Document ID: EPA-HQ-OAR-2002-0051-2015
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2009-05-06T04:00Z

Summary of Environmental and Cost Impacts of Proposed Revisions to
Portland Cement NESHAP (40 CFR Part 63, subpart LLL)

Docket Number EPA-HQ-OAR-2002-0051

April 15, 2009

Table of Contents

  TOC \o "3-3" \h \z \t "Heading 1,1,Heading 2,2"   HYPERLINK \l
"_Toc227746673" 1	Introduction	  PAGEREF _Toc227746673 \h  1  

 HYPERLINK \l "_Toc227746674" 2	Subpart LLL Impacts Estimated for 2010
Promulgation of NESHAP Review	  PAGEREF _Toc227746674 \h  1  

 HYPERLINK \l "_Toc227746675" 2.1	Affected Industry and Proposed Changes
to Subpart LLL	  PAGEREF _Toc227746675 \h  1  

 HYPERLINK \l "_Toc227746676" 2.2	Control Options	  PAGEREF
_Toc227746676 \h  2  

 HYPERLINK \l "_Toc227746677" 2.3	Air Quality Impacts	  PAGEREF
_Toc227746677 \h  5  

 HYPERLINK \l "_Toc227746678" 2.3.1	Hydrogen Chloride	  PAGEREF
_Toc227746678 \h  5  

 HYPERLINK \l "_Toc227746679" 2.3.2	Total Hydrocarbons	  PAGEREF
_Toc227746679 \h  6  

 HYPERLINK \l "_Toc227746680" 2.3.3	Mercury	  PAGEREF _Toc227746680 \h 
7  

 HYPERLINK \l "_Toc227746681" 2.3.4	Particulate Matter	  PAGEREF
_Toc227746681 \h  8  

 HYPERLINK \l "_Toc227746682" 2.3.5	Secondary Impacts	  PAGEREF
_Toc227746682 \h  9  

 HYPERLINK \l "_Toc227746683" 2.4	Water Quality Impacts	  PAGEREF
_Toc227746683 \h  10  

 HYPERLINK \l "_Toc227746684" 2.5	Solid Waste Impacts	  PAGEREF
_Toc227746684 \h  10  

 HYPERLINK \l "_Toc227746685" 2.6	Energy Impacts	  PAGEREF _Toc227746685
\h  11  

 HYPERLINK \l "_Toc227746686" 2.7	Cost Impacts	  PAGEREF _Toc227746686
\h  11  

 HYPERLINK \l "_Toc227746687" 2.7.1	Wet Alkaline Scrubber	  PAGEREF
_Toc227746687 \h  12  

 HYPERLINK \l "_Toc227746688" 2.7.2	Activated Carbon Injection	  PAGEREF
_Toc227746688 \h  13  

 HYPERLINK \l "_Toc227746689" 2.7.3	Regenerative Thermal Oxidizers	 
PAGEREF _Toc227746689 \h  13  

 HYPERLINK \l "_Toc227746690" 2.7.4	Baghouses and Membrane Bags	 
PAGEREF _Toc227746690 \h  14  

 HYPERLINK \l "_Toc227746691" 2.7.5	Cost of Control for Hydrogen
Chloride (HCl)	  PAGEREF _Toc227746691 \h  16  

 HYPERLINK \l "_Toc227746692" 2.7.6	Cost of Control for Total
Hydrocarbons (THC)	  PAGEREF _Toc227746692 \h  17  

 HYPERLINK \l "_Toc227746693" 2.7.7	Cost of Control for Mercury	 
PAGEREF _Toc227746693 \h  17  

 HYPERLINK \l "_Toc227746694" 2.7.8	Cost of Control for Particulate
Matter	  PAGEREF _Toc227746694 \h  18  

 HYPERLINK \l "_Toc227746695" 2.8	Summary of Impacts	  PAGEREF
_Toc227746695 \h  18  

 HYPERLINK \l "_Toc227746696" 3	References	  PAGEREF _Toc227746696 \h 
19  

 Exhibits

  TOC \h \z \t "Exhibit_Title,1"    HYPERLINK \l "_Toc227982105"  1
Summary of Proposed Changes to Subpart LLL and Type of Incremental
Impacts	  PAGEREF _Toc227982105 \h  2  

  HYPERLINK \l "_Toc227982106"  2	Regulated HAP and Appropriate Control
Devices	  PAGEREF _Toc227982106 \h  3  

  HYPERLINK \l "_Toc227982107"  3	Average Emissions of the MACT Floor
Kilns and Corresponding Proposed Emission Limits	  PAGEREF _Toc227982107
\h  3  

  HYPERLINK \l "_Toc227982108"  4	Estimated Number of Each Type of
Control Added and HAP Controlled	  PAGEREF _Toc227982108 \h  4  

  HYPERLINK \l "_Toc227982109"  5	Nationwide Baseline Emissions and
Emission Reductions	  PAGEREF _Toc227982109 \h  6  

  HYPERLINK \l "_Toc227982110"  6	Average SO2 Emissions (lb/ ton
clinker) by Kiln Type (Andover, 2008)	  PAGEREF _Toc227982110 \h  6  

  HYPERLINK \l "_Toc227982111"  7	Secondary Air, Water, and Solid Waste
Impact Factors	  PAGEREF _Toc227982111 \h  9  

  HYPERLINK \l "_Toc227982112"  8	Summary of Secondary Air, Water, and
Solid Waste Impacts	  PAGEREF _Toc227982112 \h  10  

  HYPERLINK \l "_Toc227982113"  9	Specific Fuel Consumption, Total Exit
Gas Flows, and Sulfur Dioxide Emissions for Various Kiln Types (from
Andover 2008b)	  PAGEREF _Toc227982113 \h  12  

  HYPERLINK \l "_Toc227982114"  10	RTO Input Parameters	  PAGEREF
_Toc227982114 \h  14  

  HYPERLINK \l "_Toc227982115"  11	Capital and Annual RTO Costs	 
PAGEREF _Toc227982115 \h  15  

  HYPERLINK \l "_Toc227982116"  12	PM Control Scenarios	  PAGEREF
_Toc227982116 \h  16  

  HYPERLINK \l "_Toc227982117"  13	Capital and Annualized Cost for
Existing and New Kilns	  PAGEREF _Toc227982117 \h  17  

  HYPERLINK \l "_Toc227982118"  14	Total Nationwide Impacts	  PAGEREF
_Toc227982118 \h  18  

 

1	Introduction

The EPA is proposing amendments to the current National Emission
Standards for Hazardous Air Pollutants (NESHAP) for the portland cement
manufacturing industry. The proposed amendments add or revise emission
limits for mercury, total hydrocarbons (THC), hydrogen chloride (HCl),
and particulate matter (PM) from existing and new kilns and kilns with
in-line raw mills located at a major or area sources. The EPA developed
these proposed amendments in response to the notice of reconsideration
published on December 20, 2006 and other requirements. 

