Corrosion-protected reformer tube with internal heat exchange

Patent metadata

Field	Value
Publication number	US-11780730-B2
Application number	US-201716470720-A
Country	US
Kind code	B2
Filing date	Nov 21, 2017
Priority date	Dec 19, 2016
Publication date	Oct 10, 2023
Grant date	Oct 10, 2023

Abstract

A reformer tube for producing synthesis gas by steam reforming of hydrocarbon-containing input gases is proposed wherean outer shell tube is divided by means of a separating tray into the reaction chamber and an exit chamber,a dumped bed of a steam-reforming-active, solid catalyst is arranged in the reaction chamber,at least one heat exchanger tube is arranged inside the reaction chamber and inside the dumped catalyst bed whose entry end is in fluid connection with the catalyst bed and whose exit end is in fluid connection with the exit chamber, whereingas-contacted parts of the reformer tube, in particular the at least one heat exchanger tube, are fabricated from a nickel-based alloy and coated on their inside with an aluminum diffusion layer.

First claim

The invention claimed is:

1. A reformer tube for converting a hydrocarbon-containing feed into a synthesis gas product comprising carbon oxides and hydrogen under steam reforming conditions, the reformer tube comprising:
(a) an outer, pressurized shell tube, wherein the outer, pressurized shell tube is divided into a reaction chamber and an exit chamber by means of a separating tray and wherein the reaction chamber is externally heatable;
(b) a dumped bed of a steam-reforming-active solid catalyst arranged in the reaction chamber;
(c) an entry for an input gas stream comprising an input material arranged in the region of the reaction chamber, wherein the entry for the input gas stream is in fluid connection with the dumped catalyst bed;
(d) at least one heat exchanger tube arranged inside the reaction chamber and inside the dumped catalyst bed whose entry end is in fluid connection with the catalyst bed and whose exit end is in fluid connection with the exit chamber, wherein the input gas stream after entry into the reaction chamber initially flows through the catalyst bed and subsequently flows through the heat exchanger tube in countercurrent and is thus continually cooled and wherein the heat exchanger tube is in a heat exchange relationship with the dumped catalyst bed and the input gas stream flowing therethrough; and
(e) a collection conduit for the synthesis gas product which is in fluid connection with the exit chamber,
wherein gas-contacted metallic components of the reformer tube are made of a nickel-based alloy, wherein each gas-contacted metallic component has a gas-contacted surface, wherein the gas-contacted surfaces having a temperature during operation under defined steam reforming conditions of between 650° C. and 800° C. are equipped with an aluminum diffusion layer that is configured to retard corrosion of the gas-contacted surfaces.

2. The reformer tube according to claim 1 , wherein at least one heat exchanger tube is made of a nickel-based alloy and is equipped on the inside and on the outside with an aluminum diffusion layer.

3. The reformer tube according to claim 1 , wherein a sufficient amount of aluminum is applied to the inner wall of the at least one heat exchanger tube to ensure that the aluminum concentration in the diffusion layer is at least 20 wt %.

4. The reformer tube according to claim 1 , wherein the at least one heat exchanger tube is helically coiled along at least a portion of a length of the at least one heat exchanger tube.

5. The reformer tube according to claim 1 , wherein at least two exchanger tubes are arranged inside the dumped catalyst bed.

6. The reformer tube according to claim 1 , wherein the separating tray is configured to provide gaseous separation between the reaction chamber and the exit chamber except for the input gas stream flowing through the at least one heat exchanger tube from the reaction chamber to the exit chamber.

7. The reformer tube according to claim 1 , wherein the separating tray is secured in place by the separating tray.

8. The reformer tube according to claim 1 , wherein the separating tray comprises an absence of perforations that allow gaseous flow directly from the reaction chamber into the exit chamber.

9. The reformer tube according to claim 1 , wherein the separating tray is configured to prevent gaseous flow directly from the reaction chamber into the exit chamber.

10. A reformer furnace comprising refractorily lined or refractorily faced walls, a ceiling and a floor, an interior formed thereby, at least a one reformer tube according to claim 1 , and at least one burner for heating the reformer tube is arranged in the interior or in a secondary space in fluid connection with the interior in respect of the burner flue gases.

11. The reformer furnace according to claim 10 , wherein the at least one reformer tube is arranged in the interior in free-hanging or free-standing fashion, wherein the portion of the outer, pressurized shell tube comprising the reaction chamber is arranged in the interior and the portion of the outer, pressurized shell tube comprising the exit chamber is at least partially fed through the ceiling or the floor.

12. The reformer furnace according to claim 10 , wherein a multiplicity of reformer tubes and burners are arranged in the interior such that the longitudinal axes of the flames generated by the burners are oriented parallel to the longitudinal axes of the reformer tubes.

13. A process for producing synthesis gas by catalytic steam reforming of hydrocarbon-containing input materials under steam reforming conditions in the presence of a steam-reforming-active, solid catalyst comprising the steps of:
a. provision of an input gas stream comprising the input material and addition of reforming steam, wherein a steam-carbon ratio S/C arises from the molar ratio of the supplied reforming steam amount and the carbon present in the input material,
b. catalytic conversion of the input material under steam reforming conditions into a synthesis gas products comprising carbon oxides and hydrogen, wherein the steam reforming conditions comprise operating temperatures between 650° C. and 800° C. for the gas-contacted surfaces,
c. discharging and optional workup of the synthesis gas product,
wherein the catalytic conversion in step (b) is effected in a reformer tube according to claim 1 .

Assignees

• Air Liquide
• Air Liquide

Inventors

• Ulber Dieter
• Doublet Sebastien
• Del-Gallo Pascal
• Prost Laurent

Classifications

• C01B3/384 Primary

  with external heating of the catalyst · CPC title

• B01J8/025 Primary

  in a cylindrical shaped bed · CPC title

• B01J8/062

  being installed in a furnace · CPC title

• B01J8/065

  Feeding reactive fluids · CPC title

• B01J8/067

  Heating or cooling the reactor (B01J8/062 takes precedence) · CPC title