Introduction

This document provides a list of the emission factors used in ADEQ’s annual emission inventory questionnaire. The emission factors presented in this document are used to automatically calculate the emission totals in the AEI_FORMS_YYYY.xlsx workbook. For ease of use, the chapter numbers correspond to the forms in the AEI workbook.

These emission factors can also be used to manually calculate emission totals. Instructions and sample calculations have been provided for each chapter.

Contents

Introduction	1

FORM 2.1 – GENERATORS & BOILERS	3

Generators	3

Boilers	4

FORM 2.2 – DRY CLEANING	5

FORM 2.3 – COTTON GIN	6

FORM 2.4 – SOIL VAPOR EXTRACTION	7

FORM 2.5 – AIR CURTAIN INCINERATOR	8

FORM 2.6 – ROCK PRODUCTS	9

Asphalt Plants	9

Rotary Drum Dryers	9

Asphalt Cement Storage Tank Heaters	10

Plant Load-Out, Silo Filling & Material Handling	10

Crushing & Screening Operations	11

Concrete Batch Plants	12

Fugitive Emissions	13

COOLING TOWERS	14

SUPPLEMENTAL INFORMATION	15

List of Tables

Table 1: Generator Emission Factors	3

Table 2: Boiler Emission Factors	4

Table 3: Dry Cleaning Emission Factor	5

Table 4: Soil Vapor Extraction Molecular Weights	7

Table 5: Air Curtain Incinerator Emission Factors	8

Table 6: Asphalt Drum Dryer Emission Factors	9

Table 7: Asphalt Cement Heater Emission Factors	10

Table 8: Plant Load-Out and Silo Filling Emission Factors	10

Table 9: Crushing & Screening Emission Factors	11

Table 10: Concrete Batch Emission Factor	12

Table 11: Fugitive Emission Factors - Crushing, Screening & Concrete Batch	13

Table 12: Abridges Size Distribution for Cooling Tower Emissions	14

Table 13: Size Distribution for Cooling Tower Emissions	18

FORM 2.1 – GENERATORS & BOILERS

Generators

Source: ADEQ’s HMAP Application Emission Calculation Spreadsheet (http://azdeq.gov/function/forms/download/HMA%20application%20emission%20calculations1.xlsx) & AP-42 Chapter 3.3 (http://www.epa.gov/ttn/chief/ap42/ch03/final/c03s03.pdf)

Emissions from generators are based on three factors: 1) The generator’s maximum capacity expressed as horsepower, 2) the number of hours the generator was operated, and 3) a fuel-specific emission factor. The fuel-specific emission factors are provided in Tables 1. The emission factors for gasoline were taken from AP-42 Chapter 3.3, Table 3.3-1. All other emission factors were taken from ADEQ’s HMAP Application Emission Calculation Spreadsheet.

Table 1: Generator Emission Factors

Pollutants	DIESEL - LESS THAN OR EQUAL TO 600 HP	DIESEL - GREATER THAN 600 HP	NATURAL GAS	GASOLINE
pounds/hp-hour	pounds/hp-hour	pounds/hp-hour	pounds/hp-hour
PM10	0.0022	0.0007	0.00000054	0.000721
PM2.5	0.0022	0.0007	0.00000054	0.000721
NOx	0.0310	0.0240	0.02220	0.011
SOx	0.0000121	0.0000121	0.0000041	0.000591
VOC	0.00247	0.000705	0.000826	0.015
CO	0.00668	0.0055	0.000826	0.00696

The standard form of the calculation for generator emissions is:

Emissions (tons) = Maximum Capacity (HP) X Operational Hours (hrs) X Emission Factor (lbs/HP-hr) / 2000 (lbs/ton)

Example Calculation

A 500 horsepower diesel generator was operated for 50 hours in 2014. What were the PM10 emissions for this year?

PM10 Emissions	= 500 (HP) X 50 (hours) x 0.0022 (emission factor from Table 1) / 2000

PM10 Emissions	= 0.0275 tons

Boilers

Source: ADEQ’s HMAP Application Emission Calculation Spreadsheet (http://azdeq.gov/function/forms/download/HMA%20application%20emission%20calculations1.xlsx)

Emissions from boilers are based on three factors: 1) The boiler’s maximum capacity expressed as million Btu, 2) the number of hours the boiler was operated, and 3) a fuel-specific emission factor. The fuel-specific emission factors are provided in Table 2.

