Back to Library

GCI TECH NOTES©


Volume 15, Number 4           A Gossman Consulting, Inc. Publication       September 2010


Portland Cement 2010 NESHAP Final Rule - Mercury

by

David Gossman

Introduction
On September 9, 2010, EPA published in the Federal Register new PC MACT regulations. Of the standards, the new mercury emission limits and monitoring requirements will be one of the most difficult to comply with.

2010 NESHAP Portland Cement Final Mercury Limits
40 CFR 63.1343(b)(1)
      Source       Operating Mode  Hg Limit          Units
Existing Normal 55 lb/MM tons clinker
Existing Startup & Shutdown 10 µg/dscm
New Normal 21 lb/MM tons clinker
New Startup & Shutdown 4 µg/dscm

            Mercury Compliance
            40 CFR 60.1348(a)(5)
      Mercury CEMS or sorbent trap
      First 30 days data determine initial compliance
      Hourly production rate of clinker to be determined 63.1350(d)

            Mercury Compliance
            40CFR 60.1348(b)(7)
      Normal operation - Continuous compliance documented based on 30 day rolling average
      Startup/shutdown - Continuous compliance documented based on 7 day rolling average

            Mercury Emission Tests
            40 CFR 63.1349(b)(5)
      Hourly mercury emissions and stack gas flow rate data must be obtained.
      Optionally, sorbent trap data is gathered daily.
      Stack gas flow rate monitored in accordance with 40 CFR 63.1350(k)(4)
      Note: Reporting units are specified in the rule as lb/million (lb/MM) tons of clinker.

            Mercury Monitoring Reporting
            40 CFR 63.1350(k)
      Performance Specification 12A (PS 12A) of Appendix B to Part 60 is specified for CEMS.
      Nevertheless, this section specifies a span requirement that is different from PS 12A.
         - Needs to include upper limit for only normal “mill on” operation. 
         - Must also include 2 times the emission standard.


             Site Specific Monitoring Plans
            40 CFR 63.1350(p)
      The New SSMP!
      Different one required for each Continuous Monitoring System (CMS)
      Must be available for submission at least 60 days prior to initial performance evaluation.

            Mercury CEMS Regulations
            Special Notes on PS 12A.
      It does not detect particulate mercury!
      Standards are elemental mercury and HgCl2.
      Mercury CEMS extraction point requires stack or duct – open top bag houses won’t comply.
      While other options exist, Method 30A should be considered the method of choice for RATA.

             Interesting Items from Preamble - Mercury

      Eleven (11) kilns were used to set MACT floor limits.
      EPA acknowledges that the main source of variability is raw materials and fuel.
      EPA is eliminating the restriction on the use of fly ash containing mercury.
      EPA is also eliminating restrictions on the CKD waste rate.
      ACI appears to be the only control technology EPA has thoroughly evaluated.
      EPA, in developing the standard, assumed no kilns currently control mercury emissions.

            Mercury CEMS – Times Have Changed

      One key was elimination of particulate bound mercury.
      Numerous manufacturers – some include:
        –  TEKRAN
        –  PS Analytical
        –  CEMTREX
        –  SICK MAIHAK
        –  Thermo Scientific
        –  Nippon Instruments

            CEMS Calibration
      Requires NIST traceable standards.
      NIST only has elemental standards at 41-353 µg/dscm.
      Limits of 4-10 µg/dscm require a span of 10-20 µg/dscm.
      There are apparently NIST traceable elemental Hg generators that go down to 1 µg/dscm.
      EPA will need to address this issue.

Conclusion:  A compliance strategy is clearly needed.

Step 1:

Step 2:

 Step 3: