

Date:
November 6, 2014
To:
Jeff Telander, EPA/OAQPS/SPPD
From:
Thomas Holloway, RTI International
Subject:
Methodology and Assumptions Used to Estimate the Model Costs and Impacts of BSCP Air Pollution Control Devices

I.	Introduction
In accordance with section 112 of the Clean Air Act (CAA), the U.S. Environmental Protection Agency (EPA) established national emission standards for hazardous air pollutants (NESHAP) on May 16, 2003 for the brick and structural clay products (BSCP) manufacturing industry. The NESHAP regulated emissions of hydrogen fluoride (HF), hydrogen chloride (HCl), and particulate matter (PM) -- a surrogate for hazardous air pollutant (HAP) metals -- from tunnel kilns located at BSCP facilities. On March 13, 2007, the D.C. Circuit Court vacated the emission standards for BSCP manufacturing due to issues associated with the methodology used to determine the minimum regulatory "floors" for new and existing units. Therefore, the EPA is proposing new standards for BSCP manufacturing, including standards for HF, HCl, chlorine (Cl2), mercury (Hg), and non-Hg HAP metals (or PM surrogate). The purpose of this memorandum is to present the methodology and assumptions used in estimating the model costs and environmental and energy impacts for the control technologies used to meet these new standards.
II.	General Model Parameters
Model costs and impacts were developed for two sizes of BSCP control devices -- large control devices (LCD) and small control devices (SCD), reflecting the size subcategories of the BSCP NESHAP, which are based on a kiln capacity threshold of 10 tons per hour (tph). The model costs and impacts were estimated based on a variety of model parameters -- (1) general parameters such as production rate, operating hours, gas flow rate, electricity and waste disposal unit costs, labor wage rates, and uncontrolled emissions; and (2) control-specific parameters such as control device horsepower (hp) requirements, sorbent requirements, and sorbent unit cost. This section discusses the basis for the general model parameters, which are presented in Appendix A at the end of this memorandum.
The model production rates (in tph) and operating hours (in hours per year [hr/yr]) were based on data from the BSCP inventory (Holloway, 2014). The BSCP inventory is a combination of (1) industry responses to the 2008 BSCP section 114 survey; (2) responses to a survey similar to the 2008 BSCP section 114 survey that was administered by the Brick Industry Association; and (3) industry data from the 2003 BSCP database (from the original 2003 BSCP NESHAP) for plants not included in the 2008 surveys. The average kiln production rate (7.0 tph) and operating hours (7,300 hr/yr) for the small model were calculated from those tunnel kilns with a kiln capacity less than 10 tph. The average kiln production rate (15 tph) and operating hours (7,800 hr/yr) for the large model were calculated from those tunnel kilns with a kiln capacity of 10 tph or greater. The model kiln production rates were based on a mix of permitted and design capacities, i.e., those capacities to which the kilns are actually limited. The model kiln operating hours were based on a mix of actual kiln operating hours from industry responses to the 2008 BSCP survey (Holloway, 2014) and facility operating hours from the 2003 BSCP database for those facilities not included in the 2008 survey. Since the kiln is the center of the production process at the BSCP facility, it is reasonable to assume facility operating hours would be the same as kiln operating hours.
The model exhaust gas flow rates (in actual cubic feet per minute [acfm]) were based on data from BSCP stack tests (Raymond, 2014), with the model flow rate for the small model (23,100 acfm) calculated from stack test data for tunnel kilns with a kiln capacity less than 10 tph, and the model flow rate for the large model (38,700 acfm) calculated from stack test data for tunnel kilns with a kiln capacity of 10 tph or greater. In those cases where flow rate data were only available in units of dry standard cubic feet per minute (dscfm), those flow rates were converted to units of acfm using Equation 1 below, based on stack temperature and moisture content data from the stack test (assuming a stack pressure equivalent to standard atmospheric pressure):
Equation 1 -- Flow rate conversion
	
where:
	Qacfm =	exhaust flow rate (acfm),
	Qdscfm =	exhaust flow rate (dscfm),
	Tstack =	stack temperature (converted from degrees Fahrenheit [°F] to degrees Rankine [°R]),
	Tstandard =	standard temperature (528°R), and
	% H2O =	moisture content (percent [%]).
Unit costs for electricity ($0.073/kilowatt-hour [kWh]) and waste disposal ($40/ton waste) were based on the average of those unit costs from the 2008 BSCP survey responses (Holloway, 2014). The operator wage rate ($22.67/hr) was based on mean hourly wage data from the May 2011 Bureau of Labor Statistics for NAICS 327100 (Clay Product and Refractory Manufacturing) for an Industrial Engineering Technician (BLS, 2012). Wage rates from the Bureau of Labor Statistics were used because they were more conservative than those provided by BSCP survey respondents. The maintenance wage rate ($24.94/hr) was assumed to be 10 percent higher than the operator wage rate, similar to the ratio of maintenance to operator wage rates provided by one BSCP company in its response to the 2008 survey (Holloway, 2014).
The capital recovery factor (0.0944) was calculated using Equation 2 below, assuming a 7 percent interest rate and 20-year equipment life for the control devices expected to be used to comply with the new standards for BSCP manufacturing:
Equation 2 -- Capital recovery factor:
	
where:
	i =	interest rate (%) and
	n =	payment period, e.g., equipment life (yrs).
Model uncontrolled emissions estimates (in pounds per ton [lb/ton]) were used to estimate the amount of material captured by the control devices, based on each device's control efficiency. The pollutants of interest were HF, HCl, chlorine (Cl2), PM, HAP metals, and sulfur dioxide (SO2). The model uncontrolled emissions estimates for HF, HCl, PM, Cl2, and SO2 were based on the average of uncontrolled emissions data from BSCP stack tests (Raymond, 2014). The model uncontrolled emissions estimate for total HAP metals was assumed to be 1.1 percent of the PM estimate, based on the average ratio of metals to PM emissions in BSCP stack tests (Raymond, 2014).
III.	Model Costs
This section discusses the methodology and assumptions used to estimate the model costs for the new or retrofit emission control devices that BSCP facilities are expected to install in order to comply with the new standards for the BSCP industry. The cost estimates are presented in 2011 dollars. The model cost tables for new and retrofit control devices are presented in Appendices B and C, respectively. (Note: The annual operating costs for replacement control devices presented in this memorandum are a conservative estimate. The operating costs for control devices to be replaced have not been subtracted out.)
Dry sorbent injection/fabric filter (DIFF). Dry sorbent injection followed by a fabric filter (DIFF) can be used to reduce emissions of both particulates and acid gases from BSCP tunnel kilns. This type of control system is already in use in the BSCP industry (Holloway, 2014) and is expected to be installed on uncontrolled kilns or retrofitted to replace less efficient kiln controls to enable facilities to comply with the new BSCP standards.
The DIFF costs were estimated using the cost algorithms from the original BSCP rulemaking (Shrager, 2003), which were generated following guidelines in the OAQPS Control Cost Manual (EPA, 2002). The algorithms were updated to include more recent model parameters, including the general parameters discussed previously and the following parameters specific to DIFF control devices:
Control efficiency (e.g., 99.5% HF, 94% PM)
Fan horsepower (150 hp [small]/190 hp [large])
Total horsepower for other motors (30 hp)
Stoichiometric ratio of hydrated lime (2.65 [small], 1.79 [large])
Bag life (5 yrs)
Gas-to-cloth ratio (3.4 feet per minute [ft/min])
Bag area (28 square feet [ft2])
Compressed air (0.9 cubic feet [ft3] of compressed air/1,000 ft3 of gas)
Time to replace bags (2.25 hr/bag)
Hydrated lime unit cost ($160/ton)
Bag fabric cost ($8.15/ft2)
Compressed air unit cost ($0.24/1,000 ft3)
Bag capital recovery factor (0.244, based on 5-yr bag life and 7% interest)
With two exceptions, the values of the model DIFF parameters were determined based on averages of industry responses to the 2008 BSCP survey (Holloway, 2014). The DIFF control efficiencies and stoichiometric ratios of hydrated lime were determined differently, as discussed below.
The control efficiencies for new and retrofit DIFF were estimated based on the average of those stack tests with better efficiencies than the baseline control efficiency (which was determined based on the average of all available stack tests with control efficiency data) (Raymond, 2014). For example, the baseline HF control efficiency for a DIFF is estimated to be 98 percent; in stack tests with HF control efficiencies better than 98 percent, the average HF control efficiency is 99.5 percent.
The stoichiometric ratio of hydrated lime for new and retrofit DIFF was estimated based on average reagent rates from industry responses to the 2008 BSCP survey (Holloway, 2014), average uncontrolled emissions data from stack tests (Raymond, 2014), and molecular weight information for the primary pollutants and hydrated lime, scaled up from baseline using the ratio of the aforementioned control efficiencies (99.5 percent/98 percent).
The model DIFF capital costs were estimated by taking DIFF capital cost data from industry responses to the 2008 BSCP survey (Holloway, 2014), escalating the costs to 2011 dollars using the Chemical Engineering Plant Cost Index (CEPCI) (CE, 2011), scaling the costs to the large and small model sizes using the six-tenths cost rule (see Equation 3 below), taking the average of the scaled costs for each model size, and rounding the results to three significant figures.
Equation 3 -- Six-tenths cost rule:
	
