-------
Hardwood Kappa Number
i
For fiber lines processing hardwood, EPA has concluded that an unbleached
i
kappa number into bleaching of 13 or below is readily achievable, and is indicative of mills
with effectively operated extended delignification technology in place.
i
Hairdwood fiber line data similar to the softwood fiber line data presented
above are available in the same databases. Data showing the relationship of pulping
technology to kappa number for hardwood fiber lines in the BAT baseline database are
presented in Figure 3-3. The data are presented for fiber lines using extended cooking,
oxygen delignification, or both technologies. Data are also presented for fiber lines using
i
conventional pulping technology where these lines occur at mills that also have fiber lines
with extended cobking and/or oxygen delignification. As shown on Figure 3-3, mills with
[
oxygen delignificjation, and extended cooking and oxygen delignification, uniformly achieve
an unbleached kappa number of 13 or below. Mills with extended cooking can achieve an
unbleached kappa number below 13, if the mill chooses to operate in that range. Fiber lines
1 i • - ' . *
at mills using conventional pulping achieve unbleached kappa numbers of 13 and above.
[
i
Similar data are available in the EPA analytical database. Data showing the
relationship of pulping technology to unbleached kappa number at hardwood mills in this
database are presented in Figure 3-4. All fiber lines in this database using extended
delignification technology achieve an unbleached kappa number of 13 or below. Only two of
14 fiber lines using conventional pulping technology achieve kappa numbers below 13.
: ~*
When coupled with a long-term average AOX discharge value of 0.26 kg/kkg,
discussed in the previous section, requirements on kappa number into the bleach plant should
further EPA's goal of promoting the use of extended delignification technologies.
PULPl\0707-01.mcr 3-9
-------
1
R
Q
en
05
tt
CUD
a
PL,
«
a,
•a
P
o
O)
^
CUD
-------
03
•s
•a
c
OJD
^
"3
a
OX)
a
•d
o
o
I
a
a
0
LO
-------
3.1.2.3 Pulping Area Filtrate Recycle
EPA's requirement to recycle pulping area filtrates is a critical step in reducing
overall mill wastewater discharges and in eliminating a significant source of weak black liquor
discharge that would otherwise go to the mill's wastewater treatment plant. Recycling of
pulping area filtrates to the chemical recovery cycle prevents the discharge of weak black
liquor, which contains inorganic pulping chemicals and dissolved wood substances. The
dissolved wood substances include polynuclear aromatic hydrocarbons, degraded
carbohydrates, low-molecular weight organic acids, and wood extractives (resins and fatty
acids). The toxicity of the materials contained in black liquor is well documented (9). In
addition to the reductions in the discharges of toxic materials, recycle of pulping area- filtrates
also results in reductions in mill BOD, COD, and color discharges.
Tier I requires the recycle of all filtrates prior to the point where kappa into
bleaching is measured. As depicted on Figure 3-5, this includes the closure of the screening
system, so that all wash water flows countercurrent from the decker to the mill's chemical
recovery system. Screening removes unacceptable material from the main pulp stream. The
fibrous portion of this material is returned to the pulping process or is burned to recover fuel
value in on-site boilers. There will be some solid material, typically sand and grit, that must
be discharged from the closed screening system. This solid material will carry a minimal
amount of water with it, typically under 0.01 m /klcg. About 50 percent of U.S. bleached
kraft mills currently employ closed screening (14).
While not a performance criteria that would be an NPDES permit limitation,
EPA assumes that mills choosing to participate at Tier I will implement BMPs equal to ox-
more stringent than those necessary to comply with the minimum BMP requirements in 40
CFR 430.03.
PULPl\0707-01.mcr 3-12
-------
si
o
I
IT)
I
OJO
en
I
en
-------
As depicted in Figure 3-5, if oxygen delignification is employed, the filtrates
from the post-oxygen washer(s) must be recycled to chemical recovery (typically after it is
used as screening dilution water). However, it should be noted that the flow scheme depicted
in Figure 3-5 is not the only way to meet the filtrate recycle criterion of Tier I.
3.1.2.4 Specification of Tier I Technology
EPA considered whether it would be better to specify acceptable technologies
that would qualify a mill for entry into Tier I, rather than to limit the kappa number. EPA
rejected this approach because it would inhibit development of equivalent technologies that
EPA cannot foresee today and because it is inconsistent with the traditional performance-
based structure of technology-based effluent limitations under the Clean Water Act. EPA
determined that specifying a kappa number limit, rather than specific technologies, provides
industry with the most flexibility, and will ultimately lead to most innovative development of
advanced technologies. The kappa number limit is consistent with the overall pollution
prevention goals of the incentives program. Technologies that reduce kappa into bleaching,
coupled with the recycle of pulping area filtrates, return inorganic pulping chemicals as well
as dissolved wood substances to the recovery cycle and reduce bleaching chemical
requirements. In addition, the kappa number limit captures a range of extended
delignification technologies, perhaps some yet to be developed, rather than requiring any
specific technology. Mills can use their ingenuity to comply with the kappa number limit.
Considering resources and capabilities available to them, and mill specific requirements, they
are likely to develop more efficient and cost-effective methods to achieve the Tier I
limitations than EPA would compel through the use of a prescriptive technology requirement
under Tier I.
3.1.3 Tier I Fiber Line Configurations
Many fiber line variations are available to achieve the Tier I limits. EPA
expects that the most common approach will be to use the technology basis of BAT Option B.
This includes extended delignification (accomplished by delignification and/or extended
PULPl\0707-01.mcr 3-14
-------
cooking followed;by complete substitution of chlorine dioxide for elemental chlorine) as well
as the following nine elements:
• Adequate chip thickness control;
• Use of dioxin- and furan-precursor-free defoamers (water-based
', defoamers or defoamers made with precursor-free oils);
• i Effective .brown stock washing (i.e., washing that achieves a soda loss
; of less than or equal to 10 kg Na2SO4 per kkg of pulp (equivalent to 99
percent recovery of pulping chemicals from the pulp));
• i Elimination of hypochlorite (i.e., replacement of hypochlorite with
equivalent bleaching power in the form of additions of peroxide and/or
oxygen to the first extraction stage and/or additional chlorine dioxide hi
final brightening stages);
• Oxygen and peroxide enhanced extraction, which allows elimination of
hypochlorite and/or use of a lower kappa factor in the first bleaching
stage;
• ; Use of strategies to minimize kappa factor and dioxin and furan
precursors in brown stock pulp;
• High-shear mixing during bleaching to ensure adequate mixing of pulp
• and bleaching chemicals;
• ; Closed brown stock pulp screen room operation, such that screening
> filtrates are returned to the recovery cycle; and
• Efficient biological wastewater treatment, achieving removal of 90
percent or more of influent BOD.
In addition to the above technology elements, mills with Tier I fiber lines (like any Subpart B
mill) will need to implement best management practices to prevent or otherwise contain leaks
i
and spills and to control intentional diversions of spent pulping liquor, soap, and turpentine.
See 40 CFR 430.03. The major elements of the above mill configuration are shown in Figure
3-5. ' ;
Because the Tier I technology basis is equivalent to BAT Option B, the Tier I
I
cost estimates, pollutant load reduction estimates, and non-water quality environmental impact
i
PULPl\0707-01.mcr ' 3-15
-------
estimates presented, in Sections 5, 6, and 7, respectively, are the same as those calculated for
BAT Option B.
3.2 TierH
3.2.1 Tier H Technology Basis
Under Tier II, the AOX performance requirement is a long-term average
discharge of 0.10 kg/kkg or less, measured at the end of pipe. In addition, Tier II fiber lines
must recycle to the chemical recovery system all pulping area effluents that contain black
liquor solids. Tier II fiber lines must also achieve total pulping area condensate, evaporator
system condensate, and bleach plant wastewater discharge flow of 10 m3/kkg or less reported
as an annual average. Tier II mills also must meet limitations for dioxin, furan, chloroform,
and the 12 chlorinated phenolic pollutants.
The Tier II technology basis includes all the elements described under Tier I.
In addition, Tier II.mills will maximize the capability of extended delignification technology,
thereby reducing the amount of chlorine dioxide and other chemicals used in bleaching. EPA
expects that mills choosing to participate at Tier II will implement stringent BMPs to move
toward the elimination of leaks and spills, while also capturing and recycling - rather than
discharging - liquors during fiber line disruptions through detailed scheduling of planned
outages (e.g., maintenance) and contingency planning for unplanned disruptions. Tier II mills
will have evaporators that minimize the amount of black liquor carry over and associated
steam strippers, allowing extensive condensate reuse. EPA expects that Tier II mills also will
employ improved water reuse within the bleach plant, and may recycle a portion of bleach
plant filtrate back through the fiber line to the recovery cycle.
Tier II mills that achieve extensive condensate reuse through steam stripping or
other treatments that result in HAP reductions may also be eligible for the "clean condensate
alternative", a MACT compliance alternative.
PULPl\0707-01.mcr 3-16
-------
The major differences between the Tier I and Tier II technology basis is that,
under Tier II, the degree of delignification prior to bleaching is maximized and additional
water conservation and reuse is practiced, further reducing the amount of all pollutants
i • .
discharged in the mill effluent, including BOD, COD, color, and chlorinated organic
pollutants. |
Three mills in the United States are approaching the reduced wastewater flow
levels required by Tier II. Although the flow volume projected or reported by these mills
excludes pulping |area or evaporator condensates, which EPA includes within its Tier II flow
F
limitation, EPA expects that, over the next ten or eleven years, eondensate reuse strategies and
discharge flow reduction technologies will mature to allow mills to achieve the pulping area
f
eondensate, evaporator eondensate, and bleach plant wastewater flow level included as part of
the Tier II limitations.
3.2.2 Tier II Performance
3.2.2.1 AOX
EPA is setting the AOX limit for Tier II based on a long-term average (0.10
kg/kkg) that is currently achieved by the best mills in the industry using components of the
Tier II technology basis.
i
I ' ' '
As reported in Table 3-1, EPA's analytical database contains data for six mills
that use extended; cooking and/or oxygen delignification and ECF bleaching of softwood.
!
Final effluent AOX discharged from these mills ranges from 0.081 to 0.33 kg/kkg. The best
three mills achieve a range of 0.12 to 0.081 kg/kkg.
i
i
Based on these data, EPA has concluded that a long-term average AOX level of
0.10 kg/kkg reflects the performance of the Tier II technology basis, for mills using ECF-
based bleaching. iEPA promulgated an annual average limit equivalent to this long-term
average, and is also promulgating a daily maximum limit based on this long-term average
PULPl\0707-01.mcr 3-17
-------
performance multiplied by an appropriate variability factor. The variability factors used were
developed for BAT Option B. The Option B variability factor forms a rational basis for the
Tier II variability factor because it is also based.on extended delignification and ECF
bleaching technology. It could be argued that since the Tier II limits are lower than the
Option B limits, variability under Tier n may be greater than under Option B. EPA
considered this but determined that any such effect would be offset by the better process
control strategies utilized by mills employing Tier II level technology and more stringent
implementation of BMPs, which will result in more uniform pulp characteristics and effluent
quality. Therefore, EPA is using the Option B variability factor to represent the expected
AOX variability under Tier II. Annual average limits (equivalent to the long-term average),
daily maximum limits, and the 1-day maximum variability factor are presented in Table 3-3.
Table 3-3
Tier II AOX Limits and Performance Levels for ECF Mills
Option
TierH
Long-ter m Average (Annual
Average Limit)
(kg/kkg)
0.10
1-day Variability
Factor
2.28
Daily Maximum
Limit (kg/kkg)
0.23
EPA collected and analyzed bleach plant effluent samples from two kraft mills
that produce TCF bleached pulp during four sampling episodes: 112, 113, and Mill 114
Episodes A and B. The results from Episodes 112 and 113 are from two separate bleach lines
at the same mill. At the time of sampling, the mill operated two bleach lines (one for
hardwood and one for softwood), each of which alternated between ECF or TCF bleached
pulp production. Thus, while the hardwood line was operating TCF, the softwood line was
operating ECF, and vice versa. During Episode 112, wastewaters from TCF bleaching of
softwood pulp were collected while ECF hardwood and TCF softwood pulps were produced.
During Episode 113, wastewaters from TCF bleaching of hardwood pulp were collected while
TCF hardwood and ECF softwood pulps were produced. Mill 114 produced only softwood
TCF pulp during two separate sampling periods identified as Episodes A and B.
PULPl\0707-01.mcr
3-18
-------
Both mills use oxygen delignification and a bleach sequence with a chelant
stage followed by a series of peroxide stages. Mill 112/113 also uses extended cooking on
both fiber lines. :
At Mill 112/113, AOX was detected (at concentrations up to 2,830 u.g/L
compared to the method minimum level of 20 ng/L) in each bleach plant filtrate sample
i
collected during production of TCP hardwood and softwood pulps. The average mass loading
of AOX in these jbleach plant effluents was 0.015 kg/kkg for hardwood and 0.0021 kg/kkg for
softwood. These; low, but detectable, AOX loadings are likely the result of the frequent
swings between ECF and TCP that occur at this mill (i.e., as a result of incomplete flushing
of the bleach plaijit between campaigns) or cross-over of some chlorine-containing wastewater
from one line to the other (because chlorine dioxide was generated on site and used on one
line while each TCP sampling campaign occurred on the other line). Another possible source
of minimal background levels of AOX is the use of chlorine-containing compounds to
disinfect the mill raw water supply. EPA did not determine, however, if this mill uses
chlorine containing compounds to disinfect its raw water supply.
i ' •
\
At Mill 114, AOX was detected in the bleach plant effluent (at 22 p,g/L in the
acid filtrate and at 69 p,g/L in the alkaline filtrate) on the first day of Episode A but it was
not detected in any bleach plant filtrate sample collected on any other day during Episodes A
or B at this mill.; This mill used chlorine to disinfect the mill water during Episode A (but
not during Episode B), which could have led to a detectable concentration of AOX in bleach
plant effluent. A' few days prior to the start of the TCP bleaching campaign (Episode A), the
mill completed a campaign of chlorine-based bleaching. The fact that a detectable amount of
i
AOX was present in only the samples collected on the first sampling day may be a result of
i
incomplete flushing of the bleach plant between the end of the chlorine-based bleaching
I
campaign and the! TCP campaign. The results from the other samples from this mill show
that AOX is consistently not present above the minimum level of the analytical method.
From these data, EPA concluded that AOX is not generated at levels above the minimum
level when TCP bleaching is performed on a consistent, steady-state basis, as would be the
case at a fiber line certified to be TCP.
PULPl\0707-01.mcr 3-19
-------
3.2.2.2 Pulping Area Filtrate Recycle
Tier II includes a requirement to recycle pulping area effluents that contain
black liquor solids, for the same reasons discussed in Section 3.1.2.3.
3.2.2.3 Discharge Flow
Under the Tier II BAT limitations, mills are required to maintain total pulping
area condensate, evaporator system condensate, and bleach plant wastewater discharge flow of
10 m3/kkg or less, reported as an annual average. EPA is setting an Advanced Technology
limit on flow within the plant because the model technologies EPA expects to be the basis of
Tier BE and Tier III consist primarily of process changes, not end-of-pipe technologies;
measuring the effectiveness of the flow minimization technologies after bleach plant,and
condensate flow is commingled with flows from other parts of the mill, (i.e., at the end of the
pipe) is not feasible. See 40 CFR 122.44(h). Once flow measurement equipment is installed
and operated, EPA expects mills will monitor flow on an ongoing basis, as they would any
other important process parameter. EPA is not establishing minimum monitoring frequencies
for flow or calibration frequencies for flow measurement devices in this regulation. Permit
writers maintain the authority to establish monitoring and calibration frequencies on a best
professional judgment basis. See 40 CFR 430.02.
Bleach Plant Effluent
Bleach plant discharge floWs for bleached kraft mills in EPA's analytical
*5 *3
database range from 6.7 to 88.6 m /kkg. The median value is 24.5 m /kkg. Twelve mills
operate bleach lines with flows between 10 and 20 m /kkg using a range of bleaching
technology from conventional bleaching with chlorine and hypochlorite to TCP bleaching.
Several mills worldwide, summarized in Table 3-4, currently have bleach plant effluent flows
below 10 m^/kkg. These mills are generally advanced technology mills with an active
research interest in technology that minimizes effluent.
PULPl\0707-01.mcr 3-20
-------
«
2
A
H
iD*
O
1
(U
H
S-J
S
i
• l»4
S
CB
i g
"• t*
3
! O
i £Q
i
i
a
**•* bu
ctts JJD- '££
S Js^S
.Ja I
^^ i ESI
6B
0
1
JS
o>
, H
[
, ' S3
, i
P^
s*~-. \^x O
y* ,— ^ CS
s ' \o ^ — ^
Mill uses a ODjEopD2 bleach line. E filtrate recycled to post-oxygen
washing. Dj filtrate reused as bleach plant wash water after treatment by
metals removal process (ion exchange). D2 filtrate is currently sewered;
Champion will experiment with closing this stage by recycling filtrate to the
Eop washer. Mill chloride and potassium balance is maintained by a chloride
removal process (crystallization) performed on precipitator ash. A portion of
the filtrate from the crystallization process is sewered to provide the potassium
and chloride purge.
tH
(D
1 §e
<3 "-C* ^
T] u 3
J=! 3 S
•ts *e 43
oo
"5
CO
Q
§7
O « o"
r \
§*
w
"H. sf
G S
co c
00
0?
