Butane isomerization Standard process

Fig. 17. Liquid-phase butane isomerization. Standard (Indiana)-Texas process.

The other vapor-phase butane isomerization process, developed cooperatively by the Anglo-Iranian Oil Co. and the Standard Oil Development Co., is somewhat similar to the Isocel process. In the AIOC-Jersey process (18), the reactor is initially filled with bauxite, and aluminum chloride is sublimed into the vaporized feed as necessary to maintain the desired catalyst activity. Upflow of vapor through the reactor is the customary arrangement. Since carry-over of aluminum chloride is not excessive at the usual rates of catalyst addition, about half of the commercial plants employing this process were not equipped with guard chambers. 

Pentane Isomerization. Pentane isomerization, although carried out on a much smaller scale, increased the critical supply of aviation gasolines toward the end of the war. Two pentane processes—one developed by Shell and one by Standard (Indiana) —were commercialized before the end of the war. The principal differences between the butane and pentane processes are the use in pentane isomerization of somewhat milder conditions and the use of an inhibitor to suppress side reactions, principally disproportionation. In general, the problems of the butane processes are inherent also in pentane isomerization, but the quality of the feed stocks is less important. Catalyst life is much... 

The other vapor-phase butane-isomerization process was developed cooperatively by the Anglo-Iranian Oil Company and the Standard Oil Development Company. It is similar to the Isocel process, but it turns the volatility of aluminum chloride from a liability into an asset. The first plant was put into operation in October, 1942. This process is described (18) by the simplified flow diagram shown in Figure 15. 

The other commercialized pentane isomerization process is that of the Standard Oil Co. (Indiana) (20). This process differs from the Indiana-Texas butane process in that the aluminum chloride is introduced as a slurry directly to the reactor and that about 0.5% by volume of benzene is added continuously in the feed to suppress side reactions. Temperature, catalyst composition, space velocity, and hydrogen chloride concentration are generally similar to those in the corresponding butane process, but the reactor pressure is about 100 pounds lower. The Pan American Refining Co. operated the Indiana pentane isomerization process commercially during the last nine months of the war and produced about 400 barrels of isopentane per calendar day. 

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