Document ID: EPA-HQ-OAR-2002-0051-1891
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2006-12-20T05:00Z

MEMORANDUM

SUBJECT:	Summary of Environmental and Cost Impacts of Final Amendments
to Portland Cement NESHAP 

FROM:	Mike Laney, RTI

	David Green, RTI

	Keith Barnett, EPA

TO:	Docket Number OAR-2002-0051

DATE:	December 8, 2006

Affected Industry

The portland cement manufacturing industry is comprised of an estimated
94 cement plants operating a total of 158 non-hazardous waste burning
kilns. Based on industry projections (PCA 2006), it is estimated that by
the fifth year following promulgation of the amendments (i.e., 2006 –
2010), 20 new kilns will come on line and clinker production capacity
will increase by approximately 21,000,000 tons. 

To illustrate impacts of the final amendments, impacts are calculated
for a preheater/precalciner kiln having a clinker production capacity of
650,000 tons per year. Impacts are also estimated for the 5 year period
following promulgation using information from the Portland Cement
Association (PCA) on estimated clinker capacity expansions from 2006 to
2010 (PCA, 2006). It is estimated that the clinker production capacity
will increase by 21,000,000 tons and 20 new kilns will begin operation,
or an average of 1,050,000 tons of clinker production per kiln, over the
5-year period following promulgation of the final amendments. To comply
with the final amendments for mercury, it is assumed that five new kilns
will install alkaline scrubbers. To comply with the limits for total
hydrocarbons (THC), it is estimated that five new kilns will install
add-on controls: three  will add on activated carbon injection (ACI)
systems and two will install a scrubber and a regenerative thermal
oxidizer (RTO) system.

For mercury control, activated carbon injection (ACI) was also
considered as a beyond-the-floor option for existing kilns. A
beyond-the-floor option for mercury reductions from new kilns consisting
of a wet scrubber and ACI was evaluated.

Air Quality Impacts

Mercury

To meet the limit for mercury emissions from new kilns, some
owner/operators will install wet alkaline scrubbers. Mercury emissions
will also be reduced as a co-benefit from new kilns that, in order to
comply with the limits for total hydrocarbons (THC), will install either
a scrubber and regenerative thermal oxidizer (RTO) system or an
activated carbon injection (ACI) system.

Reductions in mercury emissions were calculated for a model kiln
producing 650,000 tons of clinker/yr controlled by a wet alkaline
scrubber. Uncontrolled emissions were assumed to range from 41 µg/dscm
to 100 µg/dscm, equivalent to approximately 150 to 350 lb/yr.
Reductions in mercury emissions using wet scrubbers have been reported
to range from 30 to 90 percent depending on type of fuel burned
(EPA1998). For all coal types, a mercury removal efficiency of 42
percent from electric utility boiler flue gases is assumed for an
alkaline scrubber installed after a particulate matter control device
(Cole, 2006). Using mercury emissions ranging from 150 to 350 lb/yr,
emission reductions from a new scrubber-equipped 650,000 ton/yr kiln
will range from 63 to 147 lb/yr. Kilns controlled by a scrubber/RTO
system for THC control would get the same mercury emission reduction as
kilns controlled by scrubbers only.

Kilns that add an ACI system for control of THC emissions would also get
a reduction in mercury emissions. ACI systems will reduce mercury
emissions by an estimated 80 percent. For a 650,000 ton/yr kiln, mercury
emissions would be reduced by 120 to 280 lb/yr.

For the 5-year period following promulgation, it is estimated that five
new kilns will install scrubbers to control mercury emissions. To meet
the THC limits, an estimated two kilns will install scrubber/RTO systems
and three kilns will install ACI sytems. Total nationwide reductions in
mercury emissions in the fifth year after promulgation of the amendments
that results from the equipping five new kilns with scrubbers, two with
scrubber/RTO systems and three with ACI systems estimated to be 1,294 to
3,019 pounds (0.65 to 1.51 tons).

A beyond-the-floor option evaluated for new kilns considered the
addition of an ACI system in combination with an alkaline scrubber. ACI
systems added after a scrubber would further reduce mercury emissions by
an estimated 80 percent in addition to the 42 percent reduction with a
scrubber. Mercury emission reductions under this option were estimated
using baseline emissions of 11 to 100 µg/dscm, equivalent to mercury
emissions of approximately 40 to 350 lb/yr. For a new 650,000 ton/yr
kiln, total mercury emissions under this beyond-the-floor option would
be reduced by an estimated 30 to 265 lb/yr.