^— 4
^^
i^*^S
Jd-
Greenfield mill started up in March 1996. Total mill discharge of 10-15
m3/kkg at start-up, bleach plant discharge of 4 m3/kkg. Provision for total mill
discharge to be reduced to 5 m3/kkg.
&<
o
o .«"
^ 5
"fl ^
S£
^
1 — 1
^-^
Id-
Hardwood line has a four stage sequence. Countercurrent filtrate recycle is
used. First two stages are closed, last two are open to the sewer.
Softwood line has a three-stage sequence. Filtrate is recovered from the first D
stage and the alkaline stage. Second D stage filtrate is sewered.
**"> oo
M co
tL,
0 g
jj~ W
Jf
ffi O co
|
1
£5
O" TQ
^ &
)§ CO
^^
Vl
Designed to achieve 5 m3/kkg.
fe
o
o
I
"H
1
- -a
r"J ^
00 00
^, N
>r^
Planned discharge target once bleach plant rebuild is complete.
d>
g
03
S
OO
g
Q"
o
a
1
s" °^
-------
Three mills in the United States, each using a different technology approach,
achieve bleach plant discharge flow rates under 10 m3/kkg. The Champion, Canton, North
Carolina mill has implemented BFR™-closed cycle technology on its softwood line, and
achieved a bleach plant discharge flow rate of 8 m3/kkg as of March 1997 (20). The
Champion fiber line uses oxygen delignification and ECF bleaching. The Union Camp mill in
Franklin, Virginia uses oxygen delignification, ozone, .and ECF-based bleaching and achieves
a bleach plant discharge flow of 9.4 m3/kkg (5). The Louisiana Pacific mill in Somoa,
California uses a TCP sequence based on oxygen delignification and peroxide bleaching, and
discharged 6.8 m3/kkg of bleach plant effluent as of 1995 (5). Considering the current bleach
plant discharge status of these leading mills, EPA determined that 10 m3/kkg was an
appropriate Tier n long-term average discharge flow limit for bleach plant filtrate and pulping
area and evaporator condensates. While pulping area and evaporator condensates are not
included in the flow totals provided above, these and other mills choosing Tier II will have 10
years to develop and implement the technical approaches necessary to achieve the flow limits.
Opportunities to reduce pulping area and evaporator condensate discharges are discussed
further below.
Pulping Area and Evaporator Condensates
o
Modern kraft mills generate approximately 10 m /kkg of pulping area and
evaporator condensates (21)(22)(23)(24), as totaled below:
Condensate Stream Volume (m3/kkg)
Clean evaporator condensates 8
Dirty condensates
Foul evaporator condensates 1.2
Digester condensates 0.7
Total condensates * 10
Reference (23)(24)
This dirty condensate is frequently steam stripped to remove reduced sulfur compounds (TRS)
and methanol. The relative volume of condensate flow compared to other sources of process
PUU>i\0707-oi.itiCT 3-22
-------
water discharge in a modern mill using ECF bleaching technology is shown below (adapted
from 24): ;
Mill Area Discharge Flow (m3/kkg>
Debarking 1.5 - 4.0
Pulping Area Condensates 10
Bleaching 16
Pulp Drying 9
Some of these flows may be recycled; for example, white water for pulp drying may be
reused for bleach plant washing, and condensates may be reused for brown stock washing or
as make-up water in recausticizing.
Dirty condensates contain many impurities, including alcohols (primarily
methanol), ketoniss, terpenes, sulfur compounds, phenolics, and organic acids, at
concentrations between trace levels and 1 percent by weight. Thus, they can contribute
significantly to many of the adverse environmental effects of kraft mill operations. Foul
condensates have also been linked to toxicity in kraft mill effluent, even after treatment in a
5-day retention aerated lagoon (25).
i • ' •
Treatment and reuse of condensates avoids the discharge of pollutants contained
in condensates, described above. In addition, reuse of condensates is an important component
of water usage and heat conservation programs in a kraft mill operation. Increasing the
quantity of condensates reused and, for some reuse applications, improving the quality of
I
condensates via treatment offers the potential for further reduction in water usage rates and
atmospheric emissions of volatile organic compounds such as methanol from unit processes at
which condensates are reused (22). The latter is the rationale behind the clean condensate
alternative to MACT compliance.
Water conservation that results from condensate reuse will lower mill
consumption of fresh water resources and reduce mill wastewater discharge volume. End-of-
pipe treatment system efficiency for all pollutants will increase with reduced process water
PULPl\0707-01.mcr 3-23
-------
throughput. For example, suspended solids and BOD in effluent generally decrease in
proportion to the amount of water saved (26).
Most mills reuse some condensates, either steam-stripped condensates or clean
evaporator condensates, which are a ready source of hot water. EPA observed during
engineering site visits several mills that had virtually eliminated the discharge of pulping area
and evaporator system condensates through reuse of clean and steam-stripped dirty
condensates (27)(28)(29). Several mills described in NCASI Technical Bulletin
702, which characterizes kraft mill condensates, are also shown to practice virtually complete
condensate reuse (30). Typical areas for reuse include brown stock washing and
recausticizing (22).
Condensates should be free of dioxin and furan precursors if they are used for
pulp washing just prior to bleaching, such as in post oxygen washing. It has been
hypothesized that condensates inadequately treated to remove volatile black liquor
components, but used to wash oxygen delignified pulp, are a source of precursors.
A key factor to consider in evaluating condensate reuse at advanced technology,
minimum-impact mills is that increased bleach filtrate recycle eliminates one of the traditional
primary opportunities for condensate reuse. At advanced technology mills, bleach filtrates are
used as make-up water and wash water on the brown stock side of the fiber line, usually on
the post-oxygen washer. When this is the case, condensates cannot be used for the same
purpose. The challenge at mills developing closed-cycle technology is to find ways to reuse
condensates as beach plant wash water, or in other areas of the mill.
For use in bleach plant washing, condensates need to be free of sulfur
compounds and color to consistently and reliably use them, because the slightest
contamination in the condensate will create a foul odor or other undesirable properties in the
pulp. Additional energy-efficient treatment of condensates, beyond the typical level of steam
stripping, may be'required before they can be fully reused for bleaching, or in other areas of
the mill. Active research is ongoing in this area; in-plant biological treatment and additional
PULPl\0707-01.mcr
3-24
-------
steam stripping are being explored by the industry and technology vendors as possible
treatments (22)(23)(24).
i • • •
In |the case of in-plant biological treatment, pulp mill condensates were hard-
i
piped to a pure-oxygen activated sludge process in a mill-scale trial, and bench-scale studies
of activated sludge treatment of evaporator condensates have been conducted. The results of
these studies suggest that biotreatment of kraft mill condensates to an acceptable quality for
reuse is feasible, and the cost of such treatment is comparable to the cost of control of vent
gases from vacuum drum brown stock washer systems (22). Steam stripping has been used for
years to remove reduced sulfur compounds and methanol from digester area condensates and
the high waste load fraction of foul evaporator condensates. Recent research has focused on
treating a greater quantity of the evaporator condensate, not just the high waste load fraction,
to obtain condensate of sufficient quantity and quality to use it for bleach plant washing (23).
Such an approach is most energy efficient when the stripper is directly integrated between
evaporator effects in the evaporation plant (24).
Technical progress is rapidly advancing in this area, however. The Metsa
Rauma mill in Finland, a greenfield mill that began operation in March 1996, reuses clean
and steam-stripped foul condensates for bleach plant washing (31). Sodracell prefers
condensates over fresh water for bleach plant washing, because metals concentrations in the
condensates are lower than in fresh water (32).
. [
Considering ongoing research efforts and progress made to date in reusing
l
pulping area and evaporator condensates for bleached pulp washing and in other mill
applications, and in view of the 10-year development and implementation horizon for Tier II
limits, EPA has determined that the appropriate Tier II flow limitation is a combined
discharge of 10 m3/kkg or less of bleach plant filtrate and pulping area and evaporator
condensate. EPAj believes it is appropriate to include condensates as part of the specified
wastewater flow yolume because technologies are now becoming available that allow for their
recycle and reuse;! use of these technologies therefore ensures that the cumulative volume of
wastewater flow is reduced to the greatest extent possible.
PULPl\0707-01.mcr ' 3-25
-------
Reuse of condensates is consistent with a MACT compliance alternative known
as the "clean condensate alternative". See 40 CFR 63.447. This alternative focuses on
reducing HAP emissions throughout the mill by reducing the HAP mass in condensate streams
that are recycled to other process areas in the mill. By lowering the HAP mass loading in the
recycled streams, by treatment such as steam stripping, less HAP will ultimately be volatilized
to the atmosphere. Reducing the HAP content of recycled condensates can be used as a
compliance alternative to the kraft pulping standards for the subject equipment in the high-
volume, low-concentration (HVLC) system. To do so, a mill must demonstrate that the total
HAP emissions reductions achieved as a result of condensate treatment are equal to or greater
than the total HAP emission reductions that would have been achieved by compliance with
the kraft pulping system standards for equipment in the HVLC system. This alternative
facilitates the segregation, treatment, and reuse of condensates and thus will assist mills in
achieving the wastewater flow objectives. Inclusion of pulping and evaporator condensates in
the Tier II flow limitations therefore is consistent with the "clean condensate" MACT
compliance alternative and will promote flow reduction through recycle and reuse of the
greatest possible volume of process wastewater. In addition, under the promulgated MACT
standards, EPA has excluded specific sources at kraft mills that burn condensates derived from
steam stripper overhead vent gases from RCRA, further facilitating steam stripping of
condensates.
Compliance with the 10 m3/kkg limit should be assessed on an annual average
basis. Instantaneous discharge flow measurements will vary, and during upset conditions
could be significantly higher. Part of the challenge in achieving this limit will be to avoid
upset conditions and maintain steady-state conditions in the mill water balance so this annual
average discharge flow limit can be achieved! It is anticipated that Tier II mills will capture
and recycle - rather than discharge - liquors during fiber line disruptions through detailed
planning of maintenance outages and contingency planning for unexpected disruptions.
PULPlWOV-Ol.mcr 3-26
-------
3.2.3 Tier II Fiber Line Configurations
Many potential approaches are available to achieve the Tier II limitations, and
more are likely to be developed over the next 10 years. Two of these potential approaches
are presented below. The first relies on oxygen deligniflcation and 100 percent chlorine
dioxide substitution for chlorine, and is referred to in this document as the Tier II - ECF
configuration. The second is based on oxygen delignification and ozone bleaching, with some
chlorine dioxide used for final brightening. A mill using this approach could ultimately
convert to TCF operation by using peroxide for final brightening. This is referred to in this
document as the Tier II - Toward TCF configuration. Cost estimates, pollutant load reduction
estimates, and non-water quality environmental impacts presented in Sections 5, 6, and 7,
respectively, are based on a model mill converting to these two configurations.
Tier II - ECF Configuration .
To comply with Tier II criteria, a mill which preferred ECF technology would
probably have all of the elements described under Tier I, as well as the following
characteristics, although other process options exist, and more can be expected to be
developed over the next few years.
Two-stage oxygen delignification and/or extended cooking with oxygen
delignification to achieve a kappa number into bleaching of 10 to 12 for
softwood and 8 to 10 for hardwood (this facilities use of a lower
chlorine dioxide application rate, enabling the mill to achieve the AOX
limitation);
Improved water reuse within the bleach plant, including partial recycle
of E stage filtrate to post-oxygen washing;
An evaporator upgraded to segregate condensates effectively, integral
stripper, and carryover of black liquor solids below 5 ppm (expressed as
Na); and
Best management practices to prevent or otherwise contain leaks and
spills to the maximum extent feasible and eliminate intentional
diversions of spent pulping liquor, soap, and turpentine.
PULPl\0707-01.mcr 3-27
-------
Some Tier II mills might need to increase the capacity of evaporators, recovery
boilers, or recausticizing departments to accommodate the increased recovery of weak black
liquor and the increased demand for white liquor associated with two-stage oxygen
delignification.
As discussed in Section 3.2.2, to comply with the flow criteria for Tier II,
extensive reuse of the condensates would be required. Reuse of condensates necessitates new
or modernized evaporators because older evaporators generally allow small quantities of black
liquor to carry over to the condensate, which can prevent the condensate being used for
washing bleached pulp. The most recent evaporator systems produce very clean condensate,
through use of integral steam strippers, that can be used for various purposes in the mill, and
are also more energy efficient than older evaporators.
The two-stage oxygen delignification system for softwood lines would achieve
a 65 percent reduction in incoming kappa number, which is the most efficient level of oxygen
delignification currently known to be operating. High-efficiency oxygen delignification
minimizes kappa into bleaching, thus minimizing the bleaching chemicals needed to achieve
adequate brightness, and further reducing the potential for forming chlorinated organics,
including dioxin and furan. Some of the more advanced oxygen delignification systems
currently operating (e.g., Metsa Rauma in Finland (31)) use interstage washing; EPA assumes
most mills upgrading their fiber line to achieve Tier II performance will operate using this
approach.
Using the foregoing mill configuration, a high brightness softwood pulp with
traditional five-stage bleaching would use the following sequence to comply with the Tier II
limits: OWODE0 DED. The E stage would probably be pressurized to increase the
bleaching accomplished in this stage. As a result, the kappa factor could be low to minimize
AOX formation. For the many mills currently operating a short bleach sequence (C/DE0D or
similar), the sequence OWODE D could be used to comply with the Tier II limits. A
schematic diagram of a fiber line with this three-stage bleaching configuration is provided in
PULPl\0707-01.mcr 3-28
-------
Figure 3-6. This three-stage sequence was used as the basis to estimate costs, pollutant load
reductions, and non-water quality environmental impacts of a Tier II - ECF configuration.
Tier II - Toward TCP Configuration
An alternative technical approach to the ECF process discussed above would be
to select an ozone-based process design that could lead eventually to TCF bleaching, at
minimal cost, while avoiding retirement of bleaching equipment before the end of its useful
life. A bleaching sequence such as OWOZE0DQD could be used. Where the mill has only
one chlorine dioxide stage for brightening pulp, the sequence OWOZEQD would be used,
which is depicted in Figure 3-7. This latter sequence was used as the basis to estimate costs,
pollutant load reductions, and non-water quality environmental impacts of a Tier II - Toward
TCF configuration. This approach could also be operated in TCF mode, using a sequence
such as OWOZE0PP.
The Tier II - Toward TCF configuration would have the same elements
described above for the Tier II - ECF configuration, with the following modifications:
Use of ozone in place of chlorine and/or chlorine dioxide in first-stage
bleaching;
Oxygen-enhanced extraction (Eo); and
Improved water reuse within the bleach plant, including recycle of Eo
stage filtrate to the post-oxygen washing.
The key difference from the ECF alternative discussed above is that an ozone
bleaching stage is included. Use of ozone reduces the kappa number of the pulp prior to
brightening with chlorine dioxide to well below the level normal with oxygen delignification.
i
Typical kappa number target would be about 5. This would reduce even further the quantity
of chlorine dioxide required, and also make it possible to recycle the ozone and extraction
stage filtrates (amounting to about 50 percent of the bleach plant filtrate) to the recovery
PULPl\0707-01.mcr , '< 3-29
-------
§
«
2
s
I
H
a>
i-
5
OA
E
s
-------
S3
O
§
1
o
H
i
B
s*
3
CJ)
-------
system without installing special equipment for removing chloride from the recovery cycle.
In some cases, the use of ozone would avoid the need to increase the production of chlorine
dioxide. Hydrogen peroxide could be used to reinforce the Eo stage, but this is not current
practice in the best known mill in the U.S. that uses ozone (33). Hydrogen peroxide has
not been included in the technology basis because it is not needed to enhance the bleaching
process, given the bleaching power of ozone. Mills that do not currently use hydrogen
peroxide would not need to install hydrogen peroxide storage and handling facilities.
3.3 Tierm
3.3.1 Tier m Technology Basis
For Tier III, the ultimate performance requirement for AOX is a long-term.
average discharge of 0.05 kg/kkg or less, measured at the end of pipe. In addition, Tier III
Advanced Technology fiber lines must recycle to chemical recovery systems all pulping-area
effluent generated prior to bleaching that contain black liquor solids. Tier III mills must also
meet limitations for dioxin, furan, chloroform, and the 12 chlorinated phenolic pollutants.
The Tier ffl performance requirements reflect expected performance achievable with minimum
impact techniques that are currently being developed. These technologies are not now
completely defined, and additional technologies and innovations are expected to be developed
over the next 15 to 16 years. No mill is currently meeting the Tier III performance
requirements.
