(201a) Novel Organic Solvents for the Bunsen Reaction

A novel group of solvents, including ionic liquids and organic molecular solvents, have been explored for their potential use in the Bunsen reaction of the sulphur iodine thermochemical cycle. Ionic liquids are solvents composed entirely of ions. They offer significant advantages over traditional solvents and their properties can be tailored for any given application. Ionic liquids have high solvating ability and high thermal stability, making then good candidates for the Bunsen reaction.

It is proposed that the Bunsen reaction can be operated with iodine as the limiting reagent in the presence of a hydrophobic solvent into which the hydriodic acid can be extracted. This is advantageous over using excess iodine as there is the potential to obtain concentrated, ‘dry' hydriodic acid and avoid the formation of HIx.

An experimental study has been undertaken in order to identify those solvents with the most promising properties. Liquid-liquid extraction tests have been performed so as to assess the selectivity of each solvent for hydriodic acid. The solubility of sulphur dioxide in a number of solvents has also been investigated and hydriodic acid recovery methods have been explored. The Bunsen reaction has been performed in the presence of selected organic solvents and the separation characteristics analysed.

The results of the experimental study into ionic liquid solvents will be presented.