This memorandum summarizes the environmental and cost impacts of the
proposed amendments and the methodology used to estimate the impacts.
The impacts in this memorandum are based on an estimated 163 existing
kilns and a projected number of 20 new kilns over the five year period
following promulgation of the final standard. The kilns that would be
affected by the proposed revisions do not burn hazardous waste. Kilns
that burn hazardous waste are regulated under the hazardous waste
combustor rule (see 40 CFR part 63 subpart EEE). Section II discusses
the impacts of this NESHAP review (scheduled for promulgation in 2010),
including an overview of the proposed amendments that may lead to these
impacts.

2	Subpart LLL Impacts Estimated for 2010 Promulgation of NESHAP Review

2.1	Affected Industry and Proposed Changes to Subpart LLL

The portland cement manufacturing industry is comprised of an estimated
107 plants capable of producing clinker and operating a total of
approximately 178 kilns, including kilns that burn hazardous waste (PCA,
2006). Hazardous waste burning kilns and grinding only facilities are
not affected by the proposed rule and are not part of this analysis.
Although the number of kilns fluctuates year-to-year due to closings of
older, inefficient kilns and new or reconstructed kiln startups, the
number of existing nonhazardous waste kilns used in this analysis is
163. The four types of kilns used in the U.S. are wet kilns, long dry
kilns, preheater kilns (PH) and precalciner kilns (PC). Information on
type of kiln and clinker capacity is based on 2005 data from the
Portland Cement Association (PCA 2006).

Environmental impacts were estimated for each of the existing 163 kilns
using emissions test results when available. Where emissions data were
not available, average emission factors were calculated from the
available emissions data and used to estimate kiln emissions. Impacts
are estimated for the fifth year after promulgation of the final
standard. Based on industry capacity expansion estimates (PCA, 2006), it
is projected that over this 5-year period, 20 new kilns will come on
line and clinker production capacity will increase by approximately
24,000,000 tons. For analysis purposes, new kilns are assumed to be
precalciner kilns having a clinker production capacity of 1,200,000 tons
per year. Because of their energy efficiency and higher production
capacity, all new kilns are expected to be precalciner kilns.

The impacts of concern are incremental impacts, specifically the impacts
associated with proposed changes in the NESHAP in comparison to the
current, or baseline, regulations without the proposed changes. To
estimate the impacts of the proposed amendments, current or baseline
emissions are first estimated. Baseline emissions are then compared to
projected emissions under the proposed revisions. Emission reductions
resulting from the proposed amendments are based on the addition of
control devices that are considered likely to be used to comply with the
emission limits. The proposed subpart LLL amendments are scheduled to be
promulgated in 2010. Changes in requirements being proposed as part of
the 2010 NESHAP revision that are expected to result in incremental
impacts in emissions are summarized in Exhibit 1.

Exhibit 1	Summary of Proposed Changes to Subpart LLL and Type of
Incremental Impacts

Proposed rule change	Type of Incremental Impact

Addition of a mercury limit for existing kilns of 43 lb/million (MM)
tons clinker and new kilns of 14 lb/MM tons clinker.	Costs to install
wet scrubbers or activated carbon injection system. Associated emissions
reductions are also estimated.

Addition of a THC limit for existing kilns of 7 ppmv and a THC limit for
new kilns from 6 ppmv.	Cost to install activated carbon injection
systems and, in some cases, regenerative thermal oxidizers. Emission
reductions are also estimated.

Addition of an HCl limit for existing kilns of 2 ppmv and, for new
kilns, 0.1 ppmv. Only applies to kilns located at major sources.	Cost to
install wet scrubbers. Emissions reductions are also estimated.

A reduction in the PM stack emission limit for existing kilns from 0.5
lb of PM/ton of clinker (0.3 lb/ton of feed) to 0.085 lb of PM/ton of
clinker. For new kilns, a reduction to 0.080 lb/ton of clinker.	Costs to
replace standard fabric bags with more expensive membrane bags and, in
some cases, replace ESP with baghouses. Emission reductions are also
estimated.

Addition of mercury CEMS on all existing and new kilns.	Capital costs of
installation and annual costs of operation.

Addition of THC CEMS to all existing kilns. Already required on new
kilns.	Capital costs of installation and annual costs of operation.

Addition of HCl CEMS to all existing and new kilns, unless controlled by
a wet scrubber.	Capital costs of installation and annual costs of
operation.

Addition of bag leak detectors on all existing baghouses. Already
required on new kilns.	Capital costs of installation and annual costs of
operation.

2.2	Control Options

The proposed amendments regulate emissions of the following HAP:

Mercury,

THC, a surrogate for non dioxin/furan organic HAP,

HCl, and

PM, a surrogate for nonvolatile metal HAP.

Add-on control devices considered in this analysis and their removal
efficiencies for each HAP are summarized in Exhibit 2.

Exhibit 2	Regulated HAP and Appropriate Control Devices

HAP	Control Device	Removal Efficiency

Mercury	Wet scrubber

ACI w/ polishing baghouse	80%

90%

THC	ACI w/ polishing baghouse

RTO (preceded by wet scrubber)	75-80%

98%

HCl	Wet scrubber	95-99.9%

PM 	Baghouse	>99.9%

ACI	activated carbon injection

RTO	regenerative thermal oxidizer

As can be seen from Exhibit 2, a control device may remove more than a
single HAP. For example, activated carbon injection systems will remove
mercury as well as THC. For purposes of this analysis it is assumed that
an activated carbon injection (ACI) system would include a polishing
baghouse. Most cement kiln dust (CKD) is recycled back to the kiln. As a
result, ACI systems cannot be installed upstream of the main PM control
device because the additional carbon that would end up in the CKD would
make the CKD unsuitable for recycling back to the kiln. As a result, any
ACI systems would need to be installed after the main PM control device
and would utilize a polishing baghouse to capture the spent carbon. An
ACI polishing baghouse will also result in increased reductions in PM
emissions.

It is expected that several sources will install wet scrubbers to reduce
emissions of HCl. Scrubbers will also remove oxidized species of mercury
as well as reduce emissions of SO2.

In a few instances, it may be necessary to install a regenerative
thermal oxidizer (RTO) for the control of THC. To avoid fouling,
plugging and corrosion of the RTO, it is assumed that an RTO would be
preceded by a wet scrubber, which is the case at the two cement plants
that currently use RTO’s. Currently, only one of the plants
continuously operates the RTO and scrubber. The two RTO’s that have
been installed on cement kilns in the U.S. have both used wet scrubbers
upstream and are considered necessary to prevent operational problems
with the RTO. Installing an RTO (with its upstream wet scrubber) for THC
control will also reduce emissions of HCl, mercury and SO2.

To determine the type of control device needed to comply with the
proposed standards, baseline emissions for each kiln were compared to
the average emissions of the top performing kilns used to develop the
MACT floor limit and the percent reduction that would be needed to reach
the average emission level was calculated. Being able to reduce
emissions to the average emission level rather than the proposed
emission limit will guarantee that the kiln can comply with the proposed
limits most or all of the time. Average emissions plus a variability
factor were used to establish the proposed MACT floor limits for each
HAP. (A detailed explanation of how the MACT floors for existing and new
sources were derived is contained in a separate document in the docket.)
The average emissions of the MACT floor kilns, i.e., the top 12 percent
of existing kilns, and the average emission of best performing kiln
(MACT for new sources) along with the corresponding proposed emission
limits are shown in Exhibit 3.

