United States
Environmental Protection
Agency
Hazardous Waste Engineering
Research Laboratory
Cincinnati OH 45268
Research and Development
EPA-600/S2-84-175 Dec. 1984
Project Summary
Capital and O&M Cost
Relationships for Hazardous
Waste Incineration
Robert McCormick
The objective of this study was to
develop relationships between capital
and operation/maintenance (O&M)
costs for hazardous waste incineration
and the various waste-specific, design-
specific, and operational factors that
affect these costs. These cost relation-
ships have been designed so that total
capital investment, annual O&M cost.
and unit (dollars per Ib, etc.) disposal
cost estimates can be calculated for a
variety of waste compositions, different
incineration system designs and con-
figurations, and a wide range of system
operating conditions and performance
requirements. Sequential elements of
the estimation procedure are: (1) input
data specifications, (2) design assump-
tions and engineering calculations, (3)
capital cost estimation, (4) annual O&M
cost estimation, and (5) unit disposal
cost calculation.
The input data specifications include
physical/chemical waste characteris-
tics and throughput rates, generic in-
cinerator design type, capacity, and
operating temperature, particulate and
acid gas removal requirements, energy
recovery utilization, and operating sched-
ule. When these data are specified by
the user, conceptual design, material
balance, energy balance, capital cost,
and O&M cost calculations are per-
formed in sequential fashion. The pro-
jected accuracy of this cost estimation
procedure is ±30 to 40 percent.
This Project Summary was developed
by EPA's Hazardous Waste Engineering
Research Laboratory, Cincinnati. OH.
to announce key findings of the research
project that is fully documented in a
separate report of the same title (see
Project Report ordering information at
back).
Introduction
The U.S. Environmental Protection
Agency (EPA) is currently performing a
Regulatory Impact Analysis (RIA) of the
RCRA performance standards for hazard-
ous waste incineration facilities. One of
the key elements of this RIA effort is the
development of representative cost data
for hazardous waste incineration, includ-
ing:
• Capital costs for new facilities de-
signed in accordance with the Re-
source Conservation and Recovery Act
(RCRA) requirements.
• Operation and maintenance (O&M)
costs for these facilities.
• Retrofit costs for existing facilities to
comply with RCRA standards.
This cost information is also needed by
the Incineration Research Branch (IRB) of
the Industrial Environmental Research
Laboratory, U.S. EPA, to complement
technical/environmental evaluations of
hazardous waste incineration technol-
ogies, and to aid in identifying future
research priorities.
The report summarized herein focuses
on capital and O&M costs of incineration.
Retrofit costs are addressed in a compan-
ion report entitled, "Retrofit Cost Relation-
ships for Hazardous Waste Incineration."
The objective of the study was to
develop relationships between capital
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and O&M costs for hazardous waste
incineration and the various waste-
specific, design-specific, and operational
factors that affect these costs. These
costs relationships were to be designed
so that total capital investment, annual
O&M cost, and unit ($/lb., etc.) disposal
cost estimates could be calculated for a
variety of waste compositions, different
incineration system designs, and config-
urations, and a wide range of system
operating conditions and performance
requirements. This degree of parametric
cost estimating capability was considered
essential for the RIA effort and for future
IRB utilization.
Based on these objectives, a capital and
O&M cost estimation model has been
developed in computer-ready format.
Sequential elements of the model are: (1)
input data specifications, (2) design as-
sumptions and engineering calculations,
(3) capital cost estimation, (4) annual
O&M cost estimation, and(5) unit disposal
cost calculation.
Input requirements for the model in-
clude basic physical/chemical properties
of the wastes in question, plus a limited
number of facility design and operating
specifications. Based on these input data
and numerous technical assumptions in
line with current industry practice, a wide
array of engineering calculations are
performed to specify and design the
required hardware for the facility and to
estimate the rates at which fuel, power,
and other chemicals/utilities are con-
sumed.
Based on the preliminary design speci-
fications, equipment costs are estimated
using a series of empirical relationships
between cost and capacity, materials of
construction, or other relevant design
features. Estimated costs for equipment
installation and contingencies are then
combined with the equipment costs to
determine total capital investment.
Variable costs for fuel, power, etc. are
estimated from the consumption rate
calculations previously mentioned and a
series of regionalized unit cost data.
Semi-variable costs such as labor and
maintenance, fixed charges to capital,
and energy recovery credits (optional) are
also estimated to determine the net
annual O&M cost. This cost is then
divided by the annual waste throughput
to arrive at the final unit disposal cost
estimate.
