Flue Gas Desulfurization by Mechanically and Thermally Activated Sodium Bicarbonate

Abstract

This paper presents the results of study on structural parameters (particle size, surface area, pore volume) and the sorption ability of mechanically and thermally activated sodium bicarbonate. The sorption ability of the modified sorbent was evaluated by: partial and overall SO2 removal efficiency, conversion rate, normalized stoichiometric ratio (NSR). Sodium bicarbonate was mechanically activated by various grinding techniques, using three types of mills: fluid bed opposed jet mill, fine impact mill and electromagnetic mill, differing in grinding technology. Grounded sorbent was thermally activated, what caused a significant development of surface area. During the studies of SO2 sorption, a model gas with a temperature of 300°C, of composition: sulfur dioxide at a concentration of 6292 mg/mn3, oxygen, carbon dioxide and nitrogen as a carrier gas, was used. The best development of surface area and the highest SO2 removal efficiency was obtained for the sorbent treated by electromagnetic grinding, with simultaneous high conversion rate.

Scale-up experiments of SO2 removal and the promoting behavior of NO in moving beds at medium temperatures

“…In Table 1, it manifests the higher specic surface area of 111.04 m 2 g À1 for ne NaHCO 3 than that for NaHCO 3 of 28.435 m 2 g À1 , and the adsorption average pore size is reduced by the BJH method. A similar case researched by Walawska et al 53 identied similar conclusions that both smaller particle size and larger specic surface area were responsible for the higher conversion and instantaneous efficiency. Fig.…”

Effect of sorbent reactivity on flue gas desulphurization in fluidized‐bed boilers under air firing mode

“…Parameters determined according to Polish standards [27][28] Superscript: daf-dry and ashless state; diff-calculated by difference ad -on an air dried basis Figure 1. Test stand for testing the reactivity and absolute sorption and the conversion degree, based on Walawska et al [29] fed into the reaction column. The velocity of the gas was 1.25 m Á s À1 .…”

“…[10,11] The former allows studying the behaviour of the limestone for long time tests, simulating the mean residence time existing in a fluidized bed combustor, and the latter makes it possible to study the limestone sulphation in similar operating conditions to those in fluidized bed boilers. As well as the operating conditions, such as temperature, particle size, SO 2 concentration, attrition, [12][13][14] etc., the quality of sorbent [15] is the basic parameter that determines the effects of dry flue gas desulphurization methods. The effects should be understood not only as the meeting of required sulphur dioxide concentration levels, but also the minimizing of the streams of sorbents used and the improvement of the quality of products after flue gas desulphurization (reduction of free CaO).…”

The Influence of SO2 and HCl Concentrations on the Consumption of Sodium Bicarbonate during Flue Gas Treatment

“…There are already a number of publications dedicated to individual aspects of dry flue gas treatment by sodium bicarbonate or the whole process in general. The topics investigated include the determination of effects of various operational parameters, , dry injection modeling, the influence of particle size, comparison of sorbents, ,, process design, the possibility of deep removal of pollutants, and assessment and/or comparison of compact flue gas treatment systems. , Valuable information on real process data can be found in conference proceedings of some commercial subjects. , Unfortunately, not all publications are consistent in terms of conclusions. Authors of individual publications are not in agreement on whether the controlling step is the product layer diffusion, chemical reaction, or both .…”