Inherently safe oxygen/hydrocarbon gas mixer

Patent metadata

Field	Value
Publication number	US-12491479-B2
Application number	US-202017611770-A
Country	US
Kind code	B2
Filing date	Jul 15, 2020
Priority date	Jul 26, 2019
Publication date	Dec 9, 2025
Grant date	Dec 9, 2025

Abstract

A method of safely mixing a hydrocarbon with an oxidant is provided. The hydrocarbon and oxidant are saturated with a non-flammable liquid in pre-mix zones that are flooded with the non-flammable liquid and fluidly connected to a common mixing zone that is partially flooded with the non-flammable liquid. The saturated hydrocarbon and oxidant combine within the common mixing zone forming bubbles of a homogeneous gas mixture of hydrocarbon and oxidant, preferably in a ratio of hydrocarbon to oxidant that is outside of the flammability limit, that can exit the non-flammable liquid into a headspace where it can be retrieved for use in an oxidative reaction process such as oxidative dehydrogenation.

First claim

The invention claimed is:

1 . A gas mixer, comprising:
i) a first pre-mix zone configured to be flooded with a non-flammable liquid and configured to receive a first gas to provide a first saturated gas saturated with a vapor of the non-flammable liquid; ii) a second pre-mix zone, physically separated from the first pre-mix zone by a pipe, the second pre-mix zone configured to be flooded with the non-flammable liquid and configured to receive a second gas to provide a second saturated gas saturated with another vapor of the non-flammable liquid; iii) a common mixing zone configured to be partially flooded with the non-flammable liquid to define a head space and a flooded region, the flooded region separately fluidly connected to the first pre-mix zone and the second pre-mix zone, and the common mixing zone configured to separately receive the first saturated gas and the second saturated gas; and iv) a homogeneous gas mixture outlet configured to remove from the head space a homogeneous gas mixture comprising the first gas and the second gas; wherein:
the first gas is different from the second gas;
each of the first and second gases is selected from the group consisting of a hydrocarbon-containing gas and an oxidant-containing gas;
the first saturated gas and the second saturated gas are combinable in the flooded region to provide the homogeneous gas mixture;
the first pre-mix zone is disposed within the second pre-mix zone;
a hollow interior of the pipe forms the first pre-mix zone;
the first pre-mix zone is flooded with the non-flammable liquid, through a valve disposed at a front end of the pipe, from a liquid supply line; and
the first gas is introduced into the first pre-mix zone, through a check valve, from a gas supply line.

2 . The gas mixer of claim 1 wherein the non-flammable liquid comprises water.

3 . The gas mixer of claim 1 wherein at least one member selected from the group consisting of the first pre-mix zone and the second pre-mix zone is configured to receive the first gas and the second gas via a nozzle.

4 . The gas mixer of claim 1 wherein at least one member selected from the group consisting of the first pre-mix zone and the second pre-mix zone is configured to receive the first gas or second gas via a sparger.

5 . The gas mixer of claim 1 wherein at least one member selected from the group consisting of the first pre-mix zone and the second pre-mix zone is configured to receive the first gas or second gas via an aerator nozzle.

6 . The gas mixer of claim 1 further comprising a mechanism configured to introduce the non-flammable liquid into at least one member selected from the group consisting of the first pre-mix zone, the second pre-mix zone, and the common mixing zone.

7 . The gas mixer of claim 1 further comprising a mechanism configured to remove the non-flammable liquid from at least one member selected from the group consisting of the first pre-mix zone, the second pre-mix zone, and the common mixing zone.

8 . The gas mixer of claim 1 wherein at least one member selected from the group consisting of the first pre-mix zone and the second pre-mix zone is configured to receive the first gas or second gas via porous material.

9 . The gas mixer of claim 1 further comprising a mechanism configured to control a temperature of the non-flammable liquid in at least one member selected from the group consisting of the first pre-mix zone, the second pre-mix zone and the common mixing zone, wherein the mechanism is selected from the group consisting of:
i) heat from a product recycle line;
ii) an external heater; and
iii) internal heater.