HCl Emissions

Alkaline scrubbers added to kilns to reduce mercury emissions and THC
emissions will also reduce emissions of HCl from kiln exhaust gases.
Emission reductions of HCl were calculated from a baseline of 54 ppmv
HCl for a kiln uncontrolled for HCl, i.e., without a wet scrubber and
assuming emissions of 15 ppmv for a kiln controlled for HCl (II-B-67,
Docket No. A-92-53).  For a new preheater/precalciner kiln operating at
650,000 tons of clinker per year, the reduction in HCl emissions is
estimated at 107 tons/yr (II-B-67, Docket No. A-92-53). 

Total nationwide reduction in HCl emission as a result of the addition
of five scrubbers added to kilns for mercury control and two
scrubber/RTO systems for THC control will be an estimated 1,209 tons in
the fifth year following promulgation of the amendments.

Sulfur Dioxide (SO2) and Particulate Matter (PM) Emissions

Alkaline scrubbers added for mercury and THC control will also reduce
emissions of SO2. Calculations of reductions in SO2 emissions are based
on emissions of 0.8 lb SO2/ton of feed with 75 percent removal (II-A-4
and II-B-67, Docket A-92-53). The reduction in SO2 from a new kiln
operating at 650,000 tons of clinker per year is estimated at
approximately 322 tons/yr (II-B-67, Docket A-92-53). 

Assuming an average new kiln production of 1,050,000 (21,000,000/20)
tons of clinker/yr, new kilns equipped with scrubbers (five for mercury
control and two for THC control) will result in total nationwide
reductions in SO2 emissions of approximately 3,638 tons in the fifth
year following promulgation. 

Note that we have determined that reducing SO2 emissions also results in
a reduction in fine particle emissions because some SO2 is converted to
sulfates in the atmosphere. Therefore, the use of alkaline scrubbers
will reduce fine PM emissions in addition to SO2.

Dioxin/Furans (D/F)

Emissions of D/F will be reduced with the installation of alkaline
scrubbers. It is assumed that any vapor phase D/F emissions in the kiln
exhaust stream will be controlled by the scrubber. The reduction in D/F
emissions was determined to be the difference between emissions before
and after the application of the packed bed scrubber. The emissions data
available at the original proposal show that most of the kilns could
comply with the 0.2 TEQ ng/dscm limit. An alternate standard of 0.4 TEQ
ng/dscm with a temperature limit at the inlet to the PMCD was also
established.  It was assumed that those kilns with emissions above the
0.4 TEQ ng/dscm would find a way to meet the 0.4 limit. Thus, the
average of these data is 0.12 TEQ ng/dscm. It is conservatively
estimated that the scrubber would achieve a 50 percent reduction in D/F
emissions, or a reduction of 0.06 TEQ ng/dscm. For a new kiln operating
at 650,000 tons of clinker/yr, the reduction in D/F emissions in
grams/yr (g/yr) will be 0.097 g/yr.

New kilns equipped with a scrubber/RTO system are expected to reduce D/F
emissions by 95 percent as a result the RTO. Annual reduction in D/F
emissions from a new 650,000 ton/yr kiln equipped with a scrubber/RTO
are estimated to be 0.19 g/yr.

 

ACI systems installed on kilns for THC control would also reduce D/F
emissions by an estimated 50 percent. For a new 650,000 ton/yr kiln, D/F
emissions would be reduced by an estimated 0.097 g/yr. 

Nationwide reductions in D/F emissions will be an estimated 0.79 g for
scrubber-only equipped kilns, 0.61 g for scrubber/RTO-equipped kilns,
and 0.71 g for ACI-equipped kilns, or a total nationwide reduction in
emissions of 2.1 g in the fifth year following promulgation of the
amendments. 

