An improved adsorption–catalytic process for removing volatile organic compounds from exhaust gases

Abstract

New methods are developed for conducting adsorption–catalytic processes to remove volatile organic compounds (VOCs) from exhaust gases at industrial enterprises. New flowsheets are proposed for these processes, in particular a system with localized heating of a part of the catalyst bed to initiate the combustion of adsorbed VOCs, and a system separating a full adsorption–catalytic bed into parallel sections with nonsimultaneous regeneration. Studies combine pilot-scale experiments and mathematical modeling. The flowsheet, in which the initiating heater is located directly in the catalytic adsorbent bed considerably reduces (by at least two orders of magnitude) the energy expenditures on regeneration, both in terms of specific energy consumption for purifying a unit volume of exhaust gases and in terms of the power required for the heater. Separating the bed into several sections allows a severalfold reduction in the maximum concentrations of pollutants and the gas temperature at the outlet of the adsorption–catalytic system during its operation. The proposed methods are characterized by high efficiency of gas purification and low energy consumption, so they can be widely used in protecting the atmosphere against VOC emissions.