312 METHOD 3 - GAS ANALYSIS FOR THE
Contents
1. 11 5 5 1 The liguid level in each pipette must not fall below the bottom of the capillary tubing during this 4 minute interval 11 5 5 2 The meniscus in the burette must not change by more than 0 2 ml during this 4 minute interval 11 5 6 If the analyzer fails the leak check procedure check all rubber connections and stopcocks to determine whether they might be the cause of the leak Disassemble clean and regrease any leaking stopcocks Replace leaking rubber connections After the analyzer is reassembled repeat the leak check procedure 12 0 Calculations and Data Analysis 12 1 Nomenclature M Dry molecular weight g g mole lb lb mole SCO Percent CO by volume dry basis 0 Percent O by volume dry basis CO Percent CO by volume dry basis SN Percent N by volume dry basis 325 0 280 Molecular weight of N or CO divided by 100 0 320 Molecular weight of O divided by 100 0 440 Molecular weight of CO divided by 100 12 2 Nitrogen Carbon Monoxide Concentration Determine the percentage of the gas that is N and CO by subtracting the sum of the percent CO and percent O from 100 percent 12 3 Dry Molecular Weight Use Equation 3 1 to calculate the dry molecular weight of the stack gas M 0 440 5C0 0 320 0 0 280 SN CO Eq 3 1 NOTE The above Equation 3 1 does not consider the eff2. Pump Rigid Container Figure 3 2 Integrated Gas Sampling Train Time olo u 0 lt Figure 3 3 329 Traverse Q Point liter min olo Deviation Q Qavg Qavg x 100 Must be lt 10 Sampling Rate Data olo
3. and 14 to 18 percent CO 7 2 2 Gas cylinder containing 2 to 4 percent CO and about 15 percent O 8 0 Sample Collection Preservation Storage and Transport 8 1 Single Point Grab Sampling Procedure 8 1 1 The sampling point in the duct shall either be at the centroid of the cross section or at a point no closer to the walls than 1 0 m 3 3 ft unless otherwise specified by the Administrator 8 1 2 Set up the equipment as shown in Figure 3 1 making sure all connections ahead of the analyzer are tight If an Orsat analyzer is used it is recommended that the analyzer be leak checked by following the procedure in Section 11 5 however the leak check is optional 8 1 3 Place the probe in the stack with the tip of the probe positioned at the sampling point Purge the sampling line long enough to allow at least five exchanges Draw a sample into the analyzer and immediately analyze it for percent CO and percent O according to Section 11 2 8 2 Single Point Integrated Sampling Procedure 8 2 1 The sampling point in the duct shall be located as specified in Section 8 1 1 319 8 2 2 Leak check optional the flexible bag as in Section 6 2 6 Set up the eguipment as shown in Figure 3 2 Just before sampling leak check optional the train by placing a vacuum gauge at the condenser inlet pulling a vacuum of at least 250 mm Hg 10 in Hg plugging the outlet at th
4. 312 METHOD 3 GAS ANALYSIS FOR THE DETERMINATION OF DRY MOLECULAR WEIGHT NOTE This method does not include all of the specifications e g eguipment and supplies and procedures e g sampling essential to its performance Some material is incorporated by reference from other methods in this part Therefore to obtain reliable results persons using this method should also have a thorough knowledge of Method 1 1 0 Scope and Application 1 Analytes Analyte CAS No Sensitivity Oxygen O 7182 44 77 2 000 ppmv Nitrogen N 7727 37 9 N A Carbon dioxide CO 124 38 9 2 000 ppmv Carbon monoxide CO 630 08 0 N A 1 2 Applicability This method is applicable for the determination of CO and O concentrations and dry molecular weight of a sample from an effluent gas stream of a fossil fuel combustion process or other process 1 3 Other methods as well as modifications to the procedure described herein are also applicable for all of the above determinations Examples of specific methods and modifications include 1 a multi point grab sampling method using an Orsat analyzer to analyze the individual 313 grab sample obtained at each point 2 a method for measuring either CO or O and using stoichiometric calculations to determine dry molecular weight and 3 assigning a value of 30 0 for dry molecular weight in lieu of actual measurements for processes burnin
5. e check is optional Calculate the dry molecular weight as indicated in Section 12 0 Repeat the analysis and calculation procedures until the individual dry molecular weights for any three analyses differ from their mean by no more than 0 3 g g mole 0 3 lb lb mole Average these thr molecular weights and report the results to the nearest 0 1 g g mole 0 1 1b lb mole 11 4 Standardization A periodic check of the reagents and of operator technique should be conducted at least once every three series of test runs as outlined in Section 10 1 11 5 Leak Check Procedure for Orsat Analyzer Moving an Orsat analyzer frequently causes it to leak Therefore an Orsat analyzer should be thoroughly leak checked on site before the flue gas sample is introduced into it The procedure for leak checking an Orsat analyzer is as follows 11 5 1 Bring the liquid level in each pipette up to the reference mark on the capillary tubing and then close the pipette stopcock 11 5 2 Raise the leveling bulb sufficiently to bring the confining liquid meniscus onto the graduated portion of the burette and then close the manifold stopcock 11 5 3 Record the meniscus position 324 11 5 4 Observe the meniscus in the burette and the liguid level in the pipette for movement over the next 4 minutes 11 5 5 For the Orsat analyzer to pass the leak check two conditions must be met
