A SHELL-AND-TUBE TYPE REACTOR FOR REFORMING NATURAL GAS AND A PREPARATION METHOD OF SYNGAS OR HYDROGEN GAS BY USING THE SAME

Abstract

The present invention relates to a shell-and-tube type reactor for reforming natural gas and a method for manufacturing syngas or hydrogen gas by using the same. According to the present invention, a shell-and-tube type reactor for reforming natural gas comprises a reaction catalyst for reforming natural gas, which is filled in a reactor shell; at least one tube for separating hydrogen; and a tube for an exothermic reaction or a tube type heat-exchanger for heating, which is disposed at the center of the reactor so as to have excellent operating efficiency and enable production of high-purity hydrogen and collection of carbon dioxide simultaneously along with a reaction.

Claims

1. A shell-and-tube type reactor for reforming natural gas, comprising a reaction catalyst for reforming natural gas, which is filled in a reactor shell; at least one tube for separating hydrogen; and a tube for an exothermic reaction or a tube type heat-exchanger for heating, which is disposed at the center of the reactor.

2. The shell-and-tube type reactor of claim 1, wherein the upper or lower part of the tube for the exothermic reaction or the tube type heat-exchanger for heating and the upper or lower part of the tube for separating hydrogen are fixed in the reactor by a tube sheet.

3. The shell-and-tube type reactor of claim 1, wherein the temperature (T.sub.1) of the tube for an exothermic reaction or the tube type heat-exchanger for heating is higher than the temperature (T.sub.2) of the reaction catalyst filled in the reactor shell, and wherein syngas is formed via an endothermic reaction by the reaction catalyst for reforming natural gas in the reactor shell as heat moves radially to the outside of the reactor from the tube for the exothermic reaction or the tube type heat-exchanger, which is disposed at the center of the reactor.

4. The shell-and-tube type reactor of claim 1, wherein hydrogen among the syngas formed by the reaction catalyst for forming natural gas in the reactor shell penetrates the tube for separating hydrogen and is then concentrated or separated towards the inside of the tube for separating hydrogen.

5. The shell-and-tube type reactor of claim 1, wherein a hydrogen separation membrane is formed outside or inside of the tube for separating hydrogen.

6. The shell-and-tube type reactor of claim 1, wherein the tube for separating hydrogen comprises a porous support; a diffusion barrier located on the porous support; and a palladium-based separation membrane as a hydrogen separation layer located on the diffusion barrier.

7. The shell-and-tube type reactor of claim 1, wherein the tube for separating hydrogen is formed from a ceramic comprising silica, alumina, zirconia, yttria, ceria, YSZ, or a combination thereof; a metal comprising nickel, copper, iron, palladium, ruthenium, rhodium, platinum, or a combination thereof; or a complex composition in which the metal and ceramic are mixed.

8. The shell-and-tube type reactor of claim 1, wherein the tube for separating hydrogen comprises a porous support, a hydrogen separation layer located on a first side of the porous support; and a catalyst layer for a water-gas-shift reaction (WGS) located on the hydrogen separation layer or a second side of the porous support.

9. The shell-and-tube type reactor of claim 1, wherein the reactor has a steam methane reforming (SMR) region at the front and a water-gas-shift (WGS) region at the back in the direction of moving gas of the reactor, wherein the regions are controlled by a temperature difference.

10. The shell-and-tube type reactor of claim 9, wherein the SMR region is set to a temperature range of 500° C. to 600° C., and the WGS region is set to a temperature range of 300° C. to 400° C.

11. The shell-and-tube type reactor of claim 1, wherein the tube for the exothermic reaction is filled with at least one catalyst which can catalyze the exothermic reaction.

12. The shell-and-tube type reactor of claim 1, wherein the reactor has a means of supplying natural gas and steam into the inside of the reactor shell from the bottom part of the reactor, and a means of exhausting fluid, in which hydrogen among the syngas formed by the reaction catalyst for reforming natural gas in the reactor shell is removed, and a means of exhausting concentrated or separated hydrogen from the tube for separating hydrogen in the upper part of the reactor.

13. The shell-and-tube type reactor of claim 1, wherein the reaction catalyst for reforming natural gas, which is filled into the reactor shell, is a metal foam-based catalyst for a reforming reaction.

14. The shell-and-tube type reactor of claim 13, wherein when the catalyst is coated onto the metal foam, a pole is inserted into the reactor in order to prevent interdiffusion resulting from contact between the tube for separating hydrogen and metal foam.

15. A shell-and-tube type reactor for reforming natural gas, comprising a tube for an exothermic reaction or a tube type heat-exchanger for heating, which is disposed at the center of the reactor; and a reaction catalyst for reforming natural gas, which is filled in a reactor shell.

16. A method for manufacturing syngas or hydrogen from natural gas by using the shell-and-tube type reactor for reforming natural gas of claim 1, wherein the shell-and-tube type reactor for reforming natural gas comprises a reaction catalyst for reforming natural gas, which is filled in a reactor shell; at least one tube for separating hydrogen; and a tube for an exothermic reaction or a tube type heat-exchanger for heating, which is disposed at the center of the reactor.

17. A method for manufacturing syngas or hydrogen from natural gas by using the shell-and-tube type reactor for reforming natural gas of claim 15, wherein the shell-and-tube type reactor for reforming natural gas comprises a tube for an exothermic reaction or a tube type heat-exchanger for heating, which is disposed at the center of the reactor; and a reaction catalyst for reforming natural gas, which is filled in a reactor shell.