EPA expects that Tier III mills will have all of the technology elements
described under Tier II. In addition, Tier III mills will likely recycle the majority of bleach
plant filtrates back to the recovery cycle. To achieve the required degree of mill closure., the
model Tier III mill will remove metals from bleach filtrate and chloride from the mill liquor
cycle if chlorine dioxide is used for bleaching, and may perform more extensive steam
stripping or other treatment of condensates than for Tier II to allow for full reuse. EPA also
expects that Tier III mills will have advanced process control systems and negligible losses of
black liquor. Finally, Tier III mills will likely have extended liquid storage capacity as part
PULPl\0707-01.mcr 3-32
-------
of their water recycle and liquor management systems to help maintain the hydraulic balance
required for low discharge flow operation. It is anticipated that Tier III mills will capture and
recycle - rather than discharge - liquors during fiber line disruptions through detailed planning
of maintenance outages and contingency planning for unexpected disruptions..
3.3.2 Tier in Performance
3.3.2.1 AOX
EPA has established the AOX criterion for Tier III at 0.05 kg/kkg to reflect the
performance projected to be achievable by mills using extended delignification and ECF
bleaching technology, coupled with cutting-edge minimum effluent technology. As stated in
the discussion of Tier II above, mills using TCP bleaching technology can achieve final
effluent AOX values less than "ML."
E(JF bleaching technology combined with significant bleach plant discharge
flow reduction achieved through the recycle and reuse of bleach plant filtrates can have a
significant impact on final effluent AOX load. Champion International is implementing its
Bleach Filtrate Recycle (BFR™) process at its Canton, North Carolina mill. The BFR™
technology is operating on Canton's softwood ODE D bleach line and the goal is to recycle
the D1 and E stage filtrates through brown stock washing and ultimately to the chemical
recovery cycle. With the Dj and E stages closed, Champion expects a 90 percent reduction
in AOX from the softwood fiber line (16). When this reduction is applied to typical AOX
discharge levels at mills with extended delignification and ECF bleaching (see Table 3-1),
AOX in the range of 0.008 to 0.033 is expected to result.
The Alberta Pacific Forest Industries mill in Boyle, Alberta (AlPac) operates a
swing line that pulps and bleaches hardwood 90 percent of the time, and softwood 10 percent
of the time, using extend delignification and ECF bleaching technology. During the period
January 1995 to May 1996, the final long-term average effluent AOX load for this mill was
0.056 kg/kkg (34). The AOX data for this mill do not reflect the degree of flow
PULPl\0707-01.mcr 3-33
-------
reduction necessary to achieve pulping area and evaporator condensate and bleach plant flow
rate of 5 m3/kkg. As noted previously, flow reduction would contribute to further reduction
in the total mass of chlorinated organic pollutants discharged.
A mill with an OZE0D bleach sequence sampled by EPA discharged 11 m3/kkg
bleach plant filtrate containing 0.085 kg/kkg AOX (35). Final treated effluent AOX data
representing this bleach line are not available. However, assuming that a 45 percent reduction
in AOX would be achievable by end-of-pipe treatment, a bleach line with this ECF
technology would result in a final effluent AOX discharge under 0.05 kg/kkg. Also, further
flow reduction to below 5 m3/kkg would further reduce the discharge of chlorinated organic
pollutants.
Based on these data, EPA has concluded that a long-term average AOX level of
0.05 kg/kkg reflects the performance of the Tier III technology basis. EPA promulgated an
annual average limit equivalent to this long-term average, and is also promulgating a daily
maximum limit based on this long-term average performance multiplied by an appropriate
variability factor. The variability factors used were developed for BAT Option B. The
Option B variability factor forms a rational basis for the Tier III variability factor because the
core technologies that underlie both Option B and Tier III are extended delignification and
ECF bleaching. As described above for Tier II, it could be argued that since the Tier III
limits are lower than the Option B limits, variability under Tier III may be greater than under
Option B. However, any such effect likely would be offset by the better process control
strategies utilized by mills employing Tier HI level technology. Therefore, EPA is using the
Option B variability factor to represent the expected AOX variability under Tier III. Annual
average limits, daily maximum limits, and the 1-day maximum variability factor are presented
in Table 3-5.
PULPl\0707-01.mcr 3-34
-------
Table 3-5
Tier III AOX Limits and Performance Levels for ECF Fiber Lines
Option
TierDI
Long-term Average (Annual
Average Limit} (kg/kkg)
0.05
1-day Variability
Factor
2.28
Daily Maximum
Limit (kg/Jkkg)
0.11
3.3.2.2 Pulping Area Filtrate Recycle
Tier III includes a requirement to recycle pulping area effluents that contain
black liquor solids, for the same reasons discussed in Section 3.1.2.3.
3.3.2.3 Discharge Flow
Under the Tier III BAT limitations, mills are required to maintain total pulping
area condensate, evaporator system condensate, and bleach plant wastewater discharge flow of
o '
5 m /kkg or less, reported as an annual average. Monitoring requirements are the same as
stated above, under Tier II.
EPA has determined that best mills in the world that have implemented
minimum effluent technology can achieve total discharge rates of bleach plant filtrate well
under 10 m3/kkg. These mills are listed in Table 3-4. Significant progress continues to be
made in this area, and a few mills are heading toward total pulp mill closure. Several pulp
and paper companies have stated that mill closure is a desirable environmental goal
(2)(36)(37)
Metsa-Rauma's greenfield pulp mill, designed to use no chlorine chemicals in
bleaching, began operations in March 1996. The goal of the mill's TCP process is a gradual
closing of the mill's water cycles, resulting in a drastic reduction of mill effluents and water
consumption. Currently the mill discharges 4 to 5 m3/kkg bleach filtrate, with a total mill
discharge of 12 ni3/kkg. In 1997, the Rauma mill plans to reduce total discharge to 10
i
PULPl\0707-01.mcr ' . 3-35
-------
m3/kkg, with a future goal of 5 m3/kkg. Clean and foul condensates from black liquor
evaporation are collected separately. Foul condensates are purified by stripping, and then
used (along with the clean condensates) for pulp washing, including bleached pulp washing
(31).
Champion's Canton, North Carolina mill continues to work toward achieving a
bleach plant flow below 5 m /kkg using its BFR™ process. Louisiana-Pacific expects to
reduce discharge of its bleach plant effluent at the Samoa, California mill to about 2-3 m3/kkg
once it has optimized the bleach plant water balance and completed recausticizing area
improvements to allow partial reuse of current Q stage discharges (5).
As described above, the mills leading the world in minimum effluent
o
technology are reducing bleach plant filtrate discharges to under 5 m /kkg. In addition, some
of these mills are reusing condensates to wash bleached pulp, and are developing other
strategies to reuse pulping area and evaporator condensates when extensive bleach plant
recycle is also practiced. Considering ongoing research efforts and progress made to date in
reusing pulping area and evaporator condensates for bleached pulp washing and in other mill
applications at minimum effluent mills, as described in Section 3.2.2.3, and in view of the
15-year development and implementation horizon for Tier III limits, EPA has determined that
the appropriate Tier El flow limit is a combined discharge of 5 m3/kkg or less of bleach plant
filtrate and pulping area and evaporator system condensate.
3.3.3 Tier HI Fiber Line Configurations
Both ECF and TCF technical approaches are possible to comply with the
Tier El criteria. Both approaches are discussed below. The ECF approach is referred to in.
this document as the Tier III - ECF configuration, and similarly, the TCF approach is the Tier
III - TCF configuration. Cost estimates, pollutant load reduction estimates, and non-water
quality environmental impacts presented in Sections 5.0, 6.0, and 7.0, respectively, are based
on a model mill converting to these configurations. However, in view of the substantial
degree of mill process closure required, and the time allowed for compliance, it is likely that
PULPl\0707-01.mcr 3-36
-------
innovative technologies will be developed which would differ from the two alternatives
discussed below.
Tier III - ECF Configuration
To comply with Tier III criteria, a mill which preferred ECF technology would
probably have all of the elements described under Tier I, as well as the following
characteristics:
• ; Recycle of virtually all bleach plant filtrates to the recovery cycle.
• System to remove metals from recycled bleach plant filtrates.
• System to remove potassium and chloride from the liquor cycle.
• ; An evaporator upgraded to segregate condensates, effectively, integral
stripper, and carryover of black liquor solids below 5 ppm (expressed as
Na).
• Best management practices to prevent or otherwise contain leaks and
i " spills to the maximum extent feasible and eliminate intentional
• diversions of spent pulping liquor, soap, and turpentine. The BMP
1 system would include extended storage capacity.
• Advanced process control systems.
The only commercial scale process for removing metals from recycled bleach
plant filtrates and potassium and chloride from the liquor cycle is in operational trials at the
Champion mill in Canton, NC (38)(39). The Champion system is known as the
"Bleach Filtrate Recycle™',' (BFR™) process and incorporates a system to remove chlorides
and potassium from the recovery boiler, a system to remove low-solubility metals from the
acid filtrate from, the bleach plant, and modifications to the bleach plant water system to
minimize water input. The BFR™ process is mentioned frequently in this report because it is
the most advanced system of its type operating in the U.S. Alternative processes exist, and
several organizations (PAFRICAN, MoDo, Eka Chemicals) have active research and
development programs which can be expected to result in further alternatives and competitors.
PULPl\0707-01.mcr 3-37
-------
Within the BFR™ process, bleach plant filtrates are reused for pulp washing
and ultimately recovered in the kraft recovery cycle. Chloride from bleaching a potassium
from the wood are purged using a Chloride Removal Process (CRP), which operates on the
basis of the greater solubility of sodium and potassium chloride relative to sodium sulfate.
Electrostatic precipitator ash, which is enriched in chloride and potassium, is dissolved and
recrystallized to produce solid sodium sulfate which is dissolved in black liquor and recovered
in the recovery boiler, and an aqueous chloride and potassium waste stream discharged to
wastewater treatment which acts as the purge of these substances from a BFR™ mill (17).
Mineral impurities from the wood such as calcium, magnesium, and manganese
are purged from the system using a Metals Removal Process (MRP) to avoid the build-up of
these substances and the subsequent adverse effects on mill operations. The MRP utilizes ion
exchange to remove the minerals of concern from the first C1O2 bleach stage filtrate, while
exchanging them with an equivalent amount of sodium ions (17).
The BMP system would probably incorporate greater storage than for a normal
mill to assist in maintaining hydraulic balance and to avoid discharges during transient upsets.
Well designed, modern process control systems, and a high quality of operator
training would be necessary to attain sufficiently stable operation to comply with Tier III
criteria.
It would be possible, but not necessary, to use an enhanced oxygen
delignification system, as was the case under the Tier II - ECF configuration since the BFR™
system can remove the necessary amount of chlorides from a mill that has normal oxygen
delignification, as demonstrated by operation at the Canton mill. A bleach sequence such as
ODEot)DED could be used. Where the mill has only one chlorine dioxide stage for
brightening pulp, the sequence ODE0 D would be used, which is depicted in Figure 3-8. The
cost estimates, pollutant load reductions, and non-water quality environmental impacts of a
Tier in - ECF configuration are based on this three-stage sequence, along with the other Tier
HI ECF technology components discussed above. Note that using the BFR™ technology does
PULPl\D707-01.mcr 3-38
-------
i
«
2
g>
s
c
o
'a
•»•*
H
op
OS
en
-------
increase bleach chemical usage, including chlorine dioxide, since some pulp washing
efficiency is lost due to the recycle of filtrates within the bleach plant.
Other ECF approaches may also be developed that the Tier III requirements
that do not rely on BFR™ technology. For example, two-stage oxygen and ozone
delignification could be used so only a small amount of chlorine dioxide would be used for
final brightening. Such a mill could potentially recycle bleach plant filtrates and achieve Tier
HE requirements without the use of the chloride removal process. In addition, some mills are
currently hoping to achieve the functional equivalent of MRP by installing an Ahstrom X-
filter for green liquor filtration (5) so that metals will be removed from the process in filter
dregs. EPA believes that these and other competitive technologies will evolve over the 16-
year period mills have to comply with the Tier m requirements.
Tier HI - TCF Configuration
A Tier HI TCF mill would have all the characteristics discussed in Section
3.2.3 for a Tier II -.Toward TCF Configuration as well as the following:
• Recycle of virtually all bleach plant filtrates to the recovery cycle;
• Equipment to remove metals from bleach filtrates;
• Hydrogen peroxide bleaching stage capable of using large charge
effectively;
• Advanced process control system; and
• Extended storage for the BMP system.
EPA used the bleach sequence is OwO(ZQ)PP (depicted in Figure 3-9) as the
model mill basis for the Tier III - TCF configuration cost estimates, pollutant load reduction
estimates, and non-water quality environmental impacts presented in Sections 5.0, 6.0, and
7.0, respectively. This is only one of many possible TCF bleach sequences. Because much
of existing mill equipment can be used to provide the necessary retention time and washing
PULPl\0707-01.mcr 3-40
-------
C
o
•-a
2
o
U
fa
U
H
I
4>
*PM<
H
•
I
to
-------
capacity for the peroxide brightening stages, bleach sequences are often determined by
existing mill configurations.
To achieve bright, strong pulp while bleaching with peroxide, the kappa
number of the pulp must be reduced to low levels prior to final brightening with hydrogen
peroxide. This is achieved with the two-stage oxygen delignification followed by an ozone
stage. 'Existing TCP mills have used a variety of approaches to achieve substantial brightness
gains with hydrogen peroxide. These include raising temperature in existing towers, replacing
an existing tower with a pressure vessel, and installing a short pressurized peroxide reactor
immediately upstream of an existing bleaching tower. The model mill Tier III - TCP
configuration is based on the latter technology.
EPA has noted that the two most modern TCP kraft mills in Europe have both
observed serious problems with mineral scale formation when attempting to operate at effluent
flows substantially below 10 m3/kkg. Therefore, EPA's Tier III TCP model mill uses a
system to remove calcium and related metals, similar to that used in the BFR™ process.
PULPl\0707-01.mcr
3-42
-------
4.0 SCHEDULE TO IMPLEMENT ADVANCED TECHNOLOGIES
In;order to promote the pollution prevention objectives of the Voluntary
Advanced Technology Incentives Program, EPA has determined that existing mills choosing
to participate in the program should receive a reasonable amount of time, beyond the time
available for compliance with baseline BAT, to achieve the Advanced Tier performance levels
they select.
The extended tune frames discussed in this section are not available for new
sources enrolled in the Voluntary Advanced Technology Incentives Program because the
Clean Water Act requires new sources to comply with NSPS upon starting operation.
However, new sources interested in participating in the Voluntary Advanced Technology
Incentives Program after commencing operation may nevertheless do so, for example, by
achieving the baseline NSPS requirements at the time discharges commence and later
achieving the more stringent AOX and flow requirements of Tiers II or III. Once limitations
equivalent to the selected advanced tier performance levels are placed in the mill's permit and
the mill achieves; those limits, it is eligible to receive incentives.
4.1 Schedule to Achieve Compliance with Tier Limits
EPA assumes that most mills, for practical purposes, will decide whether to
participate in the Voluntary Advanced Technology Incentives Program within one year of the
promulgation date in order to assure that they will have the maximum amount of time to
achieve the various tier limitations.
EPA has determined that the following schedule by which existing sources can
achieve Advanced Technology performance requirements is reasonable: 5 years for Tier I, 10
years for Tier II, and 15 years for Tier III. These periods are in addition to the initial year
during which mills subject to Subpart B would decide whether to enroll in the Voluntary
Advanced Technology Incentives Program. The 5-, 10-, and 15-year periods correspond to
the time EPA believes a mill would need in order to arrange its financing and to develop,
PULPl\0707-01.mcr ; 4-1
-------
install, and test the chosen Advanced Technologies under Tiers I, II, and III, respectively.
Support for the 5-, 10-, and 15-year periods is presented below.
4.1.1 Tier I
Five years is a reasonable time frame to achieve the Voluntary Advanced
Technology BAT limitations corresponding to Tier I. The technology basis of the Tier I
limits, extended delignification and 100 percent chlorine dioxide substitution for elemental
chlorine, is commercially available, and can be designed, installed, and stabilized within the 5-
year period. When spread over five years, the capital costs of the associated technologies
become more affordable (although they are still significantly higher than the capital costs
associated with the baseline BAT). The 5-year period makes the technology more affordable
because it gives mills increased flexibility to schedule the significant capital investment within
the mill's normal capital investment cycle (i.e., to purchase and install the necessary
equipment when capital is available). Therefore, EPA believes the 5-year period will enable
individual mills to participate in the Voluntary Advanced Technology Incentives Program that
otherwise might not have the financial resources to make the necessary capital investment.
4.1.2 TierH
Ten years is a reasonable time frame to achieve the Voluntary Advanced
Technology BAT limitations corresponding to Tier II because the development and
implementation of technologies to reduce bleach plant and condensate flow to 10 m3/kkg pose
technical and economic difficulties that EPA believes will take mills up to 10 years to resolve.
