Reactor for pyrolysis conversion of hydrocarbon gases

Patent metadata

Field	Value
Publication number	US-11826749-B2
Application number	US-202117242610-A
Country	US
Kind code	B2
Filing date	Apr 28, 2021
Priority date	Mar 7, 2018
Publication date	Nov 28, 2023
Grant date	Nov 28, 2023

Abstract

A pyrolysis reactor ( 12 ) and method for the pyrolysis of hydrocarbon gases (e.g., methane) utilizes a pyrolysis reactor ( 12 ) having a unique burner assembly ( 44 ) and pyrolysis feed assembly ( 56 ) that creates an inwardly spiraling fluid flow pattern of the feed gases to form a swirling gas mixture that passes through a burner conduit ( 46 ) with a constricted neck portion or nozzle ( 52 ). At least a portion of the swirling gas mixture forms a thin, annular mixed gas flow layer immediately adjacent to the burner conduit ( 46 ). A portion of the swirling gas mixture is combusted as the swirling gas mixture passes through the burner conduit ( 46 ) and a portion of combustion products circulates in the burner assembly ( 44 ). This provides conditions suitable for pyrolysis of hydrocarbons or light alkane gas, such as methane or natural gas.

First claim

We claim:

1. A subsonic pyrolysis reactor for the pyrolysis of hydrocarbon gases comprising:
a pyrolysis reactor vessel having a reactor wall that defines a pyrolysis reaction chamber;
a burner assembly having a burner conduit with a circumferential wall that surrounds a central longitudinal axis and extends from opposite upstream and downstream ends of the burner conduit, the circumferential wall tapering in width from the downstream and upstream ends to an annular constricted neck portion located between the downstream and upstream ends of the burner conduit, the downstream end of the burner conduit being in fluid communication with the reaction chamber of the pyrolysis reactor, the upstream end of the burner conduit forming a burner assembly inlet;
a pyrolysis feed assembly in fluid communication with the burner assembly inlet, with the central axis passing through the pyrolysis feed assembly, the feed assembly comprising:
a downstream feed assembly wall that extends circumferentially around and joins the upstream end of the burner assembly inlet, the downstream feed assembly wall being oriented perpendicular to the central axis;
an upstream feed assembly wall that is axially spaced upstream from the downstream wall along the central axis and extends perpendicularly across the central axis;
a gas partition wall axially spaced between the downstream and upstream feed assembly walls that is oriented perpendicular to the central axis and has a central opening that surrounds the central axis of the burner conduit, the partition wall defining an annular hydrocarbon gas inlet flow space between the downstream feed assembly wall and the partition wall and an annular oxygen gas inlet flow space between the partition wall and the upstream feed assembly wall so that hydrocarbon gas feed and oxygen gas feed are introduced and passed through said flow spaces perpendicularly to the central axis of the burner conduit in an inwardly spiraling fluid flow pattern within said flow spaces about the central axis of the burner conduit; and wherein
the area extending from the central opening of the partition wall to the burner assembly inlet defining a mixing chamber of the pyrolysis feed assembly, with oxygen gas feed from the oxygen gas inlet flow space and hydrocarbon gas feed from the hydrocarbon gas inlet flow space being discharged into the mixing chamber so that the oxygen and hydrocarbon feed gases are mixed together and form a swirling gas mixture within the mixing chamber, the swirling gas mixture passing through the burner conduit; and wherein
the annular constricted neck portion has a geometry that facilitates a recirculation and backflow of gases within the pyrolysis reaction chamber near the central longitudinal axis in combination with annular swirling jet gas flow adjacent to the reactor wall.

2. The pyrolysis reactor of claim 1 , wherein:
at least one of the annular hydrocarbon gas and oxygen gas inlet flow spaces is provided with circumferentially spaced apart guide vanes oriented to facilitate the spiraling fluid flow within said at least one of the inlet flow spaces.

3. The pyrolysis reactor of claim 2 , wherein:
the guide vanes are movable to selected positions to provided selected azimuthal-to-radial velocity ratios of each of the light alkane gas feed stream and the oxygen gas feed stream within the annular inlet flow spaces.

