US 12,448,341 B2
Process to prepare propylene
Elbert Arjan De Graaf, Pooler, GA (US); and Raymond Paul Fletcher, Amsterdam (NL)
Assigned to GASOLFIN B.V., Amsterdam (NL)
Appl. No. 17/917,043
Filed by GASOLFIN B.V., Amsterdam (NL)
PCT Filed Apr. 10, 2020, PCT No. PCT/US2020/027651
§ 371(c)(1), (2) Date Oct. 5, 2022,
PCT Pub. No. WO2021/206730, PCT Pub. Date Oct. 14, 2021.
Prior Publication US 2023/0146172 A1, May 11, 2023
Int. Cl. C07C 4/06 (2006.01); B01J 29/40 (2006.01); C07C 7/04 (2006.01)
CPC C07C 4/06 (2013.01) [B01J 29/405 (2013.01); C07C 7/04 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A process to prepare propylene from a mixture of hydrocarbons having an olefin content of between 5 and 50 wt. % and boiling for more than 90 vol. % between 35 and 280° C. or from a hydrocarbon feed comprising paraffins, naphthenics, and/or aromatics, wherein the process comprises the following steps:
(a) feeding the mixture of hydrocarbons, having a temperature between 450 and 750° C., to a reactor where the feed is contacted with a first cracking catalyst at a hydrocarbon partial pressure of below 3 bar and at a weight hourly space velocity of between 0.5 and 100 h−1;
(b) isolating propylene from the effluent of step (a) wherein a first high boiling fraction remains;
(c) feeding all or part of the first high boiling fraction, having a temperature between 400 and 750° C., to a reactor where the first high boiling fraction is contacted with a second cracking catalyst at a hydrocarbon partial pressure of below 3 bar and at a weight hourly space velocity of between 0.5 and 100 h−1 and wherein the temperature of the mixture of hydrocarbons as fed to the reactor in step (a) is lower than the temperature of the first high boiling fraction as fed to the reactor in step (c), wherein the second cracking catalyst has a higher acidic density than the first cracking catalyst;
(d) isolating propylene from the effluent of step (c) wherein a second high boiling fractions remains;
(e) recycling all or part of the second high boiling fraction to step (a) and/or to step (c); and
(f) contacting part of the first high boiling fraction and/or all or part of the second high boiling fraction with hydrogen in the presence of an aromatic conversion catalyst as present in a reactor to obtain a fraction rich in aromatics, wherein all or part of the fraction rich in aromatics is recycled to step (c) and/or to step (f), and wherein the aromatic conversion catalyst is a heterogenous catalyst comprising ZnO, a medium pore zeolite, and a binder.