Systems for catalytic activation of isopentane-enriched mixtures

Patent metadata

Field	Value
Publication number	US-10487277-B2
Application number	US-201916364836-A
Country	US
Kind code	B2
Filing date	Mar 26, 2019
Priority date	Mar 27, 2018
Publication date	Nov 26, 2019
Grant date	Nov 26, 2019

Abstract

Systems operable to produce liquid transportation fuels by converting a hydrocarbon feed stream that comprises both isopentane and n-pentane. The system separates the hydrocarbon feed stream to form a first fraction comprising isopentane and smaller hydrocarbons, and a second fraction comprising n-pentane and larger components of the hydrocarbon feeds stream. Each fraction is then catalytically-activated in a separate activation reactor containing a separate activation catalyst, where the conditions maintained in each reactor are selected to maximize the conversion of each fraction to olefins and aromatics, while minimizing the production of C1-C4 light paraffins. Optionally, the first activation reactor is maintained at a lower temperature than the second activation reactor. Certain embodiments are operable to combine at least a portion of the first and second activation effluents and convert the mixed effluent by either oligomerization or alkylation to produce a liquid transportation fuel or a blend component thereof.

First claim

We claim:

1. A system configured to convert a feedstock comprising pentanes to produce a liquid transportation fuel, the system comprising:
a) a hydrocarbon feed stream comprising at least 50 wt. % pentanes, including both n-pentane and isopentane, wherein the hydrocarbon feed stream further comprises less than 10 wt. % of hydrocarbons containing four or fewer carbons;
b) a first separator operable to at least partially separate various constituents in the hydrocarbon feed stream according to each constituent's characteristic vapor pressure, to produce:
i. a first fraction comprising at least 80% of the isopentane present in the feed stream, and at least 90% of hydrocarbons present in the hydrocarbon feed stream that are characterized by a vapor pressure equal to or greater than the vapor pressure of isopentane;
ii. a second fraction that comprises at least 80% of the n-pentane present in the hydrocarbon feed stream and at least 90% of any hydrocarbons containing six or more carbon atoms that were present in the hydrocarbon feed stream;

c) a first reactor containing a first activation catalyst, the first reactor operable to receive the first fraction and facilitate contact between the first fraction and the first activation catalyst, wherein the first reactor is further operable to maintain an internal temperature and an internal pressure that facilitate the catalytic conversion of at least a portion of the first fraction by the first activation catalyst to produce a first effluent comprising containing from two to five carbon atoms, monocyclic aromatics and unconverted alkanes containing from two to five carbon atoms;
d) a second reactor containing a second activation catalyst, the second reactor operable to receive the second fraction and facilitate contact between the second fraction and the second activation catalyst, wherein the second reactor is further operable to maintain an internal temperature and an internal pressure that facilitate the catalytic conversion of at least a portion of the second fraction by the second activation catalyst to produce a second effluent comprising containing from two to five carbon atoms, monocyclic aromatics and unconverted alkanes containing from two to five carbon atoms, wherein the system is further operable to maintain the first reactor at a temperature that is lower than the temperature maintained in the second reactor;
e) a condenser operable to receive and mix at least a portion of the of the first effluent with at least a portion of the second effluent, the condenser further operable to condense at least a portion of the resulting mixed activation effluent to produce a mixed liquid hydrocarbons and a gas-phase mixed effluent, the condenser comprising a first outlet operable to allow egress of the mixed liquid hydrocarbons and a second outlet to allow egress of the mixed effluent;
f) a second separator operable to receive and split the mixed effluent into a heavy hydrocarbons fraction comprising at least 50 wt. % hydrocarbons containing at least five carbon atoms, including olefins, monocyclic aromatics and unreacted molecules from the feed stock and a light hydrocarbons fraction comprising hydrogen and at least 80 wt. % hydrocarbons containing from one to four carbon atoms.

2. The system of claim 1 , wherein the second separator is a two-phase splitter.

3. The system of claim 1 , further comprising a third separator operable to separate the heavy hydrocarbons fraction to produce a liquid hydrocarbon product fraction comprising the liquid hydrocarbon product aromatics fraction comprising aromatic hydrocarbons containing at least six carbon atoms, and an olefins fraction comprising alkanes and olefins containing from five to six carbon atoms.

