Process and system for making cyclopentadiene and/or dicyclopentadiene

Patent metadata

Field	Value
Publication number	US-9896395-B2
Application number	US-201615288331-A
Country	US
Kind code	B2
Filing date	Oct 7, 2016
Priority date	Nov 4, 2015
Publication date	Feb 20, 2018
Grant date	Feb 20, 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, washing the product mixture with a wash oil, separating the washed product mixture in a separation sub-system such as compression train to obtain a C5-rich fraction comprising CPD, dimerizing the C5-rich fraction in a dimerization reactor to obtain a product effluent, followed by separating the product effluent to obtain a DCPD-rich fraction. Wash oil can be recovered and recycled. Multiple-stage of dimerization and separation steps can be used to obtain multiple DCPD-rich fractions of various 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 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;
(III) contacting the first reactor hydrocarbon effluent with a wash oil in a washing vessel, thereby obtaining:
a heavy stream comprising at least a portion of the wash oil and at least a portion of the multiple-ring aromatics; and
a washed first reactor hydrocarbon effluent comprising at least a portion of the light components, at least a portion of the C5 components, and, optionally, a portion of the wash oil but depleted in multiple ring aromatics;
(IV) separating the washed first reactor effluent in a first separation sub-system to obtain:
a first C5-rich fraction comprising CPD and depleted of the light components;
a first light components-rich fraction comprising hydrogen and C1-C4 hydrocarbons; and
an optional first recovered wash oil stream;
(V) supplying the heavy stream and, optionally, at least a portion of the optional first recovered wash oil stream to a wash oil recovery sub-system;
(VI) obtaining, from the wash oil recovery sub-system:
a heavy oil fraction comprising the multiple-ring aromatics;
a second recovered wash oil stream; and
an optional recovered C5-rich stream comprising CPD; and
(VII) recycling at least a portion of the second recovered wash oil stream, and, optionally, at least a portion of the optional first recovered wash oil stream directly or indirectly to the washing vessel.

2. The process of claim 1 , wherein the wash oil recovery sub-system comprises at least one distillation column operated at least partly under wash oil recovery conditions such that DCPD, if present in the wash oil recovery sub-system, at least partly undergoes retro-Diels-Alder reaction to produce CPD.

3. The process of claim 1 , wherein:
the wash oil recovery sub-system comprises a first wash oil distillation column and a second wash oil distillation column;
in step (V), at least a portion of the heavy stream and the optional first recovered wash oil stream are supplied to the first wash oil distillation column;
and step (VI) comprises:
(VIa) obtaining from the first wash oil distillation column an upper stream comprising recovered C5 hydrocarbons as the recovered C5-rich stream, and a lower stream comprising the wash oil and the multiple-ring aromatics;
(VIb) supplying at least a portion of the lower stream into the second wash oil distillation column; and
(VIc) obtaining from the second wash oil distillation column:
the heavy oil fraction comprising at least a portion of the multiple-ring aromatics; and
the second recovered wash oil stream.

4. The process of claim 3 , wherein a flux oil is added to the first wash oil distillation column, the second wash oil distillation column, and/or the heavy oil fraction.

5. The process of claim 1 , wherein:
the wash oil recovery sub-system comprises a first wash oil divided-wall distillation column;
in step (V), at least a portion of the heavy stream and the optional first recovered wash oil stream are supplied to the first wash oil divided-wall distillation column;
and step (VI) comprises:
(VIa) obtaining from the first wash oil divided-wall distillation column:
an upper stream comprising recovered C5 hydrocarbons as the recovered C5-rich stream,
a middle stream comprising the recovered wash oil as the second recovered wash oil stream, and
a lower stream comprising the heavy oil fraction comprising at least a portion of the multiple-ring aromatics.

6. The process of claim 5 , wherein a flux oil is added the first wash oil divided-wall distillation column and/or the heavy oil fraction.

7. The process of claim 3 , wherein the wash oil recovery sub-system is operated at least partly under wash oil recovery conditions such that dicyclopentadiene (DCPD), if present in the wash oil recovery sub-system, at least partly undergoes retro-Diels-Alder reaction to produce CPD.

8. The process of claim 2 , wherein:
the heavy stream and/or the optional first recovered wash oil stream comprises DCPD;
the second recovered wash oil stream comprises CPD; and
the heavy oil fraction is essentially free of DCPD; such as less than 10 wt % DCPD.

9. The process of claim 1 , further comprising:
(VIII) feeding at least a portion of the second recovered wash oil stream and the first light components-rich fraction into a third light components separation device;
(IX) obtaining from the third separation device:
a second light components-rich fraction comprising hydrogen and C1-C4 hydrocarbons depleted in C5+ hydrocarbons, and
a third wash oil stream; and
(X) recycling at least a portion of the third wash oil stream to the washing vessel in step (III).

10. The process of claim 1 , further comprising feeding a fresh stream of wash oil into at least one of (i) the washing vessel and (ii) the third separation device.

11. The process of claim 1 , further comprising:
(XI) supplying at least a portion of the first C5-rich fraction and, optionally, the optional recovered C5-rich stream into a second reactor operating under a first set of dimerization conditions;
(XII) obtaining a second reactor effluent from the second reactor comprising CPD and DCPD; and
(XIII) 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.

12. The process of claim 11 , further comprising:
(XIV) feeding at least a portion of the second C5-rich fraction into a third reactor operating under a second set of dimerization conditions;
(XV) obtaining a third reactor effluent from the third reactor comprising CPD and DCPD; and
(XVI) separating at least a portion of the third reactor effluent to obtain:
a second DCPD-rich fraction; and
a third C5-rich stream.

13. The process of claim 11 , further comprising:
(XVII) feeding at least a portion of the third C5-rich fraction into a fourth reactor operating under a third set of dimerization conditions;
(XVIII) obtaining a fourth reactor effluent from the fourth reactor comprising CPD and DCPD; and
(XIX) separating at least a portion of the fourth reactor effluent in a fourth separation device to obtain:
a third DCPD-rich fraction; and
a fourth C5-rich stream.

14. The process of claim 11 , further comprising:
(XX) supplying at least a portion of at least one of the following into a fifth separation device: (i) the first C5-rich stream; (ii) the optional recovered C5-rich stream; (iii) the second C5-rich stream; (iv) the third C5-rich stream, if any; (v) the fourth C5-rich stream, if any; and
(XXI) obtaining, from the fourth separation device:
a fifth C5-rich stream; and
a one-ring aromatic(s)-rich stream.

15. The process of claim 14 , further comprising:
(X) recycling at least a portion of the one-ring aromatic(s)-rich stream directly or indirectly into the washing vessel in step (III) and/or the third separation device in step (VIII).

16. The process of claim 14 , wherein at least a portion of the one-ring aromatic(s)-rich stream is distilled to obtain a benzene-rich stream and a benzene-depleted stream and the benzene depleted stream is fed directly to a

Assignees

• Exxonmobil Chemical Patents Inc

Inventors

• Iaccino Larry L
• Leung Kevin C P

Classifications

• C07C2529/44

  Noble metals · CPC title

• C07C2101/10

  Chemistry & Metallurgy · mapped topic

• C07C2103/68

  Chemistry & Metallurgy · mapped topic

• C07C13/61

  with a bridged indene ring, e.g. dicyclopentadiene · CPC title

• C07C2603/68

  Dicyclopentadienes; Hydrogenated dicyclopentadienes · CPC title