Protocols

ECOM Analyzers An economical method for achieving environmental compliance

Protocols, defined as, …a detailed plan of a scientific procedure…, are becoming an important aspect and buzzword when related to portable electrochemical sensor based emission analyzers. As industry comes under increasingly stringent Environmental regulations, affordable and reasonable methods of achieving environmental compliance are necessary to allow companies to remain competitive in their markets.

Recognizing this need, certain Regulatory Agencies, such as the EPA, (Environmental Protection Agency), the South Coast Air Quality Management District (SCAQMD), the Texas Natural Resources Conservation Commission (TNRCC), the New Mexico Department of Environmental Quality (NMDEQ), and other similar agencies in states such as Colorado, Wyoming, Louisiana, Oklahoma, New Jersey, Pennsylvania, New York, etc. are allowing the use of portable analyzers to ensure air quality compliance under specific protocols. These Protocols are the guidelines which prescribe the technical capabilities of the electrochemical analyzer to be used, as well as calibration and testing procedures which should be followed to assure valid emissions data.

There are several published protocols regarding the use of Portable Electrochemical Sensor Based Emission Analyzers. You can view these at http://www.epa.gov/ttn/emc/ctm.html , specifically CTM-022, CTM-030, and the new CTM-034.

CTM-030 and CTM-034 encompass complete testing requirements for O2, CO, and NOx. CTM-022 is only for NOx testing and is not widely used due to this fact.

The ECOM AC has been approved for use as a periodic testing tool in many states and regions. The J2KN, A-PLUS, and KL have features designed to meet specific requirements in the above-mentioned protocols, mostly relating to sample conditioning, flow and temperature control.

Listed below are features of the J2KN, A-PLUS and  KL, and how they relate to current emission testing protocols for electrochemical sensor based analyzers, specifically EPA Protocol CTM-030, "Determination of NOX, CO, and O2 Emissions from Natural Gas fired Engines, Boilers, and Process Heaters using Portable Analyzers."

Sample Interface (CTM-030, 3.1.1), Sample Acquisition and Transport is achieved by using a high flow pump to draw the gas sample directly from the exhaust stack through a high temp stainless steel probe, and a Teflon lined, insulated heated sample line. Temperatures on the sample line are automatically regulated to maintain the gas temperature well above the dew point, usually (225 deg. F - 325 deg. F). The gas sample then flows into a programmable thermo-electric cooler (40 - 45 F), which quickly condenses any moisture in the gas sample. The moisture is continuously removed from the chiller by a peristaltic pump. The gas then flows through a particulate filter, removing particulate down to 5 microns in size. This sample conditioning method is the same as the method referenced in 40CFR, Part 60, Method 7E and 6C.

An External Interface Gas Scrubber (CTM-030, 3.1.2), is employed upstream of the CO sensor. This eliminates any nitrogen and/or sulfur compounds, which may cause erroneous response on the CO sensor.

After passing through the sample conditioning portion of the analyzer, the gas is then delivered in to a manifold which very precisely controls the pressure and volume of gas going to each of the Electrochemical Sensors (CTM-030, 3.1.3). The gas - specific electrochemical sensors provide an electrical output (mV signal) proportional to the concentration of gas being measured. This signal is interpreted by the electronics of the analyzer and is presented as a ppm or % volume reading available to the operator via a backlit LCD display, integral printer, and USB signal for transmission to a computer, (CTM-030, 3.1.4).

To itemize specific requirements of CTM-030:

CTM-030
Reference    Comments about ECOM J2KN, A-PLUS and KL    

5.1    Refers to the instruments.
 
5.1.1    Sample Probe: Stainless Steel, (different lengths available).
 
5.1.2    Heated Sample Line: Teflon lined (non-reactive tubing), temperature programmable to maintain gas level above dew point.
 
5.1.3    Sample Transport Lines: All internal plumbing is non-reactive tubing.
 
5.1.4    Calibration Assembly: Supplied by ECOM as required, part of Custom Length Sample lines.
 
5.1.5    Moisture Removal System: Programmable (40-45 F) thermo-electric cooler with peristaltic pump. Gas sample is quickly cooled, moisture drops out rapidly, and continuous peristaltic pump removes moisture, minimizing moisture / gas contact.
 
5.1.6    Particulate Filters: The analyzers incorporates (2) filters for particulate removal. Postioned after the thermo-electric cooler, these filters removes particulate down to 5 microns. 

5.1.7    Sample Pump: A 2.5-4.0 liter per minute pump assures adequate sample flow through the probe, sample line, thermo-electric cooler, and filters. The pump delivers a cool, clean, and dry sample of gas to the sensor manifold.
 
5.1.8    Sample Flow Rate Control: Electronic flowmeter  and manual flowmeter measures gas flow and is displayed on the front panel of the analyzer. Any flow changes or flow restrictions are indicated on front panel. Flow rate is also recorded when using Advanced DAS.
 
5.1.9    Refers to the instruments.
 
5.1.10    Data Recorder: Backlit LCD display, Advanced DAS, which provides real-time and average readings, via USB  interface. 

5.1.11    External Interference Gas Scrubber: An in-line filter media upstream of the CO sensor eliminates nitrogen and sulfur compounds in the gas stream going to the CO sensor. Color change indicates need for replacement.
 
5.1.12   
NO Cell Temperature Indicator: A thermistor located on the sensor manifold measures the temperature of the NO sensor and all sensors and is displayed on the LCD display, printed on the tape, and downloaded to the PC.