Геохімія техногенезу (Oct 2023)
REMOVAL OF TOXIC POLUTANTS IN A FERRITE-LOADED CATALYTIC REACTOR
Abstract
It is shown that the ingress of about 704.344.218 tons of toxic carbon monoxide into the atmosphere of Ukraine per year is a serious problem that must be solved at the level of industrial production. The need to develop technical solutions to reduce emissions of carbon monoxide from the flue gases of electrode production is substantiated. It was determined that the necessary conditions for choosing a catalyst for the oxidation of carbon monoxide are cheapness, availability, distribution in Ukraine, high operational characteristics and safety during burial. The aim of the study was defined, which consists in building a model of CO oxidation in a tubular reactor on a chromium-ferrite catalyst on a zeolite carrier in order to further determine the parameters of the equipment for afterburning the gases of spent industrial kilns. The principle of operation of a reactor with a fixed catalyst bed is described. A comparison was made between a conventional reactor with a fixed catalyst bed and an ideal displacement reactor. It is shown that during a chemical reaction in which two or more reagents participate, mixing of the reaction participants is a necessary condition for its implementation. In contrast, in an ideal displacement reactor, mixing is local and occurs in each element of the flow, and there is no mixing between elements adjacent to the reactor axis. Accordingly, in a real reactor, it is possible to approach the regime of ideal displacement, if the reaction flow is turbulent and at the same time the length of the channel significantly exceeds its transverse dimension. The calculation of the catalytic reactor for the oxidation of CO is given for the actual consumption of flue gases of PrJSC “Ukrgrafit"” with a temperature from 270 to 390°C, leaving the chamber of the Ridhammer firing furnace. Using a model of an ideal displacement reactor with a fixed catalyst bed, the parameters of the flow of a gas mixture through a reactor loaded with a chromium-ferrite catalyst on a zeolite carrier in the process of catalytic oxidation of CO were calculated. Summarizing the results of modelling and development of an experimental installation for the conversion of CO from flue gases, it can be concluded that catalysts based on chromium-ferrite materials are effective. The calculated aerodynamic parameters of the flow of the gas mixture (contact time, flow speed, hydraulic resistance of the catalyst layer) for a given initial and final CO content made it possible to determine the parameters of the containers with the catalyst, which are placed in the fire channels of the Ridhammer-type firing furnace at Ukrgrafit PJSC.
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