Messer starts production of Kr and Xe in China  

Messer (Bad Soden/Frankfurt, Germany; www.messergroup.com) the largest privately run industrial gases specialist, has started up a plant for the production of the noble gases krypton and xenon. A sophisticated process extracts the rare gases from the air, which are mainly used as lamp fill gas. Messer began producing the noble gases krypton and xenon at a new production plant last November. These gases are two of the rarest elements found on the earth. They comprise only about 1.2 ppm of the atmosphere. The plant is operated by Messer’s Chinese subsidiary, Hunan Xianggang Messer. The noble gases concentrate in the liquid oxygen during the process of air separation, which is used to produce the components of air: oxygen and nitrogen. As krypton and xenon occur only in very small quantities in the air, however, a great deal of liquid oxygen is needed in order to extract reasonably large quantities. The new plant can produce 9.4 kg of the noble gases per day from 24,000 kg of liquid oxygen. The resulting gas mixture comprises 90% Kr and 10% Xe. Extracting that gas mixture from the component of air requires precisely matched process steps such as precleaning, pressure build-up, demethanization and distillation. The noble gases Kr…