Continuous Emission Monitors (CEMS) Advancements From Measuring HCl and Ammonia (NH3) to using Sensitive Moisture Measurements for Identifying Boiler Tube
Leaks
Ronald L. BakerRobert Peters
Edul Chikhliwala
EcoChem Analytics
Introduction & Overview
• Stack Monitoring Systems are already at plants to measure “acid gases” (NOx & SO2) and often CO, O2 & CO2– Note: Stack moisture content, %H2O, typically measured as well
• New or pending regulations in certain industries can require additional measurements:
– HCl Hydrogen Chloride : another acid gas– NH3 Ammonia : related to ammonia/urea injection
Hot-Wet Sampling System
Gas Filter Correlation
Reference (I0)
The radiation intensity is measured with the Gas-filled cell in the optical path
Measure (I)
The radiation intensity is measured with the free aperture in the optical path
Gas Filter Correlation
Single Beam Dual Wavelength
Reference (I0)
The radiation intensity is measured with the Reference filter in the optical path
Measure (I)
The radiation intensity is measured with the Measure filter in the optical path
Single Beam Dual Wavelength
MC3 Analyzer Optical Path
System Components
MC3 Measurement Capability
* All components at 185C or above; standard sample cell path 12 meters** User can select appropriate range within the range interval * Use of a short path cell can permit higher concentration ranges
Gas Range Interval**
CO 0-5 PPM to 0-10,000 PPM
SO2 0-10 PPM to 0-1,000 PPM
NO 0-5 PPM to 0-500 PPM
NO2 0-5 PPM to 0-500 PPM
CO2 0-1,000PPM to 0-40%
NH3 0-5 PPM to 0-500 PPM
HCl 0-10 PPM to 0-100 PPM
H2O 0-2% to 0-50%
O2 0-25%
Single MC3 analyzer can measure 8 gases plus Oxygen
Dual ranges can be selected for same gas
N2O 0-10 PPM to 0-1,500 PPM
CH4 0-10 PPM to 0-1,000 PPM
Moisture Measurements to Identify Boiler Tube Leaks
• Since 2004, there have been 8 of these hot-wet analyzers installed at seven different waste coal fired facilities.
• In addition to pollutant measurements of NOx, SO2, CO and diluents measurements of oxygen (O2) and carbon dioxide (CO2), these analyzers continuously monitor the concentration of moisture (H2O) in the flue gas stream.
• This moisture measurement, similar to the other measurements, is updated every 7-10 seconds and has been shown to be effective in identifying and or verifying a boiler tube leak.
• In the event of a tube leak, the increase in moisture can be fairly significant from the unit’s baseline moisture levels, ranging from a 1-3%+ increase. Therefore in a unit with a typical moisture level of 6.5%, a rather sudden increase to 8.5% moisture has confirmed boiler tube leaks.
• Correlations improve after each event
EcoChem MC3 Systems – Waste Coal
HCl, Ammonia and Water Calibration
“Wet” Calibrations with the Hovacal unit
Evaporator
MassFlow
Controller
Temperature ControlPump
Solution (pure water, NH3 or HCl)
Carrier Gas
Hot-WetVapor Mixture
Balance
Liquid
MassFlowMeter
(Optional)
Supply Unit
MC3 Installations - HCl
• Wasatch Integrated Waste Mgmt– 2 waste to energy units
• Wheelabrator Falls – PA– 2 waste to energy units
• Chemical & Waste Treatment Industry worldwide- 15+ analyzers including Eli Lily & Company
MC3 Installations – NH3
• TransCanada – Ocean State Power – RI– 4 units on gas turbines with SCR
• Wheelabrator Falls – PA– 2 waste to energy units-evaluating de-NOx system
• Fertilizer and Chemical Industry in USA - 20 analyzers including Rentech Nitrogen, PCS, &
CF Industries
HCl Dedicated CEMS
• Major Utility in Texas• Installation near Dallas
Question and Answers
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