Prospective principles of catalyst utilization using supercritical fluid media

Abstract

An overview of prospective principles of catalyst utilization using supercritical fluid media is presented. The processes in which these working media act as solvents and extractants, reagents and reaction media are considered. At the same time, we are talking about both heterogeneous catalysts and catalytic complexes dissolved in the water runoff of industrial enterprises. Using the LD-145 catalyst as an example, we studied the possibility of extending its service life instead of recycling, due to a change in the physical and chemical principles of its regeneration. We are talking about replacing the high-temperature process of vapor-air oxidation of catalyst-deactivating compounds with a supercritical fluid extraction process. At the same time, the extractant used is not widespread carbon dioxide, but propane/butane mixture, the use of which makes the process significantly more efficient. This is because a number of binary systems “deactivating compound – extractant” change the type of phase behavior from V-VI to I-II when changing carbon dioxide to propane/butane mixture. Thus, these systems, for example, involving naphthalene, phenol and some other substances in the supercritical fluid state fall outside the binodal of the binary system into the region of unlimited miscibility of components, which significantly increases the kinetics of the catalyst regeneration.