# Date: July 20, 2012

Subject: Cost to Reduce HAPs with Potential for Ecological Effects

EPA Contract No. EP-D-11-084; Work Assignment No. 0-03

From: Katie Hanks

To: John Bradfield

Bill Schrock

U.S. Environmental Protection Agency

Research Triangle Park, NC 27711

The purpose of this memorandum is to present the cost analysis for reducing hazardous

air pollutants (HAP) with the potential for environmental effects from the pulp and paper

national emission standards for hazardous air pollutants (NESHAP) source category (40 CFR

part 63, subpart S). This analysis focuses on ac id gases and key persistent and bioaccumulative

HAP because of their potential for adverse effect s to ecological receptors (e.g., wildlife, aquatic

life, natural resources).

For the ecological cost assessment, the emissi ons inventory data used for risk modeling

were reviewed to determine the predominant sour ces of the HAP of intere st for ecological risk

(referred to as ”eco HAP”). Table 1 presents the nationwide and maximum facility emissions

estimates of eco HAP from the subpart S emissions inventory.

Table 1. Emissions of Eco HAPs from the Pulp and Paper Subpart S Source Category

Pollutant Category emissions (tpy) Number of facilities in

category reporting

emissions Emissions for highest-emitting

facility

tpy lbs

HCl 259 55 31.95 63,900

Cl 2 

# 24 53 2.5 5,000

POM 0.008 29 0.0008 2

Cadmium 0.01 28 0.006 12

Mercury 0.002 27 0.0007 1



# Bleaching of virgin kraft pulp is responsible fo r nearly all of the hydrochloric acid (HCl)

and chlorine (Cl 2 

# ) emissions. Caustic scrubbers are already required to reduce HCl and Cl 2 

# by 99

percent or greater. The nationwide emissions are the residual emissions remaining after

implementation of 99 percent or better control. No other technology exists to reduce chlorinated

HAP emissions from bleaching further. Although some totally chlorine free (TCF) bleaching

# 2 processes exist, these te chnologies are not applicable for virg in kraft fibers in which the lignin

must be removed to obtain ta rget final product brightness.

About one third of the HAP metal emissions of cadmium (Cd) and mercury (Hg) are

from incineration control devices used to reduc e HAP emissions from Subpart S processes. The

remaining two thirds of metal HAP emissions ar e primarily associated with fuel burning for

paper machine dryers. Emissions of POM are al so associated with fuel burning for paper

machine dryers. Several of these incineration- based systems are already equipped with wet

scrubbers (e.g., for total reduced sulfur control in the case of th ermal incinerators) and for these

units there is no means to furt her reduce emissions. Fuel switc hing was considered, but would

not reduce emissions because most mills are already using natural gas. Natural gas has lower

emissions factors on a pound per million British th ermal unit (lb/MMBtu) basis for POM and the

HAP metals of concern, as shown in Attachment 1.

Table 2 presents estimated venturi scrubbe r control costs to further reduce POM and

HAP metals emissions from fuel-burning equipmen t. The footnotes under Table 2 provide details

and information sources used in the cost estima tes. Ballpark costs were estimated for a single

mill and then compared to the nationwide emission reduction that could be obtained if all of the

eco HAP could be eliminated. This approach cl early underestimates costs and overestimates the

emission reduction that could be achieved, and even without further refinement, results in cost

effectiveness values that are extremely high (and would only increase if refined). Apart from cost

impacts, installation of scrubbers would result in secondary air emission impacts from electrical

energy use and wastewater impacts (i.e., a new wast ewater stream to be treated and discharged

into the environment).

Based on the information presented in this brief memorandum, there do not appear to be

any feasible control measures for further re ducing HAP emissions with the potential for

