Asahi Kasei Kogyo Kabushiki Kaisha

Keizo Hirakawa

Makoto Honda

Kenji Takasa

Hiroji Nishimaru

A process for separating indole from a mixture of indole with at least one hydrocarbon or its derivative which comprises the steps of contacting the mixture with a faujasite structured zeolite to selectively adsorb indole on the zeolite and contacting a desorbent A selected from the group consisting of C.sub.2-10 aliphatic or C.sub.7-10 aromatic ether compounds, C.sub.2-10 aliphatic ester compounds and C.sub.3-10 aliphatic ketone compounds with the indole-adsorbed zeolite to separate indole and the process which comprises, in addition, the step of contacting at least one desorbent B of the formula, ##STR1## wherein R.sup.1 is a C.sub.1-3 alkyl group, and

Process for separation of indole using X and Y type zeolites

Octamethylcyclotetrasiloxane can be produced from dimethylsiloxane effectively by suppressing the by-production of undesirable other siloxanes by reacting dimethylsiloxane in the presence of an alkaline catalyst, an inert solvent and recycled by-produced cyclic dimethylsiloxanes containing at least hexamethylcyclotrisiloxane in a reactor, while distilling volatile cyclic dimethylsiloxanes produced, said recycled by-produced cyclic dimethylsiloxanes containing at least hexamethylcyclotrisiloxane having been separated from the volatile cyclic dimethylsiloxanes by recovering octamethylcyclotetrasiloxane and recycled to the reactor.

Growing community of inventors

Tokyo, Japan

Keizo Hirakawa