Process and system for making cyclopentadiene and/or dicyclopentadiene

Patent metadata

Field	Value
Publication number	US-9988324-B2
Application number	US-201615288343-A
Country	US
Kind code	B2
Filing date	Oct 7, 2016
Priority date	Nov 4, 2015
Publication date	Jun 5, 2018
Grant date	Jun 5, 2018

Abstract

Processes and systems for making cyclopentadiene and/or dicyclopentadiene include converting acyclic C5 hydrocarbon(s) into CPD in a first reactor to obtain a product mixture, separating the product mixture in a separation sub-system such as compression train to obtain a C5-rich fraction comprising CPD and essentially depleted of hydrogen and C1-C4 hydrocarbons, dimerizing the C5-rich fraction in a dimerization reactor to obtain a product effluent comprising DCPD, followed by separating the product effluent to obtain a DCPD-rich fraction. Multiple-stage of dimerization and separation steps can be optionally used to obtain multiple DCPD-rich fractions of various degrees of purity and quantity. C5-rich fractions from various stages of the process may be recycled to the first reactor, or converted into mogas components after selective hydrogenation. C5-rich fractions and mogas components may be optionally separated to produce value-adding chemicals.

First claim

What is claimed is:

1. A process for making cyclopentadiene (CPD) and/or dicyclopentadiene (DCPD), the process comprising:
(I) feeding a C5 feedstock comprising at least one acyclic C5 hydrocarbon into a first reactor;
(II) contacting the at least one acyclic C5 hydrocarbon with a catalyst under conversion conditions to obtain a first reactor hydrocarbon effluent comprising: C5 components including CPD and acyclic diolefins; light components including hydrogen and C1-C4 hydrocarbons; one-ring aromatics; and multiple-ring aromatics; wherein the catalyst comprises at least one Group 10 metal supported on a microporous metallosilicate or a silicate modified silica wherein the catalyst optionally comprises one or more of Group 1 alkali metals, Group 2 alkaline earth metals and/or Group 11 metals;
(III) separating the first rector hydrocarbon effluent to produce (i) a light components-rich fraction and (ii) a first C5-rich fraction comprising CPD;
(IV) supplying at least a portion of the first C5-rich fraction into a second reactor operating under a first set of dimerization conditions;
(V) obtaining a second reactor effluent from in the second reactor comprising CPD and DCPD; and
(VI) separating at least a portion of the second reactor effluent to obtain a first DCPD-rich fraction comprising dicyclopentadiene (DCPD).

2. The process of claim 1 , wherein the first reactor hydrocarbon effluent comprises CPD at a concentration of C(CPD)1 wt % and acyclic diolefins at a total concentration of C(ADO)1 wt %, both based on the total weight of C5 components in the first reactor hydrocarbon effluent; and
C(CPD)1/C(ADO)1≥1.5.

3. The process of claim 1 , wherein the C5 feedstock comprises at least 50 wt % of n-pentane.

4. The process of claim 1 , wherein the conversion conditions include a temperature in the range of from 400 to 800° C., a pressure in the range of from 10 to 1,000 kilopascal absolute, and a WHSV in the range of 1 to 100 hr −1 .

5. The process of claim 1 , wherein the first reactor hydrocarbon effluent comprises CPD at a concentration in the range from 15 wt % to 80 wt %, based on the total weight of the C5 components in the first reactor hydrocarbon effluent.

6. The process of claim 1 , wherein a hydrogen co-feedstock is fed into the first reactor at a molar ratio of the hydrogen co-feedstock to the C5 feedstock in a range from 0.1 to 3.0.

7. The process of claim 6 , wherein at least a portion of the hydrogen co-feedstock is admixed with the C5 feedstock before the C5 feedstock is being fed into the first reactor.

8. The process of claim 1 , wherein step (III) comprises at least one of the following:
(IIIa) cooling the first reactor hydrocarbon effluent;
(IIIb) increasing the total pressure of the first reaction effluent;
(IIIc) washing at least a portion of the first reactor hydrocarbon effluent with a wash oil;
(IIId) removing light components from the first reactor hydrocarbon effluent; and
(IIIe) removing C8+ components from the first reactor hydrocarbon effluent.

9. The process of claim 1 , wherein step (III) comprises washing the first reactor hydrocarbon effluent with a wash oil comprising at least one: cyclohexane; monoalkyl, dialkyl, and trialkyl cyclohexanes; benzene; monoalkyl, dialkyl, and trialkyl benzenes; monoalkyl, dialkyl, trialkyl, and tetraalkyl naphthalenes; other alkylated multiple-ring aromatics, and mixtures and combinations thereof.