(Once flow levels are reduced, EPA expects that mills also will be able to achieve the Tier II
AOX limitations.) Recycling a substantial portion of pulping and evaporator condensates and
bleach plant filtrates, with the attendant complexities of total mill water, chemical, and energy
balances, requires considerable time before it can be implemented successfully at the mill
scale. For example, when bleach plant filtrates are recycled, problems with scale and
corrosion can take many months to over a year to develop and be observed. Once identified,
fully correcting such problems can take significant additional time because of the time lag
PULPl\0707-01.mcr 4-2
-------
between action and observed effect in systems with high rates of recycle. In addition to
problems with scale and corrosion, mills pursuing Tier if performance levels may have to
solve challenges associated with reusing condensates, particularly if they must be used for
bleached pulp washing. Consequently, EPA expects that Tier II mills will need to invest
considerable time and effort to research and develop solutions to those technical problems. In
addition to the technical challenges, significant capital costs can be involved in achieving Tier
II limits, notably; as a result of rebuilding or replacing full pulping and bleaching lines and
upgrading associated evaporator equipment. Providing an extended time frame that allows a
mill to make such capital expenditures on a schedule consistent with its planned investment
cycle can make such large investments economically achievable. Examples supporting the 10-
year compliance period for Tier II mills are provided below.
1 t
Champion, Canton. North Carolina
The Champion mill in Canton, North Carolina, currently approaching the Tier
i
II flow and AOX levels, installed many of the relevant technologies in stages over what
ultimately will be a 10-year period. The last three years of this installation period will be
used for testing and fine-tuning the BFR™ reduced flow processes. Despite its significant
progress in reducing bleach plant flows, even this mill still needs to address the technical
challenges of further reducing condensate discharge flow before it would be fully able to
achieve the Tier II BAT limits. The Canton mill needed 10 years to plan its multi-hundred
million dollar renovation and pollution prevention investment, to arrange appropriate
financing, to install supporting technologies at appropriate intervals and to research, develop,
test, and refine its innovative flow-reducing processes. EPA believes that this mill's
experience is representative of what other mills are likely to encounter as they work to
achieve the Tier II limitations. (40)
PULPl\0707-01.mcr 4-3
-------
Union Camp. Franklin, Virginia
The development of ozone delignification is another example supporting the
10-year period to develop, install, and make Tier II technology fully operational. Ozone
delignification was studied extensively for about five years in the early 1970s by several
companies, then development was abandoned due to a combination of technical difficulties in
producing sufficiently pure ozone, lack of requirements to improve effluent quality, and lack
of cost-competitiveness.
Union Camp began studying ozone in 1985, because they foresaw the
possibility of using it to comply with local permit limitations. They searched the literature
and conducted theoretical studies in 1985, and conducted laboratory studies throughout 1986
and 1987. They designed and built a pilot plant in their Eastover, South Carolina mill in
1987 to 1988, and started a pilot-plant operation in 1988. A new bleach plant (the "F-line")
was built at the company's Franklin, Virginia mill in 1992. The F-line was designed and
built to operate with or without ozone. After initial operating difficulties and further
equipment development, the F-line was in full commercial production in late 1993, and has
operated successfully since then. (33)
The total development time for bringing ozone delignification to full-scale
commercial operation was therefore nine years from initial studies by the first successful
developers. Other companies have also developed successful ozone delignification technology
in the same time frame.
Louisiana-Pacific, Somoa, California
In September 1991, the U.S. Environmental Protection Agency, the Surfrider
Foundation, and Louisiana-Pacific Corporation (L-P) agreed to terms of a settlement for L-P's
Samoa, California mill to meet more stringent wastewater discharge standards. L-P agreed to
gradually convert the mill's bleached pulp production to 100 percent TCP pulp from
September 1992 through September 1995, using an OQPPPP bleach sequence. TCP pulp was
PULPl\0707-01.mer 4-4
-------
made in campaigns with a goal of gradually increasing duration as the market demand for
TCP pulp increased. (41) , :
Process changes made at the mill in the 1980s paved the way for conversion to
TCP bleaching and low-flow operation by the mid-1990s. Starting in 1986, pressure screens
were installed and the brown stock screening area was closed. In 1989, an oxygen
delignification system was installed. In 1990, a low-odor recovery boiler was installed, the
evaporators were| upgraded, and concentrators were installed. (41)
When operators had gained sufficient experience making TCP pulp (the pulp
properties, particularly brightness, improved from campaign to campaign), the mill began
research on ways to eliminate the bleach plant wastewater discharge. By May 1995, the mill
had eliminated the wastewater discharge from all but the chelant stage. The mill was
configured so that (eventually) half of the chelant stage discharge would be pumped to the
recausticizing area for reuse and half would be used for upstream fiber washing. L-P installed
a new green liquor filter in the recovery area in 1996 to accommodate this change. L-P also
conducted a low-solids cooking trial in October 1995, which improved closed-cycle operation.
Other improvements made during this same time included better process/hydraulic control.
(42) Thus, in the course of 10 years, through a series of planned investments focused on
creating a minimum-impact mill, L-P has installed most of the technology basis needed to
achieve the Tier II limits. •
Based on these experiences, EPA believes that the package of technologies
underlying the Tier II Voluntary Advanced Technology BAT Limitations will be technically
and economically achievable for mills aspiring to those performance levels within 10 years.
4.1.3 Tier III
Fifteen years is a reasonable time frame to achieve the Voluntary Advanced
Technology BAT limitations corresponding to Tier III. As for Tier II, flow reduction again is
the most difficult, and time-consuming task. However, because reducing flow for pulping and
PULPl\0707-01.mcr 4-5
-------
evaporator condensates and bleach plant filtrates to 5 m3/kkg or even lower approaches a
closed mill configuration, even more technically difficult and time-consuming tasks must be
successfully completed, necessitating five additional years beyond the Tier II time frame. For
example, mills would probably need to install "kidney" technologies to remove metals and
chlorides in order to control system scaling and corrosion problems while maintaining product
quality and minimizing cross-media impacts. Successful completion of these tasks at
individual mills will involve extensive research, process development, and mill trials. The
types of corrosion and scaling problems EPA anticipates could take over a year of nearly
closed-loop operation to identify and several more years of experimental modifications to mill
operations to solve. Extensive time is required for such modifications because of the time lag
in nearly closed mill systems from changing process conditions and observing the steady-state
impact on hydraulic systems, liquor systems, and associated mill equipment. Mills may also
need to embark on research, process development, and mill trials to achieve treated
condensate quality that is sufficient to extensively reuse condensates. Mills will also need
time to establish the complex mill water and energy balances necessary for nearly closed cycle
operation. For these reasons, EPA believes that 15 years is a reasonable amount of tune for a
Tier HI mill to perfect existing technologies or invent or develop new ones as necessary to
achieve the Tier III performance levels.
4.2 Interim Limitations
The following interim limitations are applicable to existing sources as they
make progress toward the ultimate incentives tiers limitations. As discussed in Section 4.0,
new sources are eligible to enroll only at the Tier II or III levels and must achieve compliaince
with the associated performance requirements upon commencing discharge. Thus interim
limitations are not applicable to new sources.
4.2.1 "Stage 1" Limitations
As described in the preamble for the promulgated regulations, EPA has
established "stage 1" limitations for dioxin, furan, chloroform, AOX and 12 chlorinated
PULPl\0707-01.mor 4-6
-------
phenolic pollutants that, for each pollutant, are equivalent to either the technology-based limit
on that pollutant, hi the mill's last permit :or the mill's current effluent quality with respect to
the pollutant. These limitations are enforceable as soon as they are placed in the mill's
permit.
EPA did not set "stage 1" limits at the baseline BAT level because the
technology basis; underlying the baseline BAT limits is not a logical first step to meeting the
ultimate Advanced Technology BAT limitations. As a technical matter, mills subject to such
interim limits most likely would need to install more chlorine dioxide generator capacity than
they ultimately would use to achieve the Advanced Technology performance requirements.
EPA believes most Advanced Technology mills ultimately will employ complete substitution
of chlorine dioxide for elemental chlorine, preceded by extended delignification processes.
Based on the current chemical application rates hi the EPA Pulp and Paper BAT Baseline
Database (14), EPA estimates the chlorine dioxide usage rates shown in Table 4-1 at mills
using complete substitution of chlorine dioxide when differing degrees of extended
delignification technology are also employed. As shown on the table, because extended
delignification technology reduces the chlorine dioxide demand, immediate compliance with
baseline BAT before mills have a chance to invest in extended delignification technology,
could lead to installation of approximately 30 to 75 percent excess chlorine dioxide generation
capacity. ;
Table 4-1
Reduction in Chloride Dioxide Usage Through Extended Delignification
Technology Basis
BAT Baseline
Tier I (oxygen
delignification)
Tier II (Toward
TCP Configuration)
* First D-Stage
dO2 Charge
(kg/fckg palp)
22
9-13, depending
on percent
delignification in
OD
eliminated
Brightening Stage
C1O2 Charge
(fcg/kkg pulp)
10
10
8
Total C1O2
Charge
32
19-23
8
Percent Reduction
over BAT Baseline
-
28-40
75
•PULPl\0707-01.mcr
4-7
-------
4.2.2 Interim Milestones
4.2.2.1 Limitations Equivalent to Baseline BAT
EPA is requiring mills at the Tier II and Tier III levels to achieve- interim
limitations equivalent to baseline BAT within six years. (Mills at the Tier I level must
achieve, by year six, limitations equivalent to the baseline BAT requirements for dioxin,
furan, chloroform and the 12 chlorinated phenolic pollutants as well as the ultimate Tier I
performance requirements for AOX, kappa number, and filtrates recycling.) The interim
milestones imposed on Tier II and III mills is a reasonable requirement because it reflects the
technology performance Tier II and Tier III mills are likely to be achieving within this period.
EPA expects that all Tier II or Tier IE mills will need to install extended delignification and
complete substitution (ECF) or TCP bleaching processes well in advance of achieving their
wastewater flow objectives in order to allow sufficient time to design, install, test, and adjust
their other flow reduction related processes. Thus, in EPA's judgment, installation of
extended delignification and ECF or TCP bleaching can and will occur within the first six
years of the advanced technology program. Once these processes are installed, the mill will
be achieving or exceeding the baseline BAT limitations.
Baseline BAT limitations also have been promulgated for AOX, measured at
the end of pipe. The limitations are 0.623 kg/kkg on a monthly average basis, and 0.951
kg/kkg measured as a daily maximum. Comparing these limitations to the AOX performance
levels of mills that have installed extended delignification technology, shown in Section
3.1.2.1, it is clear that mills will be able to achieve the BAT baseline limitations once they
have installed extended delignification and ECF bleaching technologies.
4.2.2.2 Interim Milestones
A second set of enforceable interim milestones will be applied to all mills
enrolled in the Voluntary Advanced Technology Incentives Program. The type and frequency
of these milestones is left to the permit writer's best professional judgment. As appropriate,
PULPl\0707-01.mcr 4-8
-------
milestones should include research schedules, construction schedules, mill trial schedules, or
other milestones tailored to the circumstances and advanced technology at the participating
mill. In addition to such schedule milestones, the milestones established at the Tier n and
Tier III levels would likely include intermediate pollutant load and wastewater flow
reductions.
In order to facilitate the development of appropriate interim milestones on a
case-by-case basis, EPA is proposing a regulation that would require all mills enrolling in the
incentives program to submit plans to their permitting authority detailing the strategy the mill
will follow to develop and implement the technology they intend to implement to achieve the
chosen incentive tier, and in the case of Tiers II and III, the interim numeric limitations. As
proposed, these "Milestone Plans" would need to describe each envisioned new major
technology component or process modification the mill intends to employ to achieve the
Voluntary Advanced Technology BAT limits. A master schedule would need to be included
in the plan showing the sequence of implementing the new technologies and process
modifications and identifying critical path relationships within the sequence. For each
individual technology or process modification, EPA proposes to require each enrolled mill to
provide a schedule that lists the anticipated date that associated construction, installation, or
process changes will be initiated, the anticipated date that those steps will be completed, and
the anticipated date that the full Advanced Technology process or individual component will
be fully demonstrated as operational.
For those technologies or process modifications that are not commercially
available or demonstrated on a full-scale basis at the time the plan is developed, the plan
would also need to include, a schedule for research (if necessary), process development, and
mill trials. As proposed, the schedule for research, process development, and mill trials
would also need to show major milestone dates and the anticipated date the technology or
process change will be available for mill implementation.
PULPl\0707-01.mcr 4-9
-------
With respect to the level of detail required in the plans, EPA considers the
individual major technology components and process modifications referenced above to be
items such as:
Oxygen delignification;
100 percent substitution of chlorine dioxide for chlorine;
Closed screen room operation;
Ozone delignification;
Recycle of Eop filtrate to brown stock washers; and
Reuse of clean condensate for bleached pulp washing.
The above list is not intended to be exhaustive, but rather is intended to
provide through example the scope of the projects that would need to be specified in the
milestone plan, if EPA promulgates the requirement as proposed. The Milestone Plan thus
would need to include the following:
• Overview of Technical Strategy;
• Description of Technology Elements;
• Implementation Schedule
— Master Schedule
— Research and Development Schedule;
• Contingency Plans; and
• Appendix of Supporting Documentation.
The overview of the technical strategy would need to lay out the approach the
mill intends to follow to achieve the ultimate limitation for the tier they are enrolling in. As
proposed, the description of technology elements would need to provide a written description
of each individual technology and process modification that the mill plans to employ. For
technologies or process modifications not yet fully developed, concept-level descriptions
would be sufficient.
PULPl\0707-01.mcr 4-10
-------
EPA proposes to require mills to produce the schedules using common project
management approaches, such as the Critical Path MethSd (CPM), the Program Evaluation
and Review Technique (PERT), or equivalent methods. The primary attributes of these
methods is that they show required project tasks, associated milestones, and interdependencies
among tasks within the schedule. Enrolled mills would also be authorized to show project
schedules using Gantt charts (bar charts) as long as the interdependencies among tasks are
clearly defined.
As proposed, the plan also would need to address a process for consideration
and concurrent development of appropriate alternative technologies or components as
contingency in the event that initially identified technologies or components become
problematic. These alternatives would be implemented, if necessary, at appropriate decision
points in the master schedule to ensure that the ultimate tier limits are achieved by the dates
specified in the permit.
Finally, if EPA promulgates the milestones plan requirement as proposed, the
appendix of supporting documentation would need to contain sufficient information to validate
the proposed technical strategy. Documentation such as vendor information, preliminary
engineering studies, feasibility studies, research proposals or reports, and literature on
minimum effluent and closed cycle technology may serve this purpose. EPA expects the
permitting authority to use the information contained in these plans, as well as its own best
professional judgment, to establish enforceable interim milestones applying all statutory
factors.
PULPl\0707-01.mcr 4-11
-------
-------
5.0 COSTS OF ADVANCED TECHNOLOGIES
5.1 Cost Overview
Cbsts of complying with the Voluntary Advanced Technology Incentives
Program BAT limitations and NSPS are presented in this section. The costs presented are
based on two different scenarios:
A base-case mill is upgraded to comply with the criteria of one of the
BAT Incentives Tiers. This is described herein as a "modified" mill.
A company decides to build a new fiber line. Such a fiber line might
be a replacement of one or more fiber lines at an existing mill site, hi
which case the company could enroll the fiber line in BAT Incentives
Tiers I, II, or III. In the alternative, the new fiber line might
supplement existing fiber lines at a mill site, or be installed at a
greenfield site, in which case the fiber line could be enrolled in either
NSPS Incentives Tier II or Tier IE. Whether complying with BAT or
NSPS, the capital and operation and maintenance costs of an new fiber
line would be the same.
In- practice, it is possible for an intermediate situation to exist. For example, a
company may be installing a new bleach plant, but intending to retain the existing digester
and brown stock washing area. In this case, the costs of complying with one of the more
advanced criteria would be between the two extreme cases mentioned above. EPA prepared
detailed cost estimates for making the modifications in the first case to a model mill. These
estimates are presented in Section 5.2. EPA also prepared estimates of the cost of installing
new fiber lines. These estimates are presented in Section 5.3.
EPA estimated the costs of using both ECF bleaching and TCP bleaching
wherever appropriate. Where new fiber lines are considered, TCP bleaching is slightly less
costly than ECF bleaching. The differences in capital and operating costs are small relative to
the total cost, and probably are less significant than the differences caused by site-specific
conditions and by the quality of engineering and project management. In the case where an
PULPl\0707-01.mcr 5-1
-------
existing fiber line is to be retrofitted to comply with the Incentives criteria, TCP bleaching is
generally substantially more expensive than ECF bleaching.
EPA estimated the costs presented hi this section using a modified version of
the BAT Cost Model (43). The modified model is known as the "Incentives Program
Cost Model." It uses the same equations and base data as the BAT Cost Model, with.
additional equations for the equipment and systems not included in the BAT model such as
Bleach Filtrate Recycle (BFR™) technology and TCP bleaching equipment. These equations
were developed on the same basis as the BAT equations, but in view of the limited number of
BFR™ and TCF installations, they are not supported by the broad base of data that supports
the BAT cost model equations.
