Understanding Mercury Compliance in the
NESHAP or Cement Mact
Ohio Lumex takes a close look at what's really in the NESHAP Rule ( Cement Mact )
for the Portland Cement MFG Industry pertaining to MERCURY with an overview of
requirements using Sorbent Trap Sampling for compliance
Important Dates for NESHAP or Cement Mact
Cement Mact Announcement
EPA Finalizes Amendments to Air Toxics Standards for Portland Cement Manufacturing
December 20, 2012 – In response to a federal court decision, petitions for reconsideration
and technical information received after final rules were issued in 2010, the U.S.
Environmental Protection Agency (EPA) finalized amendments to the agency’s air toxics rule
for Portland cement manufacturing. The amended rule will maintain dramatic reductions of
mercury, acid gases, particulate matter and total hydrocarbons from existing cement kilns
across the country, while ensuring that emissions from new kilns remain low. Final rule
published for release on Feb 12, 2013
Website: http://www.epa.gov/ttnatw01/pcem/pcempg.html#IMP
New Compliance Date: Sept. 9th 2015
Today’s final amendments apply to two air emissions rules for the Portland cement industry:
air toxics standards and new source performance standards. The final air toxics rule retains
emission limits for mercury, acid gases and total hydrocarbons from the 2010 rules, along with
retaining requirements that kilns continuously monitor compliance with limits for mercury, total
hydrocarbons and particulate matter (PM).
NESHAP: National Emission Standards for Hazardous Air Pollutants ( Portland Cement MFG )
Final Emissions Limits for Portland Cement MFG.
Pollutant:
Mercury
(major and area sources)
Limits for Existing Source
55 pounds per million tons of
Clinker, averaged over 30 Days
Final Limits for New Source
21 pounds per million tons of
Clinker, averaged over 30 Days
NOTE: Standards for Fugitive Emissions from open clinker storage piles
These Clinker Piles ( sources ) under this rule would be controlled by work practices which
minimize emissions by various means ( Enclosing piles, spraying piles and shielding piles from
wind )
The EPA estimates that this rule will affect about 100 Portland Cement facilities located in the
US & Puerto Rico about 86 Mfg plants and 14 facilities will be affected for clinker piles /
storage work practices.
Typical Cement Plant with Rotary Kilns
Typical Cement Plant Process
Examples of 4 main raw materials used for
Portland Cement Manufacture
Looking at Raw Materials to make Cement Clinker
Limestone
Shale
Clay
Cement Clinker
Cement clinkers are formed by
the heat processing of cement
elements in a kiln. Limestone,
Shale, Clay or Ash and iron ore in
specific proportions are heated in
a rotating kiln
Iron Ore
Cement Raw Material Breakdown
The most common materials in cement are:
Limestone 70% – 80%
Shale & or Clay 10% - 20%
Sand 2% - 5%
Iron Ore Source 1% - 2%
Limestone, Shale & Clay are sedimentary materials and are typically low in metals
including mercury.
NOTE: The exception comes when these materials are associated with volcanics.
Conclusion: Recommend sending raw material samples to Ohio Lumex lab to
analyze for mercury concentration so you have a better understanding of the
source of mercury in your cement MFG process.
Sources of Mercury in Cement
Typical Materials & Fuel – Mercury Content
Contribution to Total Emissions as a %
42.16
44.02
10.26
3.56
Limestone
Coal Ash
Coal
Other
Cement is Made in a 2 Step Process
Step1: First clinker is produced from raw materials
The raw materials are delivered in bulk to the raw mill, crushed and
homogenized into a mixture which is fed into a rotary kiln. This is an
enormous rotating pipe of 60 to 90 m long and up to 6 m in diameter. This
huge kiln is heated by a 2000°C flame inside of it. The kiln is slightly inclined
to allow for the materials to slowly reach the other end, where it is quickly
cooled to 100-200°C. Four basic oxides in the correct proportions make
cement clinker: calcium oxide (65%), silicon oxide (20%), alumina oxide
(10%) and iron oxide (5%). These elements mixed homogeneously (called
“raw meal” or slurry) will combine when heated by the flame at a temperature
of approximately 1450°C.
Step 2: Cement is then produced from cement clinker
Then the 2nd step is handled in a cement grinding mill, which may be located
in a different place to the clinker plant. Gypsum (calcium sulphates) and
possibly additional materials (such as blast furnace slag, coal fly ash ) or
inert materials (limestone) are added to the clinker. All the materials are
ground leading to a fine and homogenous powder. The process is complete
then the cement is stored in silos before being dispatched either in bulk or
bagged.
Cement Plant HG Species During Raw Mill On & Off
Mercury During - Raw Mill On & Off Operation
Raw Mill On: Kiln exhaust gases sent to raw mill, which have a relatively high
temperature and low humidity, can be utilized for the drying of raw materials in the
raw mill when the raw mill is in operation.
