Reverse acid and hydrocarbon cascading in alkylation

Patent metadata

Field	Value
Publication number	US-11286215-B2
Application number	US-202017097176-A
Country	US
Kind code	B2
Filing date	Nov 13, 2020
Priority date	May 4, 2018
Publication date	Mar 29, 2022
Grant date	Mar 29, 2022

Abstract

A cascade reactor scheme with acid and hydrocarbon flowing in reverse directions. The systems and processes for alkylation of olefins herein may include providing a first olefin to a first alkylation zone, and a second olefin to a second alkylation zone. Isoparaffin may be provided to the first alkylation zone. The isoparaffin and first olefin may be contacted with a partially spent sulfuric acid in the first alkylation zone to form a spent acid phase and a first hydrocarbon phase including alkylate and unreacted isoparaffin. The first hydrocarbon phase and second olefin may be contacted with a sulfuric acid feed in the second alkylation zone to form a second hydrocarbon phase, also including alkylate and unreacted isoparaffin, and the partially spent sulfuric acid that is fed to the first alkylation zone. Further, the second hydrocarbon phase may be separated, recovering an isoparaffin fraction and an alkylate product fraction.

First claim

What is claimed:

1. A system for the alkylation of olefins, the system comprising:
a first flow line for providing a first olefin to a first alkylation zone;
a second flow line for providing a second olefin to a second alkylation zone, wherein the second olefin may be the same or different than the first olefin;
a third flow line for providing an isoparaffin to the first alkylation zone;
the first alkylation zone comprising a reaction section and a separation section, the reaction section configured for receiving a partially spent sulfuric acid and for contacting the isoparaffin and the first olefin with the partially spent sulfuric acid under alkylation conditions, the separation section configured to separate an effluent from the reaction section to form a spent acid phase and a first hydrocarbon phase comprising alkylate and unreacted isoparaffin;
the second alkylation zone, comprising a reaction section and a separation section, the reaction section of the second alkylation zone configured for receiving a fresh sulfuric acid feed and for contacting the first hydrocarbon phase and the second olefin with the fresh sulfuric acid feed under alkylation conditions, and the separation section of the second alkylation zone configured to separate an effluent from the reaction section of the second alkylation zone to form a second hydrocarbon phase, comprising alkylate and unreacted isoparaffin, and the partially spent sulfuric acid fed to the first alkylation zone; and
a separator for separating the second hydrocarbon phase to recover an isoparaffin fraction and an alkylate product fraction.

2. The system of claim 1 , wherein the system is configured to maintain an isoparaffin to olefin mole ratio in a total feed to the first reaction zone greater than an isoparaffin to olefin mole ratio in a total feed to the second reaction zone.

3. The system of claim 1 , wherein the system is configured to maintain an isoparaffin to olefin mole ratio in a total feed to the first reaction zone at least 1.5 times an isoparaffin to olefin mole ratio in a total feed to the second reaction zone.

4. The system of claim 1 , wherein the system is configured to maintain an isoparaffin to olefin mole ratio in a total feed to the first reaction zone at least 1.75 times an isoparaffin to olefin mole ratio in a total feed to the second reaction zone.

5. The system of claim 1 , wherein the system is configured to maintain an isoparaffin to olefin mole ratio in a total feed to the first reaction zone at least 2 times an isoparaffin to olefin mole ratio in a total feed to the second reaction zone.

6. The system of claim 1 , wherein the system is configured to maintain the alkylation conditions in the first and second alkylation zones at a reaction temperature of the first alkylation zone that is less than a reaction temperature of the second alkylation zone.

7. The system of claim 1 , further comprising a flow line for feeding isoparaffin to the second alkylation zone.

8. The system of claim 1 , further comprising a flow line for feeding sulfuric acid to the first alkylation zone directly.

