Clean Air MarketsProgram Data

UC Energy Institute

University of California at Berkeley

November 10, 2003

Martin Husk

Overview

How emissions and heat input are monitored

Monitoring system certification requirements and testing

On-going quality assurance testing

Contents of the Electronic Data Report

Overview

Quality assurance standards

Data availability

Uses of the data

Questions and answers

How Emissions are Monitored

Identify which pollutants require monitoring

Identify which other parameters may require monitoring

Acid RainProgram (ARP)

SO2 mass emissions (lb/hr) NOX emission rate (lb/mmBtu) CO2 mass emissions (tons/hr) Heat Input (lb/mmBtu)

NOx Budget TradingProgram (NBTP)

NOX mass emissions (lb/hr) Heat Input (lb/mmBtu)

Acid RainProgram

SO2 mass emissions (lb/hr) NOX emission rate (lb/mmBtu) CO2 mass emissions (tons/hr) Heat Input (lb/mmBtu)

NOx Budget TradingProgram

NOX mass emissions (lb/hr) Heat Input (lb/mmBtu)

Stack Flow Rate Stack Moisture

Opacity Fuel Flow Rate

How Emissions are Monitored

Select the most appropriate monitoring type:

Continuous Emissions Monitoring System (CEMS)

Appendix D and E

Low Mass Emissions Methodology (LME)

Predictive Emissions Monitoring System (PEMS)

Continuous Emissions Monitoring System (CEMS)

Part 72 defines it as equipment used to “sample, analyze, measure and provide…a permanent record of emissions.”

CEMS consists of monitors installed in stacks and/or ducts, and a Data Acquisition and Handling System (DAHS).

Measure emissions and heat input every 15 minutes.

Types of CEMS Conventional Extractive (Wet or Dry Basis Measurement)

Hot Wet - Wet Basis

Cool Dry with condenser near the CEMS Shelter - Dry Basis

Cool Dry with condenser at the probe - Dry Basis

Dilution Extractive (Wet Basis Measurement)

In Stack Dilution

Out of Stack Dilution

In-situ (Wet Basis measurement in the stack)

Point

Path

Conventional Extractive CEMS

Conventional Extractive Systems Representative sample of the flue gas is continuously

withdrawn from the stack, transported to a CEMS shelter and analyzed

Components of an extractive system Probe

Sample lines

Filters

Moisture removal system

Pump

Analyzer

Extractive systems usually make measurements on a dry basis

Dilution Extractive CEMS(wet basis)

Flue gas is diluted with clean dry air to lower the dew-point of the sample

Eliminates the need for Heated sample lines

Moisture removal system

In Stack Dilution Critical Orifice is in the probe

Sample Temperature is Stack Temperature

Quicker response than out of stack dilution

No temperature controls to maintain

In-Situ CEMS Point

Electro-optical, or

Electrochemical sensor

Measurement over short distant (~cm)

Path Light or sound is

transmitted across the stack

The interaction with the stack gas is related back to a gas characteristic

In-Situ CEMS

Typical Applications: Opacity Measurement

Path - Light

Stack Flow Point - Differential Pressure (s-type Pitot)

Path - Ultra-sonic (sound waves)

Alternatives to CEMS CEMS are required except for cases that qualify to

use the following options: Appendix D - SO2 and Heat Input Monitoring Options

Appendix E - NOx Emission Rate Estimation Procedures

Low Mass Emissions - Estimation of SO2, NOx, and CO2 emissions and total heat input using:

Default or site-specific emission factors, and

Max. unit heat input or actual heat input from fuel usage data

Predictive Emissions Monitoring - Estimation of NOx emissions using

CEMS validation of estimation procedures

Appendix D Applicability

May be used in lieu of SO2 and/or flow and diluent monitors to determine hourly SO2 mass emissions and/or heat input rate

Gas and Oil fired units only

Principle: Fuel Flow Rate * Sulfur content = SO2 emissions

Fuel Flow Rate * Gross Calorific Value (GCV) = Heat Input

Requires Monitoring of: Hourly Fuel Usage (fuel flowmeters)

GCV and Sulfur content of the fuel (default SO2 emission rates allowed for gaseous fuels)