5.2 Modifying a Typical Mill to Comply with Tier Limitations
5.2.1 Costs of Retrofitting a Case Study Mill to Comply with Tier Limitations
The capital and operating costs of converting a model mill to comply with
limitations under the Voluntary Advanced Technology Incentives Program are shown in Table
5-1. The baseline BAT compliance costs for this model mill are also shown for comparison
purposes.
As shown on the table, EPA estimated the costs for using ECF bleaching
technology for all three tiers, and also for using a "Toward TCF" approach for Tier II and a
full TCF approach for Tier HI. The detailed technology bases underlying these cost estimates
are described in Section 3.0 of this report. The annualized costs presented on the table were
calculated m the same manner described in Section 10.2.4 of the Supplemental Technical
Development Document (STDD) (44). The costs per ton of pulp in Table 5-1 cannot be
compared directly with those for a new fiber line, since the latter include costs for
replacement of the whole fiber line.
PULPt\0707-01.mcr 5-2
-------
I
a>
1
H
a
-2
.-§
£
J
E
03
2
U
O>
a
.2
"E.
o
«*-!
O
en
O
U
fe
^r
H
T
S3
!W
.2?
o
i
8
fe
H'
fa
o
H,
t3
)M
S
a
j_i
i
i.
^
cs"
00
o
0
vd1
r-
oo
|
in"
m
ro"
s
<«
o
*«
3
s
5
c
o
i %
-o o
< U
o
00
m
o
o\
**
o
.°>
fS
6%
0
^"
CS
T-H
o
en
i— I
O
in
T— 1
69
'
_o
6§
_^ "
•CO
O
U
-a
1
c«
If
=§,
o
o
o
•o
CD
V3
g
Z.
u
i
Q
I
1
J
o
£
1
&1
§-
CO
^
_o
t5
u
w
o
-o
o
-o
I
CJ
3
"cB
o
U
I
5-3
-------
These costs represent the probable maximum for a mill to comply with the
limitations established under the Voluntary Advanced Technology Incentives Program. They
involve replacement of much of'the existing bleach plant. In many cases, mills would be
combining the modifications for the Incentives Tiers with modernization for other reasons,
such as the end of useful life of existing equipment, so the real costs would be somewhat less.
There are differing opinions as to whether ECF or TCP technology is more
appropriate for reducing effluent discharges to the levels required by the limitations for
Tiers IE and HI. The cost for both ECF and TCP technology have therefore been estimated
for Tier HI. For Tier H, costs.were estimated for an ECF approach and for a "toward TCP"
approach, which would be a logical prelude to converting the mill to TCP operation, and
would therefore be likely to be selected by mills with the intention of adopting TCP
bleaching. Details are discussed below.
5.2.2 Model Mill and Base-Case Cost Estimates
EPA estimated costs for modifying one operating case study mill, from the
technology level as it existed in late 1995 to the technology level of each of the incentives
tiers. The case study mill is an integrated, 1,000 UBt/day, bleached kraft mill, with
conventional pulping of softwood and hardwood on two lines of equal size. The mill
currently bleaches with limited chlorine dioxide substitution using a three-stage C/DE D
bleach sequence on each line. This is typical of the mills which are likely candidates for
being upgraded to obtain the benefits available to mills complying with the criteria of the
Voluntary Advanced Technology Incentives Program, as EPA assumes mills enrolling fiber
lines in the Incentives Program at the Tier II and Tier III level will most likely be those in
need of renovating or expanding large portions of the pulp mill (e.g., evaporators and
recovery boilers). Modern, efficient equipment will greatly facilitate meeting the performance
levels of the incentives tiers. The costs for upgrading to each of Tiers I, II, and III were
estimated on the assumption that each of the fiber lines at the base-case .mill would be
modified for the same selected Tier in one cohesive modernization program, which may be
spread over several years. The costs discussed herein therefore provide a comparison of the
PULPl\0707-01.mcr 5-4
-------
cost for upgrading to each tier, but do not provide any indication of the cost of converting
fiber lines already complying with Tiet II criteria to Comply with Tier III criteria.
The baseline BAT cost estimate shown hi Table 5-1 for comparison purposes is
the cost for this mill to comply with the promulgated baseline BAT limitations, based on 100
percent substitution of chlorine dioxide for chlorine and the other elements of BAT Option A,
described in the preamble.
5.2.3 Tier I Cost Estimate
The mill configuration that served as the basis of the Tier I cost estimate is
fully defined in Section 3.1.3. The configuration includes oxygen delignification followed by
ECF bleaching and is equivalent to BAT Option B.
5.2.4 Tier II Cost Estimate
EPA based the Tier II model mill cost estimates on two potential approaches.
The first relies on two-stage oxygen delignification and 100 percent chlorine dioxide
substitution for chlorine and is referred to as the Tier II - ECF configuration. The second is
based on two-stage oxygen delignification and ozone bleaching, with some chlorine dioxide
used for final brightening. A mill using this approach could ultimately convert to TCF
operation by using peroxide for final brightening. This is referred to as the Tier II - Toward
TCF configuration. The technology basis of these two approaches are fully defined in Section
3.2.3. ;
There is no specific cost allowance for the improvements in BMPs over Tier I
that would be necessary for Tier II, because it is believed that the improvements will be
realized primarily: by improved operating skill. The cost model does include an allowance of
0.5 percent of the capital cost of all new equipment installations added to the annual operating
cost, to allow for the increased level of technical support that is necessary when more
advanced equipment is installed.
PULPl\0707-01.mcr • 5-5
-------
EPA assumed for the purposes of estimating Tier II compliance costs that mills
already have condensate strippers, or will install them to comply with MACT or other
regulations.
Some of the more advanced oxygen delignification systems currently operating
(e.g. Metsa Rauma in Finland (31)) use interstage washing, and the costs for two-stage
oxygen delignification estimated for the Tier II - ECF configuration is based on the
assumption that this equipment would be included.
5.2.5 Tier m Cost Estimate
EPA developed cost estimates for both a Tier III - ECF configuration and a
Tier IE - TCF configuration. Detailed technology bases of these two approaches are provided
in Section 3.3.3. In addition to the technology bases described in Section 3.3.3, EPA made
the following technical assumptions in developing the Tier III cost estimates.
The BMP system would probably incorporate greater storage than for a normal
mill to assist in maintaining hydraulic balance, and to avoid excessive discharges during
transient upsets or maintenance outages and disruptions. An allowance for storing 10 m
waste waters per daily ton pulp production capacity in an outdoor pond is included hi the
capital cost estimate. (This is approximately five times the size of the storage assumed for
calculating costs for BMP as part of the BAT cost estimates (43).
There is an allowance for the capital cost of the BMP system for Tier III of 50
percent greater than that for Tiers I and II, since it will have to be very efficient. There is no
specific allowance for the improvements in operation of the BMP system over Tier I that
would be necessary for Tier III, for the reasons discussed above for Tier II mills.
Well designed, modem process control systems, with rigorous statistical process
control, and a commensurate level of operator training would be necessary to attain
PULPl\0707-01.mcr 5-6
-------
sufficiently stable operation to comply with Tier III limitations. An allowance for upgrading
process controls has been included hi the capital cost estimates.
EPA has noted that the two most modern TCP kraft mills in Europe have both
observed serious problems with mineral scale formation when attempting to operate at effluent
i -3
flows substantially below 10 nr/kkg. The estimated costs for a system to remove calcium
and related metals, similar to that used in the BFR™ process, are included in the estimate for
complying with Tier III criteria, whether ECF or TCP.
5.3 Building a New Fiber Line to Comply with Tier Limitations
The foregoing discussion refers to retrofitting advanced ECF and TCP
technology to an existing mill. Where a company is replacing an entire fiber line, or building
a new fiber line.; the capital costs differ substantially from retrofitting, and are discussed
below. As discussed in detail in the preamble to the promulgated regulation, EPA is
characterizing the replacement of entire fiber lines as an existing source modification if those
fiber lines are enrolled in the Voluntary Advanced Technology Incentives Program, subject to
BAT. Without enrolling in the Incentives Program, a fiber line replacement would be
considered a "new source" subject to NSPS. A new fiber line, built either at a greenfield
location or as a supplement to an existing fiber line, is a new source subject to NSPS,
regardless of whether the new line is enrolled in the Voluntary Advanced Technology
Incentives Program. However, such new fiber lines are eligible to enroll in the Voluntary
Advanced Technology Incentives Program at either the NSPS Tier II or Tier III levels.
A company may decide to replace a fiber line for a number of reasons,
typically a combination of the following:
• Increase capacity, while simultaneously shutting down one or more old
: systems;
•; Reduce costs of labor, chemicals, repairs and energy;
PULPl\0707-01.mcr 5-7
-------
• Comply with environmental or safety regulations; and
• Improve product quality.
Because it is easier to achieve the minimal effluent discharges that are required to comply
with Tier IQ limitations in a new installation than when retrofitting an old one, companies are
most likely to attempt to comply with the Tier III limitations on new (not retrofitted) fiber
lines.
5.3.1 Baseline NSPS
EPA estimated the costs of two fiber lines capable of meeting the Baseline
NSPS limitations. They are presented here for comparison purposes, and because they formed
the basis from which NSPS Tier HI costs were estimated. The first is based on ECF
bleaching, and this technology is equivalent to Option B described in Section 3.1.3. The
second is based on TCP bleaching, with a sequence based on one of the first greenfield TCP
bleach lines in the world, commissioned in Ostrand, Sweden in 1996. Refer to Bodien
(45) for a more detailed discussion of this mill. The estimated capital costs to install
these two fiber lines are shown in Table 5-2. Operating cost impacts are shown in Table 5-3.
For both technology bases, the change in operating costs for chemicals and energy relative to
a new ECF fiberline with traditional pulping technology is also shown. Other operating costs
(pulp mill, fixed costs, pulping makeup chemicals, wood, labor, and management) would
essentially be identical to a new fiber line with traditional pulping and bleaching.
Although baseline NSPS limitations are not based on TCP technology, some
companies might construct a greenfield TCP line. As shown on Tables 5-2 and 5-3, the
estimated capital cost of the TCP alternative is slightly less than the ECF alternative, and
depending on the cost of hydrogen peroxide, the operating cost could be similar.
PULPl\0707-01.mcr • 5-8
-------
Table 5-2
Capital Costs for Baseline NSPS
Configuration Hame
New bleaching sequence
Baseline NSPS
Entire ECF Fiber Line, Using OD
OODEODD
Entire TCE Fiber O»e
00 (Qw) (OP) (ZQ) (PO)
Unbleached Pulp Mill
New continuous digester
New brown stock washing line
New closed screening system
Buildings and infrastructure
Subtotal, cost in pulp mill
$53,000,000
$19,400,000
$5,900,000
$6,000,000
$84,400,000
$53,000,000
$19,400,000
$5,900,000
$6,000,000
$84,400,000
Bleach Plant
Oxygen delignification
New D-stage tower and washer
New EOD stage, with washer
New D-stage tower and washer
New E2 stage with washer
New D-stage tower and washer
Chelant stage with press washer
Pressurized PO stage with washer
Capital cost of HC ozone system
Pressurized PO stage with washer
Chelant supply system
Peroxide unloading and storage
Monitor bleach filtrates as effluent
guidelines
Buildings ;
Miscellaneous infrastructure
Subtotal, cost of bleach plant
$29,400,000
$15,500,000
$11,300,000
$15,500,000
—
—
—
—
—
—
—
$125,000
$124,000
$10,500,000
$14,400,000
$96,900,000
$29,400,000
—
—
—
—
$4,800,000
$9,500,000
$25,700,000
$9,500,000
$200,000
$125,000
—
$6,000,000
$15,900,000
$101,000,000
Modifications Outside Fiber Line
Greenfield chlorine dioxide plant
C1O2 storage
Upgrade recausticizing
Total Capital Cost
$16,200,000
$1,100,000
$3,100,000
$202,000,000
$0
$0
$4,600,000
$190,000,000
Capital costs refer to complete installed cost.
Costs are .based on a 1,000 kkg/day fiber line.
PULPl\0707-01.mcr
5-9
-------
Table 5-3
Operating Costs for Baseline NSPS
Operating Cost Element
Cost (Saving) for bleach
chemicals, relative to traditional
pulping technology
Cost of additional on-site power
demand relative to traditional
pulping technology
Increase (reduction) in operating
cost, relative to traditional
pulping technology
Baseline NSPS
Entire ECF Fiber Line* Using O3>
($/kkgjnilp)
($13.36)
$1.97
($11.39)
Entire TCF Fiber line
($/Mcgptdp)
($14.97)
$7.68
($7.29)
Costs are based on a 1,000 kkg/day fiber line.
PULPl\0707-01.mcr
5-10
-------
The comparative cost relationship between ECF and TCP technology installed
in a new line, shown in Tables 5-2 arid &3j is substantially different than when ECF and TCP
technology are retrofitted in an existing line, as shown in Table 5-1.
The reasons for this substantial difference are:
A new TCP facility would avoid costs for installing a plant to
manufacture chlorine dioxide on site, whereas an existing mill would
have already spent this money. The capital cost of a greenfield chlorine
dioxide manufacturing plant for a 1,000 kkg/day bleached kraft mill
typically costs approximately $25 million.
TCP bleach plants are physically more compact than traditional ones, so
a new TCP system requires less extensive buildings. An ECF or other
older plant being retrofitted has, of course, already spent the money on
buildings.
TCP bleaching equipment can be built mostly of normal grades of
stainless steels (typically ANSI 316 or similar), while ECF equipment
must be manufactured with more expensive alloys and plastics to resist
the corrosive action of chlorine dioxide and its degradation products
formed in the bleaching process.
5.3.2 TierHI
A new Tier III fiber line would be. different than baseline NSPS, because it
would have to reduce long-term average AOX discharges to 0.05 kg/kkg or below, and bleach
plant filtrates and pulping area and evaporator system condensates to 5 m3/kkg or below. To
implement the Tier III technology basis, a mill installing a new fiber line would need
upgrades to the black liquor evaporators to ensure that the condensate was sufficiently clean
to be used for washing the bleached pulp, upgrades to the recovery boiler to increase capacity
to burn recovered bleach plant wastes, and a system to remove minerals from recycled bleach
plant effluent to prevent scale build-up in process equipment. In addition, the ECF fiber lines
would require a system to remove chlorides for the liquor cycle, and would thus be using the
complete BFR™; process, or a competitive system with comparable performance. The TCP
fiber line would hot require a chloride removal system (the CRP component of BFR™) to be
PULPl\0707-01.mcr 5-11
-------
able to comply with the effluent flow criteria of Tier III, as chlorides are not introduced in the
bleaching process. The total capital cost of including these facilities is shown in Table 5-4.
The change in operating costs and annualized costs for these Tier III fiber lines, relative to a
ECF fiber line with traditional pulping, is also presented hi Table 5-4. If installed at a
greenfield site, or as part of a major facility expansion, as would be the case under NSPS,
considerable new evaporator and recovery boiler capacity would be provided and upgrades to
existing systems would not be necessary.
In a situation where a new fiber line is being replaced due to obsolescence, or a
completely new one is being constructed to increase mill capacity, it would be less expensive
to build and operate a TCF fiber line with oxygen delignification that would comply with Tier
O criteria than an ECF fiber line built to comply with Tier HI criteria. The TCF bleach
plants are somewhat simpler than ECF plants, and physically substantially smaller. In
addition, the TCF chemicals are generally less corrosive than chlorine dioxide, so less
expensive materials of construction can be used.
NSPS. Tier II capital and operating costs were not estimated. They would fall
between the baseline NSPS and NSPS Tier III costs presented in this section.
PULPl\0707-01.mcr 5-12
-------
Table 5-4
Capital and Annual Costs for Equipping New Fiber Lines for Tier III
Compliance
Configuration Name
EnfireECF Fiber Line, Using OD
TierHI-ECF
mntir* TCF Fiber tine
Tterm-TCF
Capital Costs
Cost without Tier HI capability, From
Table 5-2
$201,582,000
$190,285,000
Additional equipment for Tier HI
Modify evaporator for clean condensate
MRP component of BFR™
CRP component of BFR™
Recovery boiler air system upgrade
i
Capital cost, with Tier DDE. compliance
$2,147,206 •
$12,207,926
$12,081,341
$1,655,509
$229,674,000
$2,147,206
$12,207,926
—
$1,655,509
$206,296,000
Change in Annual Costs Relative to Traditional Pulping Technology (S/t pulp)
Cost (saving) for bleach chemicals
Cost of on-site power demand
Cost (saving) for operating metal and
chloride removal technology
Cost (saving) for maintenance and
technical support
Total increase (reduction) in operating
and maintenance cost
Total increase (reduction) in annualized
cost1
($13.36)
$1.97
($1.00)
($0.41)
($12.80)
($10.86)
($14.97)
$7.68
($4.00)
($2.08)
($13.37)
($17.84)
Capital costs refer to complete installed cost (total rounded to '000).