Raw Mill Off: During raw mill off, the kiln exhaust gases are directly sent to the
baghouse or ESP and then to the stack.
NOTE: Mercury emissions are typically higher in kiln operations with the raw mill-off
due to the missing adsorption capacity of the freshly ground particles in the raw mill.
So some secondary measures, such as the activated carbon injection, may further contribute
to the reduction of mercury emissions, but will impose some technical solutions if the filter
dust is recycled back into the kiln or into the cement mill.
Some Conclusions: High particulate removal efficiencies can be achieved with electrostatic
precipitators and bag filters. The reduction of dust emissions is very important in terms of
reducing heavy metal emissions. Fractions of many metals leave the kiln with the emitted
dust particles. Nevertheless, contrary to common opinion, the upgrading of Particulate
Removal equipment does not provide an effective solution to the capture of mercury
since it is mainly emitted in vapor form from the cement kiln stack.
NESHAP Rule Startup / Shutdown Work Practice Standard
Cement Plant Definitions:
Startup means: startup begins when the kilns induced fan is turned on and fuel
combustion is occurring in the main burner of the kiln. Startup ends when feed has been
continuous to the kiln for at least 120 minutes or kiln feed rate exceeds 60% of design.
Shutdown means: Shutdown begins when continuous feed to the kiln is halted and
ends when continuous kiln rotation ceases.
Kiln Operating Day: Means a 24 hour period that begins at midnight during which the
kiln operates for any time.
New Source: Means any source that commenced construction or reconstruction after
May 6, 2009
NESHAP Rule Startup / Shutdown Work Practice Standard
Kiln Startup:
•
During startup the kiln must initially use any one or combination of the following clean
fuels ( Natural Gas, Propane, Distillate Oil, Syn-Gas or Ultra Low Sulfur Diesel ) until
the kiln reaches 1200F then primary fuel can commence
•
All APC ( air pollution control ) devices must be operating prior to combusting any fuel
•
Also you must keep records as specified in 63.1355 during periods of startup & shutdown
including ( Date/time, duration, quantity of feed & fuel used during startup )
•
Requiring startup & shutdown procedures to be included in the facilities operation &
maintenance plan.
Looking at Mercury Monitoring in the
NESHAP Requirements 40CFR Part 60 & 63
• Can use HG Cems or Sorbent Trap Sampling system for HG monitoring requirements in
accordance with PS-12A for Cems & PS-12B for STS.
•
Each pair of sorbent traps can be used to sample stack gas for a minimum of 1 day and a
maximum of 7 operating days ( except during RATA ).
•
You must also develop an emissions monitoring plan in accordance with the regulation.
•
No monitoring during startup and shut down instead adopted a work practice standard, but
all plant air pollution control devices must be running during startup & shutdown.
• Must measure & record weight production of clinker in tons on an hourly basis with an
accuracy of +/- 5%.
• Stack Flow rates must be corrected for moisture when using to calculate HG emissions
NOTE: CMS can be HG Cems or Sorbent Trap System
Terms:
STS = Sorbent Trap Sampling System
CMS = Continuous Monitoring System
PS-12B = Performance Standard 12B
NESHAP Compliance 40CFR Part 60 & 63 Cont.
• Must convert HG analytical data ( ug/scm ) to reporting format of lbs/MMton clinker over 30
day average.
• The STS requires the use of a Certified stack gas flow monitor to establish sampling flow
rate/ stack flow rate ratio and hourly data logging verifying percent proportional sample to
stack flow rate.
• A rata of STS is required for initial certification and conducted annually there after for
compliance.
• You must demonstrate compliance by operating a CMS or STS using data from the first 30
operating days after the compliance date of this rule ( Sept. 9th, 2015 ).
NESHAP Compliance 40CFR Part 60 & 63 Cont.
Commingled Exhaust Requirements: Kiln & Coal mill exhaust are combined into 1 stack
Note: If the coal mill and kiln exhaust are not combined you must monitor at each exhaust location
• If you measure mercury at coal mill separately from kiln exhaust they must be added together
when calculating 30 day average ( lbs / MMton of Clinker )
• The Plant shall demonstrate compliance and develop a site specific monitoring plan.
•
You cannot use data recorded during monitoring system malfunctions, repairs of monitoring
system malfunctions, or required monitoring system quality assurance or control activities in
calculations used to report emissions.
•
A monitoring system malfunction is any sudden, infrequent, not reasonably preventable failure of
the monitoring system to provide valid data.
NESHAP Sorbent Trap Sampling System Rata criteria
When performing a RATA on a STS operate sorbent sampling system should be
done in accordance to QA requirements in Procedure 5 of Appendix F of Part 60.