where:
	C =	capital cost and
	Q =	capacity parameter (e.g., exhaust gas flow rate).
For retrofits, the capital costs were further adjusted using a retrofit factor of 1.4, which is in the middle of the range of retrofit factors for emission control devices, according to guidance from the OAQPS Control Cost Manual (EPA, 2002).
The model DIFF annual costs were estimated based on the aforementioned cost algorithms, and include the following cost items:
Operating labor (assumed to be twice the maintenance labor hours at $22.67/hr)
Supervisory labor (estimated at 15% of operating labor)
Maintenance labor (estimated based on 1.25 hr/shift from BSCP survey responses and an assumed $24.94/hr wage rate)
Maintenance materials (estimated at 100% of maintenance labor)
Electricity (estimated based on hp requirements, 0.745 kW/hp, and $0.073/kWh)
Lime (estimated based on hydrated lime makeup and $160/ton hydrated lime unit cost)
Compressed air (estimated based on 0.9 ft3/1,000 ft3 compressed air requirements and $0.24/1,000 ft3 compressed air unit cost)
Replacement bags (estimated based on 3.4 ft/min gas-to-cloth ratio, $8.15/ft2 bag fabric, and 0.244 bag capital recovery factor)
Bag replacement labor (estimated based on 3.4 ft/min gas-to-cloth ratio, 28 ft2 bag area, $29.94/hr maintenance wage rate, and 0.244 bag capital recovery factor)
Waste disposal (estimated based on waste generated and $40/ton waste)
Overhead (estimated at 60% of labor and maintenance materials)
Property taxes, insurance, and administrative charges (estimated at 4% of total capital cost)
Capital recovery (estimated as the product of a 0.0944 capital recovery factor and total capital cost, minus the cost of capital recovery for replacement bags and bag replacement labor)
Fabric filter. Fabric filters can be used to reduce emissions of particulates from BSCP tunnel kilns at plants that already have acid gas control or have inherently low acid gas emissions (e.g., due to low fluoride and chloride content in the raw materials). Stand-alone fabric filters are not currently used by the BSCP industry to control tunnel kiln emissions, although DIFF are used to control emissions from the larger tunnel kilns (Holloway, 2014). The BSCP industry has expressed the following concerns about using stand-alone fabric filters (Holloway, 2013b):
Without the dry lime injection that reduces the acid gas, there will not be enough particulates in the kiln exhaust to coat the bags and get good performance from the fabric filter.
The uncontrolled acid in the exhaust stream could rot the bags.
The exhaust gas temperatures from BSCP tunnel kilns can be high (about 400°F on average, as high as 668°F).
The use of membrane bags on low inlet loadings.
In response to these concerns, we contacted two major fabric filter vendors -- Solios Environment and McGill AirClean -- and a major filter bag vendor -- W.L. Gore & Associates -- to determine the feasibility of using stand-alone fabric filters in the BSCP industry.
A representative from one of the fabric filter vendors (Solios Environment) agreed with industry concerns that that the lack of a dust cake would negatively impact total outlet emissions and that the dust cake serves an important function for acid gas neutralization. He noted that the bag choices for high-temperature applications are limited to fiberglass, with an upper temperature limit of 500°F, and that fiberglass degrades rapidly in the presence of HF acid gas. While PTFE (Teflon) fabric also has a limit of 500°F and is impervious to most acid gases, he noted that it carries a very significant price premium. He indicated that Aramid, Ryton, and P-84 fabrics are generally limited to 400°F operation, but noted that these fabrics are sensitive to degradation not only by the acid gases but also the relatively high oxygen concentration in brick kiln gases (Hansen, 2013).
A representative from the other fabric filter vendor (McGill AirClean) stated that a brick plant should be able to use a stand-alone baghouse to control just filterable particulate emissions from a brick kiln. According to the vendor, if the concern is low dust load and not being able to establish a good dust cake, then bags with an expanded PTFE membrane could be used. He noted that membrane bags usually control outlet particulate emissions to very low levels and are not cost prohibitive any more. Like Solios, he stated that the base fabric for the membrane can be a woven fiberglass fabric, which is good for a 500°F continuous operating temperature. If there is HF in the gas stream, he said that this could damage the fiberglass, so scrubbing would be a good idea, depending on the amount of HF present. He said that acid gases in moderate concentrations usually do not cause fabric degradation if the bags are continuously operated above the acid gas dewpoints. Regarding operating temperatures above 500°F, he said there are some fabrics that are available for continuous operation at these temperatures but none with a membrane. He noted that the plant could consider flue gas cooling using a dry-bottom evaporative cooler or a gas-to-air heat exchanger to reduce the gas temperature to a level where conventional fabrics could be used safely (Childress, 2013b).
A representative from the bag fabric vendor (W.L. Gore & Associates) noted that his company had done business with the brick industry before and that they have two kinds of bags that could be used for the industry: (1) high-temperature fiberglass bags, and (2) high-temperature PTFE (Teflon) bags. Both are rated to 500°F. He indicated that a ceramic style bag would be needed for temperatures above 500°F. He could not speak to the concern regarding PM loading, but did say that there would be no problem with PM loadings as low as 1 to 2 grains per cubic foot. He noted that HF destroys fiberglass, so PTFE bags would be needed if HF emissions are a concern. He noted that PTFE bags, unlike fiberglass bags, are chemically inert, but are very expensive, about 2 to 5 times more expensive than fiberglass. He also noted that PTFE bags have high chemical and thermal resistance and would control PM but not acid gas (Holloway, 2013c).
Based on the information obtained from vendors, we believe fabric filters can potentially be an effective control option, if acid gas levels (especially HF) are already inherently low or effectively controlled and exhaust gas temperatures are not too high. The fabric filter costs were estimated using the DIFF cost algorithms, minus the capital cost for a dry sorbent injection system and annual cost for sorbent, and with a revised annual cost for waste disposal that excludes any acid gas control.
Activated carbon injection (ACI). Injecting activated carbon before the particulate control device (e.g., fabric filter) has been demonstrated to improve the removal efficiency of mercury from a variety of combustion devices (e.g., waste incinerators, industrial boilers, cement kilns). In the absence of a national mercury standard for the BSCP industry, there are currently no BSCP plants that use ACI. However, given the effective mercury control performance achieved in these other industries, we believed it prudent to explore this control technology as an option to reduce the mercury emissions from the BSCP industry.
To obtain information on the feasibility and cost of adding an ACI system to an existing DIFF control system for BSCP kilns, we first contacted a fabric filter vendor, McGill AirClean. While a representative from the vendor indicated that his company does not have data on control of mercury emissions from BSCP kilns (all of the company's mercury control experience is with municipal waste incinerators), he indicated that it should not be difficult or expensive to add an ACI system to an existing DIFF control system on a BSCP kiln. He said that a simple bag dump system with a blower could be used and would require little additional space at the site. He also noted that the slight increase in inlet PM loading to the baghouse should not affect the performance of the baghouse (Childress, 2013a).
We then contacted an ACI vendor (Cabot Norit Activated Carbon) to obtain information on the feasibility and cost of installing an ACI system for control of mercury emissions from BSCP kilns. A representative from the company stated that he thought ACI would work well with BSCP kilns. He indicated that it would cost about $0.80 to $0.90/lb for carbon (Holloway, 2013a). He also indicated that, for applications using baghouses (e.g., a DIFF), an activated carbon feed rate of 0.5 to 3 pounds per million actual cubic feet (lb/MMacf) is typical; he suggested using 2 lb/MMacf as a baseline (Thompson, 2013).
The model ACI costs for BSCP kilns were estimated based on ACI cost algorithms for a similarly-sized combustion device, specifically hazardous waste combustors (HWCs). We used the cost algorithms in the 2005 technical support document (TSD) for the HWC MACT replacement standards (EPA, 2005), using the general parameters discussed in the previous section and the carbon injection rate (2 lb/MMacf [Thompson, 2013]) and carbon unit cost (average of $0.85/lb [Holloway, 2013a]) from the ACI vendor. To determine the purchased equipment cost (PEC), the total equipment cost from the TSD was scaled to the large and small BSCP model sizes using the six-tenths cost rule, sales tax and freight charges were added, the resulting cost was escalated to 2011 dollars, and a retrofit factor of 1.15 was applied (CE, 2011; EPA, 2005). To determine the total direct capital costs, installation costs were added to the total PEC (EPA, 2005). In addition to these direct costs, indirect costs of engineering, construction and field expense, contractor fees, startup, performance test, model study, and contingencies were also estimated (EPA, 2005).
The model ACI annual costs were also estimated based on the aforementioned cost algorithms (EPA, 2005) and include the following cost items:
Operating labor (assumed based on 1 hour/day at $22.67/hour)
Supervisory labor (estimated at 15% of operating labor)
Maintenance labor (estimated based on 0.5 hour/shift and an assumed $29.94/hr wage rate)
Maintenance materials (estimated at 5% of the PEC)
Electricity (estimated based on hp requirements, 0.9 fan efficiency, 0.745 kW/hp, and $0.073/kWh)
Carbon (estimated based on carbon feed rate and $0.85/lb)
Waste disposal (estimated based on waste generated and $40/ton waste)
Overhead (estimated at 60% of labor and maintenance materials)
Property taxes, insurance, and administrative charges (estimated at 4% of total capital cost)
Capital recovery (estimated as the product of a 0.1098 capital recovery factor and total capital cost, assuming a 15-year equipment life and 7% interest)
Dry limestone adsorber (DLA). Instead of installing control equipment such as a DIFF to meet the new BSCP standards, some BSCP facilities may choose to install less expensive DLA systems on one or more of their uncontrolled tunnel kilns to reduce facility emissions below the threshold for major sources of HAP -- 10 tons per year (tpy) or more of any single HAP or 25 tpy or more of any combination of HAP. By obtaining a federally enforceable limit reducing emissions below major source thresholds, those BSCP facilities would become synthetic area sources and would not be subject to the major source BSCP NESHAP. Only those BSCP facilities that would be impacted under the new BSCP standards and that could reduce their HAP emissions below the major source threshold using a DLA system are expected to install such controls on their uncontrolled tunnel kilns.
Dry limestone adsorbers are designed to control HF emissions and also provide limited control of HCl and Cl2 emissions. The systems do not provide a mechanism for controlling PM emissions and would be expected to get only incidental PM control. This type of control system is already in use in the BSCP industry (Holloway, 2014). The DLA costs were estimated using the cost algorithms from the original BSCP rulemaking (Shrager, 2003), which were generated following guidelines in the OAQPS Control Cost Manual (EPA, 2002). The algorithms were updated to include more recent model parameters, including the general parameters discussed previously and the following parameters specific to DLA control devices:
Control efficiency (e.g., 95% HF, 30% HCl)
Fan horsepower (60 hp [small]/90 hp [large])
Total horsepower for other motors (10 hp [small]/40 hp [large])
Limestone rate (85 lb/hr [small]/120 lb/hr[large])
Limestone unit cost ($40/ton)
The model DLA control efficiencies for HF, HCl, and other pollutants were estimated based on averages of data from BSCP stack tests (Raymond, 2014), while the values of the other model DLA parameters were determined based on averages of industry responses to the 2008 BSCP survey (Holloway, 2014).
The model DLA capital costs were estimated by taking DLA capital cost data from industry responses to the 2008 BSCP survey (Holloway, 2014), escalating the costs to 2011 dollars using the CEPCI (CE, 2011), scaling the costs to the large and small model sizes using the six-tenths cost rule (see Equation 3), taking the average of the scaled costs for each model size, and rounding the results to three significant figures.
The model DLA annual costs were estimated based on the aforementioned cost algorithms, and include the following cost items:
Operating labor (assumed to be twice the maintenance labor hours at $22.67/hr)
Supervisory labor (estimated at 15% of operating labor)
Maintenance labor (estimated based on 0.75 hr/shift from BSCP survey responses and an assumed $24.94/hr wage rate)
Maintenance materials (estimated at 100% of maintenance labor)
Electricity (estimated based on hp requirements, 0.745 kW/hp, and $0.073/kWh)
Limestone (estimated based on limestone rate and $40/ton limestone unit cost)
Waste disposal (estimated based on waste generated and $40/ton waste)
Overhead (estimated at 60% of labor and maintenance materials)
Property taxes, insurance, and administrative charges (estimated at 4% of total capital cost)
Capital recovery (estimated as the product of a 0.0944 capital recovery factor and total capital cost)
Summary. Table 1 presents the model costs for the DIFF, fabric filter, ACI, and DLA control options discussed above for the small and large BSCP control devices. For additional information, see Appendix B and C at the end of this memorandum.
Table 1. Summary of Control Option Model Costs
Control Option
Cost parameters
SCD
LCD
Install new DIFF
Total capital investment
$2,000,000
$2,730,000