Costs are based on:a. 1,000 UBADt/day fiber line.
'Cost annualized using methodology described in Section 10.2.4 of the Supplemental Technical Development
Document (44). Includes cost of capital.
PULPl\0707-01.mcr
5-13
-------
-------
6.0 POLLUTANT LOAD REDUCTION ESTIMATES
EPA performed a case study analysis to determine the potential effluent
!
reduction benefits derived from the incentives program. Effluent reductions were calculated
for a case study mill complying with Voluntary Advanced Technology BAT limitations at
each incentive tier. The 1,000 metric ton per day case-study mill operates softwood and
hardwood bleach lines of equal size, and, before modifications to meet the tier limitations,
[
uses a conventional three-stage bleach sequence with chlorine on each line. Additional
characteristics of the case study mill are provided hi Section 5.2.2. The current estimated
discharge load and effluent load reductions for each incentive tier are provided in Table 6-1.
Effluent load reductions for baseline BAT are also presented for comparative purposes. The
estimates were prepared assuming that the case study mill will use ECF-based bleaching
technology at each of the tier levels. If TCP technology were used, there would be no
generation of chlorinated pollutants at any of the tier levels.
i
The load reductions in Table 6-1 are based on the long-term average
performance levels shown in Table 6-2. The performance levels shown under baseline BAT
and Tier I are the same as documented in the STDD (44). The one exception to this is the
AOX level under Tier I, which is the Tier I long-term average discussed in Section 3.1.2.
The AOX levels for Tiers II and III are the required performance levels, as
discussed in Sections 3.2.2 and 3.3.2, respectively.
The BOD loads under Tiers II and III are estimated based on the assumption
that the untreated BOD loads at Tiers II and III will be 10 and 6 kg/kkg, respectively, and
89.3 percent of this BOD will be removed in an end-of-pipe biological treatment system. The
BOD percent removal is based on the average BOD percent removal observed at bleached
papergrade kraft and soda mills in the EPA pulp and paper industry questionnaire database
(46). ;
PULPl\0707-01.mcr • 6-1
-------
f
CO
C3
u
&
Q
i*
ru
PW
C
•g
*
C3
H
en
C
fe
o s
*? *-g
pj S
W >g
a» Q;
H
6 fl
pel ^J3
^t CJ
^•t S
£3
a
If
£,!
l^
jl
^5 oj
80i
Ml
U
•S3
^}
•4-1
s
o
S
I
«
"S
a
0
Pi
O
00
O
OO
o
r-
o
\o
0
oo
1
1
0
oo
o
c^
1
o
CN
O
o
,— 4*
U4
1
§
M
0
o
CO
oo
T— (
O
0^
'^
o
o
""•
p_
\o
0
o
CN"
CN
1
§
0
O
o_
^f"
en
o
o
o
cT
o
o
T-H
O
CN"
o
o
o
06"
CO
1
t-t
o
"3
U
o
ON
0
CN
O
ON
CN
O
ON
CN
O
^-
1
en
H
tS
2
o
a
P
w-i
P
>T)
ON
ON
"*
O
>0
4
Q
t^
t"1
<%
O
g
o
o
cs
<-T
o
o
o
§
1-H
o
o
v-H
1
-O
u
^
C
•r-< w
^S
«?
s
6-2
-------
Table 6r2
i: $ '
Treatment Performance Levels Used to Estimate Incentive Tier Pollutant
Loads
Boflutatot
AOX
BOD
COD
Color
Chloroform
TCDD
TCDF
12 Chlorinated Phenolics
Units
kg/kkg
kg/kkg
kg/kkg
kg/kkg
kg/yr
ppq
ppq
ppb
Baseline
BAT „
0.51
W
38.2
84.5
0.0003
5 (ML/2)
11.3
ML/2
Tier!
0.26
(A)
25.5
53.4
0.0003
5 (ML/2)
11.3
ML/2
TierH
0.1
1.07
20^)
20^
. 0.0003
5 (ML/2)
5 (ML/2)
ML/2
Tferm
0.05
0.64
I0(b)
10(W
0.0003
5 (ML/2)
5 (ML/2)
ML/2
(a) Calculated from 'reduction in black liquor solids to treatment estimated by BAT cost model.
(b) Assumed LTA based on limited data.
ML = Minimum level.
PULPl\0707-01.mcr
6-3
-------
EPA has limited COD performance data from which it projected the achievable
performance levels under Tiers II and HI. First, EPA proposed a long-term average COD
load of 25.5 kg/kkg, based on Option B/Tier I technology. (EPA has not promulgated COD
limitations for the reasons set forth in the preamble.) EPA expects lower COD discharges
under Tiers n and III, achieved through tighter BMPs, reuse of condensates, and recycle of
bleach plant filtrates. EPA measured the end-of-pipe COD load at a mill that uses TCP
bleaching technology and has most of the elements of Tier II technology in place, but has no
end-of-pipe treatment system. The COD load at this mill was 35 kg/kkg (12). If this effluent
was treated in a biological treatment system that achieved 50 percent reduction in COD,
typical of bleached kraft mills, the COD discharge load would be under 20 kg/kkg. The
Champion mill in Canton, North Carolina achieves COD discharges in the 14 to 18 kg/kkg
range (46). This mill operates two bleach lines, a softwood line with oxygen delignification,
100 percent substitution and BFR™ technology, and a hardwood line with oxygen
delignification and 100 percent substitution. On average, this mill is assumed to approximate
what could be achieved by a mill using Tier II technology. Considering the foregoing, EPA
assumed Tier II mills could achieve 20 kg/kkg COD discharge for the purpose of estimating
pollutant load reductions.
The Rauma mill, which is approaching the Tier III technology level, achieves a
COD discharge of 6 kg/kkg (31). Considering this, the projected level of 20 kg/kkg of Tier
II, and the degree of additional filtrate recycle and water reuse that will occur at Tier III mills
compared to Tier n mills, EPA assumed that Tier III mills would achieve 10 kg/kkg COD
discharge for the purpose of estimating pollutant load reductions.
EPA has performed a detailed assessment of projected color discharges at the
Champion mill in Canton, North Carolina. EPA estimates this mill will achieve color
discharges of 18 to 22 kg/kkg once it has optimized the technology it has in place (47).
EPA also measured the end-of-pipe color load of a mill that uses TCP bleaching and has most
of the elements of Tier II technology in place but has no end-of-pipe treatment system. The
average color discharge of this mill was 16 kg/kkg (15). Biological treatment has only a
minimal impact on color, so this result can also be considered to reflect the performance of
PULPl\0707-01.mcr 6-4
-------
mills with end-of-pipe treatment. Based on the foregoing, EPA assumed Tier II mills could
achieve 20 kg/kkg color discharge for thS purpose df estimating pollutant load reductions.
Based on flow reduction requirements and the trend observed in COD data, EPA assumed
Tier III mills could achieve 10 kg/kkg color discharge.
EPA assumed levels of chloroform in end-of-pipe discharges will remain
unchanged going from Tier I to Tiers II and III once the air releases and degradation that
occurs in end-of-pipe biological treatment is accounted for. While discharges of chloroform
from the bleach plant may be reduced under the advanced tiers because there will be a real
reduction in chlorine dioxide application rates, EPA does not have any data from which to
estimate the degree of reduction likely.
TCDD, TCDF, and the 12 chlorinated phenolics will not be detected in the
bleach plant effluent under all of the technology levels shown on Table 6-2, EPA calculated
additional reductions in the mass load of these pollutants under the advanced tiers based on
the reduction in discharge flow rates under the incentives program.
PULPl\0707-01.mcr ' 6-5
-------
-------
7.0 NON-WATER QUALITY ENVIRONMENTAL IMPACTS
EPA evaluated the non-water quality environmental impacts and changes in
energy requirements associated with the incentives tiers. EPA found that the technologies that
form the basis of the incentives tiers provide a significant degree of water conservation,
particularly at Tiers II and III. EPA also expects lower secondary sludge generation rates at
incentives tier mills with activated sludge treatment because of reduction hi BOD loads
associated with the Advanced Technologies. The technology basis of each of the Incentives
Tiers will lead to overall decreases in energy consumption, primarily because of replacement
of chlorine dioxide with oxygen-based delignification and bleaching chemicals. EPA expects
a slight increase in air emissions (under 2 percent) due to increased recovery of black liquor
that will occur under the Incentives Tiers. However, these emissions are offset by reductions
in air pollution that derive from the reductions in overall energy consumption. Note that the
technology basis of Tier I is the same as BAT Option B. The impacts associated with Option
B are described fully in the Non-Water Quality Environmental Impacts section of the
Supplemental Technical Development Document (referred to as STDD, Section 11, throughout
this chapter) (44). .
7.1 Wood Consumption
7.1.1 Tier I
The impact of Tier I technology on wood consumption is the same as that EPA
estimated for BAT Option B and BMPs. EPA concluded that wood consumption would be
reduced by up to 0.3 percent as a result of greater retention of useful fiber associated with the
recovery of spills (BMPs) and improvements in washing and screening of pulp. EPA also
concluded that the installation of oxygen delignification without changing pulping conditions
would have no affect on process yield. See the more detailed discussions in the STDD,
Section 11, and the Effect of Oxygen Delignification on Yield of the Bleached Kraft Pulp
Manufacturing Process (48) for further information supporting these conclusions.
PULPl\0707-01.mcr 7-1
-------
7.1.2 TierH
A Tier II mill would benefit from the marginal increases in wood yield from
closed screening and spill recovery discussed above, but probably to a somewhat greater
extent because the technology, control systems, and operational practices in such a mill would
need to be excellent to achieve the Tier II performance requirements.
The effect of an advanced oxygen delignification system achieving 65 percent
reduction in kappa number on wood yield is not known. McDonough (49) suggests that
when oxygen delignification is extended beyond 50 percent, there will be a noticeable loss of
yield. However, he also points out that this can be mitigated by the addition of magnesium
salts. The reports published on the Rauma mill (31)(50) and Kemijarvi mill (51)
(both mills operate oxygen delignification systems at 65 percent kappa number reduction)
have not mentioned a loss of yield due to oxygen delignification. Because these mills
continue to operate at high levels of delignification, it appears that if any yield losses actually
exist, they are minimal, or at least acceptable to the mill owner even though they operate in
regions where wood costs are about double U.S. costs. Stora recently commissioned a new
bleach plant at their Skoghall mill hi Sweden which incorporates a two-stage oxygen
delignificatipn system that reduces the kappa number of the pulp from 30 to 10. (confidential
personal communication) Their laboratory work showed that this system would improve yield
slightly. Given the above information, the best assumption is that wood consumption in a
Tier n mill would be equal to or slightly less than that of a typical existing mill.
7.1.3 TierHI
Similar to Tier II, closing up screening and further improved spill recovery
beyond that practiced at a Tier n mill would provide marginal increases in wood yield at
mills employing Tier m technology.
PULPl\0707-01.mcr 7-2
-------
To achieve the very low AOX limit and effluent flows required by Tier IE,
mills may use advanced oxygen delignififiation, followed by bleaching with extremely low
doses of chlorine dioxide. Many mills would use TCP bleaching.
There are conflicting claims about the effect on yield of delignifying pulp to
very low levels with chlorine-free chemicals. There are credible claims by at least one mill
(Louisiana-Pacific, Samoa, California) which has operated a retrofitted TCP bleach line for
over two years that there is no effect on overall yield. Senior operating staff at the two new
TCP systems in Scandinavia (SCA, Ostrand and Metsa Rauma, Rauma) have stated that they
see no loss in yield in their oxygen/ozone/peroxide TCP bleaching systems relative to an ECF
system when operating full scale. These two bleach plants are "second generation" TCP lines,
and are the only bleached kraft TCP operations in the world that were designed for TCP
operation from initial concept. SCA believes that, theoretically, there must be a loss of about
1 percent in yield, but cannot see such a loss at the mill level. They have commented that the
dissolution of wood in the peroxide stages on a mill scale is less than in the laboratory.
(Personal communication with Goran Annergren, SCA.) Bodien (45) commented, that mill
staff believe there was no change in yield when the mill converted from ECF to TCP
operation in 1996. This information indicates mills using TCP technology have not
I
experienced a measurable decrease in yield.
At least some of the mills attempting to comply with Tier III criteria will be
new, or have a new fiber line on an existing mill site. Such installations will be able to
benefit from the!technology recently developed at Rauma and Ostrand, as well as future
developments in technology. Other mills will comply with Tier III criteria without fully
converting to TCP processes, thus allowing pulp producers the possibility of avoiding the
extreme cooking conditions used by some TCP mills. Therefore, for the purposes of
estimating non-water quality environmental impacts and calculating mill energy balances, EPA
assumed that there would be no change in yield for a future mill complying with Tier III
criteria.
PULPl\0707-01.mcr 7-3
-------
7.2 Effluents and Solid Waste
Implementation of the Voluntary Advanced Technology Incentives Program
will reduce effluent flow, as well as the load of organic substances and suspended solids
discharged to mills' effluent treatment systems. The reductions in hydraulic flows resulting
from the implementation of Tier I limitations will have only a modest effect on effluent
flows. Tier n and Tier III incentives, however, would reduce market pulp mill effluent flow
by up to 85 percent. Integrated mills, which make up most of the US industry, have
substantial wastewater flows from their papermaking operations. Consequently, the changes
in flow resulting from the incentives will reduce integrated mill flow by a maximum of about
50 percent.
The reduction in BOD and suspended.solids discharges under the incentives
tiers will be significant, as discussed below. The extent of reduction will be progressively
greater for the more advanced pollution prevention technologies associated with the Voluntary
Advanced Technology Incentives Program.
7.2.1 Effluent flows
In 1995, the average mill discharged approximately 95 m3/kkg effluent. EPA
estimated that baseline BAT would result in wastewater flow reductions from 10 to 50
m3/kkg. The greater reductions would be realized in mills presently discharging the highest
flows. BAT Option B/Tier I would result in an additional reduction of up to 15 m^/kkg at
mills with the highest effluent flows. See STDD, Section 11, for additional detail.
Average bleach plant effluent flows for mills with and without extended
delignification are shown below.
PULPl\0707-01.mcr 7-4
-------
Bleach Plant Effluent Flow for
Mills with and without Extended Delignification
t ^ fff\
Mills without oxygen delignification or extended cooking
Mills with oxygen delignification or extended cooking
Hardwood
24.7 m3/kkg
19.7 m3/kkg
SoftWOOd ;
37.1 m3/kkg
24.7 m3/kkg
Source: DCN 13952, Record Section 24.
Condensates contribute an additional 10 m3/kkg if they are discharged rather than reused. In
the case of Tiers II and III, discharge flow of bleach plant filtrate and pulping area and *
evaporator condensates would be reduced from these levels to a total discharge of 10 m3/kkg
and 5 m3/kkg, respectively.
7.2.2 Solid Wastes
EPA estimates that the implementation of all three incentives tiers would result
in a significant reduction in the generation of sludge in effluent treatment systems. The
reduction in sludge generation results from the decrease in organic load discharged to the
effluent treatment system. Somewhat offsetting the decrease in wastewater treatment sludge,
mills complying with Tier III criteria would generate small quantities of solid waste as they
purge calcium and manganese salts from the recausticizing system if certain mineral removal
equipment is installed. This material would be in the form of a sludge, rather than discharged
in the wastewater effluent as is current practice.
7.2.2.1 Primary Sludge
BAT Option B/Tier I technology will result in reductions in primary sludge
generation. As discussed in the STDD, Section 11, on average this will result in an 2 kg/kkg
reduction in primary sludge generation, primarily due to the reduction in losses of useful fiber
associated with recovery of spills and improved pulp washing and screening (see Section
7.1.1). .;
PULPl\0707-01.mcr 7-5
-------
Primary sludge generation of Tier II and Tier III mills would be further
reduced due to recycle of bleach plant filtrates. Bleach plant filtrates generally contain from
20 to 100 mg/L of fine fiber. This concentration is generally constant for any given mill,
regardless of flow, because it depends on the size and type of openings in the washer wire or
other filter medium. In a typical bleach plant discharging 40 m3/kkg effluent, approximately
2 kg/kkg sludge might be formed due to the fiber losses. Compliance with Tier n or Tier III
criteria would reduce this amount by about 90 percent. The exact reduction will depend on
equipment selected for washing in the "low-effluent" bleach plant.
Approximately 3 kg/kkg additional fiber would be recovered by the overall mill
optimization that would be necessary to comply with Tier II or Tier III criteria, and therefore
would reduce the generation of primary sludge.
7.2.2.2 Secondary Sludge
As discussed in Section 11 of the STDD, BAT Option B/Tier I technology will
result in a 3 percent reduction in secondary sludge generation due to a reduction in the BOD
waste load to secondary treatment.
The effects of modifying mills to comply with Incentives Tiers II and III will
be similar to those of Tier I, but greater in magnitude, because the mills will return greater
quantities of organic material to the recovery process that would otherwise be discharged as
BOD and be converted to sludge in mills' waste treatment plants.
