Patent 7717985 was granted and assigned to Donaldson Company on May, 2010 by the United States Patent and Trademark Office.
An adsorption system with a sorbent bed that includes at least two distinct layer with two different sorbent materials, one of the sorbents being a natural zeolite such as clinoptilolite. The clinoptilolite is particularly suited to be positioned at the outlet end of the bed.