Total annual cost
$613,297
$797,096
Install new fabric filter
Total capital investment
$1,200,000
$1,500,000

Total annual cost
$437,845
$526,006
Replace with DIFF
Total capital investment
$2,800,000
$3,820,000

Total annual cost
$720,811
$943,585
Retrofit fabric filter
Total capital investment
$1,680,000
$2,100,000

Total annual cost
$502,354
$606,642
Retrofit ACI system



    MACT floor
Total capital investment
$102,224
$146,697

Total annual cost
$70,589
$96,482
    Beyond the floor
Total capital investment
$102,224
$146,697

Total annual cost
$79,480
$112,768
Install DLA
Total capital investment
$1,060,000
$1,440,000

Total annual cost
$306,593
$405,045

IV.	Model Impacts
This section discusses the methodology and assumptions used to estimate the model environmental and energy impacts associated with new or retrofit emission control devices that BSCP plants are expected to install in order to comply with the new standards for the BSCP industry. The model impacts parameters and calculations are presented in Appendix D. The model impacts tables for new and retrofit control devices are presented in Appendices E and F, respectively.
A.	Emission Reductions
Model emission reductions were estimated for the major pollutants emitted from BSCP tunnel kilns, including both HAP (HF, HCl, Cl2, and HAP metals) and non-HAP (PM and SO2). In most cases, we were able to determine the model emission reductions (tpy) by multiplying the model uncontrolled emission factors (lb/ton) in Appendix A by the model production rate (tph) and operating hours (hr/yr) in Appendix A and the appropriate control efficiency (%) in Appendix D, and dividing by a conversion factor of 2,000 lb/ton.
B.	Energy Impacts
To determine the annual amount of electricity (in kilowatt-hours per year [kWh/yr]) needed to power the control device, the horsepower requirements (hp) of the control device were multiplied by a conversion factor of 0.745 kW/hp and the annual operating hours (hr/yr). The annual amount of energy (in million British thermal units per year [MMBtu/yr]) needed to generate this electricity was then determined by dividing the electricity requirements (kWh/yr) by the nationwide average power plant efficiency (35 percent) and multiplying by a conversion factor of 3,415 British thermal units per kilowatt hour (Btu/kWh).
The efficiency for each type of power plant was determined by dividing the heat content of electricity (3,415 Btu/kWh) by the heat rate for each type of plant (10,415 Btu/kWh for coal; 8,185 Btu/kWh for natural gas; 10,452 Btu/kWh for nuclear power; and 9,756 Btu/kWh for renewable energy). The nationwide average power plant efficiency was determined as a weighted average of these power plant efficiencies, based on the projected fuel mix for 2015 from Version 3.0 of EPA's Integrated Planning Model (IPM), which is a forecast model of the U.S. electric power sector (EPA, 2011). The projected fuel mix is 53 percent coal, 22 percent natural gas/other, 17 percent nuclear, and 8 percent renewable/hydroelectric (EPA, 2011).
C.	Secondary Air Emissions
Once the model energy impacts were determined, the associated model secondary air emissions were estimated. Secondary emissions typically include the criteria air pollutant emissions -- PM, carbon monoxide (CO), nitrogen oxides (NOX), and SO2 -- that result from the generation of electricity used to operate the control devices. For purposes of this analysis, the electricity was assumed to be purchased from offsite power plants. The secondary emissions were estimated by multiplying emission factors for the pollutants by the energy impacts, assuming a specific mix of fuels to generate the needed electricity. (EPA, 2011)
We used a variety of information sources to obtain the emission factors used to estimate the secondary emissions. For natural gas combustion, we used emission factors (in pounds per cubic foot [lb/ft3] of natural gas) from the AP-42 chapter on natural gas combustion to estimate the secondary emissions for PM, CO, NOX, and SO2 (EPA, 1998a). We used the AP-42 conversion factor of 1,020 Btu/ft3 of natural gas to convert the emission factors to pounds per million British thermal units (lb/MMBtu) to facilitate estimating the secondary emissions for these pollutants from natural gas (EPA, 1998a).
For solid fuel (coal) combustion, we used emission limits (in lb/MMBtu) from the new source performance standards (NSPS) for utility plants (40 CFR part 60, subpart Da; 2006 CFR edition) to estimate the secondary emissions for PM and SO2 (EPA, 2006). We used emission factors (in lb/ton coal) from the AP-42 chapter on coal combustion to estimate the secondary emissions for NOX and CO; we specifically used the AP-42 emission factors for bituminous/subbituminous coal combustion/spreader stokers (EPA, 1998b). The NOX emission factor was based on an average of the AP-42 emission factors for spreader stoker type boilers burning bituminous (11 lb/ton) and subbituminous (8.8 lb/ton) coal. We used the AP-42 conversion factor of 13,000 Btu/lb of coal to facilitate estimating the secondary emissions for NOX and CO from coal (EPA, 1998b).
All secondary air impacts were attributed to the combustion of coal, natural gas, or "other" fuels at offsite power plants. We attributed no secondary air impacts to nuclear, hydroelectric, or renewable energy generation. The secondary air impacts for "other" fuels were assumed to be equivalent to those for natural gas.
D.	Solid Waste and Wastewater Impacts
We estimated the solid waste impacts by calculating the amount of material captured by the control device. The material captured by the fabric filter includes just PM from the kiln, while the material captured by the DIFF includes:
Reaction products from the reaction of the lime with the acid gases,
Unreacted lime, and
Particulate matter from the kiln.
In the absence of information, the amount of solid waste captured by a spray dryer/electrostatic precipitator (ESP) (the control system currently employed at one BSCP facility) was assumed to be the same as that captured by a DIFF, since both emission control systems include a combination of acid gas and PM controls, unlike a stand-alone fabric filter (which captures only PM) or a DLA (which captures mostly acid gases, primarily HF).
We estimated the wastewater impacts associated with using a spray dryer/ESP by calculating the amount of water usage for the spray dryer, using the equation shown in Appendix E. There are no wastewater impacts for the other control devices.
E.	Model Impacts for Control Options
Model impacts were estimated for the following control scenarios and are presented in the appendix tables cited below:
Installation of new DIFF on uncontrolled kiln (see Table E-1)
Installation of new fabric filter on uncontrolled kiln (where acid gas levels and exhaust gas temperatures are low) (see Table E-2)
Retrofit of fabric filter after an existing acid gas control (e.g., DLA) (see Table E-2) 
Installation of DLA on uncontrolled kiln(s) to become synthetic area source (see Table E-3)
Retrofit of ACI system to an existing control system (e.g., DIFF) (see Table F­1)
Replacement of existing DLA with a new DIFF (see Table F-2)
Replacement of existing spray dryer/ESP with a new DIFF (see Table F-3)
Replacement of existing DIFF with a new, more efficient DIFF (see Table F-4)
To estimate the incremental impacts for replacement control devices, the impacts associated with baseline controls were subtracted from the impacts associated with new controls. For DLA and spray dryer/ESP controls being replaced with a DIFF, the incremental impacts include the emission reductions, energy impacts, secondary air impacts, solid waste impacts, and wastewater impacts (spray dryer/ESP controls only). For those cases where a facility replaces an existing DIFF with a new, more efficient DIFF to comply with the new standards, we assumed no change in energy requirements or the associated secondary emissions, but we estimated the difference in emissions and solid waste impacts that would accompany the improved control of PM and acid gases.
Because we had no control efficiency data for spray dryer/electrostatic precipitator (ESP), we used stack test data for the kilns equipped with this emission control as the baseline emissions and subtracted the baseline emissions for the DIFF to determine the incremental emissions reduction from replacing a spray dryer/ESP with a DIFF.
Tables 2 through 4 present the model impacts for the DIFF, fabric filter, and ACI control installation/retrofit options and control replacement options discussed above for the small and large BSCP control devices. For additional information, see the aforementioned tables in Appendices E and F at the end of this memorandum.
Table 2a. Summary of Model Emission Reductions for Control Installation/Retrofit Options
Control option
Pollutant
Emissions reductions, tpy


