Sorption, sulfur dioxide

In experiments with mixtures of condensable and noncondensable gases, adsorption of the condensable gas component can restrict or even completely block permeation of the noncondensable gas [61,62], This effect was first noticed by Barrer and Pope in experiments with sulfur dioxide/hydrogen mixtures [63] some of the data are shown in Figure 2.40. Sorption of sulfur dioxide on the pore walls... 

Figure 2.40 Blocking of hydrogen in hydrogen/sulfur dioxide gas mixture permeation experiments with finely microporous membranes [63] as a function of the amount of sulfur dioxide adsorbed by the membrane. As sulfur dioxide sorption increases the hydrogen permeability is reduced until at about 140 cm3 (SO2) (STP) /g, the membrane is completely blocked and only sulfur dioxide permeates. Data obtained at several temperatures fall on the same master curve ( , 0°C A. —10 °C , — 20.7 °C A, —33.6°C). Reprinted from R. Ash, R.M. Barrer and C.G. Pope, Flow of Adsorbable Gases and Vapours in Microporous Medium, Proc. R. Soc. London, Ser. A, 271, 19 (1963) with permission from The Royal Society...

Eckhoff SR Sorption and Reaction of Sulfur Dioxide on Yellow Dent Corn [Ph.D. Thesis]. West Lafayette, IN Purdue University 1983. 

Additives to starch exert varying effects on the kinetics of water sorption. For example, lipids do not significantly affect the content of adsorbed water. The mode of starch defatting can also influence moisture sorption by molecules of the defatting solvent occupying active centers of sorption.389 The addition of either sucrose or lipids to starch has the same effect on both branches of the hysteresis curve.386,398 Some additives, such as dimethyl sulfoxide or ammonium rhodanide, induce selectivity of the adsorption and solvation of starch 411 Sulfur dioxide accelerates water sorption regardless of the temperature.412 Pretreatment of starch with sulfur dioxide usually increases the water sorption.413 Studies on the sorption of components of water-alcohol mixtures are discussed in Section IV. 

Pure Components. Pure-component isotherms were measured for 4 gases, oxygen, nitrogen, carbon dioxide, and sulfur dioxide. The first 3 exhibited reversible sorption, while the SO2 showed a rather broad hysteresis loop. 

Lin, Y.S. Deng, S.G. Removal of trace sulfur dioxide from a gas stream by regenerative sorption processes. Sep. Purif. Technol. 1998, 13 (4), 65-77. 

Basic nitrogen species present on the surface of activated carbons or carbon fibers, like in the case of H2S, were found to enhance the sulfur dioxide uptake. Polyacrylonitrile (PAN)-based activated carbon fibers are examples of good adsorbents for SO2 removal [82, 92]. Although role of nitrogen present in the carbon matrix was not emphasized by Lee and coworkers [93] in their studies of SO2 adsorption on PAN-based activated carbon fibers, [93] Kawabuchi and coworkers noticed a significant increase in the sorption capacity when activated carbon fibers were modified with pyridine and basic nitrogen functionalities were introduced to the surface [93]. Pyridine provided basic functionality, which increased catalytic removal of SO,. . 

Harvey, R. D. and John D. Steinmetz, "Petrographic Properties of Carbonate Rocks Related to their Sorption of Sulfur Dioxide," Sept. 1971, EGN50,... 

Figure 1. Sulfur dioxide sorption of various active carbons...

Figure 10.85. Molar sorption of sulfur dioxide by polymeric membranes vs. their Gutman s donor number. [Data from Semenova S 1 Smirnov S I, J. Membrane Sci., 168, Nos.1-2, 13th March 2000, p.167-73.]...

There are essentially three types of practical processes for removing hydrogen sulhde from gas streams sorption on a solid reversible chemical or physical absorption in a Uquid medium and absorption and oxidation in an oxidizir liquid medium (direct conversion). In the direct converaon processes, not only is hydrogen sulfide removed from the sour gas stream, but it is also converted into elemental sulfur in the same liquid medium. There are two methods by w ich this conversion can be achieved. One is the so-called Wet Qaus process, in which sulfur dioxide is introduced and reacts with the hydrogen sulfide according to the following equation ... 

Ma, Y.H., and Roux, A.J., Multicomponent rates of sorption of sulfur dioxide and carbon dioxide on sodium mordenite, AIChE J., 19(5), 1055-1059 (1973). 

Kincal, S., and Culfaz, A., Sorption of sulfur dioxide on hydrogen-form and aluminum-deficient mordenites, Sep. Sci. Technol., 16(3), 229-236 (1981). 

Choudhary, V.R. Akolekar, D.B.. and Singh. A.P.. Single- and multicomponent sorption/diffusion of hydrocarbons from their iso-oclane solution in H-ZMS-5 zeolite. Chem. Eng. Sci.. 44(5). 1047-1060 (1989). Davini, P., Adsorption of sulphur dioxide on thermally treated active carbon. Fuel. 68(2), 145-148 (1989). Frimpong, S. Plank, C.A., and Laukhuf, W.L.S.. Evaluation of sorption and transport of sulfur dioxide in polycarbonate, Chem. Eng. J.. 42( I). 25-36 (1989)... 

Jeong, S.M., and Kim, S.D., Enhancement of the sulfur dioxide sorption capacity of CuO/gamma-alumina sorbent by an alkali-salt promoter. Ind. Eng. Chem. Res., 36( 12). 5425-5431 (1997). 

Comparison of effects of these two parameters indicated that the effect of relative humidity is higher ihm the effect of Ca/S ratio on spray drier SO2 sorption efficiency. The reaction between sulfur dioxide and lime requires a certain amount of humidity. It means that this gas-solid... 

Glowiak, B., and Gostomczyk, A., 1970, Sulfur Dioxide Sorption on Anion Exchangers, paper presented at Second International Clean Air Congress of the International Union of Air Pollution Prevention Association, Washington, D.C., Dec. 6-11. 

The reactive solids concept is, in principle, very simple. The hydrogen sulfide is removed from the gas by reacting with a metal oxide to form a stable, non-volatile metal sulfide. The metal sulfide is then subjected to a regeneration step in which it reacts with oxygen and/or water vapor to remove the sulfur (usually as sulfur dioxide) and produce reusable metal oxide. Both the sorption and regeneration steps are carried out at elevated temperatures. 

---