The use of a scrubber and ACI systems were evaluated as a
beyond-the-floor option for new kilns. Assuming that scrubbers and ACI
systems will each achieve a 50 percent reduction in D/F emissions, a new
650,000 ton/yr kiln would reduce D/F emissions by 0.15 g/yr

 Total Hydrocarbons (THC)

New kilns equipped with an RTO will have a reduction in emissions of
THC, including organic HAPs. Organic HAPs are an estimated 5 percent of
total THC (II-B-67, Docket A-92-53). Using a removal efficiency of 95
percent for an RTO and a THC inlet concentration of 62.5 ppmv, the
emission reduction for a new kiln equipped with a scrubber/RTO will be
196.3 tons per year. 

New kilns equipped with ACI systems will also reduce THC emissions by an
estimated 50 percent. For a new 650,000 ton/yr kiln, an ACI system will
reduce THC emissions by an estimated 103.3 tons/yr. 

To estimate nationwide emissions, it is assumed that two kilns will
install scrubber/RTO systems and three kilns will install ACI systems to
comply with the THC limits for new kilns. Nationwide emission reductions
for scrubber/RTO equipped kilns are estimated at 634 tons/yr. Nationwide
emission reductions for ACI equipped kilns are estimated at 500.6
tons/yr. Thus, total nationwide THC emission reductions in the fifth
year after promulgation will be 1,135 tons.

Secondary Impacts

Secondary air quality impacts will result from the increased electrical
and fuel demands of control equipment required to comply with the final
amendments. The addition of scrubbers, RTO’s, and ACI systems will
increase electricity demands. The additional electricity usage by an
alkaline scrubber, RTO, and ACI are as follows:

Scrubber	-	984,863 kWh/yr (Docket item II-B-67, docket A-92-53)

RTO		-	3,576,110 kWh/yr

ACI		-	3,767,000 kWh/yr (Docket item II-B-67, docket A-92-53)

The emission factors used to estimate increased emissions of NOx, CO,
SO2, and PM10 from the increased electricity demand are as follows
(IV-B-25, docket A-94-52):

NOx	-	0.00446 lb/kWhr

CO	-	0.00231 lb/kWhr 

SO2	-	0.00765 lb/kWhr

PM10	-	2.25(10-4) lb/kWhr

In addition to secondary emissions due to increased electricity demand,
the addition of an RTO will result in an increased demand for natural
gas. The gas requirement for the RTO for a 650,000 ton/yr kiln will be
83,958,000 MMcf, or about 84,000 MMBtu/yr. 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 4.2 tons/yr.

Increases in secondary emissions resulting from the increased electrical
demand of an alkaline scrubber, the increased electrical and natural gas
demands of an RTO, and the increased electrical demand of a ACI system
for a new 650,000 ton/yr kiln will be as follows:

Control	Increased Electrical Demand

(kWh/yr)	Increased Natural Gas Demand

(MMBtu/yr)	Increased Emissions (tons/yr)

	NOx	CO	SO2	PM10

Scrubber	984,863	0	2.20	1.14	3.777	0.11

RTO	3,576,110	84,000	12.17	4.13	13.68	0.40

Scrubber plus RTO	4,560,973	84,000	14.37	5.27	17.45	0.51

ACI	3,767,000	0	8.40	4.35	14.41	0.42

For the 5-year period following promulgation, the total nationwide
increase in emissions from the increased electrical and natural gas
demands of scrubbers, RTO’s, and ACI systems installed on new kilns
will be as follows:

Controls and number of systems	Increased Electrical Demand

(kWh/yr)	Increased Natural Gas Demand

(MMBtu/yr)	Increased Emissions (tons/yr)

	NOx	CO	SO2	PM10

Scrubber/RTO systems on 2 kilns	14,735,451	271,385	46.43	17.02	56.36
1.66

ACI systems on 3 kilns	18,255,462	0	40.71	21.09	69.83	2.05

Scrubbers only on 5 kilns 	7,954,663	0	17.74	9.19	30.43	0.89

Total nationwide	40,945,575	271,385	104.88	47.29	156.62	4.61

C. Water Quality Impacts

The use of alkaline scrubbers will result in increased consumption of
water (for makeup water and production of the scrubber slurry). For a
new 650,000 ton/yr kiln, the additional water requirement is estimated
at 40,556,723 gallons per year (II-B-67, Docket No. A-92-53).  Based on
the use of scrubbers on a total of seven new kilns (2 with scrubber/RTO
systems and 5 with scrubbers only) over the 5-year period following
promulgation, total water requirements at the end of the fifth year will
be approximately 458.6 million gallons. No water quality impacts are
associated with the use of RTO’s or ACI systems.