SCD
LCD
Install new DIFF
Hydrogen fluoride
15.1
34.6

Hydrogen chloride
1.72
3.94

Chlorine
0.0789
0.181

HAP metals
0.0855
0.196

Particulate matter
7.78
17.8

Sulfur dioxide
40.2
92.1
Install/retrofit fabric filter
HAP metals
0.0855
0.196

Particulate matter
7.78
17.8
Install new DLA
Hydrogen fluoride
14.4
33.0

Hydrogen chloride
0.620
1.42

Chlorine
0.0371
0.0850

HAP metals
0.0182
0.0417

Particulate matter
1.65
3.79

Sulfur dioxide
9.90
22.7
Retrofit ACI system



    MACT floor
Mercury
0.00136
0.00311
    Beyond the floor
Mercury
0.00152
0.00347

Table 2b. Summary of Model Emission Reductions for Control Replacement Options
Control option
Pollutant
Net emissions reductions, tpy


SCD
LCD
Replace dry limestone adsorber with new DIFF
Hydrogen fluoride
0.683
1.56

Hydrogen chloride
1.10
2.52

Chlorine
0.0418
0.0958

HAP metals
0.0673
0.154

Particulate matter
6.12
14.0

Sulfur dioxide
30.3
69.4
Replace spray dryer/ESP with new DIFF
Hydrogen fluoride
17.5
37.3

Hydrogen chloride
3.93
8.35

Chlorine
0.534
1.14

HAP metals
0.00
0.00

Particulate matter
0.00
0.00

Sulfur dioxide
0.606
1.39
Replace existing DIFF with new, more efficient DIFF
Hydrogen fluoride
0.228
0.521

Hydrogen chloride
0.0259
0.0594

Chlorine
0.00119
0.00272

HAP metals
0.0200
0.0458

Particulate matter
1.82
4.17

Sulfur dioxide
0.606
1.39

Table 3a. Summary of Model Energy and Solid Waste Impacts for Control Installation/Retrofit Options
Control option
Type of impact
SCD
LCD
Install new DIFF
Energy impacts, MMBtu/yr
9,620
12,563

Solid waste impacts, tpy
372
604
Install/retrofit fabric filter
Energy impacts, MMBtu/yr
9,620
12,563

Solid waste impacts, tpy
7.78
17.8
Install new DLA
Energy impacts, MMBtu/yr
3,741
7,424

Solid waste impacts, tpy
306
457
Retrofit ACI system



    MACT floor
Energy impacts, MMBtu/yr
309
553

Solid waste impacts, tpy
10.2
17.9
    Beyond the floor
Energy impacts, MMBtu/yr
309
553

Solid waste impacts, tpy
15.3
27.3

Table 3b. Summary of Model Energy, Solid Waste, and Wastewater Impacts for Control Replacement Options
Control option
Type of impact
Increase in impacts1


SCD
LCD
Replace dry limestone adsorber with new DIFF
Energy impacts, MMBtu/yr
5,879
5,139

Solid waste impacts, tpy
66.8
147
Replace spray dryer/ESP with new DIFF
Energy impacts, MMBtu/yr
-7,749
-24,555

Solid waste impacts, tpy
7.22
12.9

Wastewater impacts, gpy
-1,901
-4,063
Replace existing DIFF with new, more efficient DIFF
Energy impacts, MMBtu/yr
0
0

Solid waste impacts, tpy
7.22
12.9
1 A negative increase in impacts would be equivalent to a reduction in impacts.

Table 4a. Summary of Model Secondary Impacts for Control Installation/Retrofit Options
Control option
Secondary pollutant1
Secondary air impacts, tpy


SCD
LCD
Install new DIFF
Particulate matter
0.0710
0.0927

PM2.5
0.0238
0.0311

Carbon monoxide
0.120
0.156

Nitrogen oxides
0.951
1.24

Sulfur dioxide
2.77
3.62
Install/retrofit fabric filter
Particulate matter
0.0710
0.0927

PM2.5
0.0238
0.0311

Carbon monoxide
0.120
0.156

Nitrogen oxides
0.951
1.24

Sulfur dioxide
2.77
3.62
Install new DLA
Particulate matter
0.0276
0.0548

PM2.5
0.00925
0.0184

Carbon monoxide
0.0465
0.0923

Nitrogen oxides
0.370
0.734

Sulfur dioxide
1.08
2.14
Retrofit ACI system
(MACT floor/beyond the floor)
Particulate matter
0.00228
0.00408

PM2.5
0.000765
0.00137

Carbon monoxide
0.00385
0.00688

Nitrogen oxides
0.0306
0.0547

Sulfur dioxide
0.0891
0.159
1 PM2.5 = PM with particles less than 2.5 micrometers in diameter.

Table 4b. Summary of Model Secondary Impacts for Control Replacement Options
Control option
Secondary pollutant2
Increase in secondary air impacts, tpy1


SCD
LCD
Replace dry limestone adsorber with new DIFF
Particulate matter
0.0434
0.0379

PM2.5
0.0145
0.0127

Carbon monoxide
0.0731
0.0639

Nitrogen oxides
0.581
0.508

Sulfur dioxide
1.69
1.48
Replace spray dryer/ESP with new DIFF
Particulate matter
-0.0572
-0.181

PM2.5
-0.0192
-0.0607

Carbon monoxide
-0.0964
-0.305

Nitrogen oxides
-0.766
-2.43

Sulfur dioxide
-2.23
-7.07
Replace existing DIFF with new, more efficient DIFF
Particulate matter
0
0

PM2.5
0
0

Carbon monoxide
0
0

Nitrogen oxides
0
0

Sulfur dioxide
0
0
1 A negative increase in secondary air impacts would be equivalent to a reduction in secondary air impacts.
2 PM2.5 = PM with particles less than 2.5 micrometers in diameter.

V.	References
BLS (U.S. Department of Labor, Bureau of Labor Statistics). 2012. Occupational Employment Statistics: May 2011 National Industry-Specific Occupational Employment and Wage Estimates. NAICS 327100 - Clay Product and Refractory Manufacturing. Industrial Engineering Technician. March 27, 2012. Available at: http://www.bls.gov/oes/2011/may/naics4_327100.htm.
CE (Chemical Engineering). 2011. Plant Cost Index.
Childress, J. 2013a. "RE: From McGill AirClean Web Site." E-mail from Jerry Childress, McGill AirClean LLC, to Thomas Holloway, RTI International. April 18, 2013.
Childress, J. 2013b. "RE: From McGill AirClean Web Site." E-mail from Jerry Childress, McGill AirClean LLC, to Thomas Holloway, RTI International. June 27, 2013.
EPA (U.S. Environmental Protection Agency). 1998a. Compilation of Air Pollutant Emission Factors. Volume 1: Stationary Point and Area Sources. AP-42, Section 1.4: Natural Gas Combustion. July 1998.
EPA (U.S. Environmental Protection Agency). 1998b. Compilation of Air Pollutant Emission Factors. Volume 1: Stationary Point and Area Sources. AP-42, Section 1.1: Bituminous and Subbituminous Coal Combustion. September 1998.
EPA (U.S. Environmental Protection Agency). 2002. EPA Air Pollution Control Cost Manual. Sixth Edition. Office of Air Quality Planning and Standards, Research Triangle Park, NC. Publication No. EPA/452/B-02-001. January 2002.
EPA (U.S. Environmental Protection Agency). 2005. Technical Support Document for the HWC MACT Replacement Standards, Volume V: Emissions Estimates and Engineering Costs. Office of Solid Waste and Emergency Response, Washington, DC. September 2005.
EPA (U.S. Environmental Protection Agency). 2006. "Subpart Da -- Standards of Performance for Electric Utility Steam Generating Units for Which Construction is Commenced After September 18, 1978." Code of Federal Regulations, Title 40, Part 60. Published by Office of the Federal Register, National Archives and Records Administration. As of July 1, 2006.
EPA (U.S. Environmental Protection Agency). 2011. Regulatory Impact Analysis for the Final Mercury and Air Toxics Standards. Table 3-6: Generation Mix with the Base Case and the MATS, 2015 (Thousand GWh). Publication No. EPA-452/R-11-011. December 2011.
Hansen, L. 2013. "RE: Question regarding use of fabric filters for brick kilns." E-mail from Lars Hansen, Solios Environment Corp., to Thomas Holloway, RTI International. July 2, 2013.
Holloway, T. 2013a. Telephone Contact Summary: Jeff Thompson, Cabot Norit Activated Carbon. Contacted by Thomas Holloway, RTI International. May 16, 2013.
Holloway, T. 2013b. "RE: From McGill AirClean Web Site." E-mail from Thomas Holloway, RTI International, to Jerry Childress, McGill AirClean LLC. June 26, 2013.
Holloway, T. 2013c. Telephone Contact Summary: Chris Polizzi, W.L. Gore & Associates, Inc. Contacted by Thomas Holloway, RTI International. July 16, 2013.
Holloway, T. 2014. Updated BSCP Inventory Database and Documentation. Memorandum from Thomas Holloway, RTI International, to Jeff Telander, EPA/OAQPS/SPPD. November 6, 2014.
Raymond, G. 2014. Test Data Used in BSCP Proposed Rule. Memorandum from Gabrielle Raymond, RTI International, to Jeff Telander, EPA/OAQPS/SPPD. November 6, 2014.
Shrager, B. 2003. Final Rule: Costs for Air Pollution Control Devices on Kilns. Memorandum from Brian Shrager, RTI International, to Mary Johnson, U.S. Environmental Protection Agency. February 25, 2003.
Thompson, J. 2013. "FW: Cabot Norit Activated Carbon - question." E-mail from Jeff Thompson, Cabot Norit Activated Carbon, to Thomas Holloway, RTI International. May 31, 2013.