9. A system for the alkylation of olefins, the system comprising:
a first alkylation zone comprising a reaction section and a separation section, the reaction section configured for receiving a second partially spent sulfuric acid and for contacting an isoparaffin feed and a C5 olefin-containing feed with the second partially spent sulfuric acid under alkylation conditions, the separation section configured to separate an effluent from the reaction section to form a spent acid phase and a first hydrocarbon phase comprising alkylate and unreacted isoparaffin;
a second alkylation zone comprising a reaction section and a separation section, the reaction section configured for receiving a first partially spent sulfuric acid and for contacting the first hydrocarbon phase and a C4 olefin with the first partially spent sulfuric acid under alkylation conditions, and the separation configured to separate an effluent from the reaction zone to form a second hydrocarbon phase, comprising alkylate and unreacted isoparaffin, and the second partially spent sulfuric acid fed to the first alkylation zone;
a third alkylation zone comprising a reaction section and a separation section, the reaction section configured for receiving a fresh sulfuric acid feed and for contacting the second hydrocarbon phase and the C3 olefin with the fresh sulfuric acid feed under alkylation conditions, and the separation section configured to separate an effluent from the reaction section to form a third hydrocarbon phase, comprising alkylate and unreacted isoparaffin, and the first partially spent sulfuric acid fed to the second alkylation zone; and
a separator for separating the third hydrocarbon phase to recover an isoparaffin fraction and an alkylate product fraction.

10. The system of claim 9 , wherein the system is configured to maintain an isoparaffin to olefin mole ratio in a total feed to the first reaction zone greater than an isoparaffin to olefin mole ratio in a total feed to the second reaction zone, and to maintain an isoparaffin to olefin mole ratio in a total feed to the second reaction zone greater than an isoparaffin to olefin mole ratio in a total feed to the third reaction zone (I R1 :O R1 >I R2 :O R2 >I R3 :O R3 ).

11. The system of claim 9 , wherein the system is configured to maintain the alkylation conditions in the first and second alkylation zones at a reaction temperature of the first alkylation zone that is less than a reaction temperature of the second alkylation zone, and to maintain the alkylation conditions in the second and third alkylation zones at a reaction temperature of the second alkylation zone that is less than a reaction temperature of the third alkylation zone (T R1 >T R2 >T R3 ).

12. The system of claim 9 , further comprising a flow line for feeding isoparaffin to the second alkylation zone and the third alkylation zone.

13. The system of claim 9 , further comprising a flow line for feeding sulfuric acid to the first alkylation zone and/or the second alkylation zone directly.

14. The system of claim 9 , wherein the system is configured to maintain an acid strength for a total acid feed to the first alkylation zone less than an acid strength for a total acid feed to the third alkylation zone.

15. A system for the alkylation of olefins, the system comprising:
a flow line for providing a C5 olefin-containing feed to a first alkylation zone;
a flow line for providing a C4 olefin-containing feed to a second alkylation zone;
a flow line for providing a C3 olefin-containing feed to a third alkylation zone;
a first alkylation zone comprising a reaction section and a separation section, the reaction section configured for receiving a first partially spent sulfuric acid and for contacting an isoparaffin and the C5 olefin with the first partially spent sulfuric acid under alkylation conditions, the separation section configured to separate an effluent from the reaction section to form a second partially spent acid phase and a first hydrocarbon phase comprising alkylate and unreacted isoparaffin;
a second alkylation zone comprising a reaction section and a separation section, the reaction section configured for receiving the second partially spent sulfuric acid and for contacting the first hydrocarbon phase and the C4 olefin with the second partially spent sulfuric acid under alkylation conditions, the separation section configured to separate an effluent from the reaction section to form a second hydrocarbon phase, comprising alkylate and unreacted isoparaffin, and a spe

Assignees

• Lummus Technology Inc

Inventors

• Liu Zan
• Loezos Peter
• Medina Jackeline
• Lemoine Romain

Classifications

• B01J19/002

  Avoiding undesirable reactions or side-effects, e.g. avoiding explosions, or improving the yield by suppressing side-reactions · CPC title

• C10G2300/1092

  C2-C4 olefins · CPC title

• B01J2219/00164

  controlling the flow · CPC title

• C10G2300/1088

  Olefins · CPC title

• B01J2219/00452

  Means for the recovery of reactants or products · CPC title