A system for the selective removal of CO2, H2S, and H2 from a gaseous fluid mixture comprising CO2, H2S, and H2, which system includes a first membrane section having a nonporous metal oxide membrane, a second membrane section having a CO2-selective membrane, and a third membrane section having an H2-selective membrane. The invention also relates to a method for the preparation thereof and to foodstuffs and nanocomposites comprising said interspersed clay. A cam plate within said return stroke interlock is connected for being pivoted together with the actuating lever. Doped aerogel monoliths and their use as chemical sensors are also described.