4. The system of claim 3 , wherein the third separator is a naphtha stabilizer.

5. The system of claim 1 , further comprising an oligomerization reactor containing at least one oligomerization catalyst, the oligomerization reactor operable to receive the mixed effluent of part e) and facilitate contact between the mixed effluent and the oligomerization catalyst at a temperature and a pressure that are suitable to facilitate catalytic conversion of the mixed effluent to an oligomerization effluent comprising an increased weight percentage of hydrocarbons containing at least five carbon atoms (C5+), wherein the second separator is operable to receive and separate the oligomerization effluent, instead of the mixed effluent.

6. The system of claim 5 , wherein the second separator operable to receive and separate the oligomerization effluent into a light hydrocarbons fraction predominantly comprising hydrocarbons containing from one to four carbon atoms and hydrogen, and a heavy hydrocarbons fraction comprising hydrocarbons containing at least five carbon atoms (C5+) that is suitable for use as a blend component of a liquid transportation fuel or an intermediate thereof.

7. The system of claim 6 , further comprising a fourth separator operable to receive and separate the light hydrocarbons fraction to produce hydrogen gas and a light paraffins stream comprising paraffins containing from one to four carbon atoms.

8. The system of claim 7 , wherein the system is operable to mix at least a portion of the light paraffins stream with at least one of the first fraction and the second fraction at a location that is upstream from at least one of the first catalyst and the second catalyst.

9. The system of claim 6 , wherein the system is operable to mix at least a portion of the recycle fraction with the feed stock at a location that is upstream from the first separator.

10. The system of claim 5 , wherein the oligomerization reactor is operable to convert at least 80 wt. % of the mixed effluent that is received by the oligomerization reactor to hydrocarbons containing at least five carbon atoms that are suitable for use as a blend component of a liquid transportation fuel or an intermediate thereof.

11. The system of claim 5 , further comprising a third separator that is operable to receive and separate the heavy hydrocarbons fraction to produce a recycle fraction comprising predominantly alkanes and olefins containing five or six carbon atoms, and a liquid hydrocarbon product that predominantly comprises hydrocarbons that are characterized by a boiling-point in the range of a liquid transportation fuel.

12. The system of claim 1 , further comprising an alylation reactor containing at least one alkylation catalyst, the alkylation reactor operable to receive the mixed effluent of part e) and facilitate contact between the mixed effluent and the alkylation catalyst at a temperature and a pressure that are suitable to facilitate catalytic conversion of the mixed effluent to an alkylation effluent comprising an increased weight percentage of hydrocarbons containing at least five carbon atoms (C5+), wherein the second separator is operable to receive and separate the alkylation effluent instead of the mixed effluent to produce a light hydrocarbons fraction predominantly comprising hydrocarbons containing from one to four carbon atoms and hydrogen, and a heavy hydrocarbons fraction comprising hydrocarbons containing at least five carbon atoms (C5+) that is suitable for use as a blend component of a liquid transportation fuel or an intermediate thereof.

13. The system of claim 12 , wherein the second separator operable to receive and separate the alkylation effluent into a light hydrocarbons fraction predominantly comprising hydrocarbons containing from one to four carbon atoms and hydrogen, and a heavy hydrocarbons fraction comprising hydrocarbons containing at least five carbon atoms (C5+) that is suitabl

Assignees

• Phillips 66 Co

Inventors

• Baldridge Anthony O
• Mcdaniel Neal D
• Suttil James A
• Kundu Soumen
• Yao Jianhua
• Randolph Bruce B
• Sardashti Maziar
• Lusk Steven E
• Walston Jr Robert M

Classifications

• C10G2300/4006

  Temperature · CPC title

• C10G5/06 Primary

  by cooling or compressing · CPC title

• C10G2400/22

  Higher olefins · CPC title

• C10G45/64

  containing crystalline alumino-silicates, e.g. molecular sieves · CPC title

• C10G2300/1081

  Alkanes · CPC title