Exhibit 3	Average Emissions of the MACT Floor Kilns and Corresponding
Proposed Emission Limits

	Existing Kilns	New Kilns

HAP	Average emissions of top 12% of kilns	Proposed Limit (includes
variability factor)	Average emission of best performing kiln	Proposed
Limit (includes variability factor)

Mercury	28 lb/MM tons clinker	43 lb/MM tons clinker	12 lb/MM tons
clinker	14 lb/MM tons clinker

THC	5 ppmv	7 ppmv	4 ppmv	6 ppmv

HCl	0.3 ppmv	2 ppmv	0.02 ppmv	0.1 ppmv

PM	0.01 lb/ton clinker	0.085 lb/ton clinker	0.005 lb/ton clinker	0.080
lb/ton clinker

Because of the variety in the HAP to be controlled, it is assumed that
most kilns will require multiple controls to comply with all of the
proposed limits. The number of kilns and the types of controls assumed
in this analysis are shown in Exhibit 4. These estimates are considered
conservative and likely overstate the number and types of controls that
will be installed. Reasons for this include the inability to accurately
estimate the number of kilns that will be able to comply using work
practices such as material substitution and wasting CKD. It is believed
that many kilns may be able to reduce emissions by substituting
lower-mercury raw materials than they now use. Substitution for the
principal raw material, limestone is less likely than for the other
additives. Limestone constitutes 75 to 80 percent of the raw material
used to make clinker and most plants are located at their source of
limestone for economic reasons. Purchasing limestone from other
locations would usually be too costly due to the cost of transportation.
In addition, limestone quarries are owned by the cement plant or its
parent company and would not be available to other cement plants with
different ownership. Other non-limestone materials (e.g., clay, shale,
sand, and iron ore or slag), however, are typically purchased from
various offsite sources and transported to the plant. Plants may have
access to lower mercury materials, although the extent to which this is
feasible would have to be determined on a site-specific basis. Because
mercury is also captured in CKD that is captured in PM control devices,
the practice of wasting CKD, that is not recycling the CKD to the kiln,
can be used to reduce mercury emissions. As with raw material
substitution, the degree to which this practice can reduce mercury
emissions can only be determined using site-specific analyses. Other
site-specific factors not considered in this analysis are likely to
affect final decisions by cement plants and companies on the best
approach of complying with the limits being proposed.

In this analysis, it is assumed that emissions of mercury, THC, and HCl
will be continuously monitored using continuous emissions monitoring
systems (CEMS) and that PM will be monitored indirectly using bag leak
detector (BLD) systems to monitor baghouse performance.

Exhibit 4	Estimated Number of Each Type of Control Added and HAP
Controlled

Control Device	HAP Controlled	Total Number of Each Control 

Scrubber	Mercury

HCl	125

ACI (with polishing baghouse)	Mercury

THC

PM*	147

RTO	THC	12

Baghouse	PM	5

Membrane bags	PM	35

*Not the target of the control device, but co-controlled.

2.3	Air Quality Impacts

The impacts of the proposed standard on emissions of mercury, THC (a
surrogate for non dioxin/furan organic HAP), HCl, and PM (a surrogate
for nonvolatile metal HAP) were estimated. Impacts were estimated from a
baseline level, that is, the emission levels under the current NESHAP.
Therefore, baseline emissions were estimated. Direct impacts on the
targeted pollutants were estimated as well as co-benefits associated
with the controls added to comply with the proposed standard. Secondary
impacts were also estimated including the increase in emissions from
additional electricity or fossil fuel require to power control devices,
water quality impacts (e.g., from scrubbers), and solid waste impacts
(e.g., from disposal of spent sorbents).

2.3.1	Hydrogen Chloride

In developing the MACT floor for HCl, approximately 40 HCl emissions
measurements based on EPA Methods 321 and 26 were collected. For kilns
for which HCl emissions test data were available, annual emissions were
calculated. For kilns lacking site-specific test data, an HCl emission
factor was estimated from the available test data. Because Method 26 is
thought to be biased low due to a scrubbing effect in the front half of
the sampling train (see 63 FR 14182), the HCl data measured at 27 kilns
using Method 321 was used to calculate an emission factor for kilns for
which emissions test data were not available. Average baseline emissions
of HCl were estimated at 9.4 ppmv at 7 percent 02. Annual emissions from
a preheater or precalciner kiln were calculated as follows:

X ppmv HCl/106 volume stack gas * 54,000 dscf/ton dry feed *
lbmole/ft3/(0.73)(528) * 1.65 ton dry feed/ton clinker * tons clinker
produced/yr * 36.54 lb HCl/lbmole HCl * ton/2000 lb

For a wet kiln or long dry kiln, a gas flow rate of 66,225 per ton of
dry feed was substituted. Annual nationwide baseline HCl emissions from
all existing kilns total about 2,963 tpy.

For a new 1.2 million tpy kiln with HCl emissions at a concentration of
9.4 ppmv, baseline HCl emissions would be 48 tpy. Baseline emissions for
20 new kilns at the end of the fifth year following promulgation would
be an estimated 950 tpy.

To estimate the reduction in emissions of HCl under the proposed
standards, the number of kilns that were assumed to add controls was
estimated. Approximately 30 of the existing kilns will not be subject
to the proposed standards for HCl because they are identified in the
EPA’s National Emissions Inventory (NEI) as area sources. For these
kilns, there would be no environmental or cost impacts as a result of
the proposed standards for HCl. Based on emissions test data, it was
estimated that 115 kilns would require scrubbers to meet the proposed
HCl standards. Approximately 14 kilns have sufficiently low HCl
emissions that they were assumed to not require controls, although
because of their emissions of mercury or THC, they are assumed to add
either a wet scrubber and ACI for mercury control, or a wet scrubber and
RTO for THC control. Wet scrubbers are estimated to be capable of
reducing HCl emissions by 95 percent to 99.9 percent. Wet scrubbers were
identified as the only add-on control device available that would
significantly reduce HCl emissions. Total nationwide emission reductions
were estimated to be 2,693 tpy. For a new 1.2 million tpy kiln,
emission reductions were estimated at 45 tpy; by the end of the fifth
year, total emission reductions from new kilns would total about 900
tpy. Total nationwide baseline emissions and emission reductions for HCl
are summarized in Exhibit 5.

Exhibit 5	Nationwide Baseline Emissions and Emission Reductions

HAP	Existing or new kilns	Baseline emissions	Emission reductions

HCl	Existing 	2,963 tpy	2,693 tpy

	New (per kiln)	48 tpy	45 tpy

THC	Existing 	17,361 tpy	12,971 tpy

	New (per kiln)	56 tpy	46 tpy

Mercury	Existing 	14,834 lb/yr	13,846 lb/yr

	New (per kiln)	133 lb/yr	120 lb/yr

PM	Existing 	11,012 tpy	10,561 tpy

	New (per kiln)	204 tpy	153 tpy

As a co-benefit of controlling HCl using wet scrubbers, emission of SO2
will also be reduced. Wet scrubbers used for HCl control will also
reduce SO2 emission by 95 percent. Average uncontrolled SO2 emission
factors have been shown to vary by kiln type and are presented in
Exhibit 6. Total nationwide SO2 reductions associated with HCl control
were estimated at 106,812 tpy. For a new kiln equipped with a scrubber,
SO2 emissions reductions would be about 1,000 tpy or 20,000 tpy in the
fifth year following promulgation of the final standard.

