SIPS 2018

DETAILLED PROGRAM OVERVIEW

My Life in Molten Ionic Media
Rasmus Fehrmann¹;
¹DTU CHEMISTRY, Lyngby, Denmark;
PAPER: 56/Molten/Regular (Oral)
SCHEDULED: 11:20/Mon./Bossa (150/3rd)

ABSTRACT:
It was almost 50 years ago, during my study of Chemical Engineering (Civil Engineer) at the Technical University of Denmark (DTU), that I was "baptised" in molten alkali chloroaluminates in the group of Prof. Niels Bjerrum. Since then, I have stayed faithful to molten media for nearly the entirety of my scientific career. Firstly, my PhD degree (Licentiatus Technices at that time...) concerned unusual oxidation states of the chalcogenes in molten chloroaluminates. Selected experimental results covering rare oxidation states like +1/2, + 1/4 and +1/8 of pure Sulfur, Selenium, and Tellurium species will be highlighted here. At the end of the 1970's I turned to catalysis in molten salts, with a special focus on the chemistry of the sulfuric acid catalyst, the key material for the production of the most important chemical at the tonnage scale in the world - at that time as well as now. For the following 35 years, more than 60 journal publications and a large number of reports described the efforts of me and my numerous collaborators and students. The most important results will be shown, including the discovery of the complex and compound chemistry Vanadium in molten alkali pyrosulfate melts, and the state-of-the-art reaction mechanism modelling the working sulfuric acid catalyst. In addition, our in-situ and operando investigations of commercial industrial catalysts have been essential to link our ex-situ results to the "real world", and our efforts to achieve the global goal of the catalyst producers - the low temperature sulfuric acid catalyst- allowing more economic and sustainable sulfuric acid production, will also be highlighted. My educational background as a chemical engineer that focused on organic chemistry during my Master's and on inorganic chemistry during the PhD, combined with my Master thesis on "Hydroformylation by Rh-phosphine Catalysis" (modified Shell Process) was probably essential to me joining the early efforts of research and application of ionic liquids from year 2000. Shortly after, our first results on Supported Ionic Liquid Phase (SILP) continuous flow catalysis were published, regarding Rh-phosphine complexes dissolved in ionic liquids and subsequent impregnated in meso porous inorganic supports. This concept – parallel to the sulfuric acid catalyst also being a Supported Liquid Phase (SLP) catalyst during operation- allowed continuous conversion of gas phase olefins with H2 and CO to gas phase aldehydes, since no evaporation of solvent or catalyst took place. Thus, an attractive design of the otherwise batch operated Oxo process was provided– a concept that whose commercialization is currently being attempted by, among others, our group and an European industrial partner. Subsequently, we have also applied the SILP concept to other important catalytic industrial processes, like carbonylation of methanol to acetic acid (our patent acquired by an European chemical company), in addition to alkoxycarbonylation of alkenes (important for e.g. MMA production), and also in the Water-Gas-Shift (WGS) process through collaboration with FAU (Erlangen, DE) and the European industry . Selected results of our SILP catalyst research and applications will also be shown at this occasion. In addition, we have recently extended the SILP concept to continuous gas separation and encircled appropriate ionic liquids and porous supports for the selective reversible absorption of gasses like CO2, NOx, SO2 and H2S. Our fundamental results and the possible application of these selective SILP filters to e.g. CO2 capture, flue gas cleaning, biogas and natural gas sweetening – pursued industrially together with a Nordic partner – will be described as well. In conclusion, the importance of the concept "From Molecular Understanding to Industrial Application" – the motto of our research center at DTU (Centre for Catalysis and Sustainable Chemistry) - should be obvious from our achievements so far and undoubtedly also in the future.

References:
[1] Svovls, Selens og Tellurs Kemi i Chloroaluminatsmelter (The Chemistry of Sulfur, Selenium and Tellurium in Chloroaluminate Melts). Rasmus Fehrmann, Thesis, Chemistry Department A, The Technical University of Denmark, Lyngby 1976.

[2] Lower Oxidation States of Selenium. 2. Potentiometric Study Involving Tetravalent Selenium, Tetraselenium(2+), Octaselenium(2+), and Three Other Low Oxidation States of Selenium in a Chloroaluminate Melt. R. Fehrmann and N.J. Bjerrum, Inorg. Chem. 16, 2089, 1977.

[3] Progress on the mechanistic understanding of SO2 oxidation catalysts. O.B. Lapina, B.S. Bala'zhinimaev, S. Boghosian, K.M. Eriksen, and R. Fehrmann, Catal. Today, 51, 469, 1999.

[4] R. Fehrmann, A. Riisager and M. Haumann (Eds.), Supported Ionic Liquids - Fundamentals and Applications, Wiley-VCH, Weinheim, 2014.Applications, Wiley-VCH, Weinheim, 2014.