Catalyst particle shape
A catalytic system is provided which comprises a tubular reactor and at least one catalyst particle located within the tubular reactor. The catalyst particles have a particular geometric form which promotes heat transfer with the tubular reactor. Certain specific catalyst particles are also provided.
1. A catalytic system comprising:
a. a tubular reactor having a cylindrical form around an axis A-A; the internal surface of said tubular reactor having an internal diameter D and an internal radius of curvature R, defined in a plane perpendicular to the axis A-A;
b. at least one catalyst particle located in said tubular reactor, wherein the catalyst particle has a three-dimensional form with a primary length axis L, wherein each catalyst particle comprises:
a first end-face and a second end-face being arranged perpendicular to said primary axis L at least in the region in which they meet said primary axis L, and
first and second sidewalls extending between the first and second end-faces, each of said sidewalls having a curved profile in a cross-section perpendicular to the primary axis L, wherein said first and second sidewalls each independently have an external radius of curvature R1, R2 in said plane being 0.4-0.99 times the internal radius of curvature R of the tubular reactor,
and wherein the maximum width D1 of the catalyst particle, measured in a plane defined perpendicular to the primary axis L, is less than 0.25 times the internal diameter D of the tubular reactor,
and wherein 2×R1 is greater than D1; and 2×R2 is greater than D1.
2. The catalytic system according to claim 1 , wherein the external radii of curvature R1, R2 of each of the first and second sidewalls are the same.
3. The catalytic system according to claim 1 , wherein said catalyst particle consists of opposing first and second sidewalls extending between the first and second end-faces, and opposing third and fourth sidewalls extending between the first and second sidewalls and said first and second end-faces, each third and fourth sidewall having a curved profile in a plane defined perpendicular to the primary axis L;
wherein each of said third and fourth sidewalls independently has an external radius of curvature R3, R4 being 0.05-0.30 times the internal radius of curvature R of the tubular reactor, or;
wherein each of said third and fourth sidewalls independently has an elliptical profile in a cross-section perpendicular to the primary axis L.
4. The catalytic system according to claim 3 , wherein the external radii of curvature R3, R4 of each of the third and fourth sidewalls are the same.
5. The catalytic system according to claim 3 , wherein the transition between the first, second, third and fourth sidewalls is smooth.
6. The catalytic system according to claim 1 , wherein said catalyst particle comprises first, second and third sidewalls extending between the first and second end-faces, each of said sidewalls having a curved profile in a cross-section perpendicular to the primary axis L, wherein said first second and third sidewalls each independently have an external radius of curvature R1, R2, R3 in said plane being 0.5-0.99 times the internal radius of curvature R of the tubular reactor.
7. The catalytic system according to claim 1 , wherein at least one of said first end-face and said second end-face of said catalyst particle, has a convex form so as to define curved first and/or second end-faces of said catalyst particle.
8. The catalytic system according to claim 1 , wherein the catalyst particle comprises one or more through-channels extending from the first end-face of the catalyst particle to the second end-face of the catalyst particle.
9. The catalytic system according to claim 1 , wherein the tubular reactor is a steam methane reformer.
10. A catalytic system comprising:
a. a tubular reactor having a cylindrical form around an axis A-A; the internal surface of said tubular reactor having an internal diameter D and an internal radius of curvature R, defined in a plane perpendicular to the axis A-A;
b. at least one catalyst particle located in said tubular reactor,
wherein the catalyst particle has a three-dimensional shape comprising a body portion; said body portion being in the form of an elliptic cylinder and comprising a sidewall extending parallel to a primary axis L between a first end-face and a second end-face; wherein the first end-face and the second end-face are arranged perpendicular to said primary axis L at least in the region in which they cross said primary axis L; and
wherein the ellipse of said elliptic cylinder has a major axis 2a and a minor axis 2b, and a radius of curvature R5 defined as:
R
5
=
a
2
b
being 0.9-1.10 times the internal radius of curvature R of the tubular reactor,
and wherein the maximum width D1 of the catalyst particle, measured in a plane perpendicular to said primary axis L, is less than 0.25 times the diameter D of the tubular reactor.
11. The catalytic system according to claim 8 , wherein the maximum width D1 of the catalyst particle, measured in the semi-major axis a of said ellipse, in a plane perpendicular to said primary axis L, is less than 0.25 times the diameter D of the tubular reactor.
12. The catalytic system according to claim 10 , wherein at least one of said first end-face and said second end-face of said catalyst particle, has a convex form so as to define curved first and second end-faces of said catalyst particle.
13. The catalytic system according to claim 12 , wherein the catalyst particle comprises two or more through-channels, each of said through-channels having essentially the same cross-sectional area.