The standard form of the calculation for boiler emissions is:

Emissions (tons) = Maximum Heat Input Rate (MMBtu/hr) X Operational Hours (hrs) X Emission Factor (lbs/MMBtu) / 2000 (lbs/ton)

Table 2: Boiler Emission Factors

Pollutants	DIESEL	NATURAL GAS/LPG	PROPANE
pounds/MMBtu	pounds/MMBtu	pounds/MMBtu
PM10	0.0240	0.0072	0.0066
PM2.5	0.0240	0.0072	0.0066
NOx	0.1460	0.0952	0.2100
SOx	0.0015	0.0006	-
VOC	0.0025	0.0052	0.0033
CO	0.0365	0.0800	0.0354

Example Calculation

A propane boiler with a maximum heat input rate of 20 MMBtu was operated for 1,500 hours during the year 2012. What are the Nitrogen Oxide (NOx) emissions?

NOx Emissions = 20 (MMBtu) X 1,500 (hours) x 0.2100 (emission factor from Table 2) / 2000

NOx Emissions = 3.15 tons

FORM 2.2 – DRY CLEANING

Source: AP-42 Chapter 4.1 (http://www.epa.gov/ttnchie1/ap42/ch04/final/c4s01.pdf)

Emissions from dry cleaners are based on the gallons of perchloroethylene (PERC) used during the year. NOTE: If the dry cleaning operation also uses boilers, then these emissions must be calculated using FORM 2.1.

The standard form of the calculation for dry cleaning emissions is:

Emissions (tons) = PERC used (gallons) X Emission Factor (lbs/gallon) / 2000 (lbs/ton)

Table 3: Dry Cleaning Emission Factor

Pollutant	Emission Factor
pounds/gallon
PERC	13.5

Example Calculation

A dry cleaning operation consumed 50 gallons of PERC in 2012. What are the total PERC emissions?

PERC Emissions	= 50 (gallons) X 13.5 (emission factor from Table 3) / 2000

PERC Emissions	= 0.3375 tons

Derivation of Emission Factor

Specific Gravity of Perchloroethylene:	1.6227

1.6227 x 8.343 (lb/gallon of water) = 13.5382 lbs/gallon of Perchloroethylene

FORM 2.3 – COTTON GIN

Source: AP-42 Chapter 9.7 (http://www.epa.gov/ttnchie1/ap42/ch09/final/c9s07.pdf)

Source	Pollutant	Emission Factor
pounds/bale
Unloading Fan	PM-10	0.12
No. 1 Dryer & Cleaner	PM-10	0.12
No. 2 Dryer & Cleaner	PM-10	0.093
No. 3 Dryer & Cleaner	PM-10	0.033
Overflow Fan	PM-10	0.026
Lint Cleaner - High-Efficiency Cyclones	PM-10	0.24
Lint Cleaner - Screened Drums or Cages	PM-10	1.1
Cyclone Robber System	PM-10	0.052
Mote Fan	PM-10	0.13
Mote Trash Fan	PM-10	0.021
Battery Condenser - High-Efficiency Cyclones	PM-10	0.014
Battery Condenser - Screened Drums or Cages	PM-10	0.17
Master Trash Fan	PM-10	0.074

Source	Pollutant	Emission Factor
pounds/VMT
Fugitive Emissions - Haul Roads	PM-10	0.17

FORM 2.4 – SOIL VAPOR EXTRACTION

Emissions from soil vapor extraction units are based on the results of periodic testing. These test results provide the pollutant concentration and flow rate values that are used to calculate emission totals. The only constant values are the molecular weights of the various pollutants, which are provided in Table 4.

The standard form of the calculation for soil vapor extraction emissions is:

[Maximum Concentration (μg/L)] X [Mass/Volume Conversion Number (0.00000006243)] X [Flow Rate (ft3/ min)] X [minute per hour (60)] X [hours of operation (hours/year)]

Maximum Concentration = [Effluent Concentration (ppm by vol)] x [molecular weight/24.04]

NOTE: The term "molecular weight/24.04" is a conversion factor for ppm by volume to milligrams (found in AP-42, Appendix A, "Conversion Factors for Common Air Pollution Measurements," page A-27.

Table 4: Soil Vapor Extraction Molecular Weights

POLLUTANT	MOLECULAR WEIGHT
VOC	100
BENZENE	78.11
TOLUENE	92.16
ETHYLBENZENE	106.16
XYLENE	106.16

FORM 2.5 – AIR CURTAIN INCINERATOR

Emissions from air curtain incinerators are based on the amount of material burned (in tons) and the emission factors from Table 5.

