Comparison of Catalysts in the Point of View of Pellet Stove Flue Gas Purification

Abstract

Monolithic catalysts are used as a method for the flue gases purifying by oxidation of gas products from incomplete combustion. This study is focused on three different types of monolithic catalysts and quantification of their degree of influence on mass concentration of carbon monoxide (CO) and organic gaseous compounds (OGCs) in real small-scale wood pellet stove. Catalysts were placed right behind the stove at the flue gas outlet. The comparison consisted of quantification of their influence on the selected pollutants during the few-hours steady operation of the small-scale pellet stove. Reference values of the selected pollutants were defined during the combustion test without a catalyst installed. In this article, three catalysts based on different active compounds: WO3–V2O5, Pd and Pt were tested. The palladium-based catalyst has proven the best degree of conversion of CO (almost 78%). The platinum-based catalyst has proven the best degree of conversion of OGC (almost 64%). Due to a big degree of clogging by solid particles of all catalysts during the tests, it is impossible to operate the chosen stove with tested types of catalysts in normal operation at home conditions. Without any type of periodical cleaning (every few hours), there is a serious danger of leakage of the flue gas out of the stove. Further investigations should evaluate the degree of clogging in a long-term operation and should propose a method to avoid any danger of the flue gas leaking caused by the catalysts.