Appendix A
Model Parameters
Table A-1. General Parameters for BSCP Model Control Devices
Parameters
SCD
LCD
Footnotes
Process parameters




Production rate, ton/hr
7.0
15.0
1

Operating hours, hr/yr
7,300
7,800
1

Exhaust flow, acfm
23,100
38,700
2
Unit costs




Electricity cost, $/kwh
0.073
0.073
1

Waste disposal cost, $/ton
40
40
1

Operator wage rate, $/hr
22.67
22.67
3

Maintenance wage rate, $/hr
24.94
24.94
4

Capital recovery factor--system
0.0944
0.0944
5
Molecular weights




HF
20
20


HCl
36.5
36.5


SO2
64
64


CaF2
78
78
6

CaCl2
111
111
6

CaSO3
120
120
6

Ca(OH)2
74
74
7
Uncontrolled emissions, lb/ton




HF
0.594
0.594
2

HCl
0.081
0.081
2

Cl2
0.00346
0.00346
2

Non-Hg HAP Metals
0.00356
0.00356
8

PM
0.324
0.324
2

SO2
3.23
3.23
2
Uncontrolled emissions, lb/hr




HF
4.16
8.91
9

HCl
0.566
1.21
9

Cl2
0.0242
0.0519
9

Non-Hg HAP Metals
0.0249
0.0534
9

PM
2.27
4.86
9

SO2
22.6
48.5
9
1. Average from section 114 survey responses.
2. Average from test data.
3. Mean hourly wage, from Bureau of Labor Statistics, May 2011 National Industry-Specific Occupational Employment and Wage Estimates, NAICS 327100, Industrial Engineering Technician. Website: http://www.bls.gov/oes/2011/may/naics4_327100.htm. Wage rates from Bureau of Labor Statistics were used because they are more conservative than those provided by section 114 survey respondents.
4. 10 percent higher than operator rate.
5. Based on equipment life of 20 years and 7 percent interest.
6. Reaction product; CaF2 = calcium fluoride; CaCl2 = calcium chloride; CaSO3 = calcium sulfite.
7. Hydrated lime.
8. Assume 1.1 percent of PM.
9. Calculated from lb/ton times production rate.




Appendix B
Installation Model Costs
 Table B-1. Model Costs to Install New DIFF
Parameters
SCD
LCD
Footnotes
Control efficiency, percent




HF
99.5%
99.5%
1

HCl
83.3%
83.3%
2

Cl2
89.3%
89.3%
3

Non-Hg HAP Metals
94%
94%
4

PM
94%
94%
1

SO2
48.7%
48.7%
5
Design and operating parameters




Fan hp
150
190
6

Total hp for other motors
30
30
6

Hydrated lime, fraction of stoichiometric amount
2.65
1.79
7

Operator labor, hr/shift
2.5
2.5
8

Maintenance labor, hr/shift
1.25
1.25
6

Bag life, yr
5
5
6

Gas-to-cloth ratio (gross), ft/min
3.4
3.4
6

Bag area, ft2
28
28
6

Compressed air, ft3/1,000 ft3
0.9
0.9
6

Time to replace bags, hr/bag
2.25
2.25
6

Added cooling air, ft3/min
0
0
9
Calculated parameters




Hydrated lime makeup, lb/hr
91.4
132.0


Reaction products, lb/hr
29.4
63.1
10

Reacted lime, lb/hr
20.9
44.7


Particulate matter, lb/hr
2.1
4.6


Waste, lb/hr
102.1
154.9
11
Cost factors




Hydrated lime, $/ton
160
160
6

Bag fabric cost, $/ft2
8.15
8.15
6

Compressed air, $/1,000 ft3
0.24
0.24
12

Capital recovery factor--bags
0.244
0.244
13
Capital costs



Total capital investment
2,000,000
2,730,000
14
Annual costs




Operating labor
51,716
55,258


Supervisory labor
7,757
8,289
15

Maintenance labor
28,444
30,392


Maintenance materials
28,444
30,392
16

Electricity
71,462
93,325
17

Lime
53,348
82,337


Compressed air
2,185
3,912


Annualized replacement bags
13,505
22,625


Annualized bag replacement labor
3,320
5,563
18

Cage replacement
0
0
19

Waste disposal
14,900
24,162


Overhead
69,817
74,598
20

Administrative charges
40,000
54,600
21

Property taxes
20,000
27,300
22

Insurance
20,000
27,300
22

Capital recovery
188,399
257,044

Total annual cost, $/yr
613,297
797,096

1. Average from test data with better efficiency than baseline.
2. Based on ratio of enhanced HF reduction and baseline HCl reduction.
3. Based on ratio of enhanced HF reduction and baseline Cl2 reduction.
4. Assume same as PM.
5. Based on ratio of enhanced HF reduction and baseline SO2 reduction.
6. Average from section 114 survey responses.
7. Assume hydrated lime is 2.65/1.79 times the stoichiometric amount needed to get additional control re baseline (from 98% to 99.5%).
8. Assume 2 times maintenance labor (EPA, 2002).
9. Assume none.
10. CaF2 (calcium fluoride), CaCl2 (calcium chloride), and CaSO3 (calcium sulfite).
11. Inlet lime minus reacted lime plus reaction products and PM.
12. Pollution Prevention (P2) Pays, NC Division of Pollution Prevention and Environmental Assistance. Determine the Cost of Compressed Air for Your Plant. Energy Tips - Compressed Air, Compressed Air Tip Sheet #1. August 2004. Web site: http://www.p2pays.org/ref/40/39536.pdf.
13. Based on equipment life of 5 years and 7 percent interest.
14. Average of costs from section 114 survey responses scaled using 6/10 rule (based on acfm), escalated to 2011 dollars, and rounded.
15. 15 percent of operator labor.
16. 100 percent of maintenance labor.
17. Based on conversion factor of 0.745 kW/hp.
18. Performed by maintenance personnel.
19. Maybe no need to replace.
20. 60 percent of labor and maintenance materials.
21. 2 percent of TCI.
22. 1 percent of TCI.

Table B-2. Model Costs to Install New Fabric Filter
Parameters
SCD
LCD
Footnotes
Control efficiency, percent




Non-Hg HAP Metals
94%
94%
1

PM
94%
94%
2
Design and operating parameters




Fan hp
150
190
3

Total hp for other motors
30
30
3

Operator labor, hr/shift
2.5
2.5
4

Maintenance labor, hr/shift
1.25
1.25
3

Bag life, yr
5
5
3

Gas-to-cloth ratio (gross), ft/min
3.4
3.4
3

Bag area, ft2
28
28
3

Compressed air, ft3/1,000 ft3
0.9
0.9
3

Time to replace bags, hr/bag
2.25
2.25
3

Added cooling air, ft3/min
0
0
5
Calculated parameters




Waste, lb/hr
2.1
4.6
6
Cost factors




Bag fabric cost, $/ft2
8.15
8.15
3

Compressed air, $/1,000 ft3
0.24
0.24
7

Capital recovery factor--bags
0.244
0.244
8

Cost of dry injection system
800,907
1,230,278
9
Capital costs



Total capital investment
1,200,000
1,500,000
10
Annual costs




Operating labor
51,716
55,258


Supervisory labor
7,757
8,289
11

Maintenance labor
28,444
30,392


Maintenance materials
28,444
30,392
12

Electricity
71,462
93,325
13

Compressed air
2,185
3,912


Annualized replacement bags
13,505
22,625


Annualized bag replacement labor
3,320
5,563
14

Cage replacement
0
0
15

Waste disposal
311
712


Overhead
69,817
74,598
16

Administrative charges
24,000
30,000
17

Property taxes
12,000
15,000
18

Insurance
12,000
15,000
18

Capital recovery
112,884
140,940

Total annual cost, $/yr
437,845
526,006

1. Assume same as PM.
2. Average from test data with better efficiency than baseline.
3. Average from section 114 survey responses.
4. Assume 2 times maintenance labor (EPA, 2002).
5. Assume none.
6. Particulate matter.
7. Pollution Prevention (P2) Pays, NC Division of Pollution Prevention and Environmental Assistance. Determine the Cost of Compressed Air for Your Plant. Energy Tips - Compressed Air, Compressed Air Tip Sheet #1. August 2004. Web site: http://www.p2pays.org/ref/40/39536.pdf.
8. Based on equipment life of 5 years and 7 percent interest.
9. Based on cost equations in the June 19, 2009 memorandum Revised Baseline Operating Costs for Existing HMIWI, in Docket ID No. EPA-HQ-OAR-2006-0534 for the hospital/medical/infectious waste incinerator (HMIWI) rule.
10. Average of costs from section 114 survey responses scaled using 6/10 rule (based on acfm), subtracted cost of dry injection system, escalated to 2011 dollars, and rounded.
11. 15 percent of operator labor.
12. 100 percent of maintenance labor.
13. Based on conversion factor of 0.745 kW/hp.
14. Performed by maintenance personnel.
15. Maybe no need to replace.
16. 60 percent of labor and maintenance materials.
17. 2 percent of TCI.
18. 1 percent of TCI.

