Linde Aktiengesellschaft

Basf Aktiengesellschaft

Guenter Weber

Franz J Broecker

Gerd Duembgen

Gottfried Schlichthaerle

Wolfgang Pies

Erhard Kliem

Alfred Kunz

For separating sulfur from a sulfur-lye suspension, the suspension is fed into a flooded separation tank, a temperature above the melting temperature of sulfur is maintained in the separation tank, and liquid sulfur and lye are withdrawn from the separation tank. To reduce the formation of sodium thiosulfate, the area of the interfacial separation layer between liquid sulfur and lye is maintained as small as possible in separation tank (15) by providing that the liquid sulfur be fed into a relatively small diameter vertical separation pipe (4), in which the separation layer (6) between liquid sulfur and lye is established, and the liquid sulfur is drained out through separation pipe (4). (FIG. 1)

Process and device for separating a sulfur-lye suspension

For the separation of sulfur from a sulfur/alkaline solution suspension, the suspension is heated to a temperature above the melting temperature of the sulfur and is introduced under pressure into a separating tank 1, containing a separating chamber 8, alkaline solution chamber, and sulfur chamber 12. From the separating tank, settled liquid sulfur is continuously withdrawn, on the one hand, via conduit 16 and alkaline solution is continuously withdrawn, on the other hand, via conduit 9. In order to provide a system having little susceptibility to trouble, the separating chamber and alkaline solution chamber are operated in the flooded mode, thereby avoiding the necessity for a steam blanket therein.

Separation of a mixture of sulfur and alkaline solution and apparatus

Methanol is prepared by catalytic conversion of a synthesis gas mixture, containing hydrogen, carbon monoxide, carbon dioxide and/or water, at from 200.degree. to 320.degree. C. and under from 30 to 300 bar in adiabatic and/or isothermal reactions in the presence of a catalyst containing copper and zinc, by a process in which the fresh catalyst is reduced with a hydrogen-containing gas before the start-up of the process, and then the synthesis is started under conventional conditions and is continued until the formation of methanol in the reaction zone has declined substantially, after which the reaction is interrupted and the catalyst is regenerated.

Preparation of methanol

In the simultaneous scrubbing and oxidation of H.sub.2 S with a vanadate-containing aqueous alkaline scrubbing agent, so as to prevent precipitation of vanadium values, the concentration of CO.sub.3 -- ions in the scrubbing agent is adjusted, preferably to a minimum content of CO.sub.3.sup.-- ions of 12.5 g/l of scrubbing agent. The scrubbing agent is regenerated conventionally by treatment with an oxygen-containing gas in an oxidizer.

Carbonate ion control to prevent losses of vanadium in oxidation of

In a process wherein hydrogen sulphide is removed from a gaseous mixture by scrubbing with an aqueous alkaline scrubbing solution containing an oxidizing agent, which process ordinarily results in a buildup of S.sub.2 O.sub.3.sup.-- ion, in order to reduce the rate of formation of S.sub.2 O.sub.3.sup.-- ions, the pH of the alkaline scrubbing solution is maintained at below 9 preferably at 8.0-8.5, with CO.sub.2 being preferably employed as the pH adjusting reagent.

Scrubbing of hydrogen sulphide using pH control to control thiosulfate

In the scrubbing and simultaneous oxidation of hydrogen sulfide with an aqueous alkaline scrubbing solution containing five-valent vanadium as the oxidizing agent, the sulfide being converted into higher oxidation states with simultaneous reduction of the five-valent vanadium to four-valent vanadium, the scrubbing solution subsequently being regenerated for reuse in a downstream oxidizer by treatment with an oxygen-containing gas for the reoxidation of the four-valent vanadium, to avoid losses of vanadium when the pH in the scrubbing solution is below 9.5, using the vanadium in a ration which exceeds the stoichiometric ratio for the oxidation of the hydrogen sulfide.

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Linden, Germany

Guenter Weber