6. e guick disconnect and then turning off the pump The vacuum should remain stable for at least 0 5 minute Evacuate the flexible bag Connect the probe and place it in the stack with the tip of the probe positioned at the sampling point Purge the sampling line Next connect the bag and make sure that all connections are tight 8 2 3 Sample Collection Sample at a constant rate 10 percent The sampling run should be simultaneous with and for the same total length of time as the pollutant emission rate determination Collection of at least 28 liters 1 0 ft of sample gas is recommended however smaller volumes may be collected if desired 8 2 4 Obtain one integrated flue gas sample during each pollutant emission rate determination Within 8 hours after the sample is taken analyze it for percent CO and percent O using either an Orsat analyzer or a Fyrite type combustion gas analyzer according to Section 11 3 320 NOTE When using an Orsat analyzer periodic Fyrite readings may be taken to verify confirm the results obtained from the Orsat 8 3 Multi Point Integrated Sampling Procedure 8 3 1 Unless otherwise specified in an applicable regulation or by the Administrator a minimum of eight traverse points shall be used for circular stacks having diameters less than 0 61 m 24 in a minimum of nine shall be used for rectangular stacks hav
7. e of 500 to 1000 ml min is suggested 6 2 6 Flexible Bag Any leak free plastic e g Tedlar Mylar Teflon or plastic coated aluminum e g aluminized Mylar bag or equivalent having a capacity consistent with the selected flow rate and duration of the 317 test run A capacity in the range of 55 to 90 liters 1 9 to 3 2 ft is suggested To leak check the bag connect it to a water manometer and pressurize the bag to 5 to 10 cm H O 2 to 4 in H O Allow to stand for 10 minutes Any displacement in the water manometer indicates a leak An alternative leak check method is to pressurize the bag to 5 to 10 cm 2 to 4 in H O and allow to stand overnight A deflated bag indicates a leak 6 2 7 Pressure Gauge A water filled U tub manometer or equivalent of about 30 cm 12 in for the flexible bag leak check 6 2 8 Vacuum Gauge A mercury manometer or equivalent of at least 760 mm 30 in Hg for the sampling train leak check 6 3 Analysis An Orsat or Fyrite type combustion gas analyzer 7 0 Reagents and Standards 7 1 Reagents As specified by the Orsat or Fyrite type combustion analyzer manufacturer 7 2 Standards Two standard gas mixtures traceable to National Institute of Standards and Technology NIST standards to be used in auditing the accuracy of the analyzer and the analyzer operator technique 318 7 2 1 Gas cylinder containing 2 to 4 percent O
8. ect on calculated dry molecular weight of argon in the effluent gas The concentration of argon with a molecular weight of 39 9 in ambient air is about 0 9 percent A negative error of approximately 0 4 percent is introduced The tester may choose to include argon in the analysis using procedures subject to approval of the Administrator 13 0 Method Performance Reserved 14 0 Pollution Prevention Reserved 15 0 Waste Management Reserved 16 0 References 320 1 Altshuller A P Storage of Gases and Vapors in Plastic Bags International Journal of Air and Water Pollution 6 75 81 1963 2 Conner William D and J S Nader Air Sampling with Plastic Bags Journal of the American Industrial Hygiene Association 25 291 297 1964 3 Burrell Manual for Gas Analysts Seventh edition Burrell Corporation 2223 Fifth Avenue Pittsburgh PA 15219 19541 4 Mitchell W J and M R Midgett Field Reliability of the Orsat Analyzer Journal of Air Pollution Control Association 26 491 495 May 1976 5 Shigehara R T R M Neulicht and W S Smith Validating Orsat Analysis Data from Fossil Fuel Fired Units Stack Sampling News 4 2 21 26 August 1976 17 0 Tables Diagrams Flowcharts and Validation Data 327 Filter Glass Wool Flexible Tubing To Analyzer A z Sgueeze Bub Figure 3 1 Grab Sampling Train 328 Quick Disconnect Air Tight
9. g natural gas coal or oil These methods and modifications may be used but are subject to the approval of the Administrator The method may also be applicable to other processes where it has been determined that compounds other than CO O carbon monoxide CO and nitrogen N are not present in concentrations sufficient to affect the results 1 4 Data Quality Objectives Adherence to the requirements of this method will enhance the quality of the data obtained from air pollutant sampling methods 2 0 Summary of Method 2 1 A gas sample is extracted from a stack by one of the following methods 1 single point grab sampling 2 single point integrated sampling or 3 multi point integrated sampling The gas sample is analyzed for percent CO and percent O For dry molecular weight determination either an Orsat or a Fyrite analyzer may be used for the analysis 3 0 Definitions Reserved 4 0 Interferences 314 4 1 Several compounds can interfere to varying degrees with the results of Orsat or Fyrite analyses Compounds that interfere with CO concentration measurement include acid gases e g sulfur dioxide hydrogen chloride compounds that interfere with O concentration measurement include unsaturated hydrocarbons e g acetone acetylene nitrous oxide and ammonia Ammonia reacts chemically with the O absorbing solution and when present i
