Greenhouse Gas (GHG) Permit Training
GHG BACT Determinations Principles and Examples
GHG BACT Determinations
Top-down BACT Process
1. Identify all potentially applicable controls
2. Eliminate infeasible options
3. Rank controls by their effectiveness
4. Evaluate economical, energy and
environmental impacts
5. Select BACT and create permit limits
DRAFT
3
BACT in More Detail: Top Down Step 1
Step 1: Identity All Available Controls
• Technologies and methods to consider:
– Inherently lower emitting processes/practices/designs
– Add-on controls
– Combinations of inherently lower emitting processes/practices
and designs and add-on controls
– Methods/controls applied to similar source categories that may be
available through technology transfer
• Need not consider options that would fundamentally redefine
the nature of the source.
– “Redefining the source” is a question of degree and within the
discretion of the permitting authority.
– Assessment begins with consideration of the fundamental
business purpose of the project, as described in the permit
application
DRAFT
4
BACT in More Detail: Top-Down Step 1
Step 1: Identity All Available Controls (cont’d)
Consideration of sources of energy in a BACT review:
– Consideration of a cleaner version of the primary fuel is not
considered redefining the source in most cases. (e.g., it may
redefine a mine mouth facility.)
– Greater use of a secondary fuel is not considered redefining
the source in many instances.
– Consideration of a new alternative fuel or energy source may
be redefining the source and beyond the scope of a BACT
review.
DRAFT
5
BACT in More Detail: Top Down Step 1 (cont’d)
GHG Considerations – Energy Efficiency
• In the near term, options to improve energy efficiency will
be the key control technologies for combustion related
GHGs.
• Often energy efficiency is improved through many actions
with small impacts. In that context, it may be impractical
to evaluate them individually.
• Opportunities to use energy more efficiently, and thereby
reduce emissions of GHGs, are appropriate considerations
in a BACT review for a new facility.
DRAFT
6
BACT in More Detail: Top Down Step 1 (cont’d)
GHG Considerations – Benchmarking Efficiency
• Data on the energy use/efficiency of similar new units can
be used to “benchmark” overall energy efficiency.
• Benchmarking data can be used to demonstrate the
relative energy efficiency of a facility, process or unit.
• The comparison can show whether a unit is a best
performer and whether additional reductions may be
achievable.
DRAFT
7
BACT in More Detail: Top Down Step 1 (cont’d)
GHG Considerations (cont’d)
• When and how to consider CCS?
– Expect CCS to be considered in Step 1 for larger sources of
CO2: power plants, cement plants, hydrogen plant,
ammonia plant, ethanol plant, ethylene oxide production
and iron and steel manufacturing, etc.
• Is the use of biofuels a GHG control strategy?
– There is no consideration of offsite impacts in Step 1
– Often the CO2 emission rates of biofuels are similar to the
fossil alternatives.
DRAFT
8
GHG Technology Resources
• EPA GHG Technology White Papers – Electric
Generating Units, Boilers, Pulp and Paper, Cement,
Iron and Steel, Refineries, Nitric Acid Plants
http://www.epa.gov/nsr/ghgpermitting.html
• EPA GHG Mitigation Strategies Database – currently
covers Cement and Electric Generating Units
http://www.epa.gov/nsr/ghgpermitting.html
DRAFT
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GHG Technology Resources (cont’d)
• ENERGY STAR Guidelines for Energy Management
– (www.energystar.gov/guidelines)
• ENERGY STAR Industrial Sector Energy Guides
– (www.energystar.gov/epis)
• EPA’s Climate Leaders Protocols
– (http://www.epa.gov/stateply/index.html)
• EPA’s Lean and Energy Toolkit
– (www.epa.gov/lean/toolkit/LeanEnergyToolkit.pdf)
DRAFT
10
GHG Technology Resources (cont’d)
• EPA’s Voluntary Partnerships for GHG Reductions:
– Landfill Methane Outreach Program
(http://www.epa.gov/lmop/)
– Coalbed Methane Outreach Program
(http://www.epa.gov/cmop/index.html)
– Natural Gas STAR Program
(http://www.epa.gov/gasstar/index.html)
– Voluntary Aluminum Industrial Partnership
(http://www.epa.gov/highgwp/aluminum-pfc/index.html)
– CHP Partnership Program (http://www.epa.gov/chp)
DRAFT
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GHG Technology Resources (cont’d)
• SF Emission Reduction Partnership for the Magnesium
Industry
– http://www.epa.gov/highgwp/magnesium-sf6/index.html
• PFC Reduction/Climate Partnership for the Semiconductor
Industry
– http://www.epa.gov/highgwp/semiconductor-pfc/index.html
• Report of the Interagency Task Force on Carbon Capture and
Storage
– http://www.epa.gov/climatechange/policy/ccs_task_force.html
• As permitting authorities gain experience with GHG BACT
determinations, more useful information on GHG permitting
decisions will present itself in the EPA’s RACT/BACT/LAER
Clearinghouse (RBLC) -- http://cfpub.epa.gov/rblc/
DRAFT
12
GHG Benchmarking Resources
The following information sources may be helpful when
including benchmarking as part of a BACT analysis.