4. The pyrolysis reactor of claim 1 , wherein:
the reactor wall is cylindrical.

5. The pyrolysis reactor of claim 1 , wherein:
the circumferential wall of the burner conduit from the downstream end to the annular constricted neck portion, and optionally an upstream portion of the reactor wall of the pyrolysis reaction chamber that joins the circumferential wall of the burner conduit, is configured as a smooth, continuous wall that follows contour lines of an ellipsoidal cap or spherical cap shape.

6. The pyrolysis reactor of claim 1 , wherein:
the interior of the reactor wall is a refractory material.

7. The pyrolysis reactor of claim 1 , wherein:
the central opening of the gas partition wall has a diameter or width that is approximately the same as the diameter or width of the constricted neck portion at the narrowest point of the constricted neck portion.

8. The pyrolysis reactor of claim 1 , wherein:
at least one of the annular hydrocarbon gas and oxygen gas inlet flow spaces is provided with one or more inlets that are oriented to facilitate the spiraling fluid flow within said at least one of the inlet flow spaces.

9. The pyrolysis reactor of claim 1 , wherein:
at least one of the annular hydrocarbon gas and oxygen gas inlet flow spaces is provided with one or more inlets and/or guide vanes oriented to provide an azimuthal-to-radial velocity ratio from 0 to 30.

10. The pyrolysis reactor of claim 1 , wherein:
at least one of the annular hydrocarbon gas and oxygen gas inlet flow spaces is provided with one or more inlets and/or guide vanes oriented at an angle A relative to a radial line extending from the central axis, with the angle A ranging from 50° to 85° to facilitate the spiraling fluid flow within said at least one of the inlet flow spaces.

11. A pyrolysis reactor for the pyrolysis of hydrocarbon gases comprising:
a pyrolysis reactor vessel having a reactor wall that defines a pyrolysis reaction chamber;
a burner assembly having a burner conduit with a circumferential wall that surrounds a central longitudinal axis and extends from opposite upstream and downstream ends of the burner conduit, the circumferential wall tapering in width from the downstream and upstream ends to an annular constricted neck portion located between the downstream and upstream ends of the burner conduit, the downstream end of the burner conduit being in fluid communication with the reaction chamber of the pyrolysis reactor, the upstream end of the burner conduit forming a burner assembly inlet;
a pyrolysis feed assembly in fluid communication with the burner assembly inlet, with the central axis passing through the pyrolysis feed assembly, the feed assembly comprising:
a downstream feed assembly wall that extends circumferentially around and joins the upstream end of the burner assembly inlet, the downstream feed assembly wall being oriented perpendicular to the central axis;
an upstream feed assembly wall that is axially spaced upstream from the downstream wall along the central axis and extends perpendicularly across the central axis;
a gas partition wall axially spaced between the downstream and upstream feed assembly walls that is oriented perpendicular to the central axis and has a central opening that surrounds the central axis of the burner conduit, the partition wall defining an annular hydrocarbon gas inlet flow space between the downstream feed assembly wall and the partition wall and an annular oxygen gas inlet flow space between the partition wall and the upstream feed assembly wall so that hydrocarbon gas feed and oxygen gas feed are introduced and passed through said flow spaces perpendicularly to the central axis of the burner conduit in an inwardly spiraling fluid flow pattern within said flow spaces about the central axis of the burner conduit; and wherein
the area extending from the central opening of the partition wall to the burner assembly inlet defining a mixing chamber of the pyrolysis feed assembly, with oxygen gas feed from the oxygen gas inlet flow space and hydrocarbon gas feed from the hydrocarbon gas inlet flow space being discharged into the mixing chamber so that the oxygen and hydrocarbon feed gases are mixed together and form a swirling gas mixture within the mixing chamber, the swirling gas mixture passing through the burner con

Assignees

• Sabic Global Technologies Bv

Inventors

• Pannala Sreekanth
• Shtern Vladimir
• Chen Lei
• West David

Classifications

• C07C11/24

  Acetylene (production of acetylene gas by wet methods C10H) · CPC title

• B01J12/005 Primary

  carried out at high temperatures, e.g. by pyrolysis · CPC title

• B01J6/008 Primary

  Pyrolysis reactions (of hydrocarbons C10G9/00) · CPC title

• B01J4/005

  provided with baffles · CPC title

• B01J19/0053

  Details of the reactor · CPC title