Consideration of the processes likely to be used to comply with Tier n criteria
indicates that the raw waste load of BOD discharged to the effluent treatment system would
be about 10 kg/kkg pulp. Typical base case mills will discharge approximately 38 kg
BOD/kkg pulp (52). The 28 kg BOD/kkg pulp reduction in raw BOD will result in a
reduction in solid waste formation hi activated sludge treatment plants of approximately 17
kg/kkg pulp, assuming 0.6 kg of biological (secondary) sludge is generated in an activated
sludge system for each kg of BOD applied (53). Approximately one-third of mills use
PUU>lV>707-01.mcr 7-6
-------
the activated sludge process (52), representing 23 percent of total bleached kraft subcategory
production. The total bleached kraft production is 83,500 unbleached kkg/day, so the
reduction in sludge formation relative to base case sludge production of 2.5 million tons/year
is 112,000 tons/year (dry basis), or about 4 percent. Tier III limitations will have a similar
effect, driving raw BOD discharges down to about 6 kg/kkg pulp, thus reducing the formation
of secondary sludge by 126,000 tons/year relative to baseline (5 percent reduction). See the
STDD, Section 11, for additional details supporting these calculations.
Approximately two-thirds of mills in the bleached papergrade kraft subcategory
use aerated stabilization basins (ASBs), some in combination with activated sludge treatment
(52). Though generating much less sludge than activated sludge treatment, ASBs often
become partially filled with sludge after a number of years of operation, and require dredging.
Lightly loaded ASBs have the ability to mineralize organic sludge, and may never require
clean out. As discussed above, the incentives tiers will reduce the discharge of BOD and
suspended solids to treatment and thus reduce ASB dredging frequencies.
7.2.2.3 Other Solid Waste Generation
EPA expects no increase in solid waste generation at Tier I or Tier II mills.
Bleach plants atithe L-P Samoa, SCA Ostrand, and Rauma mills already discharge under 10
m3/kkg effluent and they have not experienced increased solid waste generation. In order to
meet Tier II flow criteria, mills like these would need to reduce the discharge of evaporator
and digester condensates, which could require additional stripping (to reduce TRS or methanol
content) or cooling. Neither of these operations is likely to generate more solid waste than
the present method of disposal or use.
As Tier III mills approach process closure, they will need to remove some
nonprocess elements from the system as solids instead of discharging them as dissolved matter
in the effluent, to prevent process equipment scaling. The dissolved matter is primarily
calcium, manganese, and iron. The two most likely methods of disposal are by filtering these
minerals from the green liquor (in which their solubility is low) in the recausticizing
PULPl\0707-01.mcr 7-7
-------
department, or by using a process such as the Metals Removal Process (MRP) described by
Caron (17). There are several green liquor filters operating to remove minerals (50)(54).
These are cross-flow or "fabric-sock" filters that replace or supplant the conventional green
liquor clarifier.
A full-scale MRP is currently being operated at the Champion mill in Canton,
North Carolina (17). A high proportion of the metals entering the mill with wood or as
impurities in purchased chemicals are washed from the pulp in the first acid stage in the
bleach plant. The MRP removes metals from this stream. While the system at Champion is
proprietary, the principle can be applied in several ways. Jaegel estimated that the total
quantity of minerals to be removed from a completely closed (effluent-free) system would be
16 kg/kkg pulp (54). Since Tier EH mills will not be completely closed but rather have some
bleach plant discharge, the total quantity of minerals removed from a Tier III mill would be
less, in the range of 10 to 15 kg/kkg.
In a conventional, relatively "open," kraft mill, nonprocess elements such as
potassium and chloride are eliminated from the system by discharge in the mill's wastewater.
Tran has shown that as mills approach process closure, the concentrations of chloride and
potassium throughout the liquor system rise, which can cause plugging on the fireside surfaces
of the chemical recovery boilers (55). Thus, chloride and potassium need to be purged
from the system to maintain efficient recovery boiler operation.
Potassium and chloride concentrate in the dust caught in the electrostatic
precipitator of the kraft mill recovery boiler. This dust is normally returned to the liquor
cycle. To control the concentrations of potassium and chloride in the mill's liquor cycle,
Tier II and Tier m mills will have to remove and discharge potassium and chloride. This can
be done by discharging a portion of the precipitator dust, which is a mixture of inorganic salts
of sodium and potassium, or by using a specialized process designed for this purpose, such as
CRP. See Section 3.3.3 for a description of CRP. Potassium and chloride discharged through
these mechanisms would have been previously discharged at a traditional mill with the pulp
mill and bleach plant effluents; the point of discharge from the cycle has simply moved. The
PULPl\0707-01.mcr 7-8
-------
benefit derived from the Tier II and Tier III technology, however, is that the organic material
that was also previously discharged is now burned if! the recovery boiler.
The precipitator dust discharge, which may be up to 20 kg/kkg pulp, has been
described as a solid waste discharge in some documents. However, in many mills the dust
never exists in dry form except between the plates of the precipitator, and is normally
discharged as a solution in the effluent .
In any event, EPA estimates that the quantity of chloride discharged from a
Tier II or Tier III mill will be substantially less than is discharged from a traditional mill
because of the reduction in use of chlorine-based bleaches, and the probability that mills
wishing to operate within the incentives limitations will avoid purchasing chemicals
contaminated with chlorides.
Most of the potassium in a mill system enters with the wood and purchased
chemicals (55). The potassium entering with the wood will be discharged by any mill,
whether operating like a pre-1970 mill, or in accordance with Tier III criteria. EPA estimates
that the quantity of potassium entering with the chemicals, and hence being discharged, will
be less in the more advanced mills, because the quantity of chemicals purchased will drop due
to recycle as well as the mill operator's desire to avoid purchasing contaminated chemicals to
minimize the problems caused by potassium in the mill.
7.3 Energy Impacts
7.3.1 Overview of the Energy Impacts
Sections 304(b) and 306 of the Clean Water Act specifically direct EPA to
consider the energy requirements of effluent limitations guidelines and standards it establishes.
EPA estimated the impacts of BAT Option IB/Incentive Tier I on a mill-by-mill basis. These
1 Quantities are small. The BFR™ process at Canton, North Carolina, which is the largest chloride removal
system operating in the U.S., discharges approximately 30 i
PULPl\0707-01.mcr 7-9
system operating in the U.S., discharges approximately 30 m3/day, or 0.03 percent of total mill discharge flow.
-------
estimates are presented in Section 11 of the STDD. For Tiers II and III, EPA estimated the
energy use associated with a typical model mill in the bleached papergrade kraft and soda
subcategory. The energy impacts were calculated for the same model mill and associated
base-case conditions used to prepare cost estimates, described in Section 5.0. For each tier,
EPA analyzed the following changes in energy use:
• On-site electrical demand within the mill;
• Electrical demand for wastewater treatment;
• Steam demand for pulp cooking, bleaching, black liquor evaporation.,
etc.; and
• Off-site electrical demand resulting from manufacture of bleaching
chemicals. •
Table 7-1 presents EPA's estimate of the effect of the incentives tiers on
energy consumption relative to base-case conditions, scaled to the entire Bleached Papergrade .
Kraft and Soda Subcategory production. Electrical and thermal energy are combined and
converted to an "oil equivalent" in Table 7-1 to conveniently compare the total energy
demand of each Tier. Assumptions used in the conversion to "oil equivalent" are presented in
Section 7.3.3.
The energy savings associated with Tier II principally derive from replacement
of chlorine dioxide by oxygen-based bleaching agents that require less energy to manufacture.
There would be a further reduction in total energy consumption if Tier III was implemented
throughout the industry, due again primarily to the replacement of chlorine dioxide with more
energy-efficient bleaching chemicals.
PULPl\0707-01.mcr 7-10
-------
.2
O
U
TS
C 0
O O
l>
—
2
et
H
55
a 55
03
VO
"^ — ^
oo
tN
ts
' — '
VO
i
i'-
CO
O
.5
CO
C3
Increase (decre
consumption
r--
CS
CN
r-
>o
ON
vo
•vo
s
1
"OT
o
^
CO
C3
[Increase (decre
consumption
o^
r^-
cs
1 — I
o
£
oo
ON
S'.
1
o
DH
M
W
CO
S
o
u
Total increase I
consumption
43
co
S— i
n
0
Co1
n
tN
^ — ^
VO'
cn
S-
o
c^f
1
3
0
"c3
a
1
_a
1
1 Increase (decre
generate power
o
o
o
o"
von
o"
ON
^
O
o
o"
o^
c»f
1
o"
CS
o^
G-
o
o"
2~
1
,
•d _,
sis
115
O & C!
o w *^^
_ (5 ^_^
1 ° tl
/«s a> O
CO 4> ^
1 Increase (decre
relative to total
bleached kraft i
(..
^
g
9
«
o w
7-11
-------
7.3.2 Estimation of Energy Impacts
EPA evaluated the effect of each process change associated with complying
with the incentives tiers on demand for steam and electrical energy. The process changes
which have a significant effect are listed in Table 7-2. Items described as "insignificant" or
"minor" were excluded from calculations of changes in energy consumption because they have
no discernible impact within the accuracy of the estimate. In addition to the explicit process
changes, EPA accounted for the consequential effects that reducing effluent flow and BOD
load would have on energy consumption in the mills' wastewater treatment plants (WWTP).
The actual process changes required, along with the actual quantities of steam
and electricity involved are mill specific, and were calculated for the incentives model mill by
the cost model. Details of the assumptions and associated equations for energy impacts are
defined in the BAT Cost Model Support Document (43).
The manufacture of sodium chlorate for on-site chlorine dioxide generation is a
major factor in offsite electrical energy demand. Production of chlorine dioxide requires
approximately 11 kWh/kg, whereas the equivalent quantity of oxygen only about 1 kWh/kg.
Thus, use of oxygen delignification to reduce chlorine dioxide demand results in net electrical
energy savings off-site. In addition to reductions in chlorine dioxide use, all of the potential
bleach plant modifications with the technology basis of the incentives tiers will reduce the
demand for electrolytically produced caustic, and so will also reduce demand for off-site
electrical energy. The difference in power required for the various alternative bleaching
processes are calculated in the cost model, and are included in the results presented in Table
7-1.
7.3.2.1 Energy Impacts of Tier I
Tier I technology basis is identical to BAT Option B, so the averages of the
mill-by-mill calculations for Option B, presented in Section 11 of the STDD, were used to
represent the Tier I energy impacts, as shown in Table 7-1.
PULPl\0707-01.mcr 7-12
-------
Table 7-2
Process Changes Affecting Energy Consumption
Process modification
Improve brown stock washing and
screen room closure
Extended cooking
Oxygen delignification
High chlorine dioxide substitution
Best Management ^Practices
Evaporator upgrade
Evaporator load reduction
Measures to compensate for
increased load on recovery boiler:
• Recovery boiler upgrade
• Anthraquinone pulping
additive
• Black liquor oxidation
Recausticizing upgrade
Reduction in effluent flow due to
above
Reduction in effluent BOD due to
above
Ozone delignification
Peroxide stages, including E
Steam demand
Reduced demand for fossil fuel
corresponding to fuel value of
recovered black liquor
Reduced demand from reduction
in water to evaporate
Reduced demand for fossil fuel
corresponding to fuel value of
recovered black liquor
Reduced demand for fossil fuel
corresponding to fuel value of
recovered black liquor
Heat demand for oxygen reactor
Minor increase
Reduced demand for fossil fuel
corresponding to fuel value of
recovered black liquor
Steam demand to evaporate
recovered water
Steam demand increase
Steam demand decrease
Steam generated from above-
mentioned black liquor replaces
some steam from fossil fuel
None
Reduction in net demand since
steam generated in reaction is
used for evaporator
Insignificant
None
None
None
Minor
Electrical demand
Minor, may be plus or minus
Insignificant in fiber line
Net reduction in off-site power for
bleach chemical manufacture
Additional mixing energy in fiber
line
Net reduction in power for bleach
chemical manufacture
Increased energy for pulp mixing
Increased energy off site for
bleach chemical manufacture
Insignificant
Insignificant
Insignificant
Minor change
None
Increase
Minor change
Minor reduction in pumping
energy
Reduction in WWTP power
Approximate 10 kWh/kg ozone
Energy for mixing in fiberline
Net decrease, due to replacing
chlorine dioxide
PULPl\0707-01.mcr
7-13
-------
Table 7-2 (Continued)
Process modification
Bleach filtrate recycle
Reduction in effluent flow due to
above
Reduction in effluent BOD due to
above
Steam demand
Steam for evaporator/crystallizer
None
None
Electrical demand
Minor
Minor reduction in pumping
energy
Reduction in WWTP power
PULPl\0707-01.mcr
7-14
-------
7.3.2.2 Energy Impacts of Tier II
Calculations of the energy impacts of Tier II and Tier III were based on the
changes estimated for a 1,000 kkg/day fiber line extrapolated to the total U.S. bleached kraft
production. The process elements that impact energy consumption at mills meeting Tier II or
Tier III criteria are listed in Table 7-2.
The principal differences between a Tier II - ECF mill and a BAT Option B
mill with respect to energy consumption are:
• The additional stage of oxygen delignification would require more
electrical energy on site; and
• The lower prebleaching kappa number would reduce chlorine dioxide
demand.
The net effect of implementing Tier II technology in a 1,000 kkg/day mill
would therefore be to decrease total electrical power demand by 1 to 2 MW, depending on
whether the mill chose the ECF or "Toward-TCF" process concept.
Bleached kraft pulp production in the U.S. is approximately 83,500 kkg/day,
and the effect of applying Tier II technology to the whole industry relative to the base case, is
shown in Table 7-1.
7.3.2.3 Energy impacts of Tier IH •
Two scenarios are considered for Tier III. The first (ECF) assumes that the
mill would recycle bleach plant filtrates to the recovery system, and remove metals and
chlorides by Champion's BFR™ or a competitive process. The second scenario (TCP)
assumes that the:mill would use ozone and peroxide to replace all of the chlorine dioxide,
thus allowing recycle of most or all of the bleach plant filtrates to the mill's recovery system.
PULPl\0707-01.mcr '7-15
-------
Tier IE with ECF Bleaching
To comply with Tier III limitations while using ECF technology, a mill would
likely have to return bleach filtrates to the recovery cycle (as in the BFR™), or concentrate
and. burn them separately as proposed by EKA Chemicals, H.A. Simons, Zerotech Inc., and
others. The following discussion is based on the BFR™ process.
The principal differences between a Tier El mill using the BFR™ or ;similar
process relative to BAT Option B with respect to energy consumption are:
• There is an additional steam requirement for the evaporator/crystallizer
in the chloride removal system amounting to approximately 125 kg/kkg
pulp, equivalent to 0.34 GJ/kkg (39).
• There is an additional power requirement of approximately 15 kWh/kkg
pulp (39) for the pumps required for transporting the fluids in the
BFR™ process.
• The organic waste recovered from the bleach plant would increase steam
. generation in the recovery boiler by the equivalent of 0.5 GJ/kkg pulp.
Bleached kraft pulp production in the U.S. is approximately 83,500 kkg/day,
and the effect of applying Tier III - ECF technology to the whole industry relative to the base
case is shown in Table 7-1.
Tier III with TCF Bleaching
The principal differences between a TCF Tier III mill and a BAT Option B
mill with respect to energy consumption are:
• The more powerful oxygen delignification system and the Z and Eop
stages would recover black liquor solids generating additional steam.
This is due to recovery of most of the organic material removed in
bleaching.
PULPl\0707-01.mcr 7-16
-------
The additional stage of oxygen delignification would require more
electrical energy on site.
The lower prebleaching kappa number would reduce chlorine dioxide
demand to zero, avoiding the need to generate power off site to
manufacture the sodium chlorate feedstock for the mill's chlorine
dioxide generator.
The replacement of chlorine dioxide with ozone would require
approximately 100 kWh/kkg pulp, primarily for the ozone stage,
including both on-site ozone generation and the mixing energy required
for fiber processing. For the 1,000-kkg/day capacity model mill, this
represents 4.2 MW.
The net effect of implementing Tier III technology in a 1,000-kkg/day mill
would therefore be to decrease total electrical power demand by approximately 3.1 MW, and
decrease the need to burn fossil fuel to raise steam for process heating at the mill by the
equivalent of 77 GJ/day.
Where the pulp mill is integrated with paper mills, all the additional steam
produced by the more efficient process would probably be used on site with consequent
reduction in use of fossil fuel for steam generation. In the interests of maximum energy
efficiency, the mill would cogenerate electrical power. In the case of a market kraft mill,
there could be more electrical power available from burning the recovered organic material
than would be required at the mill. One example is the Rauma mill (50)(56). In such
cases, the excess power would be sold, so that the above mentioned conservation of fossil fuel
would appear at -a remote electrical generating utility instead of at the mill site.
The effect of applying Tier III - TCP technology to the whole industry, relative
to the base case,:is shown in Table 7-1.