The Rata must be conducted during normal kiln operation and Raw Mill is ON.
Sorbent Trap Sampling System
RATA Criteria Section 2 breakthrough depends on stack gas Hg concentration.
The allowable section 2 breakthrough is:
≤ 10% of Section 1 mass if HG is > 1 µg/m3
≤ 20% of Section 1 mass if HG is > 0.5 and ≤ 1 µg/m3
≤ 50% of Section 1 mass if HG is > 0.1 and ≤ 0.5 µg/m3
There is no breakthrough criterion if HG is < 0.1 µg/m3
Sorbent Traps for Compliance in accordance with PS-12B
•
Compliance with HG emissions standard based on first 30 operating days after the
compliance date of this rule.
•
Calculate the 30 kiln operating day emissions rate value using the assigned hourly Hg
emissions concentrations and the respective flow and production rate values collected
during the 30 kiln operating day monitoring period.
•
If you operate an integrated sorbent trap monitoring system conforming to PS-12B
you may use a monitoring period at least 24 hours but no longer than 168 hours
in length. You should use a monitoring period that is a multiple of 24 hours except
during a RATA as allowed in PS-12B.
* Review the QA/QC requirements in PS-12B Table 12B-1 for Sampling & Analysis
Performance Standard-12B QA/QC Criteria
TABLE12B-1
QA/QC CRITERIA FORSORBENTTRAP MONITORINGSYSTEMOPERATION ANDCERTIFICATION
QA/QC test or specification
Acceptance criteria
Frequency
Consequences if not met
Pre-monitoring leak check
?4% of target sampling rate
Prior to monitoring
Monitoring must not commence until
the leak check is passed.
Post-monitoring leak check
?4% of average sampling rate
After monitoring
Invalidate the data from the paired
traps or, if certain conditions are met,
report adjusted data
a from a single trap
(see Section 12.7.1.3).
Ratio of stack gas flow rate to
sample flow rate
Hourly ratio may not deviate fromEvery hour throughout monitoringInvalidate the data from the
paired
the reference ratio by more than period
traps or, if certain conditions are met,
±25%.
report adjusted data from a single trap
(see Section 12.7.1.3).
Sorbent trap section 2
breakthrough
?5% of Section 1 Hg mass
Paired sorbent trap agreement
?10% Relative Deviation (RD) if Every sample
the average concentration is > 1.0
?g/m3 ?20% RD if the average
concentration is ? 1.0 ?g/m
3
Every sample
Invalidate the data from the paired
traps or, if certain condition
ns are met,
report adjusted data from a single trap
(see Section 12.7.1.3).
Eitherinvalidate the data from the
paired traps or report the results from
the trap with the higher Hg
concentration.
Performance Standard-12B QA/QC Criteria Cont.
TABLE 12B-1 Cont.
QA/QC test or specification
Acceptance criteria
Frequency
Consequences if not met
Spike Recovery Study
Average recovery between 85%
and 115% for each of the 3 spike
concentration levels
Prior to analyzing field samples and
prior to use of new sorbent media
Field samples must not be
analyzed until the percent recovery
criteria has been met.
Multipoint analyzer calibration
Each analyzer reading within ±10%
of true value and r2≥0.99
On the day of analysis, before
analyzing any samples
Recalibrate until successful
Analysis of independent calibration
standard.
Within ±10% of true value
Following daily calibration, prior to
analyzing field samples
Recalibrate and repeat
independent standard analysis until
successful.
Spike recovery from section 3 of
both sorbent traps
75-125% of spike amount
Every sample
Invalidate the data from the paired
traps or, if certain conditions are
met, report adjusted data from a
single trap (see Section 12.7.1.3).
Relative Accuracy
RA ≤20.0% of RM mean value; or if
RM mean value ≤5.0 μg/scm,
absolute difference between RM
and sorbent trap monitoring system
mean values ≤1.0 μg/scm
RA specification must be met for
initial certification
Data from the system are invalid
until a RA test is passed.
Gas flow meter calibration
An initial calibration factor (Y) has
been determined at 3 settings; for
mass flow meters, initial calibration
with stack gas has been performed.
For subsequent calibrations, Y
within ±5% of average value from
the most recent 3-point calibration
At 3 settings prior to initial use and
at least quarterly at one setting
thereafter
Recalibrate meter at 3 settings to
determine a new value of Y.
Temperature sensor calibration
Absolute temperature measured by
sensor within ±1.5% of a reference
sensor
Prior to initial use and at least
quarterly thereafter
Recalibrate; sensor may not be
used until specification is met.