Table B-3. Model Costs to Install New DLA
Parameters
SCD
LCD
Footnotes
Control efficiency, percent




HF
95%
95%
1

HCl
30%
30%
1

Cl2
42%
42%
1

Non-Hg HAP Metals
20%
20%
2

PM
20%
20%
1

SO2
12%
12%
1
Design and operating parameters




Fan hp
60
90
3

Total hp for other motors
10
40
3

Limestone, lb/hr
85
120
3

Operator labor, hr/shift
1.5
1.5
4

Maintenance labor, hr/shift
0.75
0.75
3
Calculated parameters




Reaction products, lb/hr
13.1
28.0
5

Reacted limestone, lb/hr
14.4
30.8


Particulate matter, lb/hr
0.1
0.1


Waste, lb/hr
83.8
117.3
6
Cost factors




Limestone, $/ton
40
40
3
Capital costs



Total capital investment
1,060,000
1,440,000
7
Annual costs




Operating labor
31,030
33,155


Supervisory labor
4,654
4,973
8

Maintenance labor
17,066
18,235


Maintenance materials
17,066
18,235
9

Electricity
27,791
55,146
10

Limestone
12,410
18,720


Waste disposal
12,230
18,295
11

Overhead
41,890
44,759
12

Administrative charges
21,200
28,800
13

Property taxes
10,600
14,400
14

Insurance
10,600
14,400
14

Capital recovery
100,057
135,926

Total annual cost, $/yr
306,593
405,045

1. Average from test data.
2. Assume same as PM.
3. Average from section 114 survey responses.
4. Assume 2 times maintenance labor (EPA, 2002).
5. CaF2 (calcium fluoride), CaCl2 (calcium chloride), and CaSO3 (calcium sulfite).
6. Inlet limestone minus reacted limestone plus reaction products and PM.
7. Average of costs from section 114 survey responses scaled using 6/10 rule (based on acfm), escalated to 2011 dollars, and rounded.
8. 15 percent of operator labor.
9. 100 percent of maintenance labor.
10. Based on conversion factor of 0.745 kW/hp.
11. Some facilities have minimal waste disposal costs.
12. 60 percent of labor and maintenance materials.
13. 2 percent of TCI.
14. 1 percent of TCI.





Appendix C
Retrofit/Replacement Model Costs
Table C-1. Model Costs to Replace Existing Control Device with DIFF
Parameters
SCD
LCD
Footnotes
Control efficiency, percent




HF
99.5%
99.5%
1

HCl
83.3%
83.3%
2

Cl2
89.3%
89.3%
3

Non-Hg HAP Metals
94%
94%
4

PM
94%
94%
1

SO2
48.7%
48.7%
5
Design and operating parameters




Fan hp
150
190
6

Total hp for other motors
30
30
6

Hydrated lime, fraction of stoichiometric amount
2.65
1.79
7

Operator labor, hr/shift
2.5
2.5
8

Maintenance labor, hr/shift
1.25
1.25
6

Bag life, yr
5
5
6

Gas-to-cloth ratio (gross), ft/min
3.4
3.4
6

Bag area, ft2
28
28
6

Compressed air, ft3/1,000 ft3
0.9
0.9
6

Time to replace bags, hr/bag
2.25
2.25
6

Added cooling air, ft3/min
0
0
9
Calculated parameters




Hydrated lime makeup, lb/hr
91.4
132.0


Reaction products, lb/hr
29.4
63.1
10

Reacted lime, lb/hr
20.9
44.7


Particulate matter, lb/hr
2.1
4.6


Waste, lb/hr
102.1
154.9
11
Cost factors




Hydrated lime, $/ton
160
160
6

Bag fabric cost, $/ft2
8.15
8.15
6

Compressed air, $/1,000 ft3
0.24
0.24
12

Capital recovery factor--bags
0.244
0.244
13

Retrofit factor
1.4
1.4
14
Capital costs



Total capital investment
2,800,000
3,820,000
15
Annual costs




Operating labor
51,716
55,258


Supervisory labor
7,757
8,289
16

Maintenance labor
28,444
30,392


Maintenance materials
28,444
30,392
17

Electricity
71,462
93,325
18

Lime
53,348
82,337


Compressed air
2,185
3,912


Annualized replacement bags
13,505
22,625


Annualized bag replacement labor
3,320
5,563
19

Cage replacement
0
0
20

Waste disposal
14,900
24,162


Overhead
69,817
74,598
21

Administrative charges
56,000
76,400
22

Property taxes
28,000
38,200
23

Insurance
28,000
38,200
23

Capital recovery
263,913
359,932

Total annual cost, $/yr
720,811
943,585

1. Average from test data with better efficiency than baseline.
2. Based on ratio of enhanced HF reduction and baseline HCl reduction.
3. Based on ratio of enhanced HF reduction and baseline Cl2 reduction.
4. Assume same as PM.
5. Based on ratio of enhanced HF reduction and baseline SO2 reduction.
6. Average from section 114 survey responses.
7. Assume hydrated lime is 2.65/1.79 times the stoichiometric amount needed to get additional control re baseline (from 98% to 99.5%).
8. Assume 2 times maintenance labor (EPA, 2002).
9. Assume none.
10. CaF2 (calcium fluoride), CaCl2 (calcium chloride), and CaSO3 (calcium sulfite).
11. Inlet lime minus reacted lime plus reaction products and PM.
12. Pollution Prevention (P2) Pays, NC Division of Pollution Prevention and Environmental Assistance. Determine the Cost of Compressed Air for Your Plant. Energy Tips - Compressed Air, Compressed Air Tip Sheet #1. August 2004. Web site: http://www.p2pays.org/ref/40/39536.pdf.
13. Based on equipment life of 5 years and 7 percent interest.
14. Average for various control devices (EPA, 2002).
15. Average of costs from section 114 survey responses scaled using 6/10 rule (based on acfm), escalated to 2011 dollars, multiplied by retrofit cost factor, and rounded.
16. 15 percent of operator labor.
17. 100 percent of maintenance labor.
18. Based on conversion factor of 0.745 kW/hp.
19. Performed by maintenance personnel.
20. Maybe no need to replace.
21. 60 percent of labor and maintenance materials.
22. 2 percent of TCI.
23. 1 percent of TCI.

Table C-2. Model Costs to Retrofit Fabric Filter to Existing Control Device
Parameters
SCD
LCD
Footnotes
Control efficiency, percent




Non-Hg HAP Metals
94%
94%
1

PM
94%
94%
2
Design and operating parameters




Fan hp
150
190
3

Total hp for other motors
30
30
3

Operator labor, hr/shift
2.5
2.5
4

Maintenance labor, hr/shift
1.25
1.25
3

Bag life, yr
5
5
3

Gas-to-cloth ratio (gross), ft/min
3.4
3.4
3

Bag area, ft2
28
28
3

Compressed air, ft3/1,000 ft3
0.9
0.9
3

Time to replace bags, hr/bag
2.25
2.25
3

Added cooling air, ft3/min
0
0
5
Calculated parameters




Waste, lb/hr
2.1
4.6
6
Cost factors




Bag fabric cost, $/ft2
8.15
8.15
3

Compressed air, $/1,000 ft3
0.24
0.24
7

Capital recovery factor--bags
0.244
0.244
8

Cost of dry injection system
800,907
1,230,278
9

Retrofit factor
1.4
1.4
10
Capital costs



Total capital investment
1,680,000
2,100,000
11
Annual costs




Operating labor
51,716
55,258


Supervisory labor
7,757
8,289
12

Maintenance labor
28,444
30,392


Maintenance materials
28,444
30,392
13

Electricity
71,462
93,325
14

Compressed air
2,185
3,912


Annualized replacement bags
13,505
22,625


Annualized bag replacement labor
3,320
5,563
15

Cage replacement
0
0
16

Waste disposal
311
712


Overhead
69,817
74,598
17

Administrative charges
33,600
42,000
18

Property taxes
16,800
21,000
19

Insurance
16,800
21,000
19

Capital recovery
158,193
197,576

Total annual cost, $/yr
502,354
606,642

1. Assume same as PM.
2. Average from test data with better efficiency than baseline.
3. Average from section 114 survey responses.
4. Assume 2 times maintenance labor (EPA, 2002).
5. Assume none.
6. Particulate matter.
7. Pollution Prevention (P2) Pays, NC Division of Pollution Prevention and Environmental Assistance. Determine the Cost of Compressed Air for Your Plant. Energy Tips - Compressed Air, Compressed Air Tip Sheet #1. August 2004. Web site: http://www.p2pays.org/ref/40/39536.pdf.
8. Based on equipment life of 5 years and 7 percent interest.
9. Based on cost equations in the June 19, 2009 memorandum Revised Baseline Operating Costs for Existing HMIWI, in Docket ID No. EPA-HQ-OAR-2006-0534 for the HMIWI rule.
10. Average for various control devices (EPA, 2002).
11. Average of costs from section 114 survey responses scaled using 6/10 rule (based on acfm), subtracted cost of dry injection system, escalated to 2011 dollars, multiplied by retrofit cost factor, and rounded.
12. 15 percent of operator labor.
13. 100 percent of maintenance labor.
14. Based on conversion factor of 0.745 kW/hp.
15. Performed by maintenance personnel.
16. Maybe no need to replace.
17. 60 percent of labor and maintenance materials.
18. 2 percent of TCI.
19. 1 percent of TCI.