The standard form of the calculation for air curtain incinerator emissions is:

Emissions (tons) = Amount of Material Burned (tons) X Emission Factor (lbs/ton) / 2000 (lbs/ton)

Table 5: Air Curtain Incinerator Emission Factors

Pollutants	Emission Factor
pounds/ton
PM-10	0.24
CO	2.22
NOx	2.00
SO2	0.10
VOC	3.80
HAPs	0.35

Example Calculation

An air curtain incinerator burns 1,500 tons of material in 2012. What are the total SO2 emissions?

SO2 Emissions =	1500 (tons) X 0.10 (emission factor from Table 5) / 2000

SO2 Emissions = 0.075 tons

FORM 2.6 – ROCK PRODUCTS

Form 2.6 contains should be used by a facility that has an asphalt plant, concrete batch plant, crushing & screening operation or any combination of these three. The form several sections: Asphalt Plant, Crushing & Screening Operations, Concrete Batch Plant, Fugitive Sources, and Location Information. Each section should be filled as applicable.

Asphalt Plants

Sources: ADEQ’s HMAP Application Emission Calculation Spreadsheet (http://azdeq.gov/function/forms/download/HMA%20application%20emission%20calculations1.xlsx)

Rotary Drum Dryers

Several pollutants from rotary drum dryers are dependent on the type of control device used and the type of material being produced. PM10 emissions are dependent on whether a venturi scrubber or fabric filter is used as a control device. All other pollutants (SOx, CO, NOx, HAPS) are based only on the amount of material produced. Table 6 contains the pollutant emission factor for each operating scenario.

The standard form of the calculation for asphalt plant emissions is:

Emissions (tons) = Amount of Asphalt Produced (tons) X Emission Factor (lbs/ton) / 2000 (lbs/ton)

Table 6: Asphalt Drum Dryer Emission Factors

Controls	Pollutants	NATURAL GAS	DIESEL/FUEL OIL #2	WASTE/FUEL OIL #6
pounds/ton	pounds/ton	pounds/ton
Venturi Scrubber	PM10	0.0190	0.0190	0.0190
Fabric Filter	PM10	0.0230	0.0230	0.0230
SOx	0.0034	0.0110	0.0580
CO	0.1300	0.1300	0.1300
VOC	0.0320	0.0320	0.0320
NOx	0.0260	0.0550	0.0550

Example Calculation

10,000 tons of asphalt is produced at an asphalt plant in 2012. The drum dryer is fueled by natural gas and uses a fabric filter baghouse as a control device. What are the total PM10 and SOx emissions for this plant?

PM10 Emissions =	10,000 (tons) X 0.0230 (emission factor from Table 6) / 2000

PM10 Emissions =	0.115 tons

SOx Emissions =	10,000 (tons) X 0.0034 (emission factor from Table 6) / 2000

SOx Emissions =	0.017 tons

Asphalt Cement Storage Tank Heaters

Emissions from asphalt cement storage tank heaters are dependent on the type of fueled burned to provide heat to the tank.

The standard form of the calculation for air curtain incinerator emissions is:

Emissions (tons) = Amount of Fuel Consumed (gallons) X Emission Factor (lbs/ton) / 2000 (lbs/ton)

Table 7: Asphalt Cement Heater Emission Factors

Pollutants	NATURAL GAS	LPG	DIESEL/FUEL OIL #2
pounds/ft3	pounds/gallon	pounds/gallon
PM10	0.0000	0.0005	0.0020
NOx	0.0001	0.0145	0.0200
SOx	0.0000	0.0001	0.0002
VOC	0.0000	0.0006	0.0006
CO	0.0000	0.0020	0.0012

Example Calculation

1,000 gallons of No. 2 oil were used in the asphalt cement tank heater in 2012. What are the total HAP emissions?

HAP Emissions =	1,000 (gallons) X 0.027 (emission factor from Table 7) / 2000

HAP Emissions =	0.0135 tons

Plant Load-Out, Silo Filling & Material Handling

This section covers fugitive emissions sources that are specific to asphalt plants; load-out, silo filling and material handling operations. Plant load-out refers to the amount of material loaded into trucks from the asphalt plant. Silo filling refers to the amount of material (asphalt) loaded into silos before being loaded-out. Material handling refers to the transfer of material from storage piles using front-end loaders to feed hoppers or other pieces of equipment.

The standard form of the calculation fugitive emissions is:

Emissions (tons) = Activity Level (unit varies) X Emission Factor (lbs/activity level unit) / 2000 (lbs/ton)

Table 8: Plant Load-Out and Silo Filling Emission Factors

Pollutants	Plant Load-Out	Silo Filling	Material Handling
pounds/ton	pounds/ton	pounds/ton
PM10	0.0009	0.0009	0.0036
VOC	0.0110	0.0110	-
CO	0.0017	0.0017	-

Crushing & Screening Operations

This section details the emission factors for crushing and screening operations.

