Concentration profile sulfur dioxide

The experimental work was roughly divided into three divisions. The first part consisted of determination of the initial temperature of the drop and the resulting temperature profiles for different supersaturation ratios. The second part consisted of using sulfur dioxide concentrations of 1000, 2000 and 3000 ppm to test the concentration of sulfur dioxide in pure water drops at given supersaturation ratios and exposure times. The third part was a study of the effect of dissolved salts and suspended carbon particles on the concentration of the sulfur dioxide in the drops. 

Concentration changes observed between mother liquor in the flash zone and liquid product in the melt zone of an experimental triple-point crystallizer have been dramatic. A qualitative concentration profile typical of those observed in the experimental unit is shown in Figure 8. The mother liquor concentration is relatively uniform above the packed bed, but a sharp drop in contaminant concentration occurs within the top several inches of the loosely packed crystal bed. Concentration changes of the order 500 to 5000 have been observed for representative sulfurous compounds and trace contaminants, including hydrogen sulfide, carbonyl sulfide, methyl mercaptan, ethane, and ethylene. Concentration profiles calculated for the packed bed of solid carbon dioxide using a conventional packed bed axial dispersion model agree very well with the observed experimental profiles. 

The temperature and density structure of the troposphere, along with the concentrations of major constituents, are well documented and altitude profiles have been measured over a wide range of seasons and latitudes for the minor species water, carbon dioxide, and ozone. A few profiles are available for carbon monoxide, nitrous oxide, methane, and molecular hydrogen, while only surface or low-altitude measurements have been made for nitric oxide, nitrogen dioxide, ammonia, sulfur dioxide, hydrogen sulfide, and nonmethane hydrocarbons. No direct measurements of nitric acid and formaldehyde are available, though indirect information does exist. The concentrations of a number of other important species, such as peroxides and oxy and peroxy radicals, have never been determined. Therefore, while considerable information concerning trace constituent concentrations is available, the picture is far from complete. 

Single Pellet One Reaction. The sulfation reaction which is considered here for calcium carbonate is given by Eq. 3, and the temperature and concentration profiles of a typical growing limestone particle are shown in Figure 2. The rate of disappearance of sulfur dioxide is assumed to be the first order and is given by... 

The development of mathematical models to describe the thermochemical process occurring in a fluidized bed involves setting up the material and energy balance equations. The total process is represented in terms of a set of independent equations which are solved simultaneously to obtain such quantities as combustion efficiency, sulfur retention, oxygen utilization, oxygen and sulfur dioxide concentration profiles in the bed, etc. 

The solution of Eq. 87 with Eq. 88 will establish the sulfur dioxide concentration profile along the fluidized bed combustor. 

Figure 10. Concentration profiles of oxygen, wAi and sulfur dioxide, wbh, in the bed corresponding to rfccs = 0.995, rjsAE = 0.99,Y=Y = 0.04 cm and =...

Because the PPR is operated as an adiabatic reactor, the strongly exothermic oxidation reaction (iii) causes a temperature wave traveling through the bed, giving rise to a peak outlet temperature in the initial period of the acceptance cycle, as. shown in Fig. 26. In this figure, the temperature profile predicted by a mathematical model developed at the Shell laboratory in Amsterdam is compared with the profile measured in an industrial reactor to be described later. During the initial oxidation period, the copper is not yet active for reaction with sulfur oxides, so there is a slip of sulfur in the initial period, as can be seen in Fig. 27. It can be inferred that the sulfur dioxide concentration profile of the effluent of the industrial reactor is in close agreement with the profile predicted on the basis of a kinetic model developed at the Shell laboratory in Amsterdam. 

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