Dehydrogenation of Formic Acid over a Homogeneous Ru-TPPTS Catalyst: Unwanted CO Production and Its Successful Removal by PROX

Formic acid (FA) is considered as a potential durable energy carrier. It contains ~4.4 wt % of hydrogen (or 53 g/L) which can be catalytically released and converted to electricity using a proton exchange membrane (PEM) fuel cell. Although various catalysts have been reported to be very selective towards FA dehydrogenation (resulting in H2 and CO2), a side-production of CO and H2O (FA dehydration) should also be considered, because most PEM hydrogen fuel cells are poisoned by CO. In this research, a highly active aqueous catalytic system containing Ru(III) chloride and meta-trisulfonated triphenylphosphine (mTPPTS) as a ligand was applied for FA dehydrogenation in a continuous mode. CO concentration (8–70 ppm) in the resulting H2 + CO2 gas stream was measured using a wide range of reactor operating conditions. The CO concentration was found to be independent on the reactor temperature but increased with increasing FA feed. It was concluded that unwanted CO concentration in the H2 + CO2 gas stream was dependent on the current FA concentration in the reactor which was in turn dependent on the reaction design. Next, preferential oxidation (PROX) on a Pt/Al2O3 catalyst was applied to remove CO traces from the H2 + CO2 stream. It was demonstrated that CO concentration in the stream could be reduced to a level tolerable for PEM fuel cells (~3 ppm)

Renewable dimethyl carbonate for tertiary amine quaternisation: Kinetic measurements and process optimisation

Quaternary ammonium salts (QAS) are an important part of the increasing surfactant market. Conventional production processes employ toxic alkyl halides in a Menshutkin reaction with a tertiary amine (DMDA). Dimethyl carbonate (DMC) can provide a renewable route, while also leading to more benign, and non-corrosive products. This work aims to use linear ramp-flow in a plug flow reactor (PFR), combined with in-line 1H NMR spectroscopy to determine reaction kinetics. These kinetics will be used to further optimise the production process with a computational model. Solvent effects were first studied in a batch reactor. Methanol (MeOH) was found most suitable as a solvent. Subsequently, the reaction kinetics were measured in a PFR set-up. The used ramp-flow was successfully validated with data from batch and steady-state experiments. Arrhenius parameters were determined with the ramp-flow method, which proved to be an accurate and efficient technique. The kinetic data was implemented in a computational model. After validation of the model with experimental data, it was employed to extrapolate this data and optimise the reaction. The optimum QAS productivity was predicted at 122 kg h-1 L-1, obtained at 270 °C, 0.25 min residence time, and a molar ratio of 1:2.5:10 (DMDA:DMC:MeOH). These conditions would provide significant intensification of the QAS production processes

By the Skin of their Tongues : Artist Video Scripts

This anthology contains texts adapted from works by Canadian video artists. Essays focusing on the differences between presenting video-based works as time-based media or printed matter are also included. Biographical notes

So, to Speak

This anthology, the first in a series of publications entitled "Prendre Parole", contains 26 texts by Canadian visual artists who were asked to comment on how they conceive their artistic practice interweaving with the social fabric. The diverse styles of writing presented - fictional, anecdotal, polemical, biographical, philosophical - offer a wide range of critical perspectives on the relationship between art and society, and the personal/political responsibilities of being an artist. Artistic disciplines, cultural events and everyday life experiences are considered (directly and indirectly) in relation to topics such as place, language, story, science and technology, identity, time and space. Includes reprinted texts by Frenkel and Carr-Harris. 14 bibl. ref