Process for preparing alkylene oxide

#The present invention relates to a process for the preparation of alkylene oxide.

#The epoxidation of alkene into alkylene oxide by reacting the alkene with an organic hydroperoxide is known in the art.

#For instance, in the commonly known method for co-producing propylene oxide and styrene starting from ethylbenzene, the aforementioned epoxidation reaction is applied. In general this co-production process involves the steps of (i) reacting ethylbenzene with oxygen or air to form ethylbenzene hydroperoxide, (ii) reacting the ethylbenzene hydroperoxide thus obtained with propene in the presence of an epoxidation catalyst to yield propylene oxide and 1-phenyl-ethanol, and (iii) converting the 1-phenyl-ethanol into styrene by dehydration using a suitable dehydration catalyst.

#The epoxidation catalyst was a catalyst containing titanium on silica which was prepared as described in the Example according to the teaching of EP-A-345856.

#The organic hydroperoxide used contained between 30 and 40% wt of ethylbenzene hydroperoxide in ethylbenzene.

#The feed was first treated with the help of a series of 4 reactors which was operated cyclically as described in patent application WO 01/12617. The reactor containing fresh catalyst is taken into operation as the last reactor of the series, and is moved upstream each time another reactor containing fresh catalyst is taken into operation. Subsequently, the feed was sent to a bank of serially connected reactors which were operated in a fixed order.