Search

US-20260125263-A1 - RADIANT SYNGAS COOLER

US20260125263A1US 20260125263 A1US20260125263 A1US 20260125263A1US-20260125263-A1

Abstract

A system comprising a gasifier comprising one or more burners configured to accept a carbonaceous fuel and an oxidant to produce a syngas and a molten slag; a throat configured to accept the syngas and molten slag from the gasifier; and a radiant syngas cooler positioned below the gasifier configured to accept the syngas and molten slag from the throat; wherein the throat comprises an outer wall and one or more fins extending radially inwards from the outer wall.

Inventors

  • Yan Zhao
  • Wei Xin
  • SHUIGANG LIU
  • Micah S. Kiffer
  • JEFFREY W. KLOOSTERMAN

Assignees

  • AIR PRODUCTS AND CHEMICALS, INC.

Dates

Publication Date
20260507
Application Date
20241105

Claims (15)

  1. 1 . A system comprising: a gasifier comprising one or more burners configured to accept a carbonaceous fuel and an oxidant to produce a syngas and a molten slag; a throat configured to accept the syngas and molten slag from the gasifier; and a radiant syngas cooler positioned below the gasifier configured to accept the syngas and molten slag from the throat; wherein the throat comprises an outer wall and one or more fins extending radially inwards from the outer wall.
  2. 2 . The system of claim 1 , wherein the outer wall comprises one or more conduits configured to transport a coolant.
  3. 3 . The system of claim 1 , wherein the one or more fins comprise one or more conduits configured to transport a coolant.
  4. 4 . The system of claim 1 , wherein the one or more fins are angled with respect to a line drawn from the intersection of the one or more fins with the outer wall of the throat to the center of the throat.
  5. 5 . The system of claim 4 , wherein the gasifier has a geometric center and wherein the one or more burners are angled with respect to a line drawn from the one or more burners to the geometric center of the burner.
  6. 6 . The system of claim 5 , wherein the angle of the one or more burners is in the same direction as the angle of the one or more fins.
  7. 7 . The system of claim 1 , wherein the one or more fins extend into the throat by a value between 1/12 and ½ of the distance from the outer wall of the throat to the center of the throat.
  8. 8 . The system of claim 1 , wherein the one or more fins terminate in an axial direction ranging from 0.5 m to 2 m from an outlet of the throat.
  9. 9 . The system of claim 8 , wherein a bottom edge of the one or more fins makes an angle greater than 90° with the outer wall of the throat at the point where the one or more fins terminate in an axial direction towards an outlet of the throat.
  10. 10 . The system of claim 1 , wherein the one or more fins have a fin length in the axial direction of at least 0.5 times of a distance from the outer wall of the throat to the center of the throat.
  11. 11 . A method comprising: providing a carbonaceous fuel and an oxidant to a gasifier comprising one or more burners to produce a syngas and a molten slag; providing the syngas and the molten slag to a throat configured to accept the syngas and molten slag from the gasifier; and providing the syngas and the molten slag from the throat to a radiant syngas cooler positioned below the gasifier configured to accept the syngas and molten slag from the throat; wherein the throat comprises an outer wall and one or more fins extending radially inwards from the outer wall.
  12. 12 . The method of claim 11 , wherein the slag has a viscosity less than 100 Pa*sec.
  13. 13 . The method of claim 11 , wherein the one or more fins are angled with respect to a line drawn from the intersection of the one or more fins with the outer wall of the throat to the center of the throat.
  14. 14 . The method of claim 13 , wherein the syngas stream has a swirl velocity in the same direction as the angle of the one or more fins.
  15. 15 . The method of claim 11 , further comprising flowing a coolant through an interior space of the outer wall of the throat and/or the one or more fins.