Appendix E

May be used in lieu of a NOx-diluent CEMS for determining hourly NOx emission rate (lb/mmBtu)

Applicable only to Gas and Oil-Fired Peaking Units

If you qualify for Appendix E, you must use Appendix D to determine heat input rate

Appendix E Units that hold peaking status must continue to meet the

peaking unit definition from year-to-year

If a unit fails to meet the criteria it must install & certify a NOx CEM by December 31 of the year after the year for which the criteria are not met

A unit may then only re-qualify by providing three consecutive years (or ozone seasons) of qualifying capacity factor data

How Appendix E Works The average NOx emission rate (lb/mmBtu) is determined from fuel

specific NOx emission rate testing at four, equally spaced load levels

The hourly heat input rate is determined using the fuel flow monitoring procedures of Appendix D

The NOx Emission Rate is plotted vs. Heat Input Rate to create a baseline correlation curve

The baseline correlation curve is programmed into the DAHS and is used to determine the hourly NOx emission rate corresponding to the heat input rate for each hour of operation

NOx Correlation Curve Segments

0.000

0.050

0.100

0.150

0.200

0.250

0.300

0 200 400 600 800 1000 1200 1400

Heat Input Rate (mmBtu/hr)

NO

x E

mis

sio

n R

ate

(lb

/mm

Btu

)

Operating Level 1

Operating Level 2

Operating Level 3

Operating Level 4

Segment 1

Segment 2

Segment 3

Segment 4

Low Mass EmissionsMethodology (LME)

Procedure that may be used in lieu of CEMS and the Appendix D and E methodologies to report SO2, NOx, and CO2, emissions and Heat Input

Gas-fired and oil-fired units only

DAHS is not required -- EDR reports can be generated using EPA’s MDC (or any other) software

Emissions limitations Annual NOx limit: NOx < 100 tons/year

Ozone season NOx limit: NOx < 50 tons/control period

SO2 limit < 25 tons/year (ARP units only)

Predictive EmissionsMonitoring Systems (PEMS)

May be used in lieu of a NOx monitoring system

Consists of PEMS software and a DAHS

Software “predicts” what the NOx emissions will be for each hour, based on comparison testing with CEMS

Monitoring System CertificationRequirements and Testing

CEMS Testing: Gas Monitors

7-day calibration error check

Linearity check

Cycle time test

RATA/Bias test

Flow Monitors 7-day calibration error check

3 load RATA and Bias tests

7-day Calibration Error Test

Measure calibration error of each pollutant monitor while unit is combusting fuel once each day for 7 consecutive operating days

Linearity Check

3 point check of linearity of each pollutant monitor while unit is combusting fuel at conditions of typical stack temperature and pressure Low (20 - 30% of span)

Mid (50 - 60% of span)

High (80 - 100% of span)

Cycle Time Test

Determine time it takes for 95% of step change to occur going from:

a stable zero gas value to stack emission value, and

a stable high calibration gas value to stack emission value

The cycle time is the slower of the two responses

Relative Accuracy TestAudit (RATA)

Compares CEMS measurements to appropriate EPA reference method

Conduct a minimum of 9 valid runs

May discard up to 3 runs but must report all runs performed

Recommended that RATA not be commenced until completion of other required certification tests

Bias Test

Statistical test that evaluates RATA data to determine if a low bias exists in the CEMS measurements, and to determine need for calculating a Bias Adjustment Factor (BAF)

Monitoring System CertificationRequirements and Testing

Appendix D Fuel Flowmeter Accuracy Test is generally required

annually

Fuel Flow-to-Load Ratio or Gross Heat Rate-to-Load evaluation may be used as a quarterly check of the fuel flowmeter accuracy

Can be used to extend the interval between fuel Flowmeter Accuracy tests to up to 5 years

Monitoring System CertificationRequirements and Testing

Appendix E:

The NOx emission rate testing must be repeated once every 5 years

Appendix D fuel flowmeter QA required

On-going Quality AssuranceTesting for CEMS

Daily Calibration Error Test

Daily Interference Check (flow monitors only)

Quarterly Linearity Check

Quarterly Flow-to-Load Ratio (flow only)

Quarterly Leak Checks (differential pressure flow systems)