Exhibit 6	Average SO2 Emissions (lb/ ton clinker) by Kiln Type (Andover,
2008)

Precalciner	Preheater	Dry	Wet

1.75	2.03	7.14	8.27

2.3.2	Total Hydrocarbons

Total hydrocarbons (THC) are a surrogate for organic HAP other than
dioxin/furan, which are already regulated under the NESHAP for portland
cement manufacturing. Emissions stack tests, including both manual
short-term tests and long-term continuous emissions monitoring data were
used to estimate baseline mercury emissions for each kiln with THC test
data. To estimate emissions for the remaining kilns, an average THC
emission factor was used that was calculated from available emissions
test data. For purposes of this analysis, the emission factor excludes
emissions data from a kiln already controlled using an RTO as well as
from 4 kilns with uncharacteristically high THC emissions. The emission
factor used in this analysis for kilns for which data were not available
is 21 ppmv at 7 percent O2. Annual emissions for a preheater or
precalciner kiln were calculated as follows:

X ppmv THC/106 volume stack gas * 54000 dscf/ton dry feed *
lbmole/ft3/(0.73)(528) * 1.65 ton dry feed/ton clinker * tons clinker
produced/yr * 44lb/lbmole propane * ton/2000 lb

For a wet or dry kiln, the gas flow rate per ton of dry feed used in the
calculations was 66,225 dscf in place of the 54,000 dscf. Nationwide
baseline THC emissions are estimated at 17,361 tpy. Baseline emissions
from a new 1.2 million tpy kiln were estimated to be 56 tpy or about
1,125 tpy for 20 new kilns.

Emission reductions under the proposed THC limits were estimated by
determining the number of kilns that would need to reduce emissions and
the type of control device that would be used. Baseline emissions were
compared to the proposed emission limit and kilns that needed to reduce
THC emissions by 75 to 80 percent were assumed to use ACI. If a greater
removal efficiency was required, it was assumed that an RTO preceded by
a wet scrubber would be used. A THC removal efficiency of 98 percent was
used to estimate the THC reductions with an RTO. An estimated 124 kilns
were assumed to require ACI to reduce THC emissions; 8 kilns would
require an RTO preceded by a scrubber; and 4 that are already equipped
with a wet scrubber were assumed to require just an RTO. Total
nationwide THC emission reductions would be an estimated 12,971 tpy. The
emission reduction in THC for each new kiln was estimated at 46 tpy or
918 tpy by the end of the fifth year following promulgation of the final
standard. Total nationwide baseline emissions and emission reductions of
THC as well as new kiln emission reductions are summarized in Exhibit 5.

Because some kilns were assumed to install an RTO and scrubber to reduce
THC, SO2 emissions would also be reduced. Total nationwide SO2 emission
reductions associated with THC control would be about 7,274 tpy for
existing kilns.  A new 1.2 million ton/year kiln that adds a scrubber
and RTO for THC control would reduce SO2 emissions by approximately 1000
tpy.

2.3.3	Mercury

Stack test emissions data are typically used to estimate baseline
emissions and emission reductions. However, given that mercury emissions
are largely determined by the concentration of mercury in the raw
materials and fuel and are highly variable, and that mercury is recycled
to the kiln in the raw meal (if there is an in-line raw mill) as well as
CKD captured in the particulate control devices, short-term mercury
stack test data (typically a few hours) are not necessarily indicative
of long term emissions performance. An alternative to short term stack
test data would be to use mercury continuous monitoring data over a
longer time period. However, no cement kilns have continuous mercury
monitors, so this option was not available. Because mercury is an
element, and can neither be created nor destroyed in a cement kiln, all
the mercury that enters a kiln has to leave the kiln as a stack emission
with the following exceptions: 1) mercury removed by cement kiln dust
(CKD) captured in a PM control device where the CKD is wasted (i.e., not
recycled to the kiln), and 2) mercury captured in a wet scrubber (used
to control SO2 emissions) where the mercury ends up in the gypsum
produced from the de-watered scrubber slurry. The available data
indicate that almost no mercury leaves the kiln as part of the clinker.
Based on these facts, EPA determined the most accurate method available
to determine long term mercury emission performance was to obtain data
on all the kiln mercury inputs for 30 days from a large group of kilns
and assume that all mercury that enters the kiln is emitted with the two
exceptions noted above. EPA obtained 30 days of daily data on kiln
mercury concentrations in each individual raw material, fuel, and CKD
for 89 kilns, along with annual mass inputs and CKD wastage. These data
were submitted as daily concentrations for the inputs, i.e. samples were
taken and analyzed daily for mercury content. Using the daily averages,
a mean concentration was calculated and multiplied by annual materials
use to calculate an annual mercury emission. If the facility wasted CKD,
the annual mercury that left the system in the CKD was subtracted out.
If the facility had a wet scrubber, the average mercury removal
efficiency was estimated from concurrent inlet/outlet testing done at
the five kilns with wet scrubbers. This annual emission was then divided
by total inputs to calculate an average emission factor in pounds of
mercury emitted per million tons of clinker produced (lb/MM tons
clinker). For the kilns for which feed and fuel mercury content was not
collected, a mercury emission factor was calculated using the average of
the individual emission factors for the 89 kilns for which there were
data and multiplied by each kilns clinker production to estimate annual
mercury emissions from each kiln. 

Excluding data from two kilns considered outliers, the average mercury
emissions rate is 111 lb/MM tons clinker. Total nationwide baseline
emissions from existing kilns were estimated at 14,834 lb/yr. For a new
1.2 MM ton/yr kiln, mercury emissions would be about 133 lb/yr using an
emission factor of 111 lb/MM tons clinker; for 20 new kilns over the
5-year period following promulgation of a final standard, baseline
emissions from new kilns would be 2,664 lb/yr. 

For purposes of this analysis, reductions in mercury emission under the
proposed amendments would occur in one of two ways: 1) as a direct
result of controls added to remove mercury from kiln exhaust gases, or
2) as a result of controls added to remove other HAP. Available controls
for mercury include ACI and wet scrubbers. ACI is expected to have a
higher removal efficiency for mercury than wet scrubbers. ACI is
expected to achieve a 90 percent removal efficiency while a wet scrubber
is expected to achieve a removal efficiency of 80 percent. Because ACI
is less costly and has a higher removal efficiency, it was assumed that
ACI would be selected over wet scrubbers. However, it was assumed that
most kilns would have to add wet scrubbers for HCl control as well as
ACI for THC control. As a result, most kilns will be equipped with both
ACI and wet scrubbers so that mercury removal will be higher than for
either control alone. When both ACI and wet scrubbers are used, the
removal efficiency for mercury was assumed to be 98 percent. Total
nationwide emissions reductions of mercury were estimated at 13,846
lb/yr. Emission reductions for a new 1.2 million tpy kiln that uses ACI
would reduce mercury emissions by about 120 lb/yr or 2,394 lb/yr by the
end of the fifth year following the standard’s promulgation.
Nationwide baseline emission and emission reductions as well as new kiln
emission reductions are summarized in Exhibit 5.

