Catalyst roller for gravity-assisted particle flow

Patent metadata

Field	Value
Publication number	US-2018296999-A1
Application number	US-201815924734-A
Country	US
Kind code	A1
Filing date	Mar 19, 2018
Priority date	Apr 12, 2017
Publication date	Oct 18, 2018
Grant date	—

Abstract

Systems and methods are provided for controlling the flow and transport of catalyst particles within a reaction system. The flow of catalyst particles can be managed using a rotating disc or wheel that is configured within a roller volume to allow for control over the rate of catalyst flow while reducing or minimizing attrition of the catalyst particles. This can be achieved in part by maintaining a relationship between the center of the rotating disc, the inlet for catalyst particles to the roller volume, and the top wall of the roller volume so that catalyst particles are not exposed to compressive forces and/or abrasion during rotation of the disc. Additionally or alternately, the disc and roller volume surfaces can be configured to reduce or minimize the potential for catalyst particles to become trapped in “dead space” regions within the roller volume. By using a disc to provide force for transport of particles through the roller volume, the speed of catalyst movement can be controlled at relatively slow catalyst flow rates with a reduced or minimized risk for clogging or plugging within the roller volume.

First claim

1 . A catalyst roller system, comprising:
a roller volume comprising a top interior surface, a sidewall, and an inner contour surface; a plurality of catalyst particles within the roller volume, the plurality of catalyst particles comprising an average catalyst particle diameter, the catalyst particles having an angle of repose and an angle of internal friction; a catalyst inlet in fluid communication with the roller volume via the top surface; a catalyst exit in fluid communication with the roller volume; and a catalyst roller disc rotatably mounted within the roller volume, a contour clearance between the mounted catalyst roller disc and the inner contour surface being less than half of the average catalyst particle diameter for at least one location, wherein a catalyst stoppage angle defined by
a) a top of the mounted catalyst roller disc,
b) an intersection of the catalyst inlet and the top interior surface at the closest intersection point to the top of the mounted catalyst roller disc, and
c) a tangent line passing through the top of the mounted catalyst roller disc,
has a value within 15% of the angle of repose.

2 . The catalyst roller system of claim 1 , wherein the roller volume is in fluid communication with the catalyst exit via a discharge cone, the discharge cone having an angle relative to vertical greater than or equal to the angle of internal friction.

3 . The catalyst roller system of claim 1 , wherein a ratio of a) a top clearance between the top interior surface and the top of the catalyst roller disc and b) the average catalyst particle diameter is 2.0 to 10.

4 . The catalyst roller system of claim 1 , wherein the roller volume further comprises an inner guide surface, an angle of the inner guide surface, relative to vertical, being greater than or equal to the angle of internal fraction.

5 . The catalyst roller system of claim 4 , wherein the at least one location comprises an intersection of the inner contour surface and the inner guide surface.

6 . The catalyst roller system of claim 1 , wherein the inner contour surface comprises a surface removably mounted within the roller volume.

7 . The catalyst roller system of claim 1 , wherein the contour clearance is less than half of the average catalyst particle diameter for a portion of the circumference of the catalyst roller disc corresponding to 2 average catalyst particle diameters or more.

8 . The catalyst roller system of claim 1 , wherein a ratio of a) a sidewall clearance between the sidewall and the catalyst roller disc and b) the average catalyst particle diameter is 4.0 to 25.

9 . The catalyst roller system of claim 1 , wherein the inner contour surface further comprises a gas passage, the gas passage optionally being in fluid communication with a source of pressurized fluid.

10 . The catalyst roller system of claim 1 , wherein the catalyst roller disc comprises a disc edge having undulations, wherein i) a ratio of an average undulation height of the undulations to the average catalyst particle diameter is 0.5 or less; or ii) a ratio of an average undulation wavelength to the average catalyst particle diameter is 0.8 or more; or iii) a combination of i) and ii).

11 . The catalyst roller system of claim 1 , wherein the roller volume further comprises a bottom surface, the roller volume being in fluid communication with at least one of the catalyst exit and the discharge cone via the bottom surface.

12 . The catalyst roller system of claim 11 , wherein a ratio of a) a bottom clearance between the bottom surface and the catalyst roller disc and b) the average catalyst particle diameter is 0.5 or less.

13 . The catalyst roller system of claim 1 , wherein the average catalyst particle diameter is 0.5 mm to 5.0 mm.

14 . The catalyst roller system of claim 1 , wherein the catalyst stoppage angle has a value within 10% of the angle of repose.

15 . A method for transporting catalyst particles, comprising:
passing a plurality of catalyst particles into a roller volume of a catalyst roller system via a catalyst inlet, the roller volume comprising a rotatably mounted catalyst roller disc, at least one catalyst particle of the plurality of catalyst particles contacting an edge of the mounted catalyst roller disc; and rotating the mounted catalyst roller disc at a rotation speed to pass the one or more catalyst particles into a catalyst exit, wherein a catalyst stoppage angle defined by
a) a top of the mounted catalyst roller disc,
b) an intersection of the catalyst inlet and the top interior surface at the closest intersection point to the top of the mounted catalyst roller disc, and
c) a tangent line passing through the top of the mounted catalyst roller disc,
has a value within 15% of the angle of repose.

16 . The method of claim 15 , wherein the average catalyst particle diameter is 0.5 mm to 10 mm.

17 . The method of claim 15 , wherein the catalyst stoppage angle has a value within 10% of the angle of repose.

18 . The method of claim 15 , wherein a ratio of a) a top clearance between a top interior surface and the top of the catalyst roller disc and b) the average catalyst particle diameter is 2.0 to 10.

19 . The method of claim 15 , wherein a contour clearance between the mounted catalyst roller disc and an inner contour surface is less than half of the average catalyst particle diameter for at least one location.

20 . The method of claim 15 , wherein the catalyst roller system is in fluid communication with a reactor comprising a reactor catalyst volume, the rotating of the mounted catalyst roller disc comprising rotation at a speed to allow turnover of 0.001 wt % to 10 wt % of the reactor catalyst volume per hour.

Assignees

• Exxonmobil Res & Eng Co

Inventors

• Behkish Arsam
• Raterman Michael F
• Kovvali Anjaneya S

Classifications

• B01J2204/002

  the feeding side being of particular interest · CPC title

• B01J8/0045

  by means of a rotary device in the flow channel · CPC title

• B01J4/007

  provided with moving parts · CPC title

• B01J8/10 Primary

  moved by stirrers or by rotary drums or rotary receptacles {or endless belts} · CPC title

• B01J8/003 Primary

  in a downward flow · CPC title