On the performance stability of the MnOx/Al2O3 catalyst for VOC incineration under forced adsorption-catalytic cycling conditions

Abstract

The study is dedicated to experimental investigation of operation stability of the manganese oxide based catalyst under forced periodical temperature and composition cycling, typical for adsorption-catalytic process. Such process is considered as a promising energy-efficient tool for abatement of volatile organic compounds in lean waste and went gases. As shown by experiments, the catalyst successfully undergoes the series of 150 adsorption-regeneration cycles with organic contaminants (styrene, methyl ethyl ketone, acetic acid) without any visible changes of adsorption capacity, oxidation activity, texture, surface and bulk phase composition. Some decrease of oxidation activity is observed in presence of chlorinated substances (methylene chloride), though the deactivation degree is moderate. Strong catalyst deactivation may occur in presence of hydrogen sulfide, but the catalyst oxidation activity may be completely restored by periodical regeneration at high temperatures (900°C). The observed deactivation phenomena are similar to that in the steady-state conditions, therefore, the adsorption-regeneration cycling does not produce any specific loss of catalyst properties. The studied catalyst may be applied in the adsorption-catalytic process with the estimated practical life time of at least 2–3 years.