Emissions of SO2 would be also be reduced where wet scrubbers are
installed for the control of mercury. In this analysis, only two kilns
installed scrubbers for mercury, which was done in combination with ACI
to get a higher mercury removal efficiency. Emissions of SO2 would be
reduced by about 1,626 tpy. 

2.3.4	Particulate Matter

Total particulate matter (PM) emissions are being used as a surrogate
for nonvolatile metal HAP in the proposed amendments. Baseline emissions
were derived from PM data in EPA’s National Emissions Inventory (NEI)
for 2005. Because the PM standards in the current NESHAP and those being
proposed are for total filterable PM and the PM data in NEI are PM10
filterable data, the NEI data were converted to total PM filterable
emissions assuming that an average of 85 percent of total PM emissions
is PM10 filterable. Baseline emissions already account for the existing
PM control devices in use. Using clinker production for each kiln, a PM
emission rate in pounds of PM per ton of clinker was calculated. For the
kilns for which NEI data were not available, the average of the NEI data
was used to derive an emission factor. The average PM emissions rate
based on the NEI is 0.34 lb/ton of clinker. Total baseline emissions of
PM for existing kilns were estimated at 11,012 tpy. At 0.34 lb PM/ton of
clinker, PM emissions from a new 1.2 million tpy kiln would be 204 tpy;
emissions from 20 new kilns in the fifth year following promulgation of
the final standard would be 4,080 tpy.

For this analysis, it was assumed that the required reductions in PM
emissions would be accomplished by either replacement of existing
standard fabric bags with membrane bags or replacement of existing
ESP’s that are not meeting the target PM level with a baghouse.
Another scenario that would adequately reduce PM emissions occurs when
an ACI system (for THC or mercury control), including a polishing
baghouse, is assumed to be installed in series with an existing PM
control device. It is estimated that under these scenarios, PM removal
efficiency would be at least 99.9 percent or higher. Assuming that
emissions were reduced down to the average of the top performing kilns
(0.01 lb/ton clinker) in order to assure compliance with the proposed PM
emission limit of 0.085 lb/ton clinker, the reduction in PM emissions
from existing kilns were estimated at10,561 tpy. Assuming a reduction
down to the proposed PM limit for new kilns, 0.08 lb/ton clinker, the
reduction in PM emissions from a new kiln would be about 153 tpy.
Baseline emissions and emission reductions for existing and new kilns
are summarized in Exhibit 5.

2.3.5	Secondary Impacts

Secondary air quality impacts would result from the increased electrical
and fuel demands of control equipment required to comply with the
proposed amendments. The addition of add-on controls, such as scrubbers
and RTO’s, will increase electricity and natural gas demands. The
secondary impacts in this analysis include the impacts of additional
electricity and natural gas consumption and the pollution associated
with the generation of the electricity and the combustion of the natural
gas. Factors used to estimate secondary air and other impacts are
summarized in Exhibit 7.

Exhibit 7	Secondary Air, Water, and Solid Waste Impact Factors

Secondary Impact	Factor

Scrubber power demand (Andover 2008, p. 27)	3 kwh/ton clinker

RTO power demand (calculated using EPA Cost Manual)	30.9 kwh/DSCFM

RTO natural gas demand (calculated using EPA Cost Manual)	0.73
MMBtu/DSCFM

ACI power demand w/ polishing baghouse (Docket item II-B-67, 

Docket A-92-53)	6 kwh/ton clinker

Scrubber makeup water (Andover 2008, p. 26)	30 gal/ton clinker

Solid waste generated from ACI (Docket item II-B-67, Docket A-92-53)	3
lb/ton clinker

The following emission factors were used to estimate increased emissions
of NOx, CO, SO2, PM10, and CO2 from the increased electricity and
natural gas demand (Docket item IV-B-25, Docket A-94-52):

NOx	-	0.00446 lb/kWhr

NOx	-	0.1 lb/MMBtu natural gas

CO	-	0.00231 lb/kWhr 

SO2	-	0.00765 lb/kWhr

PM10	-	2.25(10-4) lb/kWhr

CO2	-	2.1 lb/kWhr

CO2	-	117 lb/MMBtu natural gas (EIA – Natural Gas Issues and Trends,
1998)

Increases in secondary emissions resulting from the increased electrical
demand of an alkaline scrubber and ACI, and the increased electrical and
natural gas demands of an RTO for existing and new kilns are summarized
in Exhibit 8.

Exhibit 8	Summary of Secondary Air, Water, and Solid Waste Impacts

	Scrubber electricity demand

(MMkwh/

yr)	RTO electricity demand

(MMkwh /yr)	RTO natural gas demand

(MMBtu/yr)	ACI electricity demand

(MMkwh/ yr)	Total electricity demand

(MMkwh/ yr)	NOx

(tpy)	CO

(tpy)	SO2

(tpy)	PM10 (tpy)	CO2

(tpy)	Make-up water

(MMgal/yr)	ACI solid waste (tpy)

Existing kilns	207	25	593,000	473	705	1,600	800	2,700	80	775,000	2,700
120,000

New kilns

Per kiln	3.6	3.5	81,000	7.2	14.3	36	17	55	2	9,900	36	1,800

All new kilns	72	6.9	162,000	100.8	180	409	208	687	20	198,000	720	25,200

Total 5th year impacts	279	32	755,000	574	885	2,010	1,010	3,390	100
973,000	3,420	145,000

The natural gas requirement for an RTO on a 1.2 million tpy kiln would
be about 81 million cubic feet, or about 81,000 MMBtu/yr (see input
parameters for RTO in cost section). The burning of natural gas will
result in an increase in NOx emissions at a rate of about 0.1 lb/MMBtu,
or an increase in NOx emissions of 4 tons/yr. Estimates of increased
electrical demand and resulting pollutant emissions for a new kiln are
also presented in Exhibit 8.

2.4	Water Quality Impacts

The use of alkaline scrubbers will result in increased consumption of
water (for makeup water and production of the scrubber slurry).
Additional makeup water demands for scrubbers are estimated to be 30
gal/ton of clinker (Andover 2008). Total additional makeup water for
existing kilns would be an estimated 2.7 billion gal/yr. For a new 1.2
million tpy kiln, the additional water requirement is estimated at
36,000,000 gallons per year. Total additional water consumption in the
fifth year following promulgation of the standard for existing and new
kilns would be 3.4 billion gal/yr. No water quality impacts are
associated with the use of baghouse, RTO or ACI systems. 

2.5	Solid Waste Impacts

Additional solids would be generated as a result of the addition of
scrubbers. However, the waste from the scrubber contains synthetic
gypsum and is typically dewatered and returned to the process where it
is mixed with clinker in the finish mill. The result is that the waste
is not disposed of in a landfill. 

Solids will be generated as a result of installation of ACI systems. An
estimated 6 lb solid waste per ton of clinker would be generated (Docket
item II-B-67, Docket A-92-53). The amount generated by a new 1.2 million
tpy kiln was estimated to be 1,800 tpy. In the fifth year following
promulgation of the standard, total solid waste from existing and new
kilns will be about 145,600 tpy. 

