NGK Insulators, Ltd. - www.ngk.co.jp - 2-56 Suda-cho, Mizuhoku, Nagoya Aichi 467-8530, Japan
email: , Tel. +81-52-872-7717, Fax +81-52-872-7985
NGK has developed zeolite membranes that show a molecular sieving effect with nano size micropores. Using this new product, NGK has successfully isolated carbon dioxide from a mixture of methane and carbon dioxide.
Since DDR-type zeolite membranes offer the potential to extract carbon dioxide and increase the purity of methane from a mixture of these gases, they are expected to find applications in natural gas refining plants and in biogas plants that generate biogas from raw garbage using methane fermentation.
Zeolite is a silicate mineral composed of silicon, aluminum, and sodium. These elements combine three-dimensionally to form a mesh-like crystal structure presenting molecular-size micropores of about 0.3 to 0.8 nm that allow smaller particles to pass.
Featuring extremely small micropores, the newly developed zeolite membranes have a crystal structure called DDR. DDR-type zeolite membranes have oval-shaped micropores measuring 0.36 x 0.44 nm.