10. ing equivalent diameters less than 0 61 m 24 in and a minimum of 12 traverse points shall be used for all other cases The traverse points shall be located according to Method 1 8 3 2 Follow the procedures outlined in Sections 8 2 2 through 8 2 4 except for the following Traverse all sampling points and sample at each point for an equal length of time Record sampling data as shown in Figure 3 3 321 9 0 Quality Control Quality Control Section Measure Effect 8 2 Use of Fyrite to Ensures the accurate confirm Orsat results measurement of CO and O 10 1 Periodic audit of Ensures that the analyzer and operator analyzer is operating technigue properly and that the operator performs the sampling procedure correctly and accurately TES Replicable analyses of Minimizes experimental integrated samples error 10 0 Calibration and Standardization 10 1 Analyzer The analyzer and analyzer operator s technique should be audited periodically as follows take a sample from a manifold containing a known mixture of CO and O and analyze according to the procedure in Section 11 3 Repeat this procedure until the measured concentration of three consecutive samples agrees with the stated value 0 5 percent If necessary take corrective action as specified in the analyzer users manual 10 2 Rotameter The rotameter need not be calibrated but shou
11. ld be cleaned and maintained according to the manufacturer s instruction 11 0 Analytical Procedure 322 11 1 Maintenance The Orsat or Fyrite type analyzer should be maintained and operated according to the manufacturers specifications 11 2 Grab Sample Analysis Use either an Orsat analyzer or a Fyrite type combustion gas analyzer to measure O and CO concentration for dry molecular weight determination using procedures as specified in the analyzer user s manual If an Orsat analyzer is used it is recommended that the Orsat leak check described in Section 11 5 be performed before this determination however the check is optional Calculate the dry molecular weight as indicated in Section 12 0 Repeat the sampling analysis and calculation procedures until the dry molecular weights of any three grab samples differ from their mean by no more than 0 3 g g mole 0 3 1b lb mole Average these thr molecular weights and report the results to the nearest 0 1 g g mole 0 1 lb lb mole 11 3 Integrated Sample Analysis Use either an Orsat analyzer or a Fyrite type combustion gas analyzer to measure O and CO concentration for dry molecular weight determination using procedures as specified in the analyzer user s manual If an Orsat analyzer is used it is recommended that the Orsat leak check described in Section 11 5 be performed before this determination 323 however th
12. n the effluent gas stream must be removed before analysis 5 0 Safety 5 1 Disclaimer This method may involve hazardous materials operations and equipment This test method may not address all of the safety problems associated with its use It is the responsibility of the user of this test method to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to performing this test method 5 2 Corrosive Reagents 5 2 1 A typical Orsat analyzer requires four reagents a gas confining solution CO absorbent O absorbent and CO absorbent These reagents may contain potassium hydroxide sodium hydroxide cuprous chloride cuprous sulfate alkaline pyrogallic acid and or chromous 315 chloride Follow manufacturer s operating instructions and observe all warning labels for reagent use 5 2 2 A typical Fyrite analyzer contains zinc chloride hydrochloric acid and either potassium hydroxide or chromous chloride Follow manufacturer s operating instructions and observe all warning labels for reagent use 6 0 Equipment and Supplies NOTE As an alternative to the sampling apparatus and systems described herein other sampling systems e g liquid displacement may be used provided such systems are capable of obtaining a representative sample and maintaining a constant sampling rate and are otherwise ca
13. pable of yielding acceptable results Use of such systems is subject to the approval of the Administrator 6 1 Grab Sampling See Figure 3 1 6 1 1 Probe Stainless steel or borosilicate glass tubing equipped with an in stack or out of stack filter to remove particulate matter a plug of glass wool is satisfactory for this purpose Any other materials resistant to temperature at sampling conditions and inert to all components of the gas stream may be used for the probe Examples of such materials may include aluminum copper guartz glass and Teflon 316 6 1 2 Pump A one way squeeze bulb or equivalent to transport the gas sample to the analyzer 6 2 Integrated Sampling Figure 3 2 6 2 1 Probe Same as in Section 6 1 1 6 2 2 Condenser An air cooled or water cooled condenser or other condenser no greater than 250 ml that will not remove O CO CO and N to remove excess moisture which would interfere with the operation of the pump and flowmeter 6 2 3 Valve A needle valve to adjust sample gas flow rate 6 2 4 Pump A leak free diaphragm type pump or eguivalent to transport sample gas to the flexible bag Install a small surge tank between the pump and rate meter to eliminate the pulsation effect of the diaphragm pump on the rate meter 6 2 5 Rate Meter A rotameter or equivalent capable of measuring flow rate to 2 percent of the selected flow rate A flow rate rang
Download Pdf Manuals
Related Search