The additional solid waste generated from baghouses, in the form of CKD
is typically considered product and is returned to the kiln or mixed
with the cement. No solid waste impacts are anticipated with the use of
an RTO system.

2.6	Energy Impacts 

Additional electricity demand would result from the addition of
scrubbers, RTO and ACI on existing and new kilns. A summary of the total
additional energy demand for existing and new kilns is presented in
Exhibit 8. In the fifth year following promulgation of the standard,
total electricity demand would be an estimated 885 million kwh/yr;
natural gas demand will be about 755,000 MMBtu/yr. 

2.7	Cost Impacts

The costs of the proposed amendments were estimated based on the type of
control device that was assumed to be necessary to comply with the
proposed emission standards. The approach used to determine the type of
control needed was described earlier. In summary, based on a kiln’s
baseline emissions of mercury, THC, HCl and PM, and the removal
efficiency necessary to comply with the proposed emission limit for each
HAP, an appropriate control device was identified. In assigning control
devices to kilns where more than one control device was considered
appropriate, it was assumed that the least costly control would be
installed. For example, if a kiln could use a scrubber or ACI to meet
the proposed mercury limit, it was assumed that ACI would be selected
over a scrubber because an ACI system would be less costly to install
and operate. ACI also is expected to achieve a higher removal efficiency
than a scrubber for mercury. In some instances, a more expensive
technology was considered appropriate because the selected control
reduced emissions of multiple pollutants. For example, even though ACI
would be less costly than a scrubber for controlling mercury, if the
kiln also needed to reduce HCl emissions, it was assumed that a scrubber
would be applied to control HCl as well as mercury because ACI would not
control HCl. However, for many kilns, this analysis assumes that
multiple controls will be needed in order to adequately control all HAP.
For example, ACI would be necessary to meet the limits for THC and/or
mercury. For the same kiln, a scrubber would also be required to reduce
HCl emissions. This approach and the resulting cost estimates are
considered very conservative in that it is not possible to consider what
other alternatives, in lieu of multiple add-on controls, may be
available to cement plants to comply with the proposed emission limits.
Because individual cement manufacturing plants may implement process or
other changes to reduce emissions, the costs of the proposed amendments
likely overstate the costs that actually will be incurred by individual
cement plants. For example, some plants may be able to reduce mercury
emissions by substituting raw materials having lower mercury
concentrations or by increasing the amount of cement kiln dust (CKD)
wasted instead of recycled (mercury can accumulate in CKD) thereby
avoiding the need for add-on controls for mercury. The feasibility of
using these and other work practices at cement plants would have to be
determined on a site-specific basis and cannot be assumed to be
applicable at all cement plants. In addition to the costs associated
with add-on controls, the proposed standard also requires continuous
monitoring to ensure compliance with the limits or, in the case of bag
leak detection systems for baghouses, to ensure the proper performance
of control devices. For this analysis, it was assumed that the cost of
continuous monitoring for mercury, THC, HCl and PM would be incurred for
each kiln. The only exception  to this was where permit or other
information was available showing that a THC CEM was already installed
on a kiln. The total cost of compliance for each kiln includes the cost
of monitoring.

2.7.1	Wet Alkaline Scrubber

Cost estimates for wet alkaline scrubbers were based on recent work by
Andover (2008a). The report describes the development of scrubber costs
that are primarily a function of the type of kiln (wet, dry, preheater,
precalciner) and the kiln’s capacity. Site-specific information was
available on the type of kiln and its clinker production capacity for
all kilns in the U.S.; consequently, the cost algorithms could be used
to develop site-specific estimates of scrubber costs.

An important component of the procedure is to estimate the volumetric
flowrate of the scrubber for each kiln based on its type and capacity.
For wet kilns, the volumetric flowrate in dry standard cubic feet per
minute (DSCFM) is estimated from:

where:

TYP	=	tons per year of clinker capacity,

SFC	=	specific fuel consumption in MM Btu/ton from Exhibit 9, and

W	=	water quantity, 4.14 lb moles/MM Btu for coal combustion.

For dry kilns, the DSCFM is estimated from:

where:

EGFW	=	Exit gas flowrate SCH/ton from Exhibit 9.

Exhibit 9	Specific Fuel Consumption, Total Exit Gas Flows, and Sulfur
Dioxide Emissions for Various Kiln Types (from Andover 2008b)

Kiln type	Specific Fuel Consumption (SFC)	Exit gas flowrate (EGFW) in
SCF/ton	lb SO2/ton of clinker

	MM Btu/ton

	Low	High	Average

wet 	4.679	5.939	5.309	108,990	8.27

long dry 	3.959	4.679	4.319	57,701	7.14

preheater 	2.699	3.239	2.969	48,084	2.03

precalciner 	2.591	3.059	2.825	44,878	1.75

After determining the volumetric flowrate for each kiln, the capital
cost (CC in 2005 dollars) for each kiln is calculated from (Andover,
2008a):

Fixed costs (FC) include labor (operating, supervisory, and
maintenance), maintenance materials, replacement parts, taxes,
insurance, etc. and were estimated from (Andover, 2008a):

Variable costs (VC) include consumption of limestone, power, and water
plus a credit for recovery of gypsum and were estimated from (Andover,
2008a):

Where:

COSTKWH	=	$0.07424/kWhr, and

SO2	=	lb SO2 per ton of clinker from Exhibit 9.

Total annualized cost (TAC) includes fixed annual costs, variable annual
costs, and capital recovery (based on a 7 percent interest rate, 20-year
lifetime, and a capital recovery factor of 0.0944). TAC is estimated
from:

2.7.2	Activated Carbon Injection

The control costs of using ACI system and polishing baghouse to control
mercury emissions and THC emissions from cement kilns were estimated
using costs that were originally developed for electric utility boilers.
Using exhaust gas flow rates as the common factor, control costs for
electric utilities were scaled to derive control costs for portland
cement kilns. Two electric utility boiler units of different capacities
and exhaust gas airflows that were comparable to exhaust gas flow rates
for cement kilns were used. Capital and annual cost factors ($/ton of
clinker) were developed using the boiler costs and gas flow data for the
different size boilers. The capital cost factors ranged from $1.81 to
$3.00/ton of clinker; the average is $2.41/ton of clinker. The total
annualized costs ranged from $0.96 to $1.13/ton of clinker; the average
is $1.41/ton of clinker. The method used to calculate the total capital
and total annualized costs are described previously (Docket item
OAR-2002-0051-1891).

2.7.3	Regenerative Thermal Oxidizers

Costs for an RTO are based on costs of an RTO installed and currently
operating on an existing kiln and the EPA Air Pollution Control Cost
Manual. To estimate capital cost for existing kilns and model new kilns,
the total capital cost of the operating RTO was scaled based on exhaust
gas flow rates for each existing kiln and the model new kiln. Input
parameters and annual cost inputs used in estimating costs are shown in
Exhibit 10. The capital and annual cost for this kiln are shown in
Exhibit 11. 

