The Essential Difference of ILLA's technology from all other off-gas treatment technologies licensed in the world is: employment of high stability adsorbents having much longer life time as compared to the conventional carbon adsorbent.

In ILLA's process, unlike conventional technologies, zeolite adsorption of organic impurities from off-gas is used. A combination of two different types of zeolite adsorbents, each performing its own function, is utilized to remove cumene and methanol from oxidation off-gas. Off-gas stream passes the first adsorbent bed where cumene is absorbed, after which it passes to the second adsorbent bed where methanol is absorbed. The desorption is provided with vapor. Zeolite has cumene adsorption capacity similar to carbon, i.e. similar to the adsorbents traditionally used in the process, which makes it easy for the zeolite treatment technology to be implemented within the existing technology operated by the producer. Zeolite lifetime is at least 5 years vs. 1.5 yrs for carbon.