More details of the input requirements,
intermediary calculations, and outputs
are described below. Limitations of the
model are also discussed
Methodology
For input data specification purposes,
wastes are divided into five categories:
combustible organic liquids, non-combus-
tible liquids (without support fuel), pump-
able slurries or sludges, non-pumpable
sludges or bulk solids, and containerized
solids. The following data are required for
each waste stream or mixture of wastes
included in each of these categories: (1)
normal or average feed rate, (2) gross
heating value, (3) fractional content of
carbon, hydrogen, oxygen, nitrogen, mois-
ture, ash, and chlorine, and (4) presence
of toxic, heavy metals or alkali metals in
the ash. Certain facility design and oper-
ating conditions must also be specified to
use the model, including (1) owner/op-
erator designation, (2) generic incinerator
design (liquid injection, rotary kiln, or
multiple chamber/ hearth type), (3) nom-
inal primary and secondary chamber
incineration temperatures, (4) minimum
excess air requirements, (5) frequency
and duration of incinerator startups, (6)
waste heat boiler utilization and generic
design (firetube or watertube), (7) partic-
ulate size distribution and control require-
ments, (8) acid gas (HCI) control require-
ments, (9) regular operating schedule and
annual facility utilization, and(10) region-
al location and climatical considerations.
These input data are self-explanatory
with the exception of "owner/operator
designation."Three distinct owner/oper-
ator scenarios are provided so that the
economic impacts of regulation can be
evaluated across different segments of
the hazardous waste incineration user
industry. These three scenarios are: (A)
commercial, institutional, or small indus-
trial firms operating <10 million Btu/hr
incinerators, (B) large industrial firms
operating 10 to 50 million Btu/hr facilities
for captive waste disposal, and (C) com-
mercial waste disposal, semi-private or
corporate central facilities in the 50 to
100 million Btu/hr range.
Certain waste characteristics and de-
sign alternatives that can impact costs
are not addressed in the study. First of all,
wastes containing significant concentra-
tions of sulfur, phosphorus, or halogens
other than chlorine are not provided for.
This limitation is imposed because few of
these types of wastes are "listed" for
RCRA purposes, and because assessment
of air pollution control costs would be
beyond the scope of the study if such
wastes were considered. Similarly, air
pollution control device (APCD) selection
is limited to venturi scrubbers for partic-
ulate contnl and packed bed absorbers
for acid gas (HCI) removal. These limita-
tions are realistic because venture and
packed bed scrubbers are the choice of
most designers.*
Before the input data can be used to
estimate capital and O&M costs, a num-
ber of design assumptions and engineer-
ing calculations are needed for conceptual
design purposes and to estimate raw
material and utility consumption rates.
The design assumptions incorporated in
the model are too numerous to address in
their entirety in this summary; however,
the major underlying assumptions are as
follows:
1. Either liquid injection, rotary kiln, or
multiple chamber hearth incinerat-
ors are used. Unique, exotic, or
hybrid designs are not considered.
2. Bottom ash from kiln and hearth
incinerators is disposed off-site at
sanitary or secure landfills, depend-
ing on ash toxicity.
3. Incinerators are equipped with suf-
ficient fuel firing capacity to reach
the designated operating temper-
ature prior to waste injection.
4. Firetube and watertube waste heat
boilers are the only energy recovery
devices considered. Where utilized,
waste heat boilers are located im-
mediately downstream from the
incinerator, recovering enough heat
to reduce combustion gas temper-
atures to 550°F.
5. Waste heat boilers are followed by
small in-line quenches to reduce
gas temperatures to adiabatic satur-
ation upstream from the APCDs. If
waste heat boilers are not em-
ployed, larger quenches are used to
achieve the same temperature re-
duction.
6. Three air pollution control system
configurations are considered: (a)
venturi scrubber for particulate
control, (b) packed bed absorber for
HCI removal, and(c) venturi scrubb-
er followed by HCI absorber. It is
assumed that at least one air pollu-
tion control device is needed. A flow
diagram for a complete scrubbing
and flue gas handling system is
presented in Figure 1.
7. All scrubbing systems have a com-
mon sump that receives the quench,
venturi scrubber, and absorber ef-
*An appendix to the report covering ionizing wet
scrubbers is currently being written and will be
published separately
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fluents. At least 5 percent of the
combined effluent is discharged to
limit solids buildup, and the remain-
der is recycled.
8. Caustic soda solution is used in
stoichiometric quantities for HCI
scrubbing and neutralization.
9. All systems are assumed to be
balanced draft, with combustion air
blowers for the incinerators and ID
fans downstream from the APCDs.
10. Reasonable on-site storage capac-
ities and/or housing structures are
provided for liquid and solid wastes.
11. The overall system is adequately
designed in terms of safety inter-
locks and materials of construction
to prevent catastrophic failure.
These design assumptions are typical
of good industry practice. Therefore, they
provide a reasonable basis for cost esti-
mation for the industry as a whole, which
is the goal of the RIA. However, these
assumptions do not reflect current prac-
tice for all facilities, so cost estimates
derived from the model may not be
representative for specific facilities.
Based on these design assumptions
and the input data previously described,
engineering calculations are performed
for conceptual design and raw material/
utility consumption rate estimations.
