Process and system for making cyclopentadiene and/or dicyclopentadiene

Patent metadata

Field	Value
Publication number	US-9919988-B2
Application number	US-201615288396-A
Country	US
Kind code	B2
Filing date	Oct 7, 2016
Priority date	Nov 4, 2015
Publication date	Mar 20, 2018
Grant date	Mar 20, 2018

Abstract

Processes and systems for making cyclopentadiene and/or dicyclopentadiene include converting acyclic C5 hydrocarbon(s) into CPD in a first reactor in the presence of a C1-C4 co-feedstock 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 optionally dicyclopentadiene (DCPD), the process comprising:
(I) feeding a C5 feedstock comprising at least one acyclic C5 hydrocarbon and a light hydrocarbon co-feedstock comprising at least one C1-C4 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 from an outlet on the first reactor comprising: C5 components including CPD and acyclic diolefins; light components including hydrogen and C1-C4 hydrocarbons; one-ring aromatics; and multiple-ring aromatics;
wherein sufficient light hydrocarbon co-feedstock is provided in step (I) such that:
the total absolute pressure of the first reactor hydrocarbon effluent at the outlet is P(fre);
the total partial pressure of C5 hydrocarbons in the first reactor hydrocarbon effluent at the outlet is P(C5);
the partial pressure of hydrogen in the first reactor hydrocarbon effluent at the outlet is P(H2);
[ P ( C 5)+ P ( H 2)]÷ P ( fre )≦0.90; and

P(fre) is greater than 100 kilopascal absolute.

2. The process of claim 1 , wherein:
the sum total of P(C5) and P(H2) is not higher than 95 kilopascal absolute; and
P(fre) is at least 110 kilopascal absolute.

3. The process of claim 1 , wherein:
the sum total of P(C5) and P(H2) is not higher than 50 kilopascal absolute; and
P(fre) is at least 110 kilopascal absolute.

4. The process of claim 1 , wherein at least a portion of the light hydrocarbon co-feedstock is recovered directly or indirectly from the first reactor hydrocarbon effluent.

5. The process of claim 1 , wherein hydrogen is also supplied to the first reactor in step (I).

6. The process of claim 5 , wherein at least a portion of the hydrogen is recovered directly or indirectly from the first reactor hydrocarbon effluent.

7. The process of claim 4 , wherein at least a portion of the hydrogen and light hydrocarbon co-feedstock are recovered from the first reactor hydrocarbon effluent as a mixture thereof, and then recycled to the first reactor as a mixture thereof.

8. The process of claim 1 , further comprising:
(III) separating the first reactor hydrocarbon effluent to produce (i) a light components-rich fraction and (ii) a first C5-rich fraction comprising CPD.

9. The process of claim 8 , further comprising:
(IV) separating at least a portion of the light components-rich fraction to obtain a hydrogen-rich fraction and at least one C1-C4-rich fraction.

10. The process of claim 9 , wherein:
in step (IV), a hydrogen-rich fraction, a methane-rich fraction, and a C2-C4 rich fraction are obtained.

11. The process of claim 10 , wherein:
a first portion of the hydrogen-rich fraction is supplied to the first reactor;
a second portion of the hydrogen-rich fraction is delivered to a disposition differing from the first reactor;
a first portion of the methane-rich fraction is supplied to the first reactor;
a second portion of the methane-rich fraction is delivered to a disposition differing from the first reactor; and
a portion of the C2-C4-rich fraction is delivered to a disposition differing from the first reactor.

12. The process of claim 11 , wherein:
the total molar amount of methane in (i) the second portion of the hydrogen-rich fraction; (ii) the second portion of the methane-rich fraction; and (iii) the first portion of the C2-C4-rich fraction is about the equal to the molar amount of methane produced in step (II).

13. 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 hydrocarbons in the first reactor hydrocarbon effluent; and
C ( CPD )1/ C ( ADO )1≧1.5.

14. The process of claim 1 , wherein the light hydrocarbon co-feedstock comprises methane, ethane, ethylene, and mixtures thereof.

15. The process of claim 1 , wherein:
in step (I), hydrogen is fed into the first reactor, and the molar ratio of the hydrogen to the C5 feedstock fed into the first reactor is in a range from 0.1 to 3.0.

16. The process of claim 1 , wherein the C5 feedstock comprises at least 50 wt % of saturated acyclic C5 hydrocarbon(s), based on the total weight of the C5 feed.

17. The process of claim 9 , wherein:
step (IV) comprises separating the light components-rich fraction by using one or more of a pressure swing adsorption process, a rapid cycle pressure swing adsorption process, a cryogenic process, a thermal swing adsorption process, and a membrane separation process.

18. The process of claim 8 , further comprising:
(V) supplying at least a portion of the first C5-rich fraction into a second reactor operating under a first set of dimerization conditions;
(VI) obtaining a second reactor effluent from the second reactor comprising CPD and dicyclopentadiene (DCPD); and
(VII) separating at least a portion of the second reactor effluent to obtain a first DCPD-rich fraction comprising DCPD and a second C5-rich fraction comprising CPD.

19. The process of claim 8 , 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.

20. The process of claim 8 , wherein (III) comprises washing the first reactor hydrocarbon effluent with a wash oil comprising at least one of: 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.

21. The process of claim 8 , wherein step (III) comprises removing light components from the first reactor hydrocarbon effluent using a compression train with inter-stage cooling and vapor/liquid separation.

22. The process of claim 18 , further comprising:
(VIII) feeding at least a portion of the second C5-rich fraction into a third reactor operating under a second set of dimerization conditions;
(IX) obtaining a third reactor effluent from the third reactor comprising CPD and DCPD; and
(X) separating at least a portion of the third reactor effluent to obtain a second DCPD-rich fraction and a third C5-rich fraction comprising CPD.

23. The process of claim 22 , wherein the process further comprises:
(XI) feeding at least a portion of the third C5-rich fraction into a fourth reactor operating under a third set of dimerization conditions;
(XII) obtaining a fourth reactor effluent comprising CPD and DCPD; and
(XIII) separating at least a portion of the fourth reactor effluent to obtain a third DCPD-rich fraction and a fourth C5-rich fraction.

24. The process of claim 8 , further comprising:
(XIV) 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.

25. The process of claim 21 , comprising:
(XV) obtaining at least one of: (i) a cyclopentane-r

Assignees

• Exxonmobil Chemical Patents Inc

Inventors

• Iaccino Larry L
• Leung Kevin

Classifications

• C07C2/52

  Catalytic processes · CPC title

• C07C7/04

  by distillation · CPC title

• C07C5/03

  of non-aromatic carbon-to-carbon double bonds · CPC title

• C07C2529/44

  Noble metals · CPC title

• B01J8/0278

  Feeding reactive fluids (for solid material B01J8/0015) · CPC title