"We've got to pause and ask ourselves: How much clean air do we need?"
— Lee Iacocca, CEO/Chairman, Chrysler Corporation, 1979-1992
After reading this funny quote today, I thought I would share with you some information about Zero Air.
What is "Zero Air" and why would you ever use it? Well, when I googled "Zero Air," I was surprised to see 11 million results!!
The EPA defines it like this:
Zero Air: Atmospheric air purified to contain less than 0.1 ppm total hydrocarbons. (http://www.epa.gov/OCEPAterms/xyzterms.html)
Although this definition only talks about purity from hydrocarbons, most systems designed to clean air, referred to as Zero Air Generators, go further.
Commonly, the following impurities are removed:
CO, NOx, SOx, H2S, ozone
While various systems use various methods to remove each of the impurities, the most important thing is to know the efficiency with which the impurities are removed and how much of each could remain. This P&ID shows the way Environics Zero Air Generator is designed (the purity levels for our system can be checked on the ZAG page if you are interested).
Another main difference between various systems is the rate and volume of flow it can provide. Commonly, continuous delivery of up to 20 standard liters per minute (SLPM) is used for research and analytical applications.
Speaking of applications, once the air is cleaned, what is it used for? The list of possible uses is long. Some examples include:
a zero reference calibration gas
ultra-pure combustion air for flame ionization detector, flame photometric detectors and nitrogen phosphorus detectors,
service air for pneumatically operated valves,
source air for ozone generators,
source of air for purging permeation tube ovens
So, in answer to Mr. Iacocca, I would say it depends on the application!
To learn more, click here.