There are many problems with flue gas desulfurization by traditional gas ionization discharge, including the large size of the plasma source, high energy consumption, and the need for a traditional desulfurization method. This paper introduces oxidization of SO2 to sulfuric acid (H2SO4) in a duct by reactive oxygen species (O2+, O3) produced by strong ionization dielectric barrier discharge. The entire plasma reaction process is completed within the duct without the use of absorbents, catalysts, or large plasma source. The reactive oxygen species O2+ reacts with gaseous H2O in the flue gas to generate ·OH radicals, which can oxidize trace amounts of SO2 in large volumes of the flue gas to produce H2SO4. Sulfuric acid is also produced by O3 oxidation of SO2 to SO3, and SO3 reacting with gaseous H2O in the flue gas. Experimental results showed that with a gas temperature of 22 °C and reactive oxygen species injection rate of 0.84 mg/L, the SO2 removal rate was 81.4 %, and the SO42? concentration in the recovered liquid H2SO4 reached 53.8 g/L. 相似文献
Electrodialysis technology was adapted to removal of heat stable salts from aqueous solutions of alkanolamine absorbents, with monoethanolamine as example. Removal of anions of heat stable salts by electrodialysis from a 30 wt % aqueous solution of monoethanolamine with the degree of carbonation of 0.2 mol of CO2 per mole of monoethanolamine was studied. The two-step removal of heat stable salts by electrodialysis allows the monoethanolamine loss to be reduced and the concentration of residual CO2 in the absorbent solution to be decreased. The suggested two-step electrodialysis treatment scheme allows the concentration of heat stable salts to be maintained on the required level from the viewpoint of their corrosion activity, the total volume of the concentrate to be decreased by 50%, and the monoethanolamine loss to be decreased by 30%. The treatment unit with the circulation volume of the monoethanol absorbent of 100 m3 h–1 was calculated for confirming the efficiency of the two-step electrodialysis treatment scheme. As compared to the one-step electrodialysis treatment scheme, the two-step scheme ensures recovery of 50% of monoethanolamine at the same efficiency of the removal of heat stable salts. 相似文献
Abstract Several sulfite solutions at the level of 0.050 mol.L?1 were kept at 25°C, in polyethylene flasks, in the presence and absence of air. The concentration of sulfite was periodically checked by the iodometric method. The presence of ethanolamine, ethylenediamine or tris(hydroximethyl)aminomethane, at 0.05 - 0.20 mol.L?1 concentration levels, showed a remarkable stabilizing effect at pH values higher than 10.5. The amine ionization was supressed by the common ion effect by using OH?, added as NaOH. The changes in the concentration of S(IV) solutions in the presence of amine were about 1 to 3 %, during the period of 85 days. The stabilizing effect depends only on the amine group and not on the mixed function alcohol/amine. It was shown that an adduct of R-NH2.SO2 type is not formed in aqueous medium. In the stock S(IV) solutions kept in highly alkaline medium a slow increase in pH was observed and disproportionation of sulfite ion was evidenced by formation of thiosulfate as revealed from ion chromatographic measurements. In the presence of oxygen dithionate ion is also formed. 相似文献
A strong ionization dielectric barrier discharge was used to produce a high concentration of reactive oxygen species that
were then injected into a simulated flue gas in a duct to remove SO2 by oxidation. Sulfuric acid (H2SO4) was produced through the following two reactions: (1) O3 oxidation of SO2–SO3, which then reacted with H2O to produce H2SO4; and (2) reaction of O2+ with H2O to produce ·OH radicals, which then rapidly and non-selectively oxidized SO2–H2SO4. When the molar ratio of reactive oxygen species to SO2 was 4:1, the SO2 removal efficiency was 94.6%, the energy consumption per cubic meter of flue gas was 13.3 Wh/m3, the concentration of recovered H2SO4 was 4.53 g/l, and the H2SO4 recovery efficiency was 28.8%. The H2O volume fraction in the simulated flue gas affected the SO2 removal efficiency, whereas the O2 and CO2 volume fractions did not. These results prove that oxidation by reactive oxygen species is a feasible method for flue gas
desulfurization. 相似文献
An effect of boric acid additives on oxidation of 2,4,6-trinitrotoluene (TNT) to 2,4,6-trinitrobenzoic acid (TNBA) with chromic anhydride in concentrated (96—100%) H2SO4 has been studied. In the presence of tetrahydrosulfatoboric acid HB(HSO4)4 formed in situ (up to 5 mol.%) or added as a preliminary prepared solution (up to 1 mol. %), TNT is selectively oxidized to TNBA in the yields up to 95—99%. The mechanism including formation of TNT dication as a key step of its oxidation at the methyl group has been suggested. 相似文献
Series sorbents of Cu, Zn, Ni, Ce and Ag metal components supported on γ-Al2O3 carrier for removing thiophene from benzene were prepared by conventional and ultrasound-assisted incipient-wetness impregnation method. The static adsorption experiments were carried out in the thiophene-benzene solution with thiophene concentration of 500?mg/L. The results show that the desulfurization activity of all γ-Al2O3 sorbents modified by different metal components obviously increase, among which the sorbent modified by silver nitrate has the best performance. The active components of sorbents from Cu, Zn, Ni, Ce nitrates loaded on γ-Al2O3 carrier are their oxides. Besides Ag2O, the products of silver nitrate thermal decomposition in sorbent prepared still have Ag0 and Ag–O–Al species. The assistant ultrasound in the process of sorbent preparation can not only shorten the impregnation time, but also enrich the pore structure of sorbent and improve the size and distribution of the Ag species, which is favorable to the removal of thiophene from benzene. The desulfurization capacity of sorbent changes with the Ag content loaded. The sorbent with 15?% quality content of Ag prepared by ultrasound-assisted impregnation method has the highest desulfurization efficiency. It could reduce the thiophene concentration to 1.7?mg/L from 500?mg/L at room temperature and ambient pressure, with the desulfurization efficiency of more than 99?%, when the ratio of sorbent to solution was 1:4?(g/mL). 相似文献
Summary: Novel crosslinked porous particles based on the ionic copolymer of 1,1,3,3‐tetramethylguanidine acrylate (TMGA) and N,N‐methylenebisacrylamide (MBA) were prepared via an inverse suspension polymerization using cyclohexane as continuous phase and Span 60 as the dispersant. The SO2 absorption–desorption properties of the P(TMGA‐co‐MBA) particles were studied for the first time. The particles showed excellent SO2 absorption properties: high capacity and rate. These absorption properties, as well as the particle volume, shape, and morphology, remained unchanged during the SO2 absorption–desorption cycles. The material appeared to be a good candidate as SO2 absorbent for fuel gas desulfurization (FGD) and purification of other SO2‐containing gases.
Optical microscope image of the P(TMGA‐co‐MBA) porous particles. 相似文献