D. Solid Waste Impacts

Additional solid waste will result from the disposal of scrubber slurry.
For a new 650,000 ton/yr kiln, the additional solid waste generated as a
result of the addition of the scrubber is estimated at 45,555 tons per
year (II-B-67, Docket No. A-92-53). Solid waste is also generated from
the use of ACI systems. An estimated 869 tons/yr of solid waste will be
generated from the addition of an ACI system to a new 650,000 ton/yr
kiln (II-B-67, Docket No. A-92-53). The total additional solid waste
generated at the end of the fifth year following promulgation of the
amendments will be an estimated 515,122 tons from scrubber slurry and
4,211 tons from ACI systems for a nationwide total of 519,333 tons. No
solid waste impacts are anticipated with the use of an RTO.

E. Energy Impacts 

The use of alkaline scrubbers on new kilns will increase electricity
consumption. The additional electricity required for an alkaline
scrubber added onto a new 650,000 ton/yr kiln is estimated at 984,863
kWh/yr (II-B-67, Docket No. A-92-53).  Increased electricity demand for
a new kiln equipped with a scrubber and RTO is an estimated 4,560,973
kWh/yr. The use of an RTO will also increase natural gas usage. For a
new 650,000 ton/yr kiln, the additional natural gas usage will be 84
million Btu/year. An ACI system will increase electrical demand by
3,767,000 for a 650,000 ton/yr kiln (II-B-67, Docket No. A-92-53).

 

For the 5-year period following promulgation, the additional electricity
demand associated with the installation of scrubbers only on five new
kilns will be 7,954,663 kWh. For the 2 new kilns equipped with a
scrubber plus an RTO, the added electrical demand will be 14,735,451
kWh. The additional natural gas usage due to the installation of RTO’s
will be 271,385 million Btu. The additional electricity demand of adding
ACI to 3 new kilns will be 18,255,462 kWh. Total nationwide increased
electrical demand in the fifth year following promulgation of the
amendments will be 40,945,575 kWh; total nationwide increased natural
gas demand in the fifth year will be 271,385 

Cost Impacts

The costs of the final amendments for portland cement manufacturing were
calculated using the following assumptions:

wet alkaline scrubbers only will be installed on five new kilns for the
control of mercury emissions;

a performance test for mercury using EPA method 29 will be done for all
new kilns;

a scrubber and RTO will be required on two new kilns for the control of
THC (a surrogate for organic HAP emissions);

ACI systems will be installed on three new kilns for the control of THC
emissions;

THC monitors will be installed on all new kilns; and

all existing and new portland cement plants will maintain records of the
amount of cement kiln dust recycled and the amount wasted.

As a beyond-the-floor option for existing and new kilns, costs were
estimated for the use of ACI systems on existing kilns and a scrubber
and ACI system on new kilns.

Existing Kilns

The only costs for existing kilns are associated with the requirement to
keep records of the amount of cement kiln dust that is recycled and the
amount that is wasted, or not recycled.

To keep records of the amount of cement kiln dust recycled and wasted,
it is estimated that the information would be recorded once per day and
would require approximately 0.25 hrs per occurrence. Assuming operations
of 365 days per year and using fully-burdened (including wages, fringe
benefits and overhead costs) hourly wage rates of $89.63/hour for
technical, $104.21/hour for managerial, and $44.79/hour for clerical,
the annual cost for maintaining the records of recycled and wasted
cement kiln dust is $9,063 per facility.

New Kilns

Under the final rule, new sources can either comply with a mercury
emission limit or an equipment standard.  For purposes of calculating
the costs of the final amendments, it is assumed that over the 5-year
period following promulgation, the owners or operators of five new kilns
will have to install an alkaline scrubber in order to comply with the
mercury emission standards and will conduct a performance test to
demonstrate compliance. To comply with the final limits for THC, it is
estimated that five new kilns will require additional controls. For
purposes of estimating costs, it is assumed that two new kilns will
comply with the THC limits by installing a scrubber and RTO. Owners or
operators of three kilns are assumed to install ACI systems in order to
comply with the THC limits for new kilns.All new kilns are required to
install THC monitors to demonstrate continuous compliance with the final
THC limit. 

