Alkene Oxides the Chlorohydrin Process

The chlorohydrin process uses slaked lime (or caustic soda) to saponify, or dehy-drochlorinate propylene and butene chlorohydrins to produce the corresponding oxides. The oxides may then be converted to the glycols by acidic hydrolysis [31.24]. 

2CH3-CHOH-CH2CI + Ca(OH)2 2CH3-CH-CH2 + CaCl2 -h 2H2O (31.26) 

Large tonnages of ethylene oxide and glycol were also produced by this route, for use in anti-freeze, until the direct oxidation of ethylene to ethylene oxide, using silver catalysts, was developed on a commercial basis. 

The process requires a high-calcium quicklime with low levels of MgO and Si02 [31.25]. The relative merits of lime and caustic soda for the dehydrochlorination stage are discussed in [31.25]. 

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