10. The process of claim 9 , wherein the wash oil comprises at least 50 wt % of toluene, based on the total weight of the wash oil used in step (III).

11. The process of claim 9 , wherein the wash oil comprises at least 50 wt % of alkylated naphthalene(s), based on the total weight of the wash oil used in step (III).

12. The process of claim 1 , wherein step (III) comprises removing C4 and lighter components from the first reactor hydrocarbon effluent using a compression train with inter-stage cooling and vapor/liquid separation.

13. The process of claim 1 , wherein the first DCPD-rich fraction comprises DCPD at a concentration of at least 80 wt % based on the total weight of the first DCPD-rich fraction.

14. The process of claim 1 , wherein in step (VI), a second C5-rich fraction comprising CPD is obtained, and the process further comprises:
(VII) feeding at least a portion of the second C5-rich fraction into a third reactor operating under a second set of dimerization conditions;
(VIII) obtaining a third reactor effluent from the third reactor comprising CPD and DCPD; and
(IX) separating at least a portion of the third reactor effluent to obtain a second DCPD-rich fraction.

15. The process of claim 14 , wherein the second DCPD-rich fraction comprises DCPD at a concentration of at least 60 wt % based on the total weight of second DCPD-rich fraction.

16. The process of claim 15 , wherein a third C5-rich fraction comprising CPD is obtained in step (IX), and the process further comprises:
(X) feeding at least a portion of the third C5-rich fraction into a fourth reactor operating under a third set of dimerization conditions;
(XI) obtaining a fourth reactor effluent comprising CPD and DCPD; and
(XII) separating at least a portion of the fourth reactor effluent to obtain a third DCPD-rich fraction and a fourth C5-rich fraction.

17. The process of claim 16 , wherein the third DCPD-rich fraction comprises DCPD at a concentration of at least 40 wt % based on the total weight of third DCPD-rich fraction.

18. The process of claim 16 , further comprising (XIII) recycling, directly or indirectly, at least a portion of at least one of the first C5-rich fraction, the second C5-rich fraction, the third C5-rich fraction, and the fourth C5-rich fraction to the first reactor.

19. The process of claim 18 , comprising:
(XVI) separating at least a portion of at least one of the first C5-rich fraction, the second C5-rich fraction, the third C5-rich fraction, and the fourth C5-rich fraction to obtain a C6-rich fraction and a C6-depleted fraction;
(XVII) recycling at least a portion of the C6-depleted fraction to the first reactor; and
(XVIII) optionally selectively hydrogenating at least a portion of the C6-rich fraction to obtain a mogas component feed.

20. The process of claim 16 , comprising (XIX) obtaining at least one of: (i) a cyclopentane-rich fraction; (ii) a cyclopentene-rich fraction; (iii) a 1,3-pentadiene-rich fraction; and (iv) a 2-methyl-1,3-butadiene fraction, from at least one of the first C5-rich fraction, the second C5-rich fraction, the third C5-rich fraction, and the fourth C5-rich fraction.

21. The process of claim 1 , further comprising:
(XIV) selectively hydrogenating at least a portion of at least one of the first C5-rich fraction, the second C5-rich fraction, the third C5-rich fraction, and the fourth C5-rich fraction, if produced, to obtain a mogas component feed; and
(XV) forming a motor gas blend from the mogas component feed.

22. The process of claim 21 , wherein the mogas component feedstock is essentially free of dienes.

23. A process for making cyclopentadiene (CPD) and/or dicyclopentadiene (DCPD), the process comprising:
(I) feeding a C5 feedstock comprising at least one acyclic C5 hydrocarbon into a first reactor;
(II) contacting the at least one acyclic C5 hydrocarbon with a catalyst under conversion conditions to obtain a first reactor hydrocarbon effluent comprising: C5 components including CPD and acyclic diolefins; light components including hydrogen and C1-

Assignees

• Exxonmobil Chemical Patents Inc

Inventors

• Iaccino Larry L
• Leung Kevin C P

Classifications

• Y02P20/582

  Recycling of unreacted starting or intermediate materials · CPC title

• C01B2203/1058

  Nickel catalysts · CPC title

• C07C2/403

  Catalytic processes · CPC title

• C01B2203/043

  Regenerative adsorption process in two or more beds, one for adsorption, the other for regeneration · CPC title

• C01B2203/046

  Purification by cryogenic separation · CPC title