Costs were estimated for a new preheater/precalciner kiln with a clinker
production capacity of 650,000 tons per year. Costs per ton of clinker
were then used to estimate nationwide costs. Nationwide costs were
estimated using industry projections of increases in kiln capacity and
number of new kilns. Using data from the Portland Cement Association
(PCA 2006), estimated capacity will increase by 21,000,000 tons of
clinker over the next 5 years and an estimated 20 new kilns will start
up for an average of 1,050,000 tons of clinker per new kiln. 

 

Wet Alkaline Scrubber

Costs estimates for the use of wet alkaline scrubbers on kilns were
derived from recently developed cost estimates for the Industrial Boiler
Rule where costs were estimated for the use of packed bed scrubbers to
control HCl emissions from industrial boilers (Oomnen, 2002). To
estimate the costs of add-on scrubbers for cement kilns, scrubber costs
for model boilers were adapted to portland cement kiln conditions.

The most relevant models from the Industrial Boiler Rule are coal fired
boilers with a baseline of either a fabric filter or an ESP.   Model
plant number 4 from Appendix A-5 of the "cost and emissions impacts memo
(Oomnen, 2002)" provides estimated "Least Cost Control ($/yr, Annualized
Based) per Model to Meet MACT Floor for Existing Sources" for a 565
million Btu/hr coal fired boiler of $1,316,000/yr.  This cost includes
estimated capital recovery and operating and maintenance costs
(developed in 2002).

Assumptions for kiln gas production from a new preheater/precalciner
cement kiln include a flue gas production factor of 54,000 DSCF/ton of
dry feed (based on a “standard” of 68 °F) and a raw material feed
rate of 1.65 ton of dry feed for every ton of clinker [Heath, E., 1996].
 Using these rates and adjusting to a consistent 32°F, and assuming 10%
moisture content, the flue gas production factor is equivalent to

54000(460+32/460+68)(1+0.1)(1.65) = 91,300 SCF/ton clinker.

The flue gas production factor for coal fired boilers is approximately
10,000 dscf/million Btu (EPA/OAP, 2004).  With 5% moisture in the flue
gas, model boiler #4 would produce about

565 x 10,000(1+0.05) = 5.93 X 106 SCF/hr

or

5.93 x 8760hr/yr = 5.20 X 1010 SCF/yr.  

This is equivalent to a new kiln producing

5.2 x1010 scf/yr (1 ton clinker/91,300 scf) = 569,400 tons clinker/yr.

The estimated control cost would be $2.31/ton of clinker ($1,316,000/yr
÷ 569,400). There are some economies of scale in capital cost;
operating costs (electricity, waste disposal, etc) are probably nearly
linear.  The cost per ton for the model new portland cement plant of
650,000 tpy clinker may be slightly lower.  EPA's control cost manual
(EPA/OAQPS, 2002) suggests that the capital cost of wet scrubbers varies
with capacity to the 0.82 power.  If the total annual cost were divided
between 25 percent capital recovery (10 year life at 7% interest) and 75
percent operating and maintenance costs, a 650,000 tpy clinker plant
would have total costs of

[($2.31 x 0.75) + (0.25)(2.31)(569,400/650,000)0.82] x 650000 =
$1,462,500/yr, or $2.25/ton.

The capital cost of a new scrubber for a 650,000 ton/yr kiln was
estimated using capital costs for packed bed scrubbers developed for the
Industrial Boiler Rule. Scaling scrubber capital costs for utility
boilers to a 650,000 ton/yr kiln gives a total capital cost of about
$2.7 million. Amortized over 10 years using 3 % and a 7% interest rates
gives annual capital cost of $318,400 and 386,700, respectively. 

Assuming that five new kilns will install an alkaline scrubber only to
comply with the mercury emission limit, the total annualized cost of
scrubbers is an estimated $11.3 to $11.8 million.will (1,050,000
tons/kiln x 5kilns x $2.25/ton). Total capital cost over the 5-year
period following promulgation is an estimated $21.9 million.

