Sulfuric vapor pressure

These sub-dew point processes can increase the overall Claus plant sulfur recovery to up to 99%, as limited by equilibrium conversion and sulfur vapor pressure losses. Elf Aquitaine s Sulfreen process, Amoco s cold bed adsorption (CBA) process, and the Mineral and Chemical Resource Company (MCRC) process licensed by Delta Hudson are all variations on the cold bed sub-dew point process. 

Consequently, at very low sulfur vapor pressure, Bi + W + WS2 coexist, whereas with increased sulfur activity the univariant assemblage Bi + WS2 + Bi2S3 becomes stable. At high temperatures WS2 coexists with a liquid ranging from Bi to beyond Bi2S3 composition. No ternary compounds were found to occur in the system. 

Experimental problems still remain to be solved. The simple laboratory techniques for high-temperature research discussed above as yet lack a method to balance the sulfur vapor pressure in a closed system . 

This relation could be verified experimentally if, under a given external sulfur vapor pressure, one measured the thickness ratio of the two partial layers on the one hand, and k and k on the other with the Hpe or nB values. The latter can be determined for the partial layers by performing d /dt measurements on the individual layers. Such measurements have in fact been performed by Hauffe and Rahmel (30), and Meussner and Birchenall (31). Since in Bq.(45) Nj Nj, we obtain the ratio of the FeS - FeS2 layer ... 

Ritchie and Ludlam investigated the reaction at sulfur vapor pressures of about 0.0025 torr and oxygen pressures of about 0.3 torr. They stated in their discussion that reaction at 100-150 °C occurred only if initiated by the presence of a surface at over 450 °C, and if the products were removed quickly from the site of reaction. However, the description of their experimental details is sufficiently vague so that it is not clear whether both of the conditions are necessary or whether one alone is sufficient. The reaction rate was independent of [O2]. This they explained as due to two compensating factors (l)the rate of oxidation is proportional to [O2 ], but (2) the rate of inhibition by SO2 is inversely proportional to the diffusion rate of SO2 into O2, and therefore proportional to [O2], making the net rate of oxidation independent of [O2]. 

Rosenqvist ( ) studied the sulfur vapor pressure above solid nickel sulfides using the equilibrium. Combining his... 

The use of the procedure of Rau et al. (2) leads to a set of thermal functions and associated enthalpies of formation which reproduce the observed sulfur vapor pressure data. That Is, the sum of the calculated partial pressures of all eight sulfur vapor species, S (g) to Sg(g), does closely reproduce the observed vapor pressure. [A difference between the calculated boiling point (at 1 atm) and the secondary reference temperature boiling point is due to the difference between the Ideal gas calculation and the real observed value.]... 

Using this value for n, it can be shown that 10 at. % soluble additive lowers the sulfur vapor pressure by about 50% and 20 at. % lowers... 

Temperature dependence of the parabolic rate constant of Mn sulfidation in pure sulfur vapor (dashed line) and in S2 containing Li2S (solid line), at sulfur vapor pressure of 1 Pa. 

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