Accidental releases of titanium tetrachloride (TiCl4) in the context of major hazards--spill behaviour using REACTPOOL.

Titanium tetrachloride is a highly toxic and corrosive substance that is used widely in the process industries. On accidental release, it creates liquid pools that can either boil or evaporate. The main feature of the liquid pool is the reaction of titanium tetrachloride with water. There are three sources of water available for reaction: free ground water, atmospheric moisture and substrate water. Unfortunately, there is no specific study that examines the liquid phase hydrolysis reaction of titanium tetrachloride. Based on thermodynamic calculations and relevant information found on the topic, it is concluded that liquid titanium tetrachloride reacts exothermically with all three sources of water yielding hydrogen chloride gas and a solid complex of titanium oxychloride. The purpose of this paper is to describe the spill behaviour of titanium tetrachloride reporting a number of results using the REACTPOOL model [T. Kapias, R.F. Griffiths, C. Stefanidis, REACTPOOL: a code implementing a new multi-compound pool model that accounts for chemical reactions and changing composition for spills of water reactive chemicals, J. Hazard. Mater. A81 (2001) 1-18]. It also addresses the dangers involved in cases of accidental release of titanium tetrachloride and reports its properties, referring to toxicity data and other relevant information. The spill behaviour of titanium tetrachloride has been incorporated into REACTPOOL. Model results indicate that the pool behaviour is mainly affected by the amount of free ground water, the wind speed and surface roughness. Although titanium tetrachloride has been involved in a number of major accidents, there are no experimental data relevant to the modelling requirements.