Barometer calibration
Absolute pressure measured by
instrument within ±10 mm Hg of
reading with a NIST-traceable
barometer
Prior to initial use and at least
quarterly thereafter
Recalibrate; instrument may not be
used until specification is met.
NESHAP HG Emissions Reporting Overview
For units that continuously monitor mercury emissions:
•
CEMS or Hg sorbent trap monitoring system, within 60 days after the reporting periods, you
must submit reports to the EPA’s WebFIRE database.
•
Each reporting period, the reports must include all of the calculated 30-operating day
rolling average values derived from the CEMS or Hg sorbent trap monitoring systems.
•
Reporting a failure to meet a standard due to a malfunction. For each failure to meet a
standard or emissions limit caused by a malfunction at an affected source, you must
report the failure in the semi-annual compliance report required by 40CFR 63.1354(b)(9)
•
Reports must contain ( Date, time, duration, and the cause of each event including
unknown causes) also number of events in the reporting period.
•
Must report monitoring malfunctions, the date, time and duration also list the affected
source or equipment. Provide estimate of the volume of pollutant emitted over the standard
and a description of method used to estimate the emissions.
NESHAP HG Emissions Reporting Overview Cont.
•
Reports must also include a description of actions taken by an owner or operator during a
malfunction at affected source to minimize emissions in accordance with 40CFR63.1348(d)
including actions taken to correct a malfunction
•
Monitoring system failures that are caused in part by poor maintenance or careless
operation are not malfunctions. You may not use data recorded during monitoring
system malfunctions, repairs associated with monitoring system malfunctions, or required
monitoring system quality assurance or control activities in calculations used to report
emissions or operating levels.
40CFR63.1344 Affirmative Defense for Violation of Emission Standards During Malfunction
In response to an action to enforce the standards set forth in § 63.1343(b) and (c) and §
63.1345 and you may assert an affirmative defense to a claim for civil penalties for violations
of such standards that are caused by malfunction. The owner or operator seeking to assert an
affirmative defense shall submit a written report to the Administrator with all necessary
supporting documentation.
Key Advantages of Sorbent Trap Monitoring System
•
Simple to Install, Implement and Operate
– Typically 1 Day To Install, 1-3 Days To Certify ( RATA )
•
Highly Accurate/Precise Method for Analysis – NIST Traceable SRM
– Multi-section sorbent tube with very low detection levels 1 – 3 ng
•
Relatively Inexpensive & Very Reliable compared to CEMs
– Generally less than 25% of the 1st Year Cost Of Hg CEMs
•
Sorbent has a 10+ Year Track Record
– Applied Widely To Coal-Utility Industry and is the EPA Reference Method for RATA (
Method 30B )
•
Sample captured directly in stack – no Hg transport issues
•
Little or no stack or facility engineering costs
•
No calibration gas costs (or daily, weekly calibrations only quarterly audit)
•
Traps are small, non-hazardous, require no special storage or handling, have no expiration
and are very simple to analyze or ship to lab ( On-Site Analysis Can be Done Quickly )
Keys to Success using STS
• Look at the Data!
– Ongoing Data Review
• Have a “Go-To” Person who will take accountability for the success of
your Mercury Monitoring
• Open Dialogue with Ohio Lumex
– We try to Catch it before you do…but, if you do the analysis, then stay in touch.
• Sampling Trends
– Low Flow (250cc/min – 400cc/min)
– Temp set to about 250° - 350° F
– Use Probe Shield if wet FGD or High Particulate
Sorbent Trap Technology is ready NOW for MACT-Level measurements
Ability to measure levels below 0.2 μg/dscm.
Consistently better than 10% relative accuracy at all
concentrations.
NIST traceable.
Sorbent Trap monitoring is the current gold standard for
Low-Level mercury measurements.
RATA fail-proof (It is the EPA Reference Method after all
meeting your annual RATA requirements is almost a
foregone conclusion.
Low maintenance.
Predictable operating costs.
Hg CEMS Issues
Sensitivity ?
Reliability ?
QA/QC ?
Questions to the Cement Plants ?
1 Which measurement technology will you choose Sorbent Trap Sampling or HG Cems ?
2 Are you ready to implement mercury measurement & compliance in the NESHAP?
3
Who will you turn to for expert advice regarding Sorbent Traps, Sampling & Analysis?
4
Do you know what your mercury concentrations are in all of your sources ?
5
Do you have the personnel ready and trained to implement your monitoring plan
Questions and Answers
• Any Question on NESHAP Compliance?
• Any Questions on Sorbent Trap Sampling?
• Any Questions Regarding Traps or Data?
OHIO LUMEX COMPANY
your partner for mercury measurement
success
Thank You for Attending
Shawn Wood
shawn.wood@ohiolumex.com
Phone: 330-405-0837
Fax: 330-405-0847
Cell: 919-931-3084