Relative Accuracy Test Audit (RATA)

Bias Test (SO2, NOx, and flow monitors only)

Calibration Error Checks Measure the calibration error of each pollutant monitor while the unit is

combusting fuel by injecting a known calibration gas into the system at the point of sample collection

Zero Gas (0 - 20% of span)

High Gas (80 - 100% of span) or Mid Gas (50-60%)

For initial certification, a CEMS must meet a tight calibration standard for 7 consecutive operating days

For ongoing QA, daily calibration error checks are required

Interference Check

Daily QA check required for stack flow monitors

Diagnostic check that confirms that monitor is ready for use

Flow-to-Load Ratio Test

Quarterly evaluation of a stack flow monitor’s accuracy

A baseline comparison of the hourly ratio of flow rate to unit load (Q/L) and a reference Q/L determined during the last flow RATA test

Leak Check

Quarterly QA check for differential pressure type flow monitors

Confirms the absence of leaks in the connections and lines

SO2 Monitoring

METHOD SO2 (Tons)AMS 106 0.0%APPD 183,429 1.8%CEM 10,028,755 95.8%F23 259,847 2.5%LME 6 0.0%

Total 10,472,142

SO2 Methodology by # of Units

APPD

59%

CEM

36%

AMS

0%F23

3%

LME

2%

AMS APPD CEM F23 LME

SO2 Methodology by Emissions

CEM96%

APPD2%

LME0%

F232%

AMS0%

AMS APPD CEM F23 LME

METHOD UnitsAMS 2 0%APPD 1810 58%CEM 1127 36%F23 106 3%LME 61 2%

Total 3106

NOx Monitoring

NOx Methodology by # of Units

CEM87%

LME4%

AMS0%

APPE9%

AMS APPE CEM LME

METHOD UnitsAMS 3 0.1%APPE 293 8.6%CEM 2966 87.4%

LME 131 3.9%

Total 3393

NOx Methodology by Emissions

CEM

100%

AMS

0%

LME

0%APPE

0%

AMS APPE CEM LME

METHOD NOx TonsAMS 463.884 0.0%APPE 5643.801 0.1%CEM 4944886 99.9%

LME 758.286 0.0%

Total 4951752

NOx Methodology by Emissions

CEM100%

APPD0%

LME0% AMS

0%

AMS APPD CEM LME

Contents of theElectronic Data Report (EDR)

EDR required each quarter or during Ozone Season

Collection of EDR data is fundamental to verifying program

EDR Files contain the following items:

Facility information

As-monitored emissions data (measured in ppm)

Contents of the ElectronicData Report (EDR)

EDR Files contain the following items:

Operational data (operating time, heat input)

Calculated mass emissions and heat input data

Monitoring Plan

Quality assurance/test data

Certification records

Quality Assurance Standards

Extensive QA process for EDR data

“Instant Feedback” based on ETS data checking

Audit process feedback provided after all data are submitted

Quality Assurance Standards

ETS data checking in two stages

File Summary: checks general format and integrity of file.

File Content: checks the data within the file recalculate all hourly data

hourly sums vs. aggregates

monitoring plan checks

Over 150 checks performed on EDR data

Quality Assurance Standards

Audit Process is run to evaluate the monitoring plan, and QA and test data

Process is run after the end of each reporting period

Feedback Emailed to sources

Resubmissions of EDR data often required

Data Availability

EDR data are submitted during the month after each calendar quarter

“As reported” EDR files posted on the CAMD web site 20 days after the end of each reporting period

Summary Emissions Reports posted on CAMD web site 20 days after the end of each reporting period

Data Availability

Annual and Ozone Season data posted on Data and Maps web site page after program compliance is determined

Hourly, monthly and quarterly posted on Data and Maps web site page after program compliance is determined

Resubmitted EDR files are updated to the Data and Maps page each quarter

Uses of the Data

EPA uses of the data

Annual Acid Rain Program and NOx Budget Program Compliance

Public access through web site

Provide to other government agencies

Compare to other agencies’ data

Uses of the Data

Your uses of the data

What EPA data do you use?

How do you access the data?

What analyses are performed based on EPA data?

Are there other pieces of data you need for your analyses?

Questions and Answers