Still-Otto process

A commercial application of the Carl Still process (predecessor to the Still Otto process) is described by Snook (1977). The plant, which is located at the ARMCO Steel Corporation in Middletown, Ohio, uses a circulating solution contaiiiing 2 wt% ammonia, and reduces the hydrogen sulfide content of die coke-oven gas from 350 to 50 grains per 100 scf. At the ARMCO plant the anunonia is removed from the acid gas with the Phosam process, and the remaining add gases are fed to a sulfuric add plant... 

Rgure 4-25. Diagram of Still Otto process hydrogen sulfide and ammonia scrubber system. Davy/Still Otto (1992)... 

Davy/Still Otto, Pittsburgh, PA, 1992, personal commuitiication Still Otto Process, July 6. 

Tippmer K. Progress in the desulphurization of coke oven gas and utilization of H2S-Still Otto s SOLOX process. Coke Making Int 1994 6 32--43. 

Carl Still (2) A process for removing hydrogen sulfide from coke-oven gas by scrubbing with aqueous ammonia, itself derived from coke-oven gas. Developed in the 1970s by Firma Carl Still, Germany. Operated at the ARMCO steel mill at Middleton, OH. See also Diamox, Still Otto. 

Still Otto A process for removing hydrogen sulfide from coke-oven gas by scrubbing with aqueous ammonia. Developed from the Carl Still (2) process. 

Most of these methods, however, are modifications of the classic Stas-Otto process (62, 311), which is still in use after over a century. By general consent it is long and tedious, yields a somewhat impure product, and gives rather poor recoveries, yet with some modification it still remains the method of choice under certain circumstances. A version of it is described below. 

NF3 was first prepared by Otto Ruffs group in Germany by the electrolysis of molten NH4F/HF and this process is still used commercially. An alternative is the controlled fluorination of NH3 over a Cu metal catalyst. 

Numerous investigators have reported the decomposition of PbOg at elevated temperatures, however, the exact processes are still not well defined. Otto (8) indicates a three step process to PbgO, but the intermediate compositions are not established. The temperature at which the decomposition pressure of oxygen reaches 0.2 atm was reported as 260 C by Otto while White and Roy (9) indicate 293 C. The enthalpies and entropies reported are in serious disagreement with adopted values and indicate failure to attain equilibrium. 

The cobalt-catalyzed hydroformylation reaction was originally discovered in 1938 by Otto Roelen and was used by the Germans in WWII to convert alkenes, Hj, and CO into aldehydes, which could then be used to make alcohols. The process is still used today, most commonly to convert propylene into butyraldehyde. Using HCo(CO)4 as the catalyst, the mechanism of hydroformylation, which is shown in Figure 19.30,... 

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