A mercury performance test will be required for each new kiln. Costs
include equipment rental, travel, testing, standby/overtime, laboratory
analysis, test report preparation, and overhead. It is estimated that a
Method 29 performance test will cost $12,270/test/kiln. Amortized over 5
years at 3% and 7% results in an annual cost of $2,679 to
$2,992/year/kiln. Assuming 20 new kilns over the 5-year period following
promulgation, total performance tests costs will be $245,400 ($12,270 x
20) with an amortized cost of $53,584 to $59,851.

Regenerative Thermal Oxidizer

Costs for an RTO are based on costs of an RTO installed and currently
operating on an existing preheater/precalciner portland cement kiln. To
estimate capital cost of the model RTO, the purchased equipment cost of
the operating RTO was scaled down based on gas flow rates of 502,300
dscfm for the operating kiln to 73,860 dscfm (gas flow of 54,000/ton of
clinker) for the new kiln model RTO. Input parameters and annual cost
inputs used in estimating costs are shown in Table 1. Total capital
investment for a new 650,000 ton/yr kiln is approximately $8 million and
total annual cost, including annualized capital (using 3% and 7%
interest rates) and operating costs, is approximately $2.2 million to
$2.4 million, or $3.43 to $3.74/ton of clinker.  Details of the capital
and annual costs are presented in Table 2.

Assuming that 2 new kilns will require an RTO to comply with the THC
emission limits, total nationwide annual cost (including annualized
capital, at 3% and 7%, and operating and maintenance) over the five-year
period following promulgation will be approximately $7.2 to 7.9 million.

Monitoring costs for new kilns were estimated based on the use of THC
continuous emission monitors (CEM) on all new kilns to demonstrate
continuous compliance with the new kiln THC limits.  Capital and annual
costs for a THC CEMS were estimated using EPA’s Continuous Emission
Monitoring System Cost Model (to be published). Total installed capital
costs (“first cost”) for extractive THC CEMS at a new cement kiln,
include the cost of the analyzer, sampling system, data acquisition,
software, etc. In addition, labor costs for planning, equipment
selection, installation, performance specification testing and
preparation of a QA/QC plan are included. These costs are estimated at
$139,826 per kiln. Annual cost includes costs for operation, maintenance
and repairs; annual relative accuracy test audits; cylinder gas audits;
annual QA and O&M reviews; and capital recovery (15 years, 3% and 7%
interest rate). Annual costs total $33,786 to $37,425/yr/kiln. Assuming
20 new kilns will startup during the 5-year period following
promulgation, total nationwide annual costs will be $675,715 to
$748,503.

Table 1. RTO Input Parameters for New Kiln Model

Input Parameters

Gas flow rate (scfm)	115,600

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)	7.209

Auxiliary fuel requirement (scfm)	176.7

Total gas flow rate (scfm)	115,777

Annual Cost Inputs

Operating factor (hr/yr)	7920

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)	10

Capital recovery factor	0.1424

Taxes, insurance, admin. factor	0.04

Pressure drop (in. w.c.)	20.0

Table 2. RTO Capital and Annual Costs for New Kiln Model

Capital Costs ($)

DIRECT COSTS

	Purchased equipment cost (PEC)	5,065,173

Direct installation costs

	Foundation and support (8% of PEC)	405,214

Enclosure building	0

Site preparation (15% of PEC)	759,776

Total direct installation (DIC)	1,164,990

TOTAL DIRECT COST (DC)	6,230,162

INDIRECT COSTS

	Installation

	Engineering (10% of PEC)	506,517

Construction & field expense (5% of PEC)	253,259

Contractor fee (10% of PEC)	506,517

Contingencies (10% of PEC)	506,517

TOTAL INDIRECT COST (IC)	1,772,810

TOTAL CAPITAL INVESTMENT (TCI = DC + IC)	8,002,973

Annual Costs ($/yr)

