US 11,053,178 B2
Parallel reactor system for ethylbenzene dehydrogenation
Joseph E Pelati, Houston, TX (US); and Jason Clark, Houston, TX (US)
Assigned to FINA TECHNOLOGY, INC., Houston, TX (US)
Filed by FINA TECHNOLOGY, INC., Houston, TX (US)
Filed on Dec. 12, 2017, as Appl. No. 15/838,569.
Claims priority of provisional application 62/436,653, filed on Dec. 20, 2016.
Prior Publication US 2018/0170836 A1, Jun. 21, 2018
Int. Cl. C07C 5/333 (2006.01); C07C 15/46 (2006.01); B01J 8/04 (2006.01)
CPC C07C 5/333 (2013.01) [B01J 8/0496 (2013.01); C07C 5/3332 (2013.01); C07C 15/46 (2013.01); B01J 8/0492 (2013.01); B01J 2208/00061 (2013.01); B01J 2208/00168 (2013.01); B01J 2208/00539 (2013.01); B01J 2208/00893 (2013.01); B01J 2219/0004 (2013.01); B01J 2219/00038 (2013.01); C07C 2523/04 (2013.01); C07C 2523/745 (2013.01); C07C 2523/78 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A multi-stage dehydrogenation process comprising:
contacting, in a first stage consisting of a first reactor and a second reactor arranged in parallel, a feed stream comprising a hydrocarbon and steam with a dehydrogenation catalyst under dehydrogenation conditions to yield a first stage effluent, wherein the contacting comprises splitting the feed stream into a first portion and a second portion, feeding the first portion of the feed stream to the first reactor and feeding the second portion to the second reactor, and wherein the first reactor and the second reactor are separate vessels and do not share a common housing;
combining a first reactor effluent from the first reactor with a second reactor effluent from the second reactor in a mixer disposed between the first stage and the second stage, to form a first stage effluent, wherein the mixer does not share a common housing with the first reactor or the second reactor;
heating the first stage effluent to form a heated first stage effluent;
contacting in a second stage comprising a third reactor connected in series with the reactors in the first stage, the heated first stage effluent with a dehydrogenation catalyst under dehydrogenation conditions to yield a second stage effluent comprising a dehydrogenation product,
wherein an overall selectivity of the multi-stage dehydrogenation process is increased relative to an overall selectivity of an otherwise similar process in which the first reactor, the second reactor, and the third reactor are connected in series, wherein the overall selectivity is defined as: [moles of dehydrogenation product produced in the first reactor, the second reactor, and the third reactor]/[total moles of hydrocarbon converted in the first reactor, the second reactor, and the third reactor];
heat exchanging the feed stream with the second stage effluent, thereby condensing a portion of the second stage effluent;
compressing the second stage effluent after the step of heat exchanging; and
separating the dehydrogenation product from the second stage effluent.