Allowing for economies of scale in capital cost, total capital costs
(TCI) were calculated as using the following cost function:

Annual costs were calculated as a function of fixed and variable costs
as follows:

2.7.4	Baghouses and Membrane Bags

The costs of a reverse air baghouses and standard fabric bags were
calculated for a kiln with a kiln exhaust gas flow rate of 185,550 DSCFM
using the EPA Air Pollution Control Cost Manual. The total costs for a
baghouse using standard fabric bags on a kiln with an exhaust gas flow
rate was estimated to be $5.7 million capital cost and $2 million
annual cost. To scale these costs for kilns with different exhaust gas
flow rates, the following cost functions were used to estimate total
capital costs (TCIstd) and total annual cost (TACstd) for a baghouse
with standard fabric bags:

Exhibit 10	RTO Input Parameters

Input Parameters

Gas flow rate (scfm)	502,312

Reference temperature (°F)	77

Inlet gas temperature (°F)	150

Inlet gas density (lb/scf)	0.0739

Primary heat recovery (fraction)	0.95

Waste gas heat content (Btu/scf)	517.00

Waste gas heat content (Btu/lb)	6995.83

Gas heat capacity (Btu/lb-°F)	0.255

Combustion temperature (°F)	1500

Heat loss (fraction)	0.01

Exit temperature (°F)	218

Fuel heat of combustion (Btu/lb)	21,502

Fuel density (lb/ft3)	0.0408

Design Parameters

Auxiliary fuel requirement (lb/min)	31.323

Auxiliary fuel requirement (scfm)	767.7

Total gas flow rate (scfm)	503,080

Annual Cost Inputs

Operating factor (hr/yr)	7,920

Operating labor rate ($/hr)	12.96

Maintenance labor rate ($/hr)	14.26

Operating labor factor (hr/sh)	0.50

Maintenance labor factor (hr/wk)	1.00

Electricity price ($/kWh)	0.050

Natural gas price ($/1000scf)	9.30

Annual interest rate (fraction)	0.07

Control system life (years)	15

Capital recovery factor	0.1098

Taxes, insurance, admin. factor	0.04

Pressure drop (in. w.c.)	20.0

The costs of reverse air baghouses and membrane bags were also
estimated. Membrane bags are more costly than standard fabric bags. For
a baghouse with membrane bags, the total capital cost was estimated to
be $7.1 million; the total annual cost was estimated to be $2.3 million.
To scale these costs for kilns with different exhaust gas flow rates,
the following cost functions were used to estimate total capital costs
(TCImb) and total annual cost (TACmb) for a baghouse with membrane
fabric bags:

Exhibit 11	Capital and Annual RTO Costs

Capital Costs ($)

DIRECT COSTS

		Purchased equipment cost (PEC)	16,000,000

	Direct installation costs

			Foundation and support (8% of PEC)	1,280,000

		Enclosure building	0

		Site preparation (15% of PEC)	2,400,000

	Total direct installation (DIC)	3,680,000

	TOTAL DIRECT COST (DC)	19,680,000

INDIRECT COSTS

		Installation

			Engineering (10% of PEC)	1,600,000

		Construction & field expense (5% of PEC)	800,000

		Contractor fee (10% of PEC)	1,600,000

		Contingencies (10% of PEC)	1,600,000

	TOTAL INDIRECT COST (IC)	5,600,000

TOTAL CAPITAL INVESTMENT (TCI = DC + IC)	25,280,000

Annual Costs ($/yr)

Operating labor	6,415

Supervisory labor	962

Maintenance labor	742

Maintenance materials	742

Natural gas	3,392,816

Electricity	776,956

Overhead (0.6 of labor and maintenance materials)	5,316

Taxes, insurance, administrative	1,011,200

Capital recovery	2,775,608

	TOTAL ANNUAL COST	7,970,758

For purposes of this analysis, if an existing baghouse needed to
increase efficiency to comply with the proposed PM emission limit, it
was assumed that standard fabric bags would be replaced with membrane
bags. The incremental costs between a baghouse with standard bags and a
baghouse with membrane bags was use to estimate the additional cost of
replacing standard bags with membrane bags. Where it was considered
necessary to replace an existing ESP with a baghouse, it was assumed
that the cost would be that of a baghouse with membrane bags. If the
existing PM control was a fabric filter and an ACI is assumed be added
for other HAP, then the kiln would be equipped with two baghouses in
series and no additional PM control was assumed to be necessary. If the
existing PM control was an ESP and the plant would add ACI, it was
assumed that the polishing baghouse would be equipped with membrane
bags. If the existing PM control was an ESP and no controls would be
added that would also control PM (e.g., ACI), then it was assumed that
the ESP would be replaced with a baghouse equipped with membrane bags.
Where baseline emissions of a kiln were below the average PM emission
level of the top 5 baghouses (see Exhibit 3), no additional control was
considered necessary. The various baseline and potential control
scenarios are summarized in Exhibit 12. 

Exhibit 12	PM Control Scenarios

Baseline PM Controla	ACI System Added for Mercury or THCb	Additional
Control Needed for PM

Baghouse	Yes	None

Baghouse	No	Membrane bags added to existing baghouse

ESP	Yes	Membrane bags installed in polishing baghouse

ESP	No	ESP replaced with baghouse with membrane bags

Baseline is at or below 0.01 lb/ton clinker (average of  top 5 kilns)
Yes or No	None

a	If information was not available on the type of PM control in use for
a kiln, the PM control was assumed to be a baghouse.

b	It is assumed that a polishing baghouse is an integral part of an ACI
system.

Monitoring costs were based on the use of bag leak detectors to monitor
baghouse performance. Costs were estimated using the CEMS Cost Model,
assuming that each baghouse has 5 compartments and there is a separate
sensor in each compartment. It was assumed that the same bag leak
detector could be used for the clinker cooler baghouse as for the kiln
baghouse, so the costs were estimated using 10 sensors. The
capital/startup cost for bag leak detector CEMS is $93,719. Annual
operations and maintenance costs for bag leak detector CEMS are $34,748.
All costs are derived from the CEMS Cost Model and include a capital
recovery factor of 0.1424 (equipment life of 10 years and a yearly
interest rate of 7%).

2.7.5	Cost of Control for Hydrogen Chloride (HCl)

The cost of complying with the proposed HCl emission standards were
estimated as the costs of installing and operating add-on control
equipment and the cost of installing and operating continuous emission
monitoring equipment. Only kilns that are major sources would be
required to comply with the proposed standard for HCl. An estimated 133
kilns were estimated to be major sources based on data from EPA’s NEI
and would be subject to the HCl standards. It was assumed that wet
scrubbers would be installed to control HCl emissions. Kilns identified
as area sources from EPA’s NEI and kilns that, based on test data,
will comply with the proposed limit without further control, were
assumed to not add a scrubber for HCl. Total capital and annual costs
for major sources include the cost of HCl CEMS at $144,000 first time or
capital cost and about $43,000 per year annual cost. The annual cost for
scrubbers also includes a credit of $45 per ton for the scrubber sludge
that would be recovered as gypsum and used in the process. Total
nationwide capital cost for existing kilns was estimated at
approximately $692 million with annual cost for existing kilns of $109
million per year. 

