OAR Box 1828 

Prepped by Ollie Stewart 

Document Number: 

139) ll-K- (B) -138 

Docket Number: 

A-83-27 

Printed 11/12/2008 11:12:53 AM Sheet 139 of 325 

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USB 

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

Office of Air Quality Planning and Standards, 

A*** Research Triangle Park, North Carolina 2771 

m 16 1984 

A-83-27 

MEMORANDUM 

II-K-(B)-138 

SUBJECT: Documentation for S02-Related Changes Made to IFCAM Since 

June 1983 

FROM: Dale Pahl , 

Standards Dtevefopment Branch (MD-13) 

TO: Bob Short 

Economic Analysis Branch (MD-12) 

This memorandum responds to your request for technical and economic 

documentation for the 12 S02-related changes that have been made to the 

IFCAM assumptions since July 1983. I have attached a summary of these 

changes to this memorandum. The documentation for each of the changes is 

keyed to the attachment. 

A.l. For coal that is not scrubbed, statistical analyses show that the 

relative standard deviation of coal sulfur content ranges from 5-25 percent 

about the mean. Thus, as indicated in Radian's draft August 18, 1983, 

statistical analysis report, a factor of 1.2 was selected to determine 

whether or not a specific coal type is in compliance with a 30-day rolling 

average SO2 emission standard. A similar analysis resulted in selection 

of a factor of 1.3 to adjust emissions when coal must be scrubbed. 

A.2. These changes reflect recently acquired performance test information 

for dry and dual alkali FGD which has been incorporated in the technology 

update report. 

A.3. While utility companies have long-term contracts to purchase coal 

of fixed sulfur content, industrial boiler operators often must purchase coal 

from the spot market. Thus, utility boiler owners can trade-off coal 

sulfur content, price, and scrubber costs (by not scrubbing a calculated 

percent of the exhaust gas stream) in order to optimize total annualized 

costs. Industrial boiler owners, however, cannot rely on being able to 

bypass the scrubber because they may need to purchase at some future time 

a high-sulfur coal which will require extensive scrubbing to comply with 

the standard. Thus, IFCAM no longer includes FGD bypass for Industrial 

boilers. 

A.4. The SOg SIP's have been updated by EEA 1n a June 22, 1983, letter 

from Tim Hogan to Bob Short to reflect all SIP revisions through early 1983. 

A.5. Changes 1n reliability were made to reflect current FGD performance 

data 1n the technology update report. The changes 1n fuel costs and 

emission rates reflect Industry reliance on a compliance fuel during 

periods of FGD malfunction. 
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A.6. The bases for these changes are set forth in the May 16, 1983, 

memorandum from Radian to Charlie Sedman. 

A.7. The basis for adding the new coal type is documented in a 

June 17, 1983, memorandum from ICF to Judi Greenwald. 

A.8. The basis for this change is presented 1n Radian's May 16, 1983, 

memorandum to Charlie Sedman. 

A.9. The changes in emission rates and coal prices are based on data 

supplied by ICF and described 1n memoranda from Craig Ebert, ICF 

(7/25/83), and Larry Jones, ESED (7/13/83). 

A.10 and 11. The change in scrubber design SO2 removal efficiency 

reflects industry practice of designing FGD units to achieve 

90 percent reduction even though the scrubber may be subsequently 

operated at lower efficiency. 

A.12. The basis for this change is outlined in Radian's November 14, 1983, 

memorandum to Charlie Sedman. 

Since most of these changes originate from either ICF (in the case 

of the coal prices) or Radian (in the case of the cost algorithms), 

you will have copies of the memoranda I have referenced 1n your files. 

However, 1f you need additional copies or more detailed information 

about any of the changes I have mentioned, please let me know. 

Attachment 

cc: Fred Porter (MD-13) 

Charlie Sedman (MD-13) 

Walt Stevenson (MD-13) 
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Attachment 

CHANGES TO IFCAM TECHNICAL ASSUMPTIONS 

SINCE JUNE 1983 

A. Model Revisions Related to SO2: 

A.l The "worst case" 30-day rolling-average coal SO2 emission rate is 

estimated to be equal to 1.2 times the annual average uncontrolled 

emission rate when coal is not scrubbed. This "1.2" factor is used 

to determine whether or not a specific coal type is in compliance 

with a 30-day rolling-average SO2 emission standard. 

The "worst case" 30-day rolling-average coal SO2 emission rate is 

estimated to be equal to 1.3 times the annual average uncontrolled 

emission rate when the coal type is not in compliance with the 30-

day rolling-average NSPS and must be scrubbed. This new "1.3" 

factor will be used to estimate the SO2 reduction requirements for 

noncompliance coal types subject to 30-day rolling-average SO2 

NSPS. 

The use of Radian Corporation estimates of the relative standard 

deviations of the sulfur variability in coal (see letter from 

Elder, R., Radian Corporation, to Medine, E., EEA, dated August 5, 

1980, and letter from Medine, E., EEA, to Short, R., EPA, dated 

August 13, 1980) in the calculation of FGD system capital cost 

estimates is discontinued. 

