Membranen für Polymerelektrolyt‐Brennstoffzellen

Membranes for Polymer Electrolyte Fuel Cells The polymer electrolyte membrane is the heart of hydrogen fuelled Polymer Electrolyte Fuel Cells (PEFC) and methanol fuelled Direct Methanol Fuel Cells (DMFC). Membranes of sulfonated fluoropolymers are already commercially available. Important goals for research and development are for PEFCs an increased operating temperature without the need for additional humidification and for DMFC the reduction of methanol transport through the membrane. The use of non‐fluorinated polymers aims at a reduction in membrane cost and environmental hazards. Membranes already in industrial product development are considered as well as novel membrane concepts in fundamental research.     

Katalysatoruntersuchungen an einer Technikumsanlage für Biomasse‐Kleinfeuerungen

In addition to the reduction of particulate matter, a catalytic supported emission reduction in small scale biomass combustion systems can also enable a conversion of toxic organic components into carbon dioxide and water. For catalyst investigations under practical conditions a special test facility was designed. The results show that products of incomplete combustion like carbon monoxide from stoves can be reduced by catalytic processes. Further developments and studies are necessary to achieve the targeted emission limits.     

Gasfluss‐Sputtern von Katalysatorschichten für Polymer‐Elektrolytmembran‐Brennstoffzellen

Gas flow sputtering (GFS) at increased pressures results in the formation of nanoscale particles of the sputtered material. This process has been evaluated regarding its applicability for synthesizing Pt catalysts for polymer electrolyte membrane fuel cells (PEMFCs). Catalyst layers of varying Pt‐loadings were deposited directly onto carbon fiber paper (gas diffusion layers, GDLs). Immediately after deposition, the catalytic activity of the resulting particulate deposits was tested by H₂‐oxidation at predefined ratios of H₂/O₂. The Pt deposits were subsequently evaluated regarding their applicability in a PEMFC environment.     

Catalytic Oxidation of Liquid Methanol as a Heat Source for an Automotive Reformer

A reactor for catalytically oxidizing liquid methanol has been developed for supplying heat to an automotive reformer. In the tests presented in this paper we show that it is possible to catalytically combust liquid methanol by dispersing the methanol and air by a nebulizer over the catalysts. In the experiments we tested several base and noble metals and found that either platinum or palladium was required at the ignition zone. The tests also showed that it was possible to achieve complete combustion when only 25 % of the catalyst bed contained a noble metal.     

Enzyme für Waschmittel

The high performance of modern laundry detergents at 30 – 60 °C is only possible with specific enzymes and specially tuned enzyme mixtures. The various enzymes form complexes with the substrates (stains) and hydrolyze the fixed proteins, polysaccharides and fats. Surfactants rinse resulting fragments into the wash liquor. The enzymes are produced by appropriate microorganisms in fermenters with a size of 40 to 125 m³. The microorganisms secrete the enzyme into the medium. After the end of the fermentation, the enzymes are separated from the microorganisms, concentrated and converted into the final product. Here, the enzyme solution is used as granulation liquid. Product safety requires a special coating. The product design is determined by the protein engineering (performance) and the design (convenience) of the particle.