7.3.3 Equivalence of Various Forms of Energy
EPA calculated an "oil equivalent" to conveniently present the combined effects
of the changes in thermal energy and electric power. The oil equivalent is based on the
PULPl\0707-01.mcr 7-17
-------
assumption that all nuclear, hydroelectric, waste fuel, natural gas, coal, cogeneration, and
wind power systems across the country are operated at their maximum capacity, and that any
increase or decrease in fuel electric power demand caused by the effluent guidelines
regulations is supplied by conventional condensing-type oil-fired power stations. (If EPA
assumed that additional electrical demand would be supplied by coal or natural gas burning
facilities, then the predicted effect on fossil fuel consumption would be quite similar. It is
expressed in terms of oil equivalents here for convenience of the reader. Coal equivalents
could also reasonably be used.) For example, a mill burning all its black liquor and hog fuel
would normally also burn some purchased fossil fuel (oil, coal, or natural gas) to raise steam.
All the black liquor must be burned, but the mill cannot normally increase the quantity of
black liquor generated, since it is directly related to the pulp production rate. The hog fuel is
relatively inexpensive, so all available material will be burned at all times, subject to any
limitations in wood burning equipment. Any change in the requirement for process steam will
be supplied by changing the quantity of fossil fuel purchased and burned.
Many mills also generate some or all of the electric power they require by
passing steam through turbines prior to using it as process heat. This power (known as
cogenerated power) is relatively inexpensive, so mills normally operate their cogeneration
equipment to its maximum potential. Some generate more power than is required on site, and
sell the surplus to the local utility or other customer. Whether the mill is a net buyer or seller
of power, any change in on-site power demand will be passed on to the national electrical
power grid, reflecting ultimately in the load on utility stations.
The overall efficiency of conversion of thermal energy in fossil fuels to
electricity delivered to consumers is approximately 25 percent. This is because thermal power
stations ultimately reject approximately two-thirds of the thermal energy derived from
combusted fuel due to the thermodynamic properties of steam. There are losses of energy to
the stack gas, and mechanical and electrical losses in the turbines, generators, and distribution
system. In addition, a small fraction of the power generated is used in the utility plant itself
for motors, electrostatic precipitators, and other necessary auxiliary equipment.
PULPI\0707-01.mcr 7-18
-------
To convert the steam demand calculated as metric tons per day to equivalent
barrels of oil, EPA made the following assumptions:.- one ton of steam equivalent to 2.7 GJ
and; steam plant operating at 75 percent efficiency; and one barrel of oil equivalent to 6 GJ.
7.4 Atmospheric Emissions
Sections 304(b) and 306 of the Clean Water Act specifically direct EPA to
consider the air pollution impacts of effluent limitations guidelines and standards it
establishes. EPA estimated the impacts of the Tiers I, II, and III on the generation and
emission of air pollutants associated with a typical model mill in the Bleached Papergrade
Kraft and Soda Subcategory. These options will affect atmospheric emissions in a number of
ways.
Pollution prevention and control technologies that form the basis of
Tiers I, II, and III involve changes in processes used to produce
bleached pulp. The impacts of the incentives tiers air emissions from
bleaching and pulping processes are expected to be similar to BAT
Option B as described in the Section 11 of the STDD.
Mills will be burning material in the recovery boiler previously
discharged with the effluent because of the substantial improvements in
overall mill closure. This will tend to increase emissions of many
substances to the atmosphere by up to one to two percent, as discussed
in Section 7.4.2.
The location of points of emissions of carbon dioxide (a greenhouse
gas) from mill sites will change, as discussed below, but the total
emission will not.
The changes in overall energy consumption discussed in Section 7.3 will
change atmospheric emissions from on-site and off-site energy
production facilities (net decrease for all three incentives tiers).
An increase in emissions of carbon monoxide will occur due to
increased chlorine dioxide substitution.
PULPl\0707-01.mcr 7-19
-------
7.4.1 Emissions Due to Mill Process Changes
The control technologies that form the basis of the incentives tiers involve
changes in the processes used to produce bleached kraft pulp. These changes affect the rate at
which air pollutants, including HAPs, are emitted from pulping and bleaching processes. The
technology basis of Tier I is the same as BAT Option B, so the impact on air emissions due
to process changes for Tier I will be as shown in Section 11 of the STDD. The impact of
Tiers n and El are expected to be similar to Tier I, with a potential decrease in chlorinated
HAP emissions due to decreased chlorine dioxide use. EPA does not have data available to
confirm these projections.
7.4.2 Emissions Due to Burning Increased Quantities of Black Liquor Solids
The technology bases of all three tiers will result in recovery and burning of
increased quantities of black liquor solids. As discussed in Section 11 of the STDD,'this
could result in a maximum 1 to 2 percent increase in air emissions from recovery boilers for
Tier I. Tiers n and III result in additional recovery of organics and black liquor solids
beyond Tier I. However, the resulting additional impact on air emissions due to changes in
recovery boiler load is negligible compared to Tier I, as the bulk of the improvement in
recovery of black liquor occurs through oxygen delignification and improved BMPs, which
are reflected in the Tier I estimates. As discussed below, these air emission increases are
partially offset by air emission reductions from lower net energy demand.
7.4.3 Emissions Due to Changes in Energy Consumption
As discussed in Section 7.3 and summarized in Table 7-1, each of the
incentives tiers will have an effect on total energy consumption. For the analysis presented in
this report, EPA estimated changes in on-site steam demand, on-site electric power
consumption, and off-site electric power consumption. On-site steam demand is met by
power boilers that burn wood, coal, or oil. Electrical demand is typically met by off-site
PULPlV0707-01.mcr 7-20
-------
electric power generating stations that burn coal or oil. For the purpose of this analysis, EPA
calculated an oil equivalent to combine the,effects of all energy changes (see Section 7.3.3).
As discussed in Section 7.4.2, incentives tiers all result in a net increase in
combustion of black liquor solids and corresponding increased steam production. This results
in decreased steam demand from on-site power boilers and lower emissions from those
sources. This slightly offsets the increased emissions from recovery boilers, discussed in
Section 7.4.2.
As discussed in Section 11 of the STDD, installed on an industry-wide basis,
BAT Option B/Tier I would result in a 2 percent decrease in energy consumption, with
resultant decreases in air emissions of 1,405,000 tons/year carbon dioxide, 6,300 tons/year
sulfur dioxide, and 16.3 tons/year total particulate HAP. Tier II and Tier III technology
results in further energy savings, discussed in Section 7.3, and commensurate reductions in air
emissions.
i - . ,
7.4.4 Greenhouse Gases
EPA concluded that the technology basis of BAT Option B/Tier I will not have
a net impact on the emissions of greenhouse gases from mills due to pulp processing, based
on consideration! of the overall mill carbon balance and energy balance. See Section 11 of the
STDD for a detailed discussion of this analysis. However, changes in energy consumption will
have the effect of reducing carbon dioxide emissions for Tier I. As energy consumption is
further reduced through use of Tier II and Tier III technology, carbon dioxide emissions
would be commensurately reduced.
7.4.5 Carbon Monoxide Emissions
EPA evaluated carbon monoxide emissions from oxygen delignification and
concluded that, because MACT I requires that vents from oxygen delignification systems be
PULPl\0707-01.mcr 7-21
-------
incinerated, there would be efficient oxidation of carbon monoxide from this source. See
Section 11 of the STDD for further discussion.
EPA estimated that baseline BAT will result in carbon monoxide emissions
from chlorine dioxide use of 1,500 tons/year. Chlorine dioxide use will go down under the
incentives tiers (and will be eliminated in the case of TCP bleaching), so carbon monoxide
emissions will be lower under the incentives program than at baseline BAT.
PULPl\0707-01.mer 7-22
-------
8.0 REFERENCES
1- Axegard, P., et al. "Minimum-Impact Mills: Issues and Challenges, 1997." In:
Proceedings of the 1997 TAPPI Environmental Conference and Exhibit.
i
2. Erickson, D., D. Zacher, D. DeCrease, "Minimum Impact Manufacturing -
Creating Sustainable Value for Our ;Key'Stakeholders." In: Proceedings of the
1996 TAPPI Minimum Effluent Mills Symposium. 1996.
3. Closset, G. "Over the Horizon and Beyond." Presented at: The 12th Sunds
Defibrator International Technical Seminar. Sundsvall, Sweden, May, 1996.
4. The Paper Task Force, Paper Task Force Recommendations'for Purchasing and
Using Environmentally Preferable Paper, 1995.
5. Gleadow, P.L., K. Vice, A.P. Johnson, D.R. Sorenson, and C.R. Hastings. "Mill
Applications of Closed-Cycle Technology." Presented 1996 International Non-
Chlorine Bleaching Conference. Orlando, Florida.
6. Comment Response Document. Volume I, "Justification for Establishing
Limitations and Standards for AOX", 1997 (Record Section 30.11, DCN 14497).
7. Pollution Prevention Technologies for the Bleached Kraft Segment of the U.S.
Pulp and Paper Industry. EPA/600/R-93/100, U.S. Environmental Protection
Agency, Washington, DC, August 1993.
8. McCubbin, N., H. Edde, E. Barnes, J. Folke, E. Bergman, and D. Owen. Best
Available Technology for the Ontario Pulp and Paper Industry. ISBN 0-7729-
9261-4. Ontario Ministry of the Environment, Canada, February 1997.
9. Technical Support Document for Best Management Practices for Spent Pulping
Liquor Management Spill Prevention and Control. U.S. Environmental Protection
Agency, Washington, DC, September 1997 (Record Section 30.9 DCN 14489).
10. Data Available for Limitations Development for Toxic and Nonconventional
Pollutants. EPA, Washington, D.C., (Record Section 22.6, DCN 14494).
11. Background Information Supporting Non-Regulatory Incentives for the Bleached
Papergrade Kraft and Soda Subcategory, July 1996 (Record Section 27.8, DCN
1395).
12. Statistical Support Document for the Pulp and Paper Industry. Subpart B. Report
prepared by ERG for EPA. (Record Section 22.5, DCN 14496).
13. Reeve, Douglas W. Chlorine Dioxide in Delignification in Pulp Bleaching.
Principles and Practice. Carlton W. Dence and Douglas W. Reeve, ed. TAPPI
Press, Atlanta, Georgia, 1996.
PULPl\0707-01.mcr 8-1
-------
14. EPA Pulp and Paper BAT Baseline Database (Record Section 21.10, DCNs 13658,
13890, and 13923).
15. EPA Pulp and Paper BAT Analytical Database and Documentation. (Record
Section 21.10, DCNs 14125 and 14126.)
16. Ferguson, K. "Champion Moves Toward Closure with BFR Startup at Canton,
NC." In: Pulp & Paper, April 1996, pp. 47-54.
17. Caron, J.R. and L.D. Williams. "Design and Integration of the Bleach Filtrate
Recycle Process." Presented at: 1996 TAPPI Minimum Effluent Mills
Symposium. ,
18. Reilama, Ismo. "Metsa-Rauma's New TCF Pulp Mill - The First Step To ward a
TEF Mill." Presented at: Environmental Technology From Finland for the Forest
Industry, Vancouver, British Columbia, Canada, April 2, 1996.
19. Ahlenius, L., G. Svensson, J. Liden, and O. Lindeberg. "MoDo's Experiences in
Closed Loop Bleaching." Presented at the 1996 TAPPI Minimum Effluent Mils
Symposium.
20. Steltencamp, M., 1997. Champion presentation to a committee of the Maine
Legislature on the status of BFR™.
21. Pekkanen, M. and E. Kiiskila. "Options to Close the Water Cycle of Pulp and
Paper Mills by Using Evaporation and Condensate Reuse." In: Proceedings of
the 1996 TAPPI Minimum Effluent Mills Symposium.
22. Barton, D.A., et al. "Biotreatment of Kraft Mill Condensates for Reuse." In:
Proceedings of the 1996 TAPPI Minimum Effluent Mills Symposium.
23. Danielsson, G. and M. Hakansson. "Steam Stripping of Contaminated
Condensates from the Black Liquor Evaporation Plants." In: Proceedings of the
1996 TAPPI Minimum Effluent Mills Symposium. !
24. ' Mattsson, M. "Extended Treatment of Secondary Condensates from the Sulphate
Process by Vapor Stripping." In: Proceedings of the 1996 TAPPI Minimum
Effluent Mills Symposium.
25. Blackwell, B.R., et al. "Review of Kraft Foul Condensates." TAPPI Journal.
Volume 62, No. 10, October 1979.
26. Wilson, P.H. "Minimizing Effluent Through Water Management." In:
Proceedings of the 1996 TAPPI Minimum Effluent Mills Symposium.
27. Union Camp, Franklin, Virginia, Site Visit Report (Record Section 7.4, DOST
08000).
PULPl \0707-01.mcr 8-2
-------
28. Champion, Canton, North Carolina, Site Visit Report (Record Section 21.5.1, DCN
12735).
29. Lqng-Term Study Mill 2, Sampling and Analysis Plan (Record Section 7.5.2.2,
DCN 03446).
30. NCASI Technical Bulletin No. 702, October 1995.
31. Metsa-Rauma, Rauma, Finlad, Site Visit Report. (Record Section 21.5.1, DCN
14797.) . ' f i- .
' . '-•• ."- "'-•• *.-3 .
32. Moldenius, S., Comments made during presentation at the International Emerging
Technologies Conference in Orlando; Florida, 1997.
33. Nutt, W.E., S.W. Eachus, B.F. Griggs, M.S. Pikulin. "Development of an Ozone
Bleaching Process." In: Proceedings TAPPI Pulping Conference. Boston, 1992.
TAPPI Press.
34. Facsimile Message, Ian Mackenzie, Alberta Environmental Protection Agency to
Don Anderson, U.S. Environmental Protection Agency, June 28, 1996.
35. Radian Corporation. Summary Report for Pulp and Paper Mill Sampling. June
1996. (Record Section 20.6.2, DCN 13968.)
36. Oskarsson, L, K. Naslund. "Ecologically Balanced Kraft Pulp Production - The
Chemical Balance." In: Proceedings of the 1996 TAPPI Minimum Effluent Mills
Symposium.
37. Ruf, W. et al. "Potassium Kraft Pulping: Possibility or Necessity?" In:
Proceedings of the 1996 TAPPI Minimum Effluent Mills Symposium. 1996.
38. Stratton, S.C., G.E. Maples. "Overview of the BFR Process and Demonstration
Project." In: Proceedings of the TAPPI Environmental Conference. Atlanta, GA,
1995.
39. Dunn, K.C., S. Stratton, P.P. Earl. "Update on the Bleach Filtrate Recycle Process
at Champion, Spring 1996." In: Proceedings of the PPI World Symposium.
Brussels, 1996.
40. Record Section 21.13.
41. Yo(ung, J. "Louisiana-Pacific's Samoa Mill Establishes TCF Pulp Production."
Pulp and Paper. August 1993, 67(8): 61-63.
42. Record Section 21.6.2.7.
43. BAT Cost Model Support Document. 1996. (Record Section 23.1.2, DCN 13953)
PULPl\0707-01.mcr ' 8-3
-------
44. Supplemental Technical Development Document for the Pulp, Paper, and
Paperboard Category Effluent Limitations Guidelines and Standards, and New
Source Performance Standards. U.S. Environmental Protection Agency,
Washington, E>.C. (Record Section 30.3, DCN 14487).
45. SCA, Ostrand, Sweden, Site Visit Report (Record Section 21.5.1, DCN 14786).
46. Telephone contact report, Neil McCubbin and Derrick Brown, February 21, 1997.
47. Champion Canton Color Balance Table. (Record Section 21.13, DCN 14433.)
48. Effect of Oxygen Delignification on Yield of the Bleached Kraft Pulp
Manufacturing Process. (Record Section 2.3.1.2, DCN 14491.)
49. McDonough, Thomas J. Oxygen Delignification in Pulp Bleaching. Principles and
Practice. Carlton W. Dence and Douglas W. Reeve, ed. TAPPI Press, Atlanta,
Georgia, 1996.
50. PPCAN 1996. "Safari 96" (a report on visits to five Finnish bleached kraft mills).
Pulp and Paper Canada, June 1996.
51. "Reinforced multi-stage oxygen delignfication - recent experiences." Paperi &
Puu,.Vol. 9, 1994.
52. U.S. EPA. National Census of Pulp, Paper, and Paperboard Manufacturing
Facilities Questionnaire Database, 1990.
53. Kocurek, M.J., ed. Pulp and Paper Manufacture, Vol. 9. "Mill Control, Quality,
Environmental, Corrosion, Electrical." TAPPI Press, Atlanta.
54. Jaegel, A. "Multimedia Environmental Performance of TCF Closed Bleach Plant
Kraft Pulp Production." In: Proceedings of the Non-Chlorine Bleaching
Conference, Orlando, March 1996. Miller Freeman Press.
55. Tran, H.N., D. Bartram and P.W. Reeve. "Chloride and Potassium in the Kraft
Recovery Cycle." In: Pulp and Paper Canada. 91: May 5, 1990.
56. Pauksta, P. "Safari 96 Report on Mills in Finlad." TAPPI Journal. September
1996.
PULPlV0707-01.mcr 8-4
-------