These calculations include: (1) land and
associated site development require-
ments; (2) storage tank capacities, agita-
tion, nitrogen blanketing, and heating
requirements; (3) pump capacities and
power requirements; (4) piping require-
ments; (5) bulk solid waste handling
equipment sizing and operational require-
ments (carts, transport vehicles, convey-
ors, and feeders); (6) atomizing air com-
pressor capacity and power requirements;
(7) square footage for buildings and
structures; (8) incinerator operating re-
quirements in terms of low-fire, supple-
mental heating, and startup fuel; combus-
tion air blower capacity and power; ash
handling water and power; and exit gas
characteristics; (9) waste heat boiler
steam generation, fuel savings, and exit
gas temperature; (10) quench water
requirements, booster pump capacity and
power requirements, and saturated exit
gas composition; (11) scrubbing system
water requirements, chemical require-
ments, pump power requirements, and
blowdown rate; and (12) induction draft
fan capacity and power requirements.
Freight-on-board costs for front-end
storage and handling equipment, incin-
erator subsystems and auxiliary equip-
Inlet
Gas
Packed
Bed
Absorber
Venturi
Scrubber
To
Atmosphere
ID Fan
Caustic Solution
Makeup Water
Blowdown
to Disposal
Figure 1. Generalized flow diagram for quench/scrubber system.
ment, packaged waste heat boilers and
necessary trim, and scrubbing/flue gas
handling equipment are based on vendor
estimates. Cost versus capacity curves
are presented for each equipment item or
subsystem, based on the design and
material-of-construction specifications
previously determined. These cost versus
capacity curves are used in conjunction
with the actual conceptual design calcu-
lations to estimate purchased equipment
costs for the facility in question
Costs for equipment delivery, installa-
tion materials and labor, engineering
design, permitting, construction expenses
and fee, and contingency are then est-
imated as percentages of the purchased
equipment cost. These factored costs,
combined with the purchased equipment
costs, constitute the depreciable fixed
capital cost estimate for the facility.
Total capital investment estimates in-
clude the depreciable fixed capital invest-
ment, plus allowances for land purchase,
startup, trial burns, and working capital.
Costs for land, trial burns, and working
capital are estimated directly, based on
facility design and operating character-
istics. Startup costs are estimated as a
percentage of the direct costs for equip-
ment purchase and installation, plus
indirect and contingency costs.
Annual O&M costs and credits are
divided into four categories for calculation
purposes: (1) variable costs, such as fuel,
power, water, caustic soda solution for
HCI scrubbing, liquid nitrogen for tank
blanketing and residue disposal (ash and
scrubber blowdown); (2) semi-variable
costs, such as labor, maintenance, and
waste analyses; (3) fixed costs, such as
depreciation, insurance, and taxes; and
(4) energy recovery credits for waste heat
boiler utilization (optional). Annual vari-
able cost estimates are based on the raw
material-utility consumption rate calcula-
tions previously described, the assumed
annual utilization percentage for the
facility, and regionalized unit cost data. In
this study, unit cost data are given for the
Chicago, Houston, Los Angeles, and
northern New Jersey metropolitan areas.
Operating labor cost estimates are
based on assumed staffing requirements
for the various categories and capacities
of hazardous waste incineration facilities,
and regionalized wage/salary rates. Six
separate staffing scenarios are provided,
with differentiation based on owner/op-
erator designation (A, B, or C) and waste
mix (liquids only or liquid and solids).
Maintenance costs are estimated as a
percentage of the depreciable fixed capita I
investment, as are the costs for deprecia-
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tion, insurance, and taxes. Energy recov-
ery credit estimates are based on the
calculated fuel conservation rate, annual
utilization percentage, and regionalized
costs for fuel.
The net annual O&M costs is deter-
mined by summing the variable, semi-
variable, and fixed operating costs and
subtracting any energy recovery credit.
Dividing this net quantity by the estimated
annual waste throughput yields the unit
disposal cost estimate, which is the
desired output.
Applicability and Limitations
The accuracy requirements stated at
the outset of this study were ± 70
percent. For most facilities, the budget-
ary pricing procedures used in this study
should provide better accuracy, i.e., ± 30
to 40 percent. This degree of accuracy is
considered acceptable for purposes of the
RIA and for first-cut comparisons of the
costs for incineration versus other waste
disposal alternatives. However, caution
should be exercised if the model is
utilized for site-specific cost estimating
purposes.
R. McCormick is with the Acurex Corporation, Mountain View, CA 94039.
B. L. Blaney is the EPA Project Officer (see below).
The complete report, entitled "Capital and O&M Cost Relationships for Hazardous
Waste Incineration." (Order No. PB 85-121 119; Cost: $19.00. subject to
change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Hazardous Waste Engineering Research Laboratory
U.S. Environmental Protection Agency
Cincinnati, OH 45268
U S GOVERNMENT PRINTING OFFICE. 569-016/7868
United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
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