Table C-3. Model Costs to Retrofit ACI System to Existing Control Device
Parameters
MACT Floor
Beyond the Floor
Footnotes

SCD
LCD
SCD
LCD
                                       
Design and operating parameters
 
 


 
 
Carbon injection rate (lb/MMft3) [CIR]
2
2
3
3
1
 
Injection blower fan power (hp) [Powerfan]
5.2
8.7
5.2
8.7
2,3

Projected equipment life (yrs) [n]
15
15
15
15
2

Interest rate (%) [i]
7
7
7
7

Calculated parameters
 
 


 
 
Carbon feed rate (lb/hr) [CFR]
2.8
4.6
4.2
7.0
4 
Cost factors






Carbon unit cost ($/lb) [CC]
0.85
0.85
0.85
0.85
5

Escalation factor [EF]
1.78
1.78
1.78
1.78
2,6,7

Capital recovery factor [CRF]
0.1098
0.1098
0.1098
0.1098
2,8

Retrofit factor [RF]
1.15
1.15
1.15
1.15
2
Direct capital costs
 
 


 
 
Purchased equipment costs
 
 


 
 
 
Total equipment [TEC] (see Note)
$24,294
$34,864
$24,294
$34,864
2,9
 
 
Sales tax
$729
$1,046
$729
$1,046
2,10
 
 
Freight
$1,215
$1,743
$1,215
$1,743
2,11
 
 
Purchased equipment with tax and freight
$26,238
$37,653
$26,238
$37,653
2,12
 
 
Purchased equipment with escalation
$46,784
$67,138
$46,784
$67,138
2,13
 
 
Purchased equipment with retrofit factor [PEC]
$53,802
$77,209
$53,802
$77,209
2,14
 
Installation cost [IC]
$16,141
$23,163
$16,141
$23,163
2,15
 
Total direct costs [TDC]
$69,942
$100,371
$69,942
$100,371
2,16
Indirect capital costs
 
 


 
 
Engineering
$10,760
$15,442
$10,760
$15,442
2,17
 
Construction and field expense
$10,760
$15,442
$10,760
$15,442
2,17
 
Contractor fees
$5,380
$7,721
$5,380
$7,721
2,18
 
Start-up
$538
$772
$538
$772
2,19
 
Performance test
$538
$772
$538
$772
2,19
 
Model study
$1,076
$1,544
$1,076
$1,544
2,20
 
Contingencies
$3,228
$4,633
$3,228
$4,633
2,21
 
Total indirect costs [TIC]
$32,281
$46,325
$32,281
$46,325
2,22
Total capital cost





Total capital investment [TCI]
$102,224
$146,697
$102,224
$146,697
2,23
Annual costs
 
 


 
 
Operating labor
$6,895
$7,368
$6,895
$7,368
2,24
 
Supervisory labor
$1,034
$1,105
$1,034
$1,105
2,25
 
Maintenance labor
$11,378
$12,157
$11,378
$12,157
2,26
 
Maintenance materials
$2,690
$3,860
$2,690
$3,860
2,27

Electricity cost
$2,298
$4,108
$2,298
$4,108
2,28

Carbon cost
$17,374
$30,498
$26,061
$46,410
2,29

Solid waste disposal cost
$409
$718
$613
$1,092
2,30

Overhead
$13,198
$14,694
$13,198
$14,694
2,31
 
Administrative charges
$2,044
$2,934
$2,044
$2,934
2,32
 
Property tax
$1,022
$1,467
$1,022
$1,467
2,33
 
Insurance
$1,022
$1,467
$1,022
$1,467
2,33
 
Capital recovery
$11,224
$16,107
$11,224
$16,107
2,34
Total annual cost
$70,589
$96,482
$79,480
$112,768
2,35
Note: Total equipment includes storage silo, feed bin, gravimetric feeders, pneumatic conveyor, and injection ports.

Footnotes:
1. Thompson, 2013. Suggested carbon concentration of 2 lb/MMft3.
2. EPA, 2005, Appendix J.
3. Scaled HWC hp estimate using ratio of exhaust flow rates: (15 hp) x Q / (66,870.6 acfm).
4. Equal to CIR / 1E6 x exhaust flow x (60 min/hr).
5. Holloway, 2013a. Indicated carbon price would be $0.80 to $0.90/lb. Used average of $0.85/lb.
6. Escalating costs from 2004 (HWC) to 2011 (BSCP) using the following factors: (HWC escalation factor, 1.1319 x 1.064) x (BSCP escalation factor, 1.4805).
7. Chemical Engineering Plant Cost Index.
8. Equal to = [i x (1 + i)n] / [(1 + i)n - 1], where i = 7 percent interest and n = 15-year equipment life.
9. Equal to 90,000 x (exhaust flow/150,000)0.7.
10. Equal to 0.03 x TEC.
11. Equal to 0.05 x TEC.
12. Equal to TEC + (sales tax) + (freight).
13. Equal to EF x (purchased equipment with tax and freight).
14. Equal to RF x (purchased equipment with escalation).
15. Equal to 0.3 x PEC.
16. Equal to PEC + IC.
17. Equal to 0.2 x PEC.
18. Equal to 0.1 x PEC.
19. Equal to 0.01 x PEC.
20. Equal to 0.02 x PEC.
21. Equal to 0.06 x PEC.
22. Equal to sum of indirect costs.
23. Equal to TDC + TIC.
24. Equal to (1 hr/d) x operating hr/yr / (24 hr/d) x operator wage rate ($/hr).
25. Equal to 0.15 x (operator labor cost).
26. Equal to (0.5 hr/shift) x (3 shifts/d) x operating hr/yr / (24 hr/d) x maintenance wage rate ($/hr).
27. Equal to 0.05 x PEC.
28. Equal to Powerfan / (1.34 hp/kW) / (0.9 Efficiencyfan) x operating hr/yr x electricity unit cost ($/kWh).
29. Equal to CFR x operating hr/yr x carbon unit cost ($/lb).
30. Equal to CFR x operating hr/yr / (2000 lb/ton) x waste disposal unit cost ($/ton).
31. Equal to 0.6 x (operating labor cost + maintenance cost).
32. Equal to 0.02 x TCI.
33. Equal to 0.01 x TCI.
34. Equal to CRF x TCI.
35. Equal to sum of annual costs.





Appendix D
Model Impacts Equations
Table D-1. Equations Used to Estimate Model Energy and Secondary Impacts
Parameters
Value
Notes, units, and equations
Energy impacts
Heat factors


Heat content of electricity (HCelec)
3,415
Btu/kWh
Heat rate


   Coal (HRcoal)
10,415
Btu/kWh
   Natural gas (HRgas)
8,185
Btu/kWh
   Nuclear power (HRnuclear)
10,452
Btu/kWh
   Renewable energy (HRrenew)
9,756
Btu/kWh
Percent of generation


Coal (% coal)
48%
Used for solid fuel
Oil/natural gas (% gas)
18%
Used for natural gas
Nuclear (% nuclear)
20%
No secondary emissions estimated
Hydroelectric (% hydro)
7%
No secondary emissions estimated
Renewable (% renew)
6%
No secondary emissions estimated
Other (% other)
1%
Used for natural gas (assumed equivalent)
Power plant efficiency (E)


Coal (Ecoal)
33%
% = HCelec / HRcoal * 100
Natural gas/other (Egas)
42%
% = HCelec / HRgas* 100
Nuclear (Enuclear)
33%
% = HCelec / HRnuclear * 100
Renewable/hydroelectric (Erenew)
35%
% = HCelec / HRrenew * 100
Average (Eavg)
35%
% = (Ecoal x % coal) + (Egas x % gas/other) + (Enuclear x % nuclear) + (Erenew x % renew/hydro)
Energy impacts calculations


Electricity requirements
model-specific
kWh/yr = total hp x (0.745 kW/hp) x operating hr/yr
Energy impacts
model-specific
MMBtu/yr = (kWh/yr) x (HCelec) x (MMBtu/1E6 Btu) / Eavg
Secondary emissions
Emission factors, natural gas


Particulate matter/PM2.5
 
1.9
lb/MM ft3 natural gas

0.00186275
lb/MMBtu natural gas
Carbon monoxide
84
lb/MM ft3 natural gas

0.0824
lb/MMBtu natural gas
Nitrogen oxide
100
lb/MM ft3 natural gas

0.0980
lb/MMBtu natural gas
Sulfur dioxide
0.6
lb/MM ft3 natural gas

0.00059
lb/MMBtu natural gas
Emission factors, solid fuel


Particulate matter
0.03
lb/MMBtu solid, liquid, gaseous fuel
PM2.5
0.00957
lb/MMBtu solid, liquid, gaseous fuel
Carbon monoxide
0.19
lb/MMBtu bituminous coal
Nitrogen oxide
0.38
lb/MMBtu solid fuel
Sulfur dioxide
1.2
lb/MMBtu solid fuel
Secondary emissions calculation


Secondary emissions, for each pollutant
model-specific
lb/yr = MMBtu/yr x [(lb/MMBtu natural gas) x (% gas/other) + (lb/MMBtu solid fuel) x (% coal)]
Solid waste and wastewater impacts
Solid waste impacts
model-specific
tpy = waste (lb/hr) x operating hr/yr / (2,000 lb/ton)
Wastewater impacts
model-specific
gpy = water usage (gpd) x operating hr/yr / (24 hr/d)
1. gpy = gallons per year; gpd = gallons per day.
2. Assume electricity generated using the above mix (from IPM Version 3.0 for the year 2015), as determined from Table 3-6 of Regulatory Impacts Analysis for the final Mercury and Air Toxics Standards. IPM = EPA Integrated Planning Model, which is a multi-regional, dynamic, deterministic linear programming model of the U.S. electric power sector that provides forecasts of least-cost capacity expansion, electricity dispatch, and emission control strategies for meeting energy demand and environmental, transmission, dispatch, and reliability constraints.
3. For natural gas, used PM, CO, NOX, and SO2 emission factors from AP-42 chapter on natural gas combustion. Assumed 1,020 Btu/ft3 of natural gas in estimating PM, CO, NOX, and SO2 secondary emissions. Also assumed that 100% of PM is PM2.5, based on statement in AP-42 that PM from natural gas combustion is estimated to be less than 1 micron in size.
4. For solid fuel, used PM and SO2 emission limits for solid fuel-fired boilers from 2006 CFR edition of NSPS for electric utility plants (40 CFR part 60, subpart Da) and used NOX and CO emission factors from AP-42 chapter on coal combustion (bituminous/subbituminous coal). The NOX emission factor was based on average of NOX emission factors for PC dry-bottom wall-fired NSPS boilers burning bituminous (12 lb/ton) and subbituminous (7.4 lb/ton) coal. Assumed 13,000 Btu/lb of coal in estimating NOX and CO secondary emissions. According to AP-42, the percentage of PM that is PM2.5 for dry-bottom coal-fired boilers is 29% with ESP, 53% with FF, and 6% if uncontrolled. Assumed 84% of utility boilers controlled with ESP and 14% with FF, leaving 2% uncontrolled, based on information from EPA document on control of emissions from coal-fired utility boilers.





