Sulfur separation

4 Sulfiir Separation. It is important that elemental sulfur separate from the rest of the solution in the oxidizer tanks, rising to the surface and being removed in the froth. It has been reported that this separation is sometimes poor (Lorton 1988), leaving more sulfur in the oxidizer solution available for conversion to thiosulfate. 

A continuous drip of a small amount of diesel oil (typically less than 1 ml/minute) into the oxidation tank solution aids in separation of sulfur into die froth, as well as producing a thick, easy to remove froth. Sometimes diesel oil addition leads to over-frothing, however, and silicone or ocenal must be added as anti-frothing agents. 

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The iron, now in a reduced ferrous form, is not consumed instead, it is continuously regenerated by bubbling air through the solution. The sulfur precipitates out of the solution and is removed from the reactor with a portion of the reagent. The sulfur slurry is pumped to a melter requiring a small amount of heat and then to a sulfur separator where the reagent in the vapor phase is recovered, condensed, and recycled back to the reactor. 

LOCAT units can be used for tail-gas clean-up from chemical or physical solvent processes. They can also be used directly as a gas sweetening unit by separating the absorber/oxidizer into two vessels. The regenerated solution is pumped to a high-pres.sure absorber to contact the gas. A light slurry of rich solution comes off the bottom of the absorber and flows to an atmospheric oxidizer tank where it is regenerated. A dense slurry is pumped off the base of the oxidizer to the melter and sulfur separator. 

SuRe [Sulphur recovery] A version of the Claus process in which the capacity of the plant is increased by using air enriched in oxygen in the production of the sulfur dioxide. There are two versions SURE SSB [Side Stream Burner], and SURE DC [Double Combustion], In the first, a small portion of the feed stream containing hydrogen sulfide is burnt sub-stoichiometrically in a second burner in the second, the hydrogen sulfide is oxidized in two stages, with cooling and sulfur separation between them. Both of these... 

Figure 2.4. Example of an AP descriptor two atom types, aliphatic nitrogen and aliphatic sulfur, separated by the shortest chemical graph path of seven.

Species For all sulfur Separate inorganic, Ht more difficult to... 

Attempts to copolymerize monomer I with sulfur resulted in formation of just the poly(arylene polysulfide) since all the sulfur separated out on cooling to room temperature. This is apparently because when eight or more sulfur atoms appear in sequence in a polymeric chain, the chain is unstable, and some of the sulfur eliminates to form the more stable eight-membered rings instead. 

In the reactor system, designed for 5-min retention time or less in each of the three reactors, sulfur dioxide is reduced to sulfur and citrate solution is regenerated. Sulfur slurry is pumped to a sulfur slurry surge drum and then to the sulfur separation system. Various alternative units... 

A clear or nearly clear liquor is recycled back to the clear liquoi surge tank and then back to the absorption system. While developing the sulfur separation step, at times high amounts of solids containing sulfur and ash have been recycled back to the absorption system with no problem. 

The product from the sulfur separation step is fed as a slurry in citrate solution through a heater to raise the temperature above 125 °C to melt the sulfur. Liquid phases are separated in a decanter under pressure. The bottom layer is drawn off as high quality molten yellow sulfur, and the citrate solution top layer is discharged to a flash drum at reduced pressure. 

But what about the intramolecular coupling process or, to take a particular example, what are the dynamics of the two sulfurs in 1,3-bis(methylthio)propane to yield radical cation 7 after one of the sulfurs has been oxidized All attempts to follow the presumed molecular folding in any of the dithia compounds with sulfur-sulfur separations of up to five carbon atoms, i.e., to resolve the S. .S formation from the initial oxidation of one of the sulfurs on the conventional pulse radiolysis time scale (> 10 ns) have failed. The answer to this puzzle could only be provided indirectly by other techniques which, incidentally, emphasizes the value of complementary experimental approaches. 

Uses Polymerization catalyst dye stripping agent in laundering reducing agent reduces nitrate to ammonia sulfur separation (when boiled with aq. SO2) as aq. sol n. for estimation of nitro groups, ferric ions, per-salts, etc. Manuf./Distrib. Akzo Nobel... 

Saxton, R.J., Robert, J. and Minhas, B.S. 2004. Ionic membranes for organic sulfur separation from liquid hydrocarbon solutions. US 6,702,945. 

Bordeaux" mixture, wettable sulfur and lime-sulfur, separately and in combinations (spray tank bottom) Agriculture F 76 1.3 XX XX 0.0006 0.0074 0.0003... 

Chlorine (Wet) - 185 85 - S - - in vapor space of sulfur separator Plus HpO. S. and organic thio and chloride... 

This may alter the characteristics of the adhesive for example tack will be lower even if tackifying resin is present. Where prolonged storage is envisaged a two-part compound may be necessary, with the accelerator and sulfur separated. As an alternative, an accelerator system based upon zinc dibenzyldithiocarba-mate may be used, as this is much less active in ammoniated latex. 

John Stringer Just one small point about this. You can never just compare these things on the basis of the price that somebody is prepared to pay it, because the amount you are involved with is far more than the market you have to go to. When we started out the sulfur separation, we thought in terms of the... 

Elemental sulfur separates from the solution during regeneration and is collected as a froth at the top of the regenerator. The sulfur froth, which contains 70% water, some ammonia, and a small amount of blue, is filtered and washed for removal of the bulk of the impurities. The sulfur is then heated with water in an autoclave at a temperature above its melting point and recovered as fairly pure molten sulfur. An extremely pure product may be obtained by further heating of the sulfur at about 600°F—at which temperature organic impurities are decomposed—followed by distillation. 

As in most other iron chelate-based redox processes, settling is the preferred first-stage sulfur separation method used in the LO-CAT process (Quinlan, 1991). In the LO-CAT process, the usual approach is to combine the settler and the oxidizer in one single dual purpose vessel. The settler section is designed as a circular-basin type thickener. It has three operating zones clarification, zone settling, and compression. The settler diameter is a function of the solution circulation rate, which is determined by the sulfur production rate. 

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