 mmscf To convert from (lb/mmBtu) to (lb/mmscf), multiply by the heat content of the fuel. If the heat content is not available, use 1020 Btu/scf.
Emissions Inventory Workshop Capture Efficiency- the percentage of air emission that is collected and routed to the control equipment. Control Efficiency- the percentage of air pollutant that is removed from the air stream. (control/destruction/removal efficiency)
2012 Emissions Inventory Workshop 33 Example: Capture efficiency is 80% Device has a control efficiency of 95% Overall Control Efficiency= % Captured * % Control Efficiency (0.80*0.95)= 0.76 or 76 %
Emissions Inventory Workshop Multiple emission control devices, affecting a common air stream. Common occurrences: Dual Catalytic convertors Combination of bag house(s) and cyclone(s)
Emissions Inventory Workshop Primary control device A The capture efficiency is 90%. The control equipment removes 80% of the air pollutant from the emission stream Secondary control device B The capture efficiency is 100%. The control equipment removes 98% of the air pollutant from the emission stream Note: secondary controls most always have 100% capture efficiency.
Emissions Inventory Workshop Primary control device A The capture efficiency is 90%. The control equipment removes 80% of the air pollutant from the emission stream Emissions reduction = 72%
Emissions Inventory Workshop Secondary control device B The capture efficiency is 100%. The control equipment removes 98% of the air pollutant from the emission stream Emission reduction = 98%
100.0 lbs/hr of PM generated lbs/hr of PM emitted not captured lbs/hr of PM captured, sent to cyclone 3 4 Amount to Hopper 90.0 lbs/hr * 0.80 = 72.0 lbs/hr lbs/hr – 72 lbs/hr = 18.0 lbs/hr to the Baghouse 7 6 Amount to Hopper 18.0 lbs/hr * 0.98 = lbs/hr January
pennies Only 90 pennies go to control device A Control device A removes 80% of the 90 pennies leaving 18 pennies Control device B sees only 18 pennies, and removes 98% leaving 0.36 pennies. 10 lbs/hr was directly emitted as fugitives (not captured by Control device A) = lbs/hr 2012 Emissions Inventory Workshop
41 Program Manager: Mark Gibbs Emission Inventory Staff: Michelle Horn Jenafer Icona Justin Milton Carrie Schroeder Matt Weis
2012 Emissions Inventory Workshop 42
January Given: 1200-hp Natural gas compressor engine Actual annual hours = 6500 Emission factor for CO = lbs/mmBtu (AP-42 table 3.2-2) Process rate= 10,000 mmBtu/yr Find the total CO emission amount in tons.
January Annual CO emissions Emission factor for CO = lbs/mmBtu (AP-42 table 3.2-2) Process rate= 10,000 mmBtu/yr
January Given: 1200-hp Natural gas compressor engine PM10 Emission Factor = lbs/mmBtu (AP-42 table 3.2-2) Annual Process Rate= 20 mmscf of natural gas Fuel heat content= 1020 mmBtu/mmscf Find the total PM10 emission amount in tons.
January Step 2- Find annual emission amount for PM10 Emission Factor = lbs/MMBtu (AP-42 table 3.2-2) Process Rate = 20,400 mmbtu