EPA Method 202

EPA Method 202 - Condesable Particulate Emissions

Method Overview

Isokinetic
In-stack filter (M17/201/201A/OTM 27) or heated out of stack filter (M5).
"Condensable" particulate matter passes through a filter and condenses in dry impingers and are caught on a CPM Filter.
Can readily be (and commonly is) combined with a filterable PM Method.
Tester may adjust out-of-stack (e.g. M5) filter temperature to suit source specific conditions.

Target Compounds

Condensable Particulate Matter (CPM) -- those substances that pass through the heated filter to condense in the dry impinger components of the sample train.

Performance Tips

The CPM is collected in dry impingers after filterable particulate material has been collected on filters maintained above 30°C (85°F) using Method 5, 17, 201A or OTM 27.
The organic and aqueous fractions of the impingers and an out-of-stack CPM filter are then taken to dryness and weighed.
The total of all fractions represents the CPM.
Compared to the December 17, 1991 promulgated Method 202, this method removes water from the impingers (dry at start of sampling) and includes the addition of a condenser followed by a water dropout impinger immediately after the final in-stack or heated filter.
- This method also includes the addition of one modified Greenburg Smith impinger and a CPM filter following the water dropout impinger.
Do not use silicone grease - it will be soluble in the final train rinse and can bias the organic CPM value high.
Run the train isokinetically or pseudo-isokinetically if combined with M201, M201A or OTM 27.
CPM is collected in the water dropout impinger, the modified Greenburg Smith impinger, and the CPM filter of the sampling train as described in this method.
- The impinger contents are purged with nitrogen (N2) immediately after sample collection to remove dissolved sulfur dioxide (SO2) gases from the impinger.
- The CPM filter is extracted with water and hexane. The impinger solution is then extracted with hexane.
- The organic and aqueous fractions are dried and the residues are weighed. The total of the aqueous and organic fractions represents the CPM.
IMPORTANT - hexane is an extremely flammable solvent! It should only be worked with under a hood!
IMPORTANT - Many resin type DI systems do not produce water of a grade that meets the 0.001% criteria for blanks.
- Blank-test your water before testing.
- If purchasing H2O, DI/UF grade is recommended.
The water is evaporated in a temperature-controlled oven at 105°C.
The hexane is evaporated under a hood at ambient temperatures.
If water has a pH of ‹7.0, acidic components are 'neutralized' in order to allow acquisition of constant weights.
This method may be used to measure emissions following a wet scrubber only when combined with a filterable particulate method that operates at high enough temperatures to cause water droplets sampled through the probe to become gaseous.

Shipping

Both Acetone and hexane must be shipped as hazardous materials. Please call for IATA codes if you need them.
Samples may be shipped at ambient temperatures.
It may prove more economical to keep acetone and hexane rinses separate, ship other samples normally, and the solvent rinses as hazardous.
Be sure to include a chain of custody for each shipping container.

Applications

THE method for measurement of condensable particulate matter (CPM).
Catches can be examined to determine the nature of the CPM.
Ammonia Slip, often prevalent for SNCRs, can be problematic causing excessive CPM;
Coal additives to aid in mercury collection (e.g. CaBr2) can affect the CPM.
- Clean Air has examined various catches using ion chromatography to determine the effects of adding bromide to the coal.