Operating labor	6,415

Supervisory labor	962

Maintenance labor	742

Maintenance materials	742

Natural gas	780,809

Electricity	178,806

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

Taxes, insurance, administrative	320,119

Capital recovery	1,139,443

	TOTAL ANNUAL COST	2,433,353



Activated Carbon Injection

The costs of using an ACI system and a polishing baghouse to control
mercury emissions from cement kilns were estimated using control costs
developed for electric utility boilers [NJDEP 2003]. These costs were
chosen as the basis for estimating ACI costs for portland cement kilns
because the costs were developed recently for actual electric utility
boilers rather than for model 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.  The Vineland and BL
England 1 units were selected as having exhaust gas flow rates
comparable to those for cement kilns.  The information for electric
utility boilers used to estimate ACI costs for portland cement kilns is
as follows:

Power Plant	Capacity

(MW)	Airflow

(acfm)	Cap. Cost

($)	Total Annual Cost

($)	Hg Removed

(lb/yr)	Cost of Hg removal

($/lb Hg)

Vineland	23	132,600	738,900	435,794	14.98	29,092

BL England 1	135	470,000	4,337,550	1,249,718	110.38	11,322

At an exhaust gas temperature of 290 °F, the standardized exhaust gas
flow rates (standard temperature of 68 F) are 93,350 scfm and 330,880
scfm for the Vineland boiler and BL England boiler, respectively. These
are equivalent to hourly exhaust gas flow rates of 5,601,000 scfh and
19,852,800 scfh.

Assumptions used regarding kiln gas production from portland cement
kilns have been 66,225 dscf/ton of dry feed for an existing long kiln
and 54,000 dscf/ton of dry feed for a new precalciner kiln [Heath 1996].
An average of 1.65 ton of dry feed is required to produce 1 ton of
clinker. Adjusting these gas flow rates to 10 percent moisture content,
they are equivalent to 120,198 scf/ton of clinker for an existing kiln
and 98,010 scf/ton of clinker for a new kiln. 

Using the utility boiler exhaust gas flows, the equivalent clinker
production would be the annual exhaust gas flow divided by the exhaust
gas flow required to produce a ton of clinker. The following illustrates
how the annual clinker production for a new preheater/precalciner kiln
equivalent to the exhaust gas flow for the Vineland boiler is
calculated:

Comparable clinker production

	=	(5,601,024 scfh x 24 x 365)/98,010 scf/ton clinker

=	500,612 tons of clinker per year

Assuming that costs will be directly proportional to the volume of flue
gas generated and the comparable clinker production derived from the
volume of flue gas, the equivalent capital cost for mercury control for
an new kiln would be $738,900/500,612 tons of clinker or $1.48/ton of
clinker. Annualized capital and annual cost data from the New Jersey
cost data were adjusted to be consistent with amortization periods and
interest rates used in this analysis. Using the Vineland data to
illustrate, total annual cost for a new kiln would be $573,210 to
$597,339 using interest rates of 3 percent and 7 percent, or $0.88 to
$0.92/yr/ton of clinker.

Again using the Vineland data and interest rates of 3% and 7%, total
nationwide annual cost assuming 3 new kilns will be equipped with ACI
systems over the 5-year period after promulgation, will be $2.8 million
to $2.9 million.

G. Summary of Impacts

Costs and environmental impacts on a model plant basis are summarized in
Table 3. Total nationwide costs and environmental impacts over the 5-yr
period following promulgation are summarized in Tables 4.

 I. References:

Heath, E. 1996. Emission Calculations for Preamble.  Submitted to Joseph
Wood, EPA/ESD.  Docket No. A-92-53, Item II-B-76.  November 14, 1996.

Oommen, R. 2002. Methodology for Estimating Cost and Emissions Impacts
for Industrial, Commercial, Institutional Boilers and Process Heaters
National Emission Standards for Hazardous Air Pollutants.  October 2002.

PCA 2006. Capacity Expansion Estimates, October 13, 2006.

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.

U. S. Environmental Protection Agency, Office of Atmospheric Programs. 
Output-Based Regulations: A Handbook for Air Regulators.  August, 2004.

U.S. Environmental Protection Agency, Office of Air Quality Planning and
Standards, Study of Hazardous Air Pollutant Emissions from Electric
Utility Steam Generating Units – Final Report to Congress, Volume 1,
EPA-453R-98-004a, February 1998.

New Jersey Department of Environmental Protection 2003. ESP with
Polishing Baghouse and PAC Costs for Mercer 1 & 2, Vineland and BL
England 1 & 2, October 16, 2003.

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