Industrial & Engineering Chemistry Research, Vol.60, No.10, 4097-4109, 2021
Simulative Investigation of the Application of Nonimpregnated Activated Carbon in a Multilayer Adsorber for the Separation of Hg-0 from Discontinuous Waste Gas Streams
In technical processes, fixed-bed adsorbers with impregnated activated carbon are used for chemisorptive mercury separation. In the case of discontinuous waste gas streams with strongly varying mercury concentrations (e.g., in crematories or metal-recycling plants), mercury may quickly break through the impregnated activated carbon layer due to the slow kinetics of chemisorptive adsorption. Under these conditions a promising purification concept is a multilayer adsorber. In the first layer, strongly fluctuating mercury concentrations should first be smoothed by physical adsorption and desorption on nonimpregnated activated carbon before the mercury is completely separated in the second layer of impregnated activated carbon by chemisorption. In this paper, experimentally validated dynamic simulations are used to show that, under suitable operating conditions and design parameters, effective smoothing of fluctuating mercury concentrations is possible in the first layer of a multilayer adsorber with nonimpregnated activated carbons.