• EPA Energy Star Industrial Energy Management
Information Center:
http://www.energystar.gov/index.cfm?c=industry.bus_industry_info_center
• DOE Industrial Technologies Program:
http://www1.eere.energy.gov/industry/
• Lawrence Berkeley National Laboratory Industrial Energy
Analysis Program: http://industrial-energy.lbl.gov/
• European Union Energy Efficiency Benchmarks:
http://ec.europa.eu/environment/climat/emission/benchmarking_en.htm
DRAFT
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GHG Benchmarking Resources (cont’d)
The following information sources may be helpful when
including benchmarking as part of a BACT analysis:
• IPCC Four Assessment Report: Climate Change 2007:
http://www.ipcc.ch/publications_and_data/ar4/wg3/en/ch7.html
• ISO TC 207 Standards on Environmental and Greenhouse Gas
Management and Related Activities:
http://www.iso.org/iso/iso_catalogue/catalogue_tc/catalogue_tc_browse.
htm?commid=54808
DRAFT
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BACT in More Detail: Top Down Step 2
Step 2: Eliminate Technically Infeasible Options
Criteria for eliminating a technology:
• Not technically feasible (i.e., not demonstrated in practice
successfully)
• Demonstrated in practice relates to the same type and size of
facility or one that has similar processes or emissions stream
(for an add-on control)
• Technology is infeasible if it cannot be reasonably installed
and operated on the source
• Should not be eliminated simply because one cannot get a
commercial guarantee from a vendor.
DRAFT
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BACT in More Detail: Top Down Step 2 (cont’d)
• GHG considerations – Feasibility of CO2
Sequestration
– Must consider all three aspects: capture, transport
and storage
– Site specific considerations include space for
equipment, rights of ways for pipelines, access to
an appropriate geological reservoir or other
storage option
DRAFT
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BACT in More Detail: Top Down Step 3
Step 3: Ranking of Controls
• Remaining available, feasible control technologies
(and combinations of technologies) are ranked in
order of overall control effectiveness for the
pollutant under review.
• Ranking options include:
– Percent pollutant removed
– Emissions rate (input- or output-based)
– Emissions reduction over time
DRAFT
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BACT in More Detail: Top Down Step 3 (cont’d)
Step 3: Ranking of Controls
• GHG measures of performance
– If plantwide measures to reduce GHGs are considered,
alternative measures of overall net emissions impact may
be more useful:
• Expected emission rate in units such as TPY, lbs/hour,
lbs/unit of input or output, etc.