Source: ADEQ’s C&S Application Emission Calculation Spreadsheet (http://azdeq.gov/environ/air/permits/download/csp_eca.xls)

Emissions from crushing and screening operations are calculated by multiplying the amount of material processed through each emission point by an emission factor for that specific point. The emission points and their respective emission factors can be found in Table 9.

The standard form of the calculation for crushing and screening emissions is:

Emissions (tons) = Number of Emission Points X Amount of Material Processed (tons) X Emission Factor (lbs/ton) / 2000 (lbs/ton)

Table 9: Crushing & Screening Emission Factors

Activity/Emission Source	Pollutant	Emission Factor	Emission Factor Units
Batch Drop Operations	PM10	0.000526	lbs/ton of material throughput
Feed Hopper	PM10	0.000526	lbs/ton of material throughput
Crushers	PM10	0.00054	lbs/ton of material throughput
Screeners	PM10	0.00074	lbs/ton of material throughput
Fine Screeners	PM10	0.0022	lbs/ton of material throughput
Stackers	PM10	0.000526	lbs/ton of material throughput
Transfer Points	PM10	0.000046	lbs/ton of material throughput

Example Calculation

A crushing and screening operation has 2 crushers, 1 screen, and 5 transfer points. 50,000 tons of material was processed at this facility in 2012. What are the PM-10 emissions for these emission points?

Crushers

PM-10 Emissions =	2 (# of crushers) X 50,000 (tons processed) X 0.00054 (emission factor from Table 9) / 2000

PM-10 Emissions =	0.027 tons

Screens

PM-10 Emissions =	1 (# of screens) X 50,000 (tons processed) X 0.00074 (emission factor from Table 9) / 2000

PM-10 Emissions =	0.0185 tons

Transfer Points

PM-10 Emissions =	5 (# of transfer points) X 50,000 (tons processed) X 0.000046 (emission factor from Table 9) / 2000

PM-10 Emissions =	0.00575 tons

Concrete Batch Plants

Source: ADEQ’s C&S Application Emission Calculation Spreadsheet (http://azdeq.gov/environ/air/permits/download/csp_eca.xls)

Emission calculations for concrete batch plants are dependent only on the amount of concrete produced and the emission factor given in Table 10.

The standard form of the calculation for concrete batch emissions is:

Emissions (tons) = Amount of Concrete Produced (cubic yards) X Emission Factor (lbs/ton) / 2000 (lbs/ton)

Table 10: Concrete Batch Emission Factor

Source	Pollutant	Emission Factor
pounds/cu yd
Concrete Batch Plant	PM-10	0.00481

Example Calculation

A concrete batch plant produces 10,000 cubic yards of concrete in in 2012. What are the PM-10 emissions for this facility?

PM-10 Emissions =	10,000 (cubic yards of concrete) X 0.00481 (emission factor from Table 10) / 2000

PM-10 Emissions =	0.02405 tons

Fugitive Emissions

Sources: ADEQ’s HMAP Application Emission Calculation Spreadsheet (http://azdeq.gov/function/forms/download/HMA%20application%20emission%20calculations1.xlsx)

The fugitive emission factors presented below can apply to both crushing and screening operations and concrete batch operations. If a facility engages in any of the activities described in Table 11 then this section of FORM 2.6 should be filled out.

The standard form of the calculation fugitive emissions is:

Emissions (tons) = Activity Level (unit varies) X Emission Factor (lbs/activity level unit) / 2000 (lbs/ton)

Table 11: Fugitive Emission Factors - Crushing, Screening & Concrete Batch

Activity/Emission Source	Pollutant	Emission Factor	Emission Factor Unit
Wind Erosion from Storage Piles	PM10	0.4229328	lbs/pile
Traffic on Unpaved Roads	PM10	0.1671	lbs/vehicle mile traveled
Explosive Blasting	PM10	41.67	lbs/blast
CO	2,211.0	lbs/blast
NOx	561.0	lbs/blast
SO2	66.0	lbs/blast

COOLING TOWERS

Author: Nick Deak

Source: PM10 calculation from New Mexico Environment Department (Pm 10 Calculation from New Mexico Environment Department)

The method detailed in this section is based on a report submitted by the New Mexico Environment Department. The standard equation from the report is provided below, as well a brief description of the variables included within it. Since the equation calculates total particulate matter emissions, a table is provided to show the respective percent mass estimates of PM2.5, PM10, and TSP/PM30 that are found at various TDS concentrations (see below). For more information, we encourage that you view the reported cited above as well as the supplemental information section of this appendix.

