Perma Pure Ammonia Scrubbers are designed to remove ammonia from a gas stream to protect the analyser from clogging due to the formation of ammonium salts. Ammonia is a highly reactive gas. It is sometimes added to stack gases to reduce the nitrogen oxide content of the gases by conversion to nitrogen and water (the DeNOx process). When present in gas samples, ammonia will readily react with other components such as sulfur dioxide in the sample to form ammonium salts. This salt is relatively low boiling, so it is present as a gas at the higher temperatures in the stack and in the heated line. When the sample cools down while passing through our dryer, it precipitates out as a solid, clogging the dryer or analyser. For this reason, we recommend installing an ammonia scrubber before the condensing cooler to prevent damage to the analysers downstream.
For Nafion tubing -based sample conditioning systems, Ammonia Scrubbers are required when any Ammonia might be present in the sample gas to protect the Nafion tubing dryers in the system, as Ammonia reacts with the membrane material and will lower the water transfer rate over time.