Robert Paul Kreh

Mediated electrosynthesis with cerium (IV) in methanesulphonic acid

Methanesulphonic acid has been found to solubilize the Ce(III)/Ce(IV) couple. This makes cerium mediated electrosynthesis practical for commercial production of several carbonyl compounds. Results are presented for the electrochemical generation of Ce(IV) in methanesulphonic acid and for naphthalene oxidation to 1,4-naphthoquinone using Ce(IV).

Selective oxidations with ceric methanesulfonate and ceric trifluoromethanesulfonate

Abstract Cerium(IV) in aqueous methanesulfonic acid and trifluoromethanesulfonic acid are excellent reagents for the oxidation of alkyl and polycyclic aromatics to aromatic aldehydes, ketones and quinones.

SIMULATION OF A MEDIATED ELECTROCHEMICAL PROCESS

Abstract Mediated electrosynthesis is a cyclic process involving electrochemical generation of a redox agent and use of that agent to effect a chemical reaction. This process is applicable to a large number of mediators and chemical substrates. Cerium in particular is an excellent mediator for syntheses of aldehydes and quinones. An ASPEN PLUS process and cost model is presented for the cerium mediated electrosynthesis of 1,4-naphthoquinone from naphthalene. The process involves two-phase reaction, phase separation, liquid-liquid extraction, electrochemical oxidation, and crystallization. The ASPEN PLUS simulator, however, does not include a module for the separation of organic and aqueous electrolyte solutions. Therefore, a liquid-liquid extractor block is developed based on distribution coefficients. The extractor model also accounts for phase entrainments. Stream compositions are controlled by maintaining fixed ratios of component mass flows. Finally, an extremely tight tolerance is required to account...

The Use of Chelants and Dispersants for Prevention and Removal of Rust Scale

A series of laboratory and pilot rig experiments are discussed to illustrate the effectiveness of various chelants and polymers in controlling or removing iron deposits in cooling systems. The organic molecules were chosen for strong interactions with iron(III) centers. Substituents have been included to increase the solubility and dispersion once these chelants and polymers are attached to ferric sites. Removal of iron oxide becomes more difficult as it ages and crystallizes, but this can be accomplished through proper selection of conditions and additives.