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If the coal type is not in compliance with a 30-day, 

SO2 emission standard or if scrubbing is required on 

fired industrial boilers, a "1.3" factor is used. 

rolling-average 

all new coalThe upper limit on 

spray drying is 90 

restrictions on coal types 

sulfur coals) with respect 

sulfur dioxide removal for 

control is also 90 percent 

sulfur dioxide emission reduction 

percent 

from lime 

(30-day rolling average). There are no 

(e.g., restricted to low and medium 

to this technology. The upper limit on 

the dual alkali FGD with and without PM 

(30-day rolling average). 

The boiler flue gas flow rate will not be 

of scrubber capital or O&M cost estimates 

partial scrubbing with flue gas bypass. 

reduced in the calculation 

in order to simulate 

The SO2 SIP's in IFCAM have been updated. The PM and N0X SIP's 

have not been revised. 

A.5 Scrubber reliability is assumed to be 95 percent. It is assumed 

that new Industrial coal-fired boilers with scrubbers burn a 

compliance backup fuel (natural gas) for 5 percent of each annual 

operating period (when the scrubber 1s down). The fuel costs and 

annual average emissions rates have been adjusted for this assumption. 

In further analyses, a reliability of 90 percent will be assumed 

for lime spray drying, and 95 percent for dual alkali. 
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A.6 FGD system coal algorithms have been revised. Reference memorandum 

from Aul, E.F. et al., Radian Corporation, to Sedman, C.B., EPA/ISB, 

dated May 16,.1983. Revised Cost Algorithms for Lime Spray Drying 

and Dual Alkali FGD Systems. These new cost algorithms have been 

incorporated into IFCAM with further algorithm revisions provided 

by Larry Jones on June 16, 1983. 

A.7 A new coal type has been added to IFCAM, < 0.80 lb S02/MMBtu. 

Regional delivered industrial coal price projections for this new 

coal type have been provided by ICF Incorporated (see memorandum 

from Ebert, C , ICF Incorporated, to Greenwald, J., EPA, dated 

June 17, 1983. Coal Prices for Very-Low Sulfur Coals 1n the NSPS 

Analyses). 

A.8 FGD system cost algorithms: The cost algorithms for the dual 

alkali FGD system with PM removal have been changed because the 

type of scrubber has been changed. The costs in the Radian 

Corporation memorandum are for a venturi scrubber. EPA has 

decided to use a tray absorber for the dual alkali FGD system 

with PM removal. As a result, the new cost algorithms are the 

equations for a dual alkali FGD system without PM removal 

(Table 3-1 in the Radian Corporation memo as modified by 

Larry Jones on June 16, 1983) plus the cost equations for a 

single mechanical collector. 

A.9 (a) Revisions of annual average SO2 emission rates by coal type 

per memorandum from L. Jones, EPA, July 13, 1983, Compliance 

Coal Options for Cost Analysis. 

Range Old Annual Average New Annual Average 

(lb S02/MMBtu) (lb SO2/MMBU1) (lb S0?/MMBtu) 

1.08-1.67 (D) 1.45 1.38 

1.67-2.50 (E) 2.10 2.08 

(b) Revision of Region 6, Southwest, bituminous coal (1.08-1.67 lb 

S02/MMBtu) price in 1985. Old: $1.03/MMBtu (January 1983 

$/MMBtu). New: $2.39/MMBtu (January 1983 $/MMBtu). Revised 

by Craig Ebert, ICF Incorporated, on July 25, 1983. 

A.10 Scrubber capital cost algorithms: The scrubber capital and annual 

O&M cost algorithms in IFCAM are functions of the assumed SO2 

removal efficiency. The model modification is to set the percent 

SO2 removal efficiency parameter ("EFFS02") to a constant, 90, on 

a 30-day rolling average basis, (regardless of the SO2 removal 

efficiency required by the current NSPS, proposed NSPS, or SIP) for 

the scrubber capital cost algorithms. Previously, this parameter 

was a variable with a lower bound of 50. This parameter remains 

a variable (with a lower bound of 50) for the scrubber annual O&M 

cost algorithms in IFCAM. Reference Item A.l examples above for an 

explanation of how this parameter, the SO2 removal efficiency rate, 

is derived. 
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A.11 Scrubber capital cost algorithms: The scrubber capital and annual 

O&M cost algorithms in IFCAM are also functions of the percent 

sulfur of the coal type. The model modification is to set the 

percent sulfur to a constant high sulfur value in each region for 

the scrubber capital cost algorithms. This revision reflects the 

assumption that a scrubber may be designed to burn a higher sulfur 

coal type. For bituminous coal types, the percent sulfur will be 

consistent with the highest sulfur bituminous coal type in the 

region. For subbituminous coal types, the percent sulfur will be 

consistent with the highest sulfur subbituminous coal type in the 

region. 

A.12 Sodium throwaway FGD systems were added for residual fuel oil and 

coal boilers. [Letter from Aul, E. (Radian Corporation) to Sedman, C. 

(EPA). November 14, 1983, on Sodium Scrubbing Algorithm (NATH).]