environmental effects from th e subpart S source category.Table2.BallparkEstimatesofCoststoFurtherReducePulpandPaperSubpartSHAPEmissionsofPotentialInterestforEcologicalRiskHAPAdjustednationwidebaselineemissions,tpy Predominantemissionsources AvailablecontrolsControlcostsforasinglemill(underestimated),$1Nationwideemissionreduction(overestimatedassumingemissionseliminated)2Costeffectiveness(underestimated),$/ton4OtherenvironmentalimpactsCd0.01‐HAPemissionscontroldevices(e.g.,thermaloxidizers);and‐Fuelburningforpapermachinedryers‐Scrubbers3‐alreadyusedbysomemills‐Fuelswitchingisnotlikelytoreduceemissionsbecausemostmillsarealreadyusingnaturalgas.40,000$0.013 3,160,775$wastewater,electricalenergyimpacts,secondaryairemissionsHg0.00240,000$0.0019 20,956,029$HCl 259 BleachingCausticscrubbersarealreadyusedtoreducechlorineandHClby99%.Nationwideemissionsaretheresidualemissionsremainingafterimplementationof99%control.Noothertechnologyexiststoreduceemissionsfurther.NAChlorine24NAPOM0.008Fuelburningforpapermachinedryers‐Scrubbers3‐FuelswitchingamongtheliquidfuelsburnedisnotlikelytoreduceemissionsbecausemostmillsarealreadyusingnaturalgaswhichhaslowerPOMemissionsthatoil.40,000$0.0082 4,851,643$wastewater,electricalenergyimpacts,secondaryairemissions1.Thecostspresentedinthetableaboveareunderestimatedbecausetheyarelowerthanthecostsasinglemillwouldface;theyarenotnationwidecostsforallaffectedmills.Examplesofper‐millcostsareasfollows.Mediangasflowfromdirect‐firedpapermachinedryerventsis63,750acfm.EPAfactsheetforventuriscrubbers(http://www.epa.gov/ttn/catc/dir1/fventuri.pdf)providesannualizedcostrangeof$5.7to$193/scfmAssumingdryergasflowis50%watervapor,thenmedianflowisapproximately50%x63,750=31875scfm.Usingtheminimumcostof$5.7/scfmx31,875scfm=$181,688/yrpermill.MedianflowfromHAPincineratoris15,000acfm(or7,500scfmassumingexhaustis50%water).Usingtheminimumcostof$5.7/scfmx7,500scfm=$42,750/yrpermill.2.Assumingemissionsareeliminatedisanoverestimatebecause:(a)controlsarelessthan100%efficient,and(b)nofurtherreductioncouldbeachievedatmillsalreadyoperatingcontrols3.AparticulatescrubberwasconsideredtoreducePOMsincePOMcompoundsarepresentintheatmosphereinparticulateform.(http://www.epa.gov/ttn/atw/hlthef/polycycl.htmlScrubberswereconsideredformercurybecausescrubberswereconsideredfortheothermetalHAPandafractionofthemercuryisinparticulateform.4.Costeffectiveness($/ton)isconsiderablyunderestimatedbecausethecostsareunderestimatedandthenationwideemissionreductionisoverestimated

# ATTACHMENT 1

‐ COMPARISON OF EMISSION FACTORS FOR POM AND HAP METALS

Analysis: Emission factors were compared to show that natural gas is the lowest

‐ emitting fuel for PO M

and the eco HAP metals. Natural gas is the prevalent fuel for thermal oxidizer controls and pape r

machine dryer burners.

AP

‐ 42 Emission Factor Comparisons for Natural Gas and Oil PO M

Nat. gas POM detected:

2.40E

‐ 05

3.00E

‐ 06

2.80E

‐ 06

1.70E

‐ 05

5.00E

‐ 06

5.18E

‐ 05 total lb/MMsc f

5.08E

‐ 08 total lb/MMBtu

Fuel Oil POM lb/1000 gal lb/MMBtu

No. 6 0.0013 8.67E

‐ 06

Dist. 0.0033 2.36E

‐ 05

Conclusion: On a lb/MMBtu basis, natural gas POM emissions are lower than for oil

.

AP

‐ 42 Emission Factor Comparisons for Metals (Cd, Hg, and Pb )

Nat. gas Fuel oil

HAP lb/MMscf lb/MMBtu lb/1000 gal lb/MMBtu

Cd 1.10E

‐ 03 1.08E

‐ 06 3.98E

‐ 04 2.74E

‐ 06

Hg 2.60E

‐ 04 2.55E

‐ 07 1.13E

‐ 04 7.79E

‐ 07

Conclusion: On a lb/MMBtu basis, natural gas Cd and Hg emissions are lower than for oil

.

Att1_EF_compare