10 . The gas mixer of claim 1 wherein at least one of the first pre-mix zone, the second pre-mix zone, and the flooded region comprises mesh screens configured to limit a size of bubbles of the first gas and second gas.

11 . The gas mixer of claim 1 further comprising:
i) an inert material inlet configured to introduce an inert material into the head space; and
ii) a suppression outlet leading to an explosion suppression system to remove the homogeneous gas mixture from the headspace.

12 . The gas mixer of claim 1 wherein the common mixing zone comprises a closed vessel having a top end and a bottom end.

13 . The gas mixer of claim 12 wherein at least one of the first and second pre-mix zones comprises an interior of a standing pipe.

14 . The gas mixer of claim 1 wherein at least one member selected from the group consisting of the first pre-mix zone, the second pre-mix zone and the common mixing zone further comprises a mechanism configured to mix gases present with the non-flammable liquid.

15 . The gas mixer of claim 14 wherein the mechanism is selected from the group consisting of:
i) a static mixer;
ii) a packed bed;
iii) a structured bed;
iv) an impeller; and
v) combinations of i) through iv).

16 . A method, comprising:
i) introducing a hydrocarbon-containing gas into a first pre-mix zone flooded with a non-flammable liquid to form a first saturated gas mixture comprising the hydrocarbon-containing gas saturated with a vapor of the non-flammable liquid; ii) introducing an oxidant-containing gas into a second pre-mix zone flooded with the non-flammable liquid to form a second saturated gas mixture comprising the oxidant-containing gas saturated with another vapor of the non-flammable liquid, the second pre-mix zone being physically separated from the first pre-mix zone by a pipe; iii) introducing, separately, the first saturated gas mixture and the second saturated gas mixture into a flooded region of a common mixing zone partially flooded with the non-flammable liquid and comprising the flooded region and a headspace; iv) mixing the first saturated gas mixture with the second saturated gas mixture within the flooded region to form a homogeneous gas mixture comprising the hydrocarbon-containing gas, and the oxidant-containing gas saturated with non-flammable liquid; and v) recovering the homogeneous gas mixture from the headspace,
wherein the first pre-mix zone is disposed within the second pre-mix zone, and
the first pre-mix zone is flooded with the non-flammable liquid through a valve disposed at a front end of the pipe.

17 . A method of operating a gas mixer comprising a first pre-mix zone physically separated from a second pre-mix zone by a pipe, each of the first pre-mix and second pre-mix zones comprising a front end and a back end, and a mixing zone continuous with the back end of each of the first and second pre-mix zones, the method comprising:
i) flooding the first and second pre-mix zones with a non-flammable liquid; ii) partially flooding the mixing zone with the non-flammable liquid such that the mixing zone has a flooded region and a head space; iii) saturating a hydrocarbon-containing gas with the non-flammable liquid in the first pre-mix zone; iv) saturating an oxidant-containing gas with the non-flammable liquid in the second pre-mix zone; v) mixing the saturated hydrocarbon-containing gas with saturated oxidant-containing gas in the flooded region to create bubbles of a homogeneous gas mixture, the homogeneous gas mixture comprising the hydrocarbon-containing gas and the oxidant-containing gas, the homogeneous gas mixture being outside of the flammability limit; vi) allowing the homogeneous gas mixture to exit the flooded region and enter the head space; and vii) removing the homogeneous gas mixture from the head space,
wherein the first pre-mix zone is disposed within the second pre-mix zone, and
the first

Assignees

• Nova Chemicals International Sa

Inventors

• Simanzhenkov Vasily
• Goodarznia Shahin
• Olayiwola Bolaji
• Serhal Kamal
• Koselek Michael

Classifications

• C07C7/14816

  oxygen; ozone · CPC title

• C07C7/04

  by distillation · CPC title

• C07C7/005

  Processes comprising at least two steps in series · CPC title

• C07C5/48

  with oxygen as an acceptor · CPC title

• B01F27/05

  Stirrers · CPC title