Acids sulfur dioxide oxidation rates

Yamamoto, K., M. Seki, and K. Kawazoe. Effect of sulfuric acid accumulation on the rate of sulfur dioxide oxidation on activated carbon surface. Nippon Kaguku Kaiski 7 1268-2179, 1973. (in Japanese, summary in English)... 

It is necessary to create vacancies on the inner surface to allow continued adsorption. Vacancies, however, are created by sulfur dioxide oxidation and the subsequent transport of the generated sulfuric acid to readily accessible inner pores. Therefore, the adsorption rate is now controlled by the rate of oxidation and transport. This interdependent relationship is characteristic of this phase of adsorption. 

In the upper atmosphere such oxidation of sulfur dioxide to its trioxide forming sulfuric acid or sulfate anion may occur at ambient temperature at a much slower rate in the presence of various free radicals. 

Calvert, J. G., and W. R. Stockwell, Mechanism and Rates of the Gas Phase Oxidations of Sulfur Dioxide and Nitrogen Oxides in the Atmosphere, in S02, NO and N02 Oxidation Mechanisms Atmospheric Considerations (J. G. Calvert, Ed.), Acid Precipitation Series, Vol. 3, pp. 1-62 (J. I. Teasley, Series Editor), Butterworth, Stoneham, MA, 1984. 

However, more than one reaction pathway may exist, in which case the rate equation will contain sums of terms representing the competing reaction pathways. For example, one of the oxidation reactions that convert the atmospheric pollutant sulfur dioxide to sulfuric acid (a component of acid rain) in water droplets in clouds involves dissolved ozone, O3 (see Sections 8.3 and 8.5) ... 

Scientists have discovered that air pollution from the burning of fossil fuels is the major cause of acid rain. Acidic deposition, or acid ram, as it is commonly known, occurs when emissions of sulfur dioxide (SO ) and oxides of nitrogen (NOx) react in the atmosphere with water, oxygen, and oxidants to form various acidic compounds. This mixture forms a mild solution of sulfuric acid and nitric acid. Sunlight increases the rate of most of these reactions. 

The use of excess formic acid to destroy excess nitric acid (5M) in nuclear fuel reprocessing waste solutions at 100°C is potentially hazardous because of an induction period, high exothermicity and the evolution of large amounts of gas, mainly carbon dioxide, dinitrogen oxide and nitrogen oxide, with some nitrogen and dini-trogen tetraoxide. The system has been studied thermokinetically, and the effects of various salts (which decrease the reaction rate) and sulfuric acid (which increases the rate) were determined [1],... 

During the sulfonation process, extensive gas (HCl, SO ) formation takes place The amounts of hydrogen chloride and sulfur dioxide gases, as well as the rate of their release, increase and the reaction time decreases when the amount of chlorosulfonic acid used in the reaction is increased incrementally During the sulfonation process using chlorosulfonic acid, other reactions such as dehydrochlorination, oxidation, quaternary degradation, and quaternary regrouping also take place. 

In the contact process sulfur trioxide is made by the catalytic oxidation of sulfur dioxide (the name of the process refers to the fact that reaction occurs on contact of the gases with the solid catalyst). The catalyst formerly used was finely-divided platinum it has now been largely replaced by vanadium pentoxide, V O. The gas containing sulfur trioxide is then bubbled through sulfuric acid, which absorbs the sulfur trioxide. Water is added at the proper rate, and 98% acid is drawn off. 

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