Selective hydrogenation using a flow index

Patent metadata

Field	Value
Publication number	US-9758446-B2
Application number	US-201514942816-A
Country	US
Kind code	B2
Filing date	Nov 16, 2015
Priority date	Nov 16, 2015
Publication date	Sep 12, 2017
Grant date	Sep 12, 2017

Abstract

A process includes hydrogenating, in a reaction zone, a highly unsaturated hydrocarbon received from a hydrocarbon stream to yield a product having an unsaturated hydrocarbon, the hydrogenating step occurring in the presence of a hydrogenation catalyst which has a selectivity for conversion of the highly unsaturated hydrocarbon to the unsaturated hydrocarbon of about 90 mol % or greater based on the moles of the highly unsaturated hydrocarbon which are converted to the product, the hydrogenating step occurring in a reaction zone under conditions which include a flow index (I F ) in a range of about 0.09 to about 35, wherein the I F is defined as:
I F = F × [ CO ] V ,
wherein F is the flow rate of the hydrocarbon stream into the reaction zone in units of kg/h, [CO] is the concentration of carbon monoxide in the hydrocarbon stream in units of mol %, and V is the volume of the reaction zone in units of ft 3 .

First claim

What is claimed is:

1. A process comprising:
hydrogenating, in a reaction zone, a highly unsaturated hydrocarbon received from a hydrocarbon stream to yield a product comprising an unsaturated hydrocarbon,
wherein the hydrogenating occurs in the presence of a hydrogenation catalyst which has a selectivity for conversion of the highly unsaturated hydrocarbon to the unsaturated hydrocarbon of about 90 mol % or greater based on the moles of the highly unsaturated hydrocarbon which are converted to the product,
wherein the highly unsaturated hydrocarbon comprises acetylene, and wherein the unsaturated hydrocarbon comprises ethylene, and
wherein the hydrogenating in the reaction zone occurs under conditions comprising a flow index (I F ) in a range of about 0.09 to about 35, wherein the I F is defined as:

I
F

=

F
×

[
CO
]

V

,

wherein F is the flow rate of the hydrocarbon stream into the reaction zone in units of kg/h, [CO] is the concentration of carbon monoxide in the hydrocarbon stream in units of mol %, and V is the volume of the reaction zone in units of ft 3 .

2. The process of claim 1 , wherein the selectivity is defined as:

S
=

100
×

(

UH
⁡

(
p
)

-

UH
⁡

(
f
)

HUH
⁡

(
f
)

-

HUH
⁡

(
p
)

)

where S is selectivity in mol %, UH(p) is moles of the unsaturated hydrocarbon in the product, UH(f)is moles of the unsaturated hydrocarbon in the hydrocarbon stream, HUH(f) is the moles of highly unsaturated hydrocarbon in the hydrocarbon stream, and HUH(p) is the moles of the highly unsaturated hydrocarbon in the product.

3. The process of claim 1 , wherein the highly unsaturated hydrocarbon further comprises methylacetylene, propadiene, or both; and wherein the unsaturated hydrocarbon further comprises propylene.

4. The process of claim 1 , further comprising:
cracking a feed stream to produce a cracked gas stream comprising the highly unsaturated hydrocarbon, carbon monoxide, and a saturated hydrocarbon.

5. The process of claim 4 , further comprising:
fractionating the cracked gas stream to yield a C 3 − stream or C 2 − stream comprising the highly unsaturated hydrocarbon, carbon monoxide, and about 90 mol % or greater of the saturated hydrocarbon contained in the cracked gas stream, wherein at least a portion of the highly unsaturated hydrocarbon in the C 3 − stream or the C 2 − stream is hydrogenated in the presence of the hydrogenation catalyst.

6. The process of claim 1 , wherein the [CO] in the reaction zone is from about 0.0001 mol % to about 0.15 mol %.

7. The process of claim 1 , wherein the hydrogenating step comprises:
contacting the hydrogenation catalyst with at least a portion of the highly unsaturated hydrocarbon in the presence of hydrogen.

8. The process of claim 1 , wherein the reaction zone comprises a first stage and a second stage, wherein at least one of the first stage and the second stage of the reaction zone contains the hydrogenation catalyst.

9. The process of claim 8 , wherein:
i) the first stage of the reaction zone and the second stage of the reaction zone are contained in a common vessel; or
ii) the first stage of the reaction zone is a first reactor, the second stage of the reaction zone is a second reactor, and the first reactor and the second reactor are connected in series.

10. A process comprising:
cracking a feed stream to produce a cracked gas stream comprising acetylene, ethylene, ethane, methane, hydrogen, carbon monoxide, and C 3 + components;
fractionating the cracked gas stream into a C 2 − stream and a C 3 + stream, wherein the C 2 − stream comprises acetylene, ethylene, ethane, methane, hydrogen, and carbon monoxide, wherein the C 3 + stream comprises the C 3 + components;
hydrogenating at least a portion of the acetylene of the C 2 − stream in the presence of a hydrogenation catalyst to yield a product comprising ethylene, wherein the hydrogenation catalyst has a selectivity for conversion of acetylene to ethylene of about 90 mol % or greater based on the moles of acetylene which are converted to the product, wherein the hydrogenating occurs in a reaction zone under conditions comprising a flow index (I F ) in a range of about 0.09 to about 35, wherein the I F is defined as:

I
F

=

F
×

[
CO
]

V

,

wherein F is the flow rate of the C 2 − stream into the reaction zone in units of kg/h, [CO] is the concentration of carbon monoxide in the C 2 − stream in units of mol %, and V is the volume of the portion of the reaction zone in units of ft 3 ;
removing ethylene from the product; and
polymerizing ethylene into one or more polymer products.

11. The process of claim 10 , wherein the selectivity is defined as:

S
=

100
×

(

UH
⁡

(
p
)

-

UH
⁡

(
f
)

Assignees

• Chevron Phillips Chemical Co Lp

Inventors

• Bergmeister Iii Joseph
• Cheung Tin-Tack Peter
• Hong Zongxuan
• Odi Timothy O
• Nolidin Charles D
• Gonzales Thomas J
• Nill Jennifer L
• Dockter David W

Classifications

• C10G45/32 Primary

  Selective hydrogenation of the diolefin or acetylene compounds · CPC title

• C10G2400/24

  Acetylene and homologues · CPC title

• C10G2400/20

  C2-C4 olefins · CPC title

• C10G70/02

  by hydrogenation · CPC title

• C10G69/06 Primary

  including at least one step of thermal cracking in the absence of hydrogen · CPC title