Process for separating propylene mixed with propane by adsorption in a simulated moving bed
AssigneeIfp
InventorsPhilibert LEFLAIVE, Luc WOLFF, Damien LEINEKUGEL LE COCQ, Nabil LAMIA, Alirio RODRIGUES, Carlos GRANDE
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Abstract
A process for separating propylene mixed with propane by adsorption in a simulated moving bed is described. The process operates in the gaseous phase or in the liquid phase, and it uses a 13X faujasite-type zeolite as adsorbent solid and butene-1 or isobutane or any mixture of these 2 components as desorbent.
Claims10
1-8. (canceled)
A process for separating propylene by adsorption from a hydrocarbon mixture that contains at least 90% by weight of propylene and propane, and which hydrocarbon mixture can additionally contain other hydrocarbons, which process is implemented in a simulated moving bed in the gaseous phase or the liquid phase and implements a 13X faujasite-type zeolite as an adsorbent solid and implements butene-1 or isobutene or a mixture of butene-1 or isobutene as desorbent, which process comprises the following stages:
- a) a stage wherein the hydrocarbon mixture is brought into contact with an adsorbent bed that contains 13X zeolite to adsorb the propylene;
- b) a stage wherein the adsorbent bed is brought into contact with the desorbent,
- c) a stage wherein a flow that contains desorbent and the least selectively adsorbed products of the hydrocarbon mixture are drawn off from the adsorbent bed,
- d) a stage wherein a flow that contains desorbent and propylene are drawn off from the adsorbent bed,
- e) a stage wherein the flow from stage c) is separated into a first flow that contains the desorbent and a second flow that contains the least selectively adsorbed feedstock products, wherein the desorbent is recycled at the inlet of the simulated moving bed unit, and
- f) a stage wherein the flow from stage d) is separated into a first flow that contains the desorbent and a second flow that contains high-purity propylene, wherein the desorbent is recycled at the inlet of the simulated moving bed unit.
A process for separating propylene according to claim 1, in which the desorbent is isobutane.
A process for separating propylene according to claim 1, which operates in the gaseous phase, wherein the temperature is between 20° C. and 150° C., and the pressure is between 0.1 and 1 MPa.
A process for separating propylene according to claim 1, which operates in the liquid phase, wherein the temperature is between 0° C. and 60° C., and the pressure is between 0.8 and 2 MPa.
A process for separating propylene according to claim 3, in which the adsorbent solid is in the form of extrudates with a diameter of between 1.0 and 2.0 mm, and with a length of between 2.0 and 16.0 mm.
A process for separating propylene according to claim 4, in which the adsorbent solid is shaped like balls with a diameter of between 0.6 and 2.0 mm.
A process for separating propylene according to claim 1, wherein the hydrocarbon mixture consists essentially of propylene and propane.
The process of claim 1 wherein the bed is kept at about 458K and about 1.83 MPa.
A method for separating propylene by adsorption from a hydrocarbon mixture comprising:
- a) contacting a hydrocarbon mixture with an adsorbent bed kept at 458K and 1.83 MPa that contains 13X faujasite-type zeolite to adsorb a propylene wherein said hydrocarbon mixture contains at least 90% by weight of propylene and propane;
- b) contacting the adsorbent bed with a desorbent wherein said desorbent is butene-1 or isobutene or a mixture of butene-1 or isobutene,
- c) drawing off a flow that contains desorbent and the least selectively adsorbed products of the hydrocarbon mixture from the adsorbent bed,
- d) drawing off a flow that contains desorbent and propylene from the adsorbent bed,
- e) separating the flow that contains desorbent and the least selectively adsorbed products of the hydrocarbon mixture into a first flow that contains the desorbent and a second flow that contains the least selectively adsorbed feedstock products, wherein the desorbent is recycled at the inlet of the simulated moving bed unit, and
- f) separating the flow that contains desorbent and propylene into a first flow that contains the desorbent and a second flow that contains high-purity propylene, wherein the desorbent is recycled at the inlet of the simulated moving bed unit.
Dependencies are inferred from the claim text.