An innovative experimental approach aiming to understand and quantify the actual fire hazards of ionic liquids

Abstract

The aim of the study is to provide advanced knowledge on the thermal and combustion hazard profiles of ionic liquids based on an original multiscale combined experimental approach. Experimental tools have been implemented and used to (a) obtain actual measurements of theoretical heats of combustion of imidazolium-based and phosphonium-based ionic liquids by use of a bomb calorimeter; (b) provide access to fundamental flammability properties of these chemicals through the use of Pyrolysis Combustion Flow Calorimeter; and (c) determine actual behaviour of ionic liquids in fire conditions, from learnings obtained by a series of combustion tests performed on 12 ionic liquids by use of the INERIS Fire Propagation Apparatus. Results so far confirm that the combustibility potential as well as the fire behaviour must be assessed on a case by case approach and is often dictated by the chemical structure of ionic liquids. The study also illustrates how the data obtained by our innovative procedure allow for consistent fire safety engineering studies serving the green use of ionic liquids in a contextual way. The work has opened a new perspective of collaborative work towards the development of a dedicated and pertinent methodology aiming at characterizing the comprehensive physicochemical hazard profiles of ionic liquids.