Description

BACKGROUND The partial combustion or gasification of carbonaceous fuels to produce synthesis gases, or syngas, having value as residential and industrial fuels, as starting materials for synthesis of chemicals and fuels, and as an energy source for generation of electricity has long been recognized and practiced on varying scales throughout the world. The term “carbonaceous fuel” as used herein is intended to also include various gas-carried and/or liquid-carried solid combustible materials and mixtures thereof, and may be selected from the group of coal, coke from coal, coal liquefaction residues, petroleum coke, soot, biomass, and particulate solids derived from oil shale, tar sands and pitch. The coal may be of any type, including lignite, sub-bituminous, bituminous and anthracite. A gasification reactor produces hot syngas comprising hydrogen and carbon monoxide which may be contacted with one or more heat exchangers to recover high quality heat as steam. One such heat exchanger is a radiant syngas cooler, or RSC. An RSC is a large and complex piece of capital equipment that provides a large heat exchange area within the pressure vessel in which radiative heat transfer plays a significant role. A key challenge to the use of an RSC is preventing molten slag from adhering to the heat exchange surface before solidifying, which may foul the cooling surface. In a gasifier with swirling flow, molten slag may be flung outwards towards the cooling surface, making fouling even more likely. BRIEF DESCRIPTION OF THE DRAWINGS The present invention will hereinafter be described in conjunction with the appended figures wherein like numerals denote like elements: FIG. 1 is a schematic view of a cutaway profile of a gasifier, throat, and radiant syngas cooler according to one or more aspects of the present invention. FIG. 2 is a top-down plan view of a gasifier in a swirling flow configuration. FIG. 3 is a top-down plan view of the gasifier of FIG. 2, zoomed in on a view of a throat with fins. FIG. 4 is a top-down cross-section of a throat in which the outer wall and one or more fins comprise cooling tubes. FIG. 5 is a modification of FIG. 4 in which the one or more fins are positioned with a fin angle. FIG. 6 is a side view of a fin according to one or more aspects of the present invention. FIG. 7A is a simplified plot of simulated tangential velocities for a throat with 14 fins with zero fin angle. FIG. 7B is a simplified plot of simulated axial velocities for a throat with 14 fins with zero fin angle. FIG. 8A is a drawing illustrating the qualitative effect of having no fins in the throat on the flow patterns of the syngas. FIG. 8B is a drawing illustrating the qualitative effect of having a throat with one or more fins having zero fin angle on the flow patterns of the syngas. FIG. 8C is a drawing illustrating the qualitative effect of having a throat with one or more fins having a fin angle in the same direction as the swirling flow on the flow patterns of the syngas. DETAILED DESCRIPTION The ensuing detailed description provides preferred exemplary embodiments only, and is not intended to limit the scope, applicability, or configuration of the invention. Rather, the ensuing detailed description of the preferred exemplary embodiments will provide those skilled in the art with an enabling description for implementing the preferred exemplary embodiments of the invention. Various changes may be made in the function and arrangement of elements without departing from the spirit and scope of the invention, as set forth in the appended claims. The articles “a” or “an” as used herein mean one or more when applied to any feature in embodiments of the present invention described in the specification and claims. The use of “a” and “an” does not limit the meaning to a single feature unless such a limit is specifically stated. The article “the” preceding singular or plural nouns or noun phrases denotes a particular specified feature or particular specified features and may have a singular or plural connotation depending upon the context in which it is used. The term “and/or” placed between a first entity and a second entity includes any of the meanings of (1) only the first entity, (2) only the second entity, or (3) the first entity and the second entity. The term “and/or” placed between the last two entities of a list of 3 or more entities means at least one of the entities in the list including any specific combination of entities in this list. For example, “A, B and/or C” has the same meaning as “A and/or B and/or C” and comprises the following combinations of A, B and C: (1) only A, (2) only B, (3) only C, (4) A and B but not C, (5) A and C but not B, (6) B and C but not A, and (7) A and B and C. The adjective “any”means one, some, or all, indiscriminately of quantity. In accordance with the present embodiments, a gasifier is arranged vertically above a radiant syngas cooler. The gasifier may have one or more injectors to d