Predicting the composition of acidic, ionic liquids in contact with HCl gas

✍ Scribed by Ernesto J. Angueira; Mark G. White

• Publisher: American Institute of Chemical Engineers
• Year: 2005
• Tongue: English
• Weight: 291 KB
• Volume: 51
• Category: Article
• ISSN: 0001-1541
• DOI: 10.1002/aic.10486

✦ Synopsis

Abstract

The acidic, chloroaluminate ionic liquid (IL) derived from the combination of 1‐ethyl‐3‐methyl‐1__H__‐imidazolium chloride (EMIM‐Cl) and aluminum chloride complex (AlCl~3~) in contact with HCl gas was modeled using the principles of equilibrium thermodynamics of chemically reacting systems as a means to understand better the reactivity of arene formylations in these IL's. The concentration of an HCl‐chloroaluminate species, ClHAl~2~Cl that has been characterized as a super acidic Brønsted species, increases with increasing HCl partial pressure. Another chloroaluminate species Al~2~Cl, which has been characterized as a strong Lewis acid, showed concentrations that decreased with increasing HCl gas phase partial pressures. The ultimate conversion of toluene to tolualdehyde could be correlated with the sum of the predicted molar amounts of ClHAl~2~Cl and Al~2~Cl, by assuming that each ClHAl~2~Cl combined with 1 tolualdehyde and each Al~2~Cl sequestered a single tolualdehyde molecule. © 2005 American Institute of Chemical Engineers AIChE J, 2005