• Expected emissions reduction could be expressed in
same units
• Must consider combinations of controls but not
every possible permutation
DRAFT
18
BACT in More Detail: Top Down Step 4
Step 4: Economic, Energy and Environmental Impacts
How to examine cost effectiveness:
• Dollars per ton of emissions eliminated (in CO2e)
• Average cost effectiveness and incremental cost effectiveness
• Steady state case
– Operating cost plus annualizing initial investment
– Annual emissions reduction at full capacity
• Life time analysis for project
– This makes sense when costs and emissions reductions are not steady
(e.g., landfills)
– Determine life time emissions reductions and costs
DRAFT
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BACT in More Detail: Top Down Step 4 (cont’d)
• Cost effectiveness criteria
– As with other pollutants, acceptable cost levels for GHG
will evolve through permitting experience
– Given the large amounts of GHGs, we expect the cost per
ton criteria will be lower than for other pollutants
• Other economic considerations that are relevant
– Cost of control relative to cost of project
– Impact on product cost and local job losses
DRAFT
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Cost Effectiveness Example:
New Natural Gas Fired Boiler
Emissions
Analysis:
Assumptions
Size of Nat Gas Boiler
Annual Operating
Hours
CO2 emission factor
CH4 emission factor
N2O emission factor
GWP CH4
CWP N2O
Annual Fuel Use
CO2 emissions
CH4 emissions
N2O emissions
250
MMBTU/hr
8760
53.02
0.001
0.0001
21
310
Hours
kg/MMBTU
kg/MMBTU
kg/MMBTU
2,190,000
116,113,800
2,190
219
CO2 emissions
CH4 emissions
N2O emissions
128,015.46
2.41
0.24
CO2 emissions
CH4 emissions
N2O emissions
TOTAL
128,015.46
50.70
74.85
128,141.02
DRAFT
MMBTU
KG
KG
KG
Tons
Tons
Tons
tons CO2e
tons CO2e
tons CO2e
tons CO2e
21
Cost Effectiveness Example:
New Natural Gas Fired Boiler (cont’d)
Measure
Efficiency
Benefit
(Fuel
Savings)
Capital
Cost
Annualized
Capital
Cost
Operating
Fuel
Savings
and Maint.
Costs
Annual
Cost or
Savings
CO2e
Emissions
Reduction
C/E
$/ton
Oxygen Trim
1%
$100K
$16.3K
-78.8K
+$25K
-$37.5K
1,281
NA
Economizer
5%
$1,000K
$163K
-$395K
+$75K
-$157K
6,405
NA
Blowdown
Heat
Recovery
0.3%
$400K
$67.2K
-$23.6K
+$50K
+$93.6K
384.3
$243
/ton
DRAFT
22
BACT in More Detail: Top Down Step 4 (cont’d)
• Energy impacts: Both the energy use and its economic
implication are addressed. Direct energy impacts (e.g., cost of
fuel) as well as indirect energy impacts (e.g., fuel scarcity).
Purchased electricity is addressed at this point
• Other environmental impacts:
– Solid and hazardous waste generation, wastewater
discharges, visibility impacts, demand on local water
resources or emissions of unregulated pollutants.
– Both on site and off site impacts considered
• Historically, the economic impact has been the most common
basis for putting aside the most effective control as not being
BACT. Energy and environmental collateral impacts have been
rarely a factor in the BACT decision process.
DRAFT
23
BACT in More Detail: Top Down Step 4 (cont’d)
• GHG Issues
– Impacts of CCS on energy use and related emissions
– Weighing of possible trade-offs of criteria pollutants and
GHGs
– Biofuel off site impacts - treatment of emissions for BACT
purposes is still under review by EPA
• Permitting authority has discretion in the
determining the weight given to the particular
impacts under consideration.
• Consideration and rationale must be documented.
DRAFT
24
BACT in More Detail: Top Down Step 5
Step 5: Selecting BACT
• Determining BACT:
– Should be the most effective control option not eliminated
in Step 4
• Permit Conditions
–
–
–
–
Emissions limit
Equipment specifications
Work practices
Monitoring, recordkeeping and reporting
DRAFT
25
BACT in More Detail: Top Down Step 5 (cont’d)
• GHG Considerations
– Output based limits can be a useful means of capturing the
impact of a multitude of energy efficiency measures
– Longer averaging periods may be appropriate for GHGs
and are useful in dealing with variations related to load,
malfunctions and start-up and shutdown.
– Design requirements and work practices may be needed to
create practical enforceable conditions for individual
efficiency measures.
DRAFT
26
Recap of EPA Perspective on Technology Issues
• Energy Efficiency
– Measures that reduce on site energy use: Should be
Considered in Step 1
– Measures that reduce off site energy use: Should be
Considered in Step 4
• Biofuels
– On site GHG emissions: Relevant in Step 1
– Off site GHG emissions impacts: Relevant in Step 4
– Other environmental impacts: Relevant in Step 4
DRAFT
27
Recap of EPA Perspective on Technology Issues
(cont’d)
• Carbon Capture and Storage (CCS)
– May be considered an add-on control
– Three key components:
• Transport,
• Capture and
• Storage (sequestration)
– Technical feasibility: Relevant to Step 2
– Cost: Relevant to Step 4
– Other impacts on energy use and environment: Relevant
to Step 4
DRAFT
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