– Total particulate matter emissions emanating from the cooling tower, measured in lbs/hr.

– Maximum water circulation rate for the cooling tower, measured in gallons per minute (gpm).

– The percentage of water droplets that escape the tower as emissions (AP-42 standard = 0.02%).

– The total amount of solids suspended within the circulating cooling water (mg/l and ppm).

The standard form of the calculation for cooling tower particulate emissions is:

Select a TDS concentration (ppm) from the drop-down menu here to find respective percent masses of the given particle sizes at the selected concentration: 3000

Example Calculation A cooling tower was found to have the following: = 4,000 mg/l, = 45,000 gpm, and = 0.005%. What are the total PM emissions coming out of the tower? Table 12: Abridges Size Distribution for Cooling Tower Emissions

Particle Size (μm)	Mass Percent
0-2.5 (PM2.5)	0.226
0-10 (PM10)	70.509
0-30 (TSP/PM30)	96.288

Using the percent mass estimates found at TDS = 4,000 mg/l, the emissions for each particle size are:

SUPPLEMENTAL INFORMATION

Author: Nick Deak

On Cooling Towers:

The full size distribution table, as opposed to the simplified version featured in the “Cooling Towers” section, includes percent masses for particles of many sizes beyond the typical 2.5, 10, and 30 micron parameters. While referencing the abridged table is appropriate, it is perfectly acceptable to use the full table or equation shown below to obtain more accurate estimates for PM2.5, PM10, and TSP/PM30 emissions. If using the full table, for instance, the linear interpolation method can be used between points to obtain more accurate estimates for each particle size. Although the relationship between percent mass and particle size/diameter () is not perfectly linear, it is close enough to where the method will still provide a more precise approximation for percent masses of all particle sizes. The equation from which the table is derived can also be used directly, which requires rearrangement for the drift droplet diameter () variable followed by linear interpolation. While this method is more involved than the others, it is also the most accurate. The equation is shown below, along with descriptions for each variable:

– Diameter, in microns, of the particle of interest.

– Diameter, in microns, of the drift droplet entrained with particulate matter.

– Density of particle, measured in g/cm3. The value assigned to this variable is 2.5 g/cm3, which represents the assumed density of salts that typically comprise dissolved solids.

– Density of water, measured in g/cm3. The value assigned to this variable is 1.0 g/cm3, assuming that the water is pure.

– Not to be confused with “TDS,” a variable that was described in the “Cooling Towers” section. The only difference is that the TDS concentration in this equation is expressed in units of ppm x 10-6.

The following example calculations will demonstrate how interpolation and the equation can be used to make particle size determinations for cooling tower emissions.

Example Calculation #1

All of the emission values found in the example calculation from the “Cooling Towers” section are conservative estimates. The reason for this is that particle sizes of exactly 2.5, 10, and 30 microns are not listed on the full or simplified tables, and thus, the percent masses are reflective of particle sizes slightly greater than those of interest. The following example will show how the linear interpolation method can be used to find more precise estimates:

Suppose a more accurate estimate for emissions is desired. A specific of 2.5 microns lies somewhere in between the data points surrounding it on the full table at TDS = 4,000 ppm; = 2.3442393 µm and = 3.516359 µm (see full table at the end of this section). Further, the percent mass at = 2.5 µm falls somewhere in between 0.196% and 0.226%; the respective percent masses of the aforementioned data points. An intuitive way to approach linear interpolation with these or any three data points, using arbitrary variables of “x” and ”y,” can be carried out as follows:

Therefore, in context of the problem, here is what the percent mass (x) is found to be at = 2.5 µm:

Applying this percent mass to the total PM emissions found in example calculation #2:

Example Calculation #2

Expanding once more on the previous example, the calculations below will show how the second equation can be used to determine the same particle size fraction. Plugging in 2.5 microns for while inserting all other known quantities and rearranging for produces:

Having obtained a value for , the next step is to perform linear interpolation with points surrounding it on the size distribution table. The steps for properly carrying this out are similar to example calculation #3, with the only difference being that values of rather than are used in the interpolation itself:

Applying this percent mass to the total PM emissions found in example calculation #2:

The value obtained here differs only slightly from example #1; however, both examples #1 and #2 differ a considerable degree from the example presented in the “Cooling Towers” section, with percent differences greater than 10%.

Table 13: Size Distribution for Cooling Tower Emissions

The 2014 AEIQ form does not ask for any operational data pertaining to Silo Filling. The AEIQ forms assume that the amount of material loaded-out equals the amount of material filled into the silo(s).

Assumes piles are stored for 8,760 hours per year.