Herbert J Bieser

40061973, Feb 1, 1977

Nov 19, 1975

5/633183

Herbert J. Bieser - Des Plaines IL

UOP Inc. - Des Plaines IL

C10G 2504
C07C 713

260676MS

An improved process for separating normal paraffins from a feed stream containing a mixture of normal paraffins and isoparaffins. The general process comprises the steps of contacting the feed stream with an adsorbent comprising a crystalline aluminosilicate thereby adsorbing normal paraffins and subsequently contacting the adsorbent with a desorbent material to remove the adsorbed normal paraffins. The improvement resides in a method of fractionating and recycling a desorbent material for re-use in the process in a manner that reduces total fractionation energy requirements. The method is particularly suitable when two desorbent materials are used in the process.

40214990, May 3, 1977

Nov 5, 1975

5/628866

Herbert J. Bieser - Des Plaines IL

UOP Inc. - Des Plaines IL

C07C 700

260674SA

An improved process for separating ethylbenzene at high purity and at high recovery from a feed stream comprising ethylbenzene and paraxylene which process employs an adsorbent comprising type X or type Y zeolite containing calcium at the exchangeable cationic sites. The process in one embodiment employs a countercurrent-flow fixed-bed flow system and includes the steps of maintaining at least three serially connected zones, an adsorption zone, a purification zone and a desorption zone, in a column of the adsorbent; contacting the feed stream with adsorbent in the adsorption zone to effect the adsorption of para-xylene; withdrawing from the adsorption zone a raffinate stream comprising ethylbenzene; contacting the adsorbent in the desorption zone with a desorbent material comprising toluene to effect the displacement of para-xylene from the adsorbent; withdrawing an extract stream comprising para-xylene from the desorption zone; and passing at least a portion of the raffinate stream to a separation means and therein separating desorbent material from ethylbenzene to produce an ethylbenzene product. The improvement resides in passing a portion of the ethylbenzene product into the adsorption zone to effect the displacement of desorbent material adsorbed by the adsorbent during a previous contacting of adsorbent with desorbent material in the desorption zone.