Ewald Heitz

The production of oxalic acid from CO2 and H2O

Oxalic acid has been prepared on a preparative scale in an undivided cell with sacrificial anodes and an aprotic electrolyte. Optimum current efficiencies (>90%) have been obtained in cells with zinc anodes, stainless steel cathodes and acetonitrile with tetrabutylammonium perchlorate as the electrolyte. Micro-pilot experiments revealed that a continuous electrochemical cell can be set up and that the reaction product can be removed by filtration. A complete process is designed by a combination of the oxalic acid production with a zinc electrolysis. No unwanted by-products appear, which is recently of increasing importance. Economic consideration shows that the process may become interesting in the future.

Investigation of hydrodynamic test systems for the selection of high flow rate resistant materials

Flow-dependent corrosion phenomena can be studied in the laboratory and on a pilot plant scale by a number of methods, of which the rotating disc, the rotating cylinder, the coaxial cylinder and the tubular flow test are the most important. These methods are discussed with regard to mass transfer characteristics and their applicability to flow-dependent corrosion processes and erosion corrosion. To exemplify the application of such methods to materials selection for seawater pumps, corrosion data of non-alloyed and low alloy cast iron are presented.

A19 High-alloy multiphase steels

This article has no abstract. Keywords: waste water (industrial); high-alloy multiphase steels

A22 Austenitic CrNiMoCu(N) steels

First page of article Keywords: waste water (industrial); austenitic CrNiMoCu(N) steels

Unalloyed and low‐alloyed steels/cast steels

First page of article Keywords: hydrochloric acid; unalloyed steels; low-alloyed steels; cast steel