Development of a composite material based on Al2O3 for use in waste combustion plants

Catalytic fluidized bed combustion is the most environmentally friendly and energy efficient way of processing various fuels, including low-grade ones. The technology involves the oxidation of volatile substances on the surface of catalyst particles diluted with an inert material in a fluidized bed. The traditional use of quartz sand as an inert material leads to accelerated destruction of the catalyst during operation by attrition. The work is devoted to the study of the effect of magnesium modification of spherical γ-Al 2 O 3 , used as a carrier for a deep oxidation catalyst (DOC) in a fluidized bed, and the development of an inert material capable of minimizing DOC losses. The modified carrier was obtained by impregnating spherical γ-Al 2 O 3 granules with a Mg-containing precursor solution (nitrate and acetate) followed by calcination of granules at 800 °C. The obtained granules were studied by X-ray fluorescence analysis (XRF), inductively coupled plasma optical emission spectroscopy (ICP-OES), low-temperature nitrogen adsorption (BET), scanning electron microscopy (SEM). Their mechanical strength and catalytic activity in CO oxidation were also determined. A linear increase in the strength characteristics of γ-Al 2 O 3 was found with the introduction of magnesium from 2 to 9 wt. %. In laboratory conditions, the use of the selected material made it possible to reduce the loss of the catalyst at 4.5 -hour attrition test by 3 times compared with quartz sand.