Containers sulfur dioxide

One method for using sodium alumiaate to desulfurize flue gas containing sulfur dioxide is described (45). This procedure led to a process where aluminum sulfate [10043-01-3] could be generated as a by-product of flue gas desulfurization (46). 

If the gas to be measured contains sulfur dioxide, it has to be scrubbed from the gas before oxidation of the reduced compounds can occur. The gas is scrubbed using an SO2 scrubber. This may contain citrate buffer solution (potassium citrate or sodium citrate). The collection efficiency of the sulfur diox ide may be as high as 99%. 

Townsend A process for removing hydrogen sulfide from natural gas by absorption in triethylene glycol containing sulfur dioxide. Part of the sulfur produced is burnt to sulfur dioxide in order to provide this solution. The hydrogen sulfide and sulfur dioxide react in the presence of water to generate elemental sulfur. Invented in 1959 by F. M. Townsend. 

The gas stream containing sulfur dioxide is either dried before passing to the catalytic oxidation step, or is oxidized in the presence of water vapor with subsequent acid condensation and removal. When acid is produced from elemental sulfur, the air used for sulfur burning is predried. In all cases, typical plant designs use sulfuric acid from the process as a drying agent. Wet catalytic oxidation is relatively uncommon. Some applications of Haldor Topsme s WSA-2 wet gas catalysis process are described in the literature (97). 

Pour the hot solution into at least 21. of cold water to which a few grams of sodium sulfite has been added and allow the white crystalline powder to settle. The water should contain a little sodium sulfite or sulfur dioxide, which will tend to prevent oxidation. Wash the precipitate several times by decantation, the wash water in each case containing sulfur dioxide and made acid with hydrochloric acid. Finally, collect the precipitate on a small Witte plate provided with a close-fitting filter paper, washing it on to the plate with portions of the filtrate and taking care not to let all the liquid drain through the filter, exposing the moist compound to the air. 

A factor of note is (he settling and adherence of panicles on metals. Particles of carbon, ammonium sulfate, and silica cause a marked increase in corrosion, und this is accentuated in atmospheres containing sulfur dioxide. The presence of such hygroscopic particles enhances the adherence of liquid and thus provides lor electrochemical attack. 

In early work, iodine was electrochemically generated from an iodide salt in anhydrous methanol containing sulfur dioxide and pyridine. The titration reaction is... 

The relative importance attached to sulfur compounds in petroleum may, at first, seem unwarranted, but the presence of sulfur compounds in any crude oil can only result in harmful effects. For example, the presence of sulfur compounds in finished petroleum products such as gasoline will cause corrosion of engine parts, especially under winter conditions when water containing sulfur dioxide (from the internal combustion) may collect in the crankcase. On the other hand, mercaptans cause the corrosion of copper and brass in the presence of air and also have an adverse effect on the color stability of gasoline and other liquid fuels. 

This material may be purified by boiling 1 g. of it with 50 cc. of water containing sulfur dioxide, filtering the solution, and keeping the filtrate at 0° for twenty-four hours. The purified product (0.74 g.), when slowly heated, becomes slightly brown at 245° and melts at 287° when rapidly heated it becomes slightly brown at 260° and melts at 298-300°. 

Removal of sulfur dioxide from a gas stream. If a fuel that contains sulfur is burned, the product gas contains sulfur dioxide. If the gas is released directly into the atmosphere, the SO2 combines with atmospheric oxygen to form sulfur trioxide. The SO3 in turn combines with water vapor in the atmosphere to form sulfuric acid (H7SO4), which eventually precipitates as acid rain. To prevent this occurrence, the combustion product gas is contacted with a liquid solution in an absorption or scrubbing process. The SO2 dissolves in the solvent and the clean gas that remains is released to the atmosphere. 

A sample gas stream containing sulfur dioxide at 15°C is to be contacted with an adsorbent while the sample collection is performed. The SO2 concentration is known to be approximately lOppmv (lOpL/L). The adsorbent to be used is activated carbon. The sampling rate is 200L/min and is to be maintained for 24 h. What... 

The method of Fan and Dasgupta (1994) relics on tlie reaction of formaldehyde with 1,3-cyclohexane-dione in acidified ammonium acetate to form the fluorescent dihydropyridine derivative in a flow injection analysis system. Formaldehyde trapped in water can be reacted with pararosaniline and sodium sulfite under mild conditions (neutral pH, room temperature equilibration) to produce a colored product that is measured at 570 nm (Petreas et al. 1986). The presence of bisulfite is an interference in this reaction so the method cannot be used to sample atmospheres that contain sulfur dioxide. In addition, the method is reported to suffer from interferences resulting from the presence of other aldehydes and phenol (Hoogenboom et al. 1987). The indirect method of Hoogenboom et al. (1987) relies on the reaction of excess bisulfite in an aqueous solution of formaldehyde with 5,5 -dithiobis(2-nitrobenzoic acid) to form a colored product, the absorbance of which is measured at 412 nm. The method reported by Naruse et al. (1995) relies on the formation of a colored product obtained by reacting the aqueous formaldehyde with acetylacetone and ammonium acetate in acetic acid. Absorbance is measured at 414 nm. 

Two-component volumetric reagents require two separate solutions. The solvent contains sulfur dioxide and base in an alcohol. The reagent is a solution of iodine in methanol with a known titer. Advantages of two-component systems include faster titrations and greater accuracy for small amounts of water. There are, however, more possibilities for side reactions within a two-component system. 

We investigated behaviour of the catalytic systems imder extreme conditions because the temperature of the catalyst during some modes of convertor operation can attain values of 1000-1100 C. Oxynitride SHS ceramics exhibited high heat (1000 h at 150-1000°C) and corrosion resistance. Prolonged exposure of the SHS ceramic catalytic systems to gaseous mixtures containing sulfur dioxide and oxygen at 700-1000°C did not cause a noticeable decrease in the catalytic activity. 

Corrosive gas samples will often react with the container. Sulfur dioxide, for example, is troublesome. In automobile exhaust, SO2 is also lost by dissolving in condensed water vapor from the exhaust. In such cases, it is best to analyze the gas by a stream process. 

Single-bed catalysts had been used to produce sulfur from dry sulfur dioxide gases. Ryason 1,2) used either Cu, Pd, Ag, Co, or Ni supported on alumina. Khalafalla and Haas (3) optimized the composition of iron-alumina catalysts to produce sulfur from dry gases containing sulfur dioxide and carbon monoxide. Querido and Short (4) demonstrated the feasibility of reducing sulfur dioxide by carbon monoxide on a copper-alumina catalyst at concentrations and temperatures typical of power plant stack gases. 

This recovery process is based on the simple chemistry of the sodium sulfite/bisulfite system. After appropriate pretreatment, the flue gas containing sulfur dioxide enters the absorber, which reduces the sulfur concentration to the required level and can accommodate a wide range of turn-down conditions (Figure 1). 

The conversion of 1,8-naphthalenesultone into 1,8-naphthalenediol651 will serve as example Potassium hydroxide (60 g), water (20 ml), and 1,8-naphthalenesultone (14 g) are melted together in a silver crucible, then heated with stirring to 200-300° for 15-20 min during which the crucible is covered. The dark product is allowed to cool, decomposed with 13% hydrochloric acid (300 ml), treated with concentrated hydrochloric acid until bubbling ceases, and then heated with water (11), in which everything dissolves except a small amount of tar. When the filtrate cools, crude 1,8-naphthalenediol (6 g) crystallizes, and a further amount (2 g) is obtained by ether-extraction of the mother liquor. After recrystallization from water containing sulfur dioxide, the product has m.p. 140°. 

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