Perox process

Perox Process, 762 Takahax Process, 765 Stretford Process, 769 Hiperion Process, 794 Sulfolin Process, 797 Unisulf Process, 802... 

The first liquid redox quinone process was the Perox process, developed in Germany in 1950. It employs p-benzoquinone, and was a forerunner to other quinone based processes. The second process discussed in this section is the naphthoquinone-based Takahax process, developed in Japan by the Tokyo Gas Company. This process, which achieved significant market penetration in Japan, was introduced in the same time frame as the Svetford process, and constituted an attempt to eliminate the use of heavy metals that is characteristic of Stretford type processes. 

The Perox process was developed in Germany after World War 11, and was the first process to utilize the redox properties of quinone compounds in the removal of hydrogen sulfide from coke-oven gas. As early as 1956, it was reported that three commercial units with a combined capacity of approximately 30 million cu ft per day were operating in Germany (Reinhardt, 1956). 

Table 9-4 Typical Operating Data of Perox Process ...

The flow scheme of the Takahax process is quite similar to that of the Perox process, and, as in the Perox process, the oxidation of hydrosulfide to elemental sulfur in the absorber occurs almost instantaneously. Therefme, there is no need for a delay tank downstream of the absorber to complete the reaction. The process requires no steam and operates at ambient pressure. 

T0138 Calgon Carbon Corporation, Perox-Pure T0168 CleanSoil, Inc., The CleanSoU Process... 

Various other techniques have also been developed particularly the Ferrox. Manchester, Perox, Lacy-K.eller. Lo-Cat. Freeport sulfur processes, etc. 

Almost all of the cumene produced is consumed by the cumene peroxidation process to phenol and acetone. Aspects of this process resemble the peroxidation processes to propylene oxide already described, except that in this case the final products are formed by an intramolecular rearrangement of the same molecule that is peroxidized rather than by a reaction of a perox-idized molecule with a second component, propylene. In the first stage of the cumene to phenol process a suspension of purified cumene in a dilute solution of sodium carbonate in water is heated to about 110°C under slight pressure. Air is blown through this suspension until about 25% of the cumene has formed the hydroperoxide (Eq. 19.49). 

Ando and co-workers reported that electron transfer photooxygenation of three- and four membered cyclic disilanes gives cyclic perox-ides. DCA-sensitized photooxygenation of 1,2-disiletenes affords cyclic peroxides, 1,2,3,6-dioxadisilins, and 1,2,5-oxadisilole-nes. Similar photooxygenation of oxadisiliranes gives 1,2,4,3,5- tri-oxadisilolanes. For these photoreactions, Si-Si bond cleavage in the radical cations of the cyclic disilanes is postulated to be the key process. 

It is also worthwhile to mention that gasochromic devices have been made by the sol-gel process (Georg, 2004) using WO3 layers prepared by the ion exchange or perox-opolytungstic acid method. 

In another process, a nonaqueous solution was the carrier of an initiator capable of generating a stable end group. For example, aqueous potassium persulfate solution was replaced by solvent-based solutions of hexafluoropropylene oxide (HFPO) dimer perox-ide.[i25]-[i37] Homopolymer and copolymers of tet-rafluoroethylene and other fluorinated monomers were synthesized by this technique. A homopolymer was produced in a 25 ml high pressure reactor, using HFPO dimer peroxide initiator in a similar manner to potassium persulfate initiator. A 0.018 mole solution (0.05 ml) of HFPO dimer peroxide in 1,1,2-trichlorotri-... 

This section reviews three groups of processes each with two representatives. The first group contains the Perox and Takahax processes, which utilize the liquid redox potential of... 

A simplified process flow diagram is given in Figure 9-11 (Krupp Wilputte, 1988). The crude gas, which contains hydrogen sulfide, hydrogen cyanide, and ammonia, is first passed through a cooler (not shown) in which the temperature and ammonia content are adjusted by direct contact with water. Prom there the gas flows to the contactor in which it is washed countercurrently with the Perox solution and practically all of the H2S and HCN are absorbed and converted to (NH4)2S and NH4CN. 

Krupp Wilputte, 1988, H2S Perox Scrubbing Process, Technical Bulletin, KWC 6.641e. 

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