Effect of Ultrasound on SO₂ Desorption from Sodium Alkali Desulphurization Regeneration Solution

Abstract

The influence of an ultrasonic field on SO 2 desorption from sodium alkali desulfurization regeneration solution was studied in this work. The SO 2 desorption experiments were carried out in the presence and absence of ultrasound at 25 kHz. The results showed that the use of ultrasound could enhance the SO 2 desorption rate from the sodium alkali desulfurization regeneration solution. By analyzing the composition of regeneration solutions with different pH values, two steps for the desorption process were proposed, both with and without ultrasound conditions, i.e., the first step was the decomposition of sulfurous acid (H 2 SO 3 ), and the second step was the decomposition of sodium bisulfite (NaHSO 3 ). Furthermore, the use of ultrasound was seen to promote the first step, while it was not seen to have a significant effect on the second step. It was also found that the decomposition of H 2 SO 3 in the first step could be considered as a gas mass transfer process from the liquid phase to the gaseous phase and the overall volumetric mass transfer coefficient, K L ·a, increased on using ultrasound compared to the value in the absence of an ultrasonic field.

Falling Film Evaporator for Desorption of Basic Aluminum Sulfate SO2-Rich Solution and Enhancement of Heat and Mass Transfer

“…Xu et al used ultrasonic waves to test the effects on the desorption of basic aluminum sulfate SO 2 -rich solution and found ultrasonic waves promoted the decomposition of only sulfurous acid, but not bisulfite ions. 24 Xue et al also found ultrasonic waves promoted the desorption of SO 2 and the SO 2 desorption efficiency under experimental conditions was up to 82%. 25 Though the above studies reported some improvements, the effects were still not significant and the research was still at the experimental stage and far from industrialization.…”

“…Thus, to improve the desorption effect and reduce energy consumption, researchers had to develop novel techniques or methods. Xu et al used ultrasonic waves to test the effects on the desorption of basic aluminum sulfate SO 2 -rich solution and found ultrasonic waves promoted the decomposition of only sulfurous acid, but not bisulfite ions . Xue et al also found ultrasonic waves promoted the desorption of SO 2 and the SO 2 desorption efficiency under experimental conditions was up to 82% .…”

Sulfur Dioxide Desorption Characteristics of Basic Alkali Aluminum Sulfate Desulfurization Rich Liquid by Falling Film Evaporation with a Spring Tube

“…The effect of ultrasound on SO 2 desorption from sodiumalkali-desulfurization-rich solution was investigated by Xu et al 11 They compared the ratio of H 2 SO 3 and NaHSO 3 in the solution. They found that the ratio reached the same values respectively in the conditions of ultrasound and without ultrasound, but the decomposition time in the ultrasound is less than that without ultrasound.…”

CFD Modeling of Micromixing and Velocity Distribution in a 1.7‐MHz Tubular Sonoreactor

“…Ultrasound as a new advanced technology is employed to intensify various physical and chemical processes by generating cavitations and acoustic streaming in liquid media. For instance, it is successfully applied in chemical reactions [1], wastewater treatment [2], areas of heat transfer [3], desorption [4,5], cleaning [6], crystallization [7,8], etc. In comparison with other technologies, notable advantages of ultrasound energy are savings and optimization of power consumption, improvement of product quality, and reduction in production time [9].…”