Process for preparing an epoxide from an oxygenate

A process for preparing an epoxide from an oxygenate, the process comprising the following steps:

• a) contacting the oxygenate with a molecular sieve-comprising catalyst, at a temperature in the range of from 350 to 1000° C. to obtain an olefinic product stream comprising ethylene, propylene and C4 hydrocarbons;
• b) separating ethylene and/or propylene and a fraction comprising C4 hydrocarbons including normal butane, isobutane, normal butene and isobutene, from the olefinic product stream;
• c) hydrogenating at least part of the fraction comprising C4 hydrocarbons in a hydrogenation unit to obtain a saturated C4 hydrocarbon stream;
• d) separating the saturated C4 hydrocarbon stream into a stream enriched in normal butane and a stream enriched in isobutane;
• e) oxidizing the isobutane in the stream enriched in isobutane into tertiary butyl hydroperoxide;
• and
• f) reacting tertiary butyl hydroperoxide obtained in step d) with ethylene and/or propylene separated from the olefinic product stream obtained in step a) to obtain the epoxide and tertiary butanol.