Costs for new kilns are based on a model preheater/precalciner kiln with
a clinker capacity of 1.2 million tpy. Total capital cost, including the
cost of CEM, is $9.8 million per kiln. Annualized cost including the
gypsum credit and monitoring is $1.8 per year per kiln. Capital and
annualized costs for existing and new kilns are presented in Exhibit 13.

Exhibit 13	Capital and Annualized Cost for Existing and New Kilns

HAP	Existing or new kilns	Capital Cost	Annualized Cost

HCl	Existing 	$692 million	$109 million/yr

	New (per kiln)	$9.8 million	$1.8 million/yr

THC	Existing 	$322 million	$103 million/yr

	New (per kiln)	$3.8 million 	$1.3 million/yr

Mercury	Existing 	$71.8 million	$27.7 million/yr

	New (per kiln)	$2.9 million	$1.25 million/yr

PM	Existing 	$54 million	$17 million/yr

	New (per kiln)	$1.1 million	$270,000/yr

2.7.6	Cost of Control for Total Hydrocarbons (THC)

Under the proposed amendments, an estimated 124 existing kilns would
install ACI systems to comply with the proposed limits for THC. Another
12 kilns are expected to install RTO systems preceded by a wet scrubber
and an estimated that 27 kilns would meet the THC limits without any
additional controls. All kilns would be required to continuously monitor
THC emissions. The capital cost for THC CEMS was estimated at $137,000;
annualized cost is an estimated $42,000. Where data were available on
kilns that were already equipped with CEMS for THC, additional
monitoring costs would not be incurred for those kilns. Total nationwide
capital cost for controls and monitoring for existing kilns was
estimated at $322 million with annualized costs of $103 million per
year.

Of the estimated 20 new kilns expected to come on line, it is estimated
that 14 will comply by installing an ACI systems to comply with the
proposed limits; 2 will install and RTO and wet scrubber, and 4 will
need no additional controls. The capital and annualized costs of ACI for
a new 1.2 million tpy kiln would be $2.9 million and 1.25 million/yr,
respectively. Capital and annualized cost for an RTO with scrubber would
be $18 million and $3.8 million/yr, respectively. The average capital
cost for 20 kilns is estimated at 3.8 million per kiln with an
annualized cost of $1.25 million per year per kiln. Capital and
annualized cost for existing and new kilns are presented in Exhibit 13.

2.7.7	Cost of Control for Mercury

The cost for complying with the proposed mercury standards were
estimated as the cost of installing and operating add-on control
equipment and the cost of installing and operating CEM for mercury.
Because of controls that were assumed to be installed for the control of
HCl (wet scrubbers) and THC (ACI and RTO with wet scrubbers), an
estimated 22 kilns would need additional control for mercury. It was
estimated that 20 kilns would install ACI and that 2 kilns, because of
higher than average mercury emissions, would install both ACI and wet
scrubbers. Total nationwide capital cost for these 22 kilns was
estimated at $72 million; total nationwide annualized cost was estimated
at $28 million per year.

Assuming that a new kiln would install ACI for mercury control, a new
1.2 million tpy kiln would incur a capital cost of $2.9 million and an
annualized cost of $1.25 million per year. Capital and annualized costs
for existing and new kilns are presented in Exhibit 13.

2.7.8	Cost of Control for Particulate Matter

It was estimated that existing ESP’s on 5 kilns would be replaced with
baghouses to comply with the proposed PM emission standards. Existing
baghouses on another 35 kilns would be retrofitted to replace standard
fabric filters with membrane bags. Total nationwide capital cost was
estimated at $54 million with annualized cost of $17 million per year.
These costs include the addition of bag leak detection systems.

Additional costs for new kilns would be incurred under the proposed
amendments assuming that membrane bags rather than standard fabric bags
would be installed in a new baghouse. For a 1.2 million tpy kiln,
capital cost would be an estimated $1.1 million; annualized cost would
be $270,000 per year. Capital and annualized costs for existing and new
kilns are presented in Exhibit 13.

2.8	Summary of Impacts

Nationwide impacts in the 5th year following promulgation are summarized
in Exhibit 14. In estimating total impacts for new kilns, the following
assumptions were used: 14 kilns would have to install ACI with polishing
baghouses and 2 kilns would install RTO with a wet scrubber to control
THC emissions; 4 kilns would not have to reduce their THC emissions; and
20 kilns would have to install wet scrubbers to reduce HCl emissions.
Because 14 kilns installed ACI (with polishing baghouses) after PM
controls, only 6 new kilns would need to install membrane bags for PM
control. Because the 20 new kilns are controlled by ACI and/or wet
scrubbers, no additional controls are necessary for mercury.

Exhibit 14	Total Nationwide Impacts

HAP	Capital Cost	Annualized Cost	Emissions Reduction

Existing Kilns

Mercury	$70 million	$27 million/yr	13,846 lb/yr mercury

1,600 tpy SO2

THC	$322 million	$103 million/yr	13,000 tpy THC

7,300 typ SO2

HCl	$692 million	$109 million/yr	2,700 tpy HCl

107,000 tpy SO2

PM	$54 million	$17 million/yr	10,600 tpy

Total Existing	$1.14 billion	$256 million/yr	HAP 5,900 tpy*

All 142,000 tpy

New Kilns

Total New	$259.6 million	$92.4 million	2, 400 lb/yr Hg

920 tpy THC

900 tpy HCl

3,080 tpy PM

20,000 tpy SO2

HAP 1,200 tpy*

All 25,000 tpy

Total, 5th Year After Promulgation	$1. 4 billion	$348.4 million/yr	HAP
7,100 tpy

All 167,000 tpy

*Assumed that organic HAP is 24% of THC and metal HAP is 1% of PM.

3	References

Andover, 2008a. Memorandum. J. Staudt, Andover Technology Partners,
Costs and Performance of Controls, prepared for EPA, September 23, 2008.

Andover, 2008b. Memorandum. J. Staudt, Andover Technology Partners, NOx,
SO2 and CO2 emissions from cement kilns (Emissions Memo), prepared for
EPA, September 23, 2008.

CEMS Cost Model. July 2006.

Heath, E. 1996. Summary of Inputs of Control Options on Model Kilns and
Clinker Cooler. Docket Item II-B-67, Docket A-92-53. April 19, 1996. 

Laney, M., D. Green and K Barnett 2006. Summary of Environmental and
Cost Impacts of Final Amendments to Portland Cement NESHAP, December 8,
2006, Docket item EPA-HQ-OAR-2002-0051-1891.

Portland Cement Association. 2006. Capacity Expansion Estimates. October
13, 2006.

Portland Cement Association. 2007. U.S. and Canadian Portland Cement
Industry Plant Information Summary December 31, 2006.

US EPA. EPA Air Pollution Cost Control Manual: Sixth Edition: Section 6:
Particulate Matter Controls: Chapter 1: Baghouses and Filters. Document
Number EPA/452/B-02-001. December 1998.

U. S. Environmental Protection Agency 2002. Office of Air Quality
Planning and Standards. EPA Air Pollution Control Cost Manual, Sixth
Edition, EPA/452/B-02-001. January 2002.

Summary of Environmental and Cost Impacts of Proposed Revisions to
Portland Cement NESHAP

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