Appendix E
Installation Model Impacts
Table E-1. Model Impacts of Installing New DIFF
Parameters
SCD
LCD
Control efficiency



HF
99.5%
99.5%

HCl
83.3%
83.3%

Cl2
89.3%
89.3%

Non-Hg HAP metals
94%
94%

PM
94%
94%

SO2
48.7%
48.7%
Parameters



Fan hp
150
190

Total hp for other motors
30
30

Waste, lb/hr
102.1
154.9
Emissions reductions, tpy



HF
15.1
34.6

HCl
1.72
3.94

Cl2
0.0789
0.181

Non-Hg HAP metals
0.0855
0.196

PM
7.78
17.8

SO2
40.2
92.1
Energy impacts, MMBtu/yr
9,620
12,563
Secondary air impacts, tpy



Particulate matter
0.0710
0.0927

PM2.5
0.0238
0.0311

Carbon monoxide
0.120
0.156

Nitrogen oxides
0.951
1.24

Sulfur dioxide
2.77
3.62
Solid waste impacts, tpy
372
604

Table E-2. Model Impacts of Installing/Retrofitting Fabric Filter
Parameters
SCD
LCD
Control efficiency



Non-Hg HAP metals
94%
94%

PM
94%
94%
Parameters



Fan hp
150
190

Total hp for other motors
30
30

Waste, lb/hr
2.1
4.6
Emissions reductions, tpy



Non-Hg HAP metals
0.0855
0.196

PM
7.78
17.8
Energy impacts, MMBtu/yr
9,620
12,563
Secondary air impacts, tpy



Particulate matter
0.0710
0.0927

PM2.5
0.0238
0.0311

Carbon monoxide
0.120
0.156

Nitrogen oxides
0.951
1.24

Sulfur dioxide
2.77
3.62
Solid waste impacts, tpy
7.78
17.8

Table E-3. Model Impacts of Installing New DLA
Parameters
SCD
LCD
Control efficiency



HF
95%
95%

HCl
30%
30%

Cl2
42%
42%

Non-Hg HAP metals
20%
20%

PM
20%
20%

SO2
12%
12%
Parameters



Fan hp
60
90

Total hp for other motors
10
40

Waste, lb/hr
83.8
117.3
Emissions reductions, tpy



HF
14.4
33.0

HCl
0.620
1.42

Cl2
0.0371
0.0850

Non-Hg HAP metals
0.0182
0.0417

PM
1.65
3.79

SO2
9.90
22.7
Energy impacts, MMBtu/yr
3,741
7,424
Secondary air impacts, tpy



Particulate matter
0.0276
0.0548

PM2.5
0.00925
0.0184

Carbon monoxide
0.0465
0.0923

Nitrogen oxides
0.370
0.734

Sulfur dioxide
1.08
2.14
Solid waste impacts, tpy
306
457





Appendix F
Retrofit/Replacement Model Impacts
Table F-1. Model Impacts of Retrofitting ACI System to Existing Control Device
Parameters
MACT Floor
Beyond the Floor

SCD
LCD
SCD
LCD
Parameters





Injection blower fan power, hp
5.2
8.7
5.2
8.7

Carbon feed rate, lb/hr
2.8
4.6
4.2
7.0
Mercury emissions reduction, tpy
0.00136
0.00311
0.00152
0.00347
Energy impacts, MMBtu/yr
309
553
309
553
Secondary air impacts, tpy





Particulate matter
0.00228
0.00408
0.00228
0.00408

PM2.5
0.000765
0.00137
0.000765
0.00137

Carbon monoxide
0.00385
0.00688
0.00385
0.00688

Nitrogen oxides
0.0306
0.0547
0.0306
0.0547

Sulfur dioxide
0.0891
0.159
0.0891
0.159
Solid waste impacts, tpy
10.2
17.9
15.3
27.3

Table F-2. Model Impacts of Replacing Dry Limestone Adsorber with New DIFF
Parameters
SCD
LCD

DLA
DIFF
Increm.
DLA
DIFF
Increm.
Control efficiency







HF
95%
99.5%

95%
99.5%


HCl
30%
83.3%

30%
83.3%


Cl2
42%
89.3%

42%
89.3%


Non-Hg HAP metals
20%
94%

20%
94%


PM
20%
94%

20%
94%


SO2
12%
48.7%

12%
48.7%

Parameters







Fan hp
60
150

90
190


Total hp for other motors
10
30

40
30


Waste, lb/hr
83.8
102.1

117.3
154.9

Emissions reductions, tpy







HF
14.4
15.1
0.683
33.0
34.6
1.56

HCl
0.620
1.72
1.10
1.42
3.94
2.52

Cl2
0.0371
0.0789
0.0418
0.0850
0.181
0.0958

Non-Hg HAP metals
0.0182
0.0855
0.0673
0.0417
0.196
0.154

PM
1.65
7.78
6.12
3.79
17.8
14.0

SO2
9.90
40.2
30.3
22.7
92.1
69.4
Energy impacts, MMBtu/yr
3,741
9,620
5,879
7,424
12,563
5,139
Secondary air impacts, tpy







Particulate matter
0.0276
0.0710
0.0434
0.0548
0.0927
0.0379

PM2.5
0.00925
0.0238
0.0145
0.0184
0.0311
0.0127

Carbon monoxide
0.0465
0.120
0.0731
0.0923
0.156
0.0639

Nitrogen oxides
0.370
0.951
0.581
0.734
1.242
0.508

Sulfur dioxide
1.08
2.77
1.69
2.14
3.62
1.48
Solid waste impacts, tpy
306
372
66.8
457
604
147

Table F-3. Model Impacts of Replacing Spray Dryer/ESP with New DIFF
Parameters
SCD
LCD

SD/ESP1
DIFF
Increm.2
SD/ESP1
DIFF
Increm.2
Parameters







Fan hp
125


250



Total hp for other motors
200


400



Water usage, gpd
6.25


12.5


Emissions reductions, tpy







HF
-2.36
15.1
17.5
-2.72
34.6
37.3

HCl
-2.21
1.72
3.93
-4.41
3.94
8.35

Cl2
-0.455
0.0789
0.534
-0.958
0.181
1.14

Non-Hg HAP metals
0.0855
0.0855
0.00
0.196
0.196
0.00

PM
7.78
7.78
0.00
17.8
17.8
0.00

SO2
39.6
40.2
0.606
90.7
92.1
1.39
Energy impacts, MMBtu/yr
17,369
9,620
-7,749
37,118
12,563
-24,555
Secondary air impacts, tpy







Particulate matter
0.128
0.0710
-0.0572
0.274
0.0927
-0.181

PM2.5
0.0430
0.0238
-0.0192
0.0918
0.0311
-0.0607

Carbon monoxide
0.216
0.120
-0.0964
0.462
0.156
-0.305

Nitrogen oxides
1.72
0.951
-0.766
3.67
1.242
-2.43

Sulfur dioxide
5.00
2.77
-2.23
10.7
3.62
-7.07
Solid waste impacts, tpy
365
372
7.22
591
604
12.9
Wastewater impacts, gpy
1,901
0
-1,901
4,063
0
-4,063
1 The negative emission reduction estimates for the SD/ESP are a result of the small dataset for kilns with this type of control and the lack of control efficiency information for SD/ESP.
2 A negative increase in impacts would be equivalent to a reduction in impacts.

Table F-4. Model Impacts of Replacing Existing DIFF with New, More Efficient DIFF
Parameters
SCD
LCD

Existing DIFF
New DIFF
Increm.
Existing DIFF
New DIFF
Increm.
Control efficiency







HF
98%
99.5%

98%
99.5%


HCl
82%
83.3%

82%
83.3%


Cl2
88%
89.3%

88%
89.3%


Non-Hg HAP metals
72%
94%

72%
94%


PM
72%
94%

72%
94%


SO2
48%
48.7%

48%
48.7%

Parameters







Fan hp
150
150

190
190


Total hp for other motors
30
30

30
30


Waste, lb/hr
100.1
102.1

151.6
154.9

Emissions reductions, tpy







HF
14.9
15.1
0.228
34.0
34.6
0.521

HCl
1.69
1.72
0.0259
3.88
3.94
0.0594

Cl2
0.0778
0.0789
0.00119
0.178
0.181
0.00272

Non-Hg HAP metals
0.0655
0.0855
0.0200
0.150
0.196
0.0458

PM
5.96
7.78
1.82
13.6
17.8
4.17

SO2
39.6
40.2
0.606
90.7
92.1
1.39
Energy impacts, MMBtu/yr
9,620
9,620
0
12,563
12,563
0
Secondary air impacts, tpy







Particulate matter
0.0710
0.0710
0
0.0927
0.0927
0

PM2.5
0.0238
0.0238
0
0.0311
0.0311
0

Carbon monoxide
0.120
0.120
0
0.156
0.156
0

Nitrogen oxides
0.951
0.951
0
1.242
1.242
0

Sulfur dioxide
2.77
2.77
0
3.62
3.62
0
Solid waste impacts, tpy
365
372
7.22
591
604
12.9

