HAP Emissions

1
HAP Emissions Permitting

• W. Clark Smith
• Air Quality Permitting
• 402.471.4204
• clark.smith_at_ndeq.state.ne.us

2
Implications

• Testing results above emissions limitations can
  have implications in permitting
• Existing sources
• Major/Minor Status under the HAP program
• More stringent testing and monitoring
  requirements
• New sources
• Different technology requirements

3
Major/Minor Status

• Sources exceeding 10 tpy of a single HAP or 25
  tpy all HAPs are considered a major source
• Being major for HAPs subjects the source to
  additional Federal requirements
• National Emissions Standard for Hazardous Air
  Pollutants, also known as Maximum Available
  Control Technology (MACT) Standards

4
Major/Minor Status

• Currently, the EPA has a once in always in
  policy on MACT standards
• If a source emits at major source levels after
  the first compliance date of a standard, they
  always have to comply with the standard
• Even if their emissions are later reduced to less
  than the major source levels
• Most significant standard for ethanol plants is
  the Miscellaneous Organic NESHAP or MON
• Compliance date - May 10, 2008

5
Major/Minor Status

• The MON covers fermentation and distillation
  units
• Those units covered must control HAP by 98 or to
  a level of 20 ppmv through
• Use of a flare or
• Use of a recovery device.
• Only 5 of 29 tests conducted in Nebraska have had
  results less than 20 ppmv

6
More stringent testing and monitoring requirements

• The operating permit program requires that we
  include
• periodic monitoring sufficient to yield reliable
  data from the relevant time period that are
  representative of the source's compliance with
  the permit. Such monitoring requirements shall
  assure use of terms, test methods, units,
  averaging periods, and other statistical
  conventions consistent with the applicable
  requirement.

7
Different technology requirements

• Proposed sources that will emit more than 2.5 tpy
  of a single HAP or 10 tpy all HAPs must apply
  Best Available Control Technology (BACT)
• BACT is
• Maximum degree of HAP reduction determined to be
  achievable.
• Done on a case-by-case basis, taking into account
• energy,
• environmental, and
• economic impacts and other costs
• Economic impacts on the source are weakened if
  the technology is achieved in practice

8
Different technology requirements

• Current requirements for fermentation units are
• Scrubbers and,
• 65 control efficiency or,
• 20 ppmv total HAP.
• As indicated above, scrubbers have difficulty
  achieving the above levels on a routine basis

9
Different technology requirements

• Because sources are having difficulty meeting the
  above limits, there may be a need to reevaluate
  our BACT determination for fermentation units
• As mentioned before, BACT is
• Maximum degree of HAP reduction determined to be
  achievable, i.e., achieved in practice
• Other control technologies
• Regenerative Thermal Oxidizers
• Thermal Oxidizers

10
Different technology requirements

• Maximum degree of HAP reduction
• Other BACT programs, e.g., PSD, require at least
  90 control efficiency generally closer to 98
• Thermal oxidizers achieve greater than 95
  control efficiency generally 98
• Determined to be achievable
• Control of HAPS using oxidizers being proposed by
  ethanol plants in Nebraska
• Control of HAPS using oxidizers being achieved in
  practice in Iowa and Minnesota

11
RTO Effectiveness

• Following slides provide examples of the
  effectiveness of an RTO
• Slides will show HAP emissions based on
• Permitted values
• Tested values (fermentation unit) at
• Lowest emission rate, and,
• Highest emission rate
• Use of a RTO, with 98 control, on the
  fermentation unit

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RTO Effectiveness
13
RTO Effectiveness
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RTO Effectiveness
15
RTO Effectiveness