Shell patents

Ethylene oxide (qv) was once produced by the chlorohydrin process, but this process was slowly abandoned starting in 1937 when Union Carbide Corp. developed and commercialized the silver-catalyzed air oxidation of ethylene process patented in 1931 (67). Union Carbide Corp. is stiU. the world s largest ethylene oxide producer, but most other manufacturers Hcense either the Shell or Scientific Design process. Shell has the dominant patent position in ethylene oxide catalysts, which is the result of the development of highly effective methods of silver deposition on alumina (29), and the discovery of the importance of estabUshing precise parts per million levels of the higher alkaU metal elements on the catalyst surface (68). The most recent patents describe the addition of trace amounts of rhenium and various Group (VI) elements (69). 

Ghlorohydrination with er -All l Hypohalites. Olefins react with ethyl hypochlorite [624-85-1] to form the corresponding chlorohydrin (49). In 1938 both Shell Development Co. (50) and Arthur D. Litde, Inc. (51) patented the preparation of chlorohydrins by the reactions of olefins with tertiary alkyl hypochlorites. Examples with ethylene and propylene in the Shell patent reported chlorohydrin yields of greater than 95% with tert-huty hypochlorite [507-40-4]. 

For commercial appHcation, catalyst activity is only one of the factors to be considered. Equally important is catalyst life, but Htde has been pubHshed on this aspect. Partly because of entrainment losses and partly through loss of acid as volatile triethyl phosphate, the catalyst loses activity unless compensating steps are taken. This decline in activity can be counteracted by the periodic or continuous addition of phosphoric acid to the catalyst during use, a fact that seems to have been disclosed as early as 1940 (94). A catalyst subjected periodically to acid addition could remain in service indefinitely, according to a report by Shell (91). A later Shell patent (85) states that complete reimpregnation with acid is required every 200 mn-days. 

Figure 3 shows a simple schematic diagram of an oxygen-based process. Ethylene, oxygen, and the recycle gas stream are combined before entering the tubular reactors. The basic equipment for the reaction system is identical to that described for the air-based process, with one exception the purge reactor system is absent and a carbon dioxide removal unit is incorporated. The CO2 removal scheme illustrated is based on a patent by Shell Oil Co. (127), and minimises the loss of valuable ethylene in the process. 

Yates, J. and Haddock, E. British Patent 1,019,120 February 2,1966 assigned to Shell International Research Maatschappij N.V. (Netheriands)... 

Biphasic catalysis is not a new concept for oligomerization chemistry. On the contrary, the oligomerization of ethylene was the first commercialized example of a biphasic, catalytic reaction. The process is known under the name Shell Higher Olefins Process (SHOP) , and the first patents originate from as early as the late 1%0 s. 

Cashewnut Shell Liquid Patents U.S. Vol. 1 and UK, Indian and Japan, Vol. 2, Cashew Export, June, Cashew Export Promotion Vcouncil, Ernakulam (1964). 

Cashewnut Shell Liquid-Extraction and Uses—A Survey of World Patents upto 1976, Cashew Export Promotion Council, Ernakulam (1978). 

Figure 10-22C. Longitudinal shell-pass baffle. (Used by permission Henry Vogt Machine Co., Patent No. 2,482,335.)...

Nitromatweed (Matweed Nitrate, Nitrosparte in Fr). Prepd by nitration of dried matweed with mixed nitric-sulfuric acids in a manner similar to the prepn of NC. Trench, Faure and MacKie (Ref 2), in 1876, patented expls containing as a base nitrosparte (or other nitrated cellulosic material such as cotton, hay, agave, hemp, flax, straw, aloe, yucca, etc) together with resin, ozokerite, collodion, glycerin, charcoal and soot. Hengst (Ref 3), in 1898, patented a smokeless powd containing nitrosparte prepd by nitration of fibers covering the coconut shell Refs 1) Merriam Webster s Diet, 2nd Ed (1963), ... 

Parkes Absorbent for Nitroglycerin. Materials patented in 1898 by Parkes, manufd by Chem-ische Fabrik at Winkel-on-Rhine, Ger, for use in Dynamites as absorbents for NG in lieu of the previously used kieselguhr. The absorbents were rubber-llke materials, prepd by the action of sulfur chloride, S2C12, on vegetable oils. It was claimed at the time that Dynamites prepd with Parkes absorbent were so insensitive, they could be used for loading shells... 

TABLE 3 Patent Literature from Shell (I/D Part)... 

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