18. The method for manufacturing syngas or hydrogen from natural gas of claim 16, wherein the temperature (T.sub.1) of the tube for an exothermic reaction or the tube type heat-exchanger for heating is higher than the temperature (T.sub.2) of the reaction catalyst filled in the reactor shell, and wherein syngas is formed via an endothermic reaction by the reaction catalyst for reforming natural gas in the reactor shell as heat moves radially to the outside of the reactor from the tube for the exothermic reaction or the tube type heat-exchanger, which is disposed at the center of the reactor.

19. The method for manufacturing syngas or hydrogen from natural gas of claim 16, wherein hydrogen among the syngas formed by the reaction catalyst for forming natural gas in the reactor shell penetrates the tube for separating hydrogen and is then concentrated or separated towards the inside of the tube for separating hydrogen.

20. The method for manufacturing syngas or hydrogen from natural gas of claim 17, wherein the temperature (T.sub.1) of the tube for an exothermic reaction or the tube type heat-exchanger for heating is higher than the temperature (T.sub.2) of the reaction catalyst filled in the reactor shell, and wherein syngas is formed via an endotheimic reaction by the reaction catalyst for reforming natural gas in the reactor shell as heat moves radially to the outside of the reactor from the tube for the exothermic reaction or the tube type heat-exchanger, which is disposed at the center of the reactor.

Description

BRIEF DESCRIPTION OF FIGURES

[0089] FIG. 1 shows a schematic diagram of the reaction process comparing the conventional reformer (FIG. 1a) and the separation membrane reformers according to one embodiment of the present invention (FIGS. 1b and 1c). FIG. 1b shows the separation membrane reactor capable of separating hydrogen simultaneously with the reforming reaction of natural gas, and FIG. 1c shows the separation membrane reactor capable of separating hydrogen simultaneously with the reforming reaction of natural gas, in which a PSA device is connected for hydrogen purification.

[0090] FIG. 2 shows a schematic diagram illustrating the process in which the production of high-purity hydrogen and the collection of carbon dioxide occur simultaneously with the reforming reaction of natural gas in the separation membrane reactor according to one embodiment of the present invention.

[0091] FIG. 3 shows a schematic diagram illustrating the structure of the tube-type separation membrane module according to one embodiment of the present invention.

[0092] FIG. 4 shows a flow-sheet illustrating the production of high-purity hydrogen and pre-combustion carbon capture storage (CCS) which occur simultaneously using the separation membrane reactor.

[0093] FIG. 5a shows a schematic diagram illustrating the cross-sectional structure of the tube for separating hydrogen which can be used in the separation membrane reactor of FIG. 1b.

[0094] FIG. 5b shows a schematic diagram illustrating the cross-sectional structure of the tube for separating hydrogen which can be used in the separation membrane reactor of FIG. 1c.

[0095] FIG. 6 shows a schematic diagram illustrating the situation where a temperature gradient is observed in the separation membrane reactor in which the hydrogen purification device is connected to the rear end as shown in FIG. 1c.

BEST MODE

[0096] Hereinafter, the present invention will be described in more detail. However, the following examples are provided for illustrative purposes only, and the scope of the present invention should not be limited thereto in any manner.

Example 1: Manufacture of Separation Membrane Reactor of the Present Invention

[0097] As illustrated in FIG. 1c and FIG. 3, the tube-type separation membrane module was manufactured according to one embodiment of the present invention, and the reaction process was designed. The Pd separation membrane having the following performance was used as a hydrogen separation membrane.

[0098] Performance of Pd separation membrane: hydrogen permeability=40 ml/min/cm.sup.2, hydrogen/nitrogen selectivity=24 (at ΔP=0.5 bar, 500° C.)

Experimental Example 1: Examination of Operating Efficiency of Separation Membrane Reactor of the Present Invention

[0099] The reforming of natural gas and hydrogen separation process were performed simultaneously using the tube-type separation membrane module manufactured in Example 1 above, and subsequently, the operating efficiency was examined.

[0100] The experimental conditions were as follows.

[0101] GHSV=1000/h, S/C (steam to carbon ratio)=3.0, reaction temperature: 550° C..fwdarw.equilibrium methane conversion rate=approx. 55% at 1 bar

[0102] The results thereof are shown in Table 1 below.

TABLE-US-00001 TABLE 1 Pressure Methane difference Operating conversion CO concentration (bar) pressure rate (%) (%) H.sub.2/CO ratio 0 1.0 48 1.6 41 0.5 1.5 48.4 1.7 39 1.0 2.0 54 1.9 37 1.5 2.5 63 2.1 35 2 3.0 69.5 2.3 33

[0103] It can be confirmed through Table 1 that the separation membrane reactor of the present invention shows an excellent methane conversion rate and hydrogen separating-ability even at the low temperature of 550° C. under the low pressure range of 1.0 bar to 3.0 bar.

Example 2: Manufacture of Separation Membrane Reactor of the Present Invention

[0104] As illustrated in FIG. 1c and FIG. 3, the tube-type separation membrane module was manufactured according to one embodiment of the present invention, and the reaction process was designed. The Pd separation membrane having the following performance was used as a hydrogen separation membrane.

[0105] Performance of Pd separation membrane: hydrogen permeability=50 ml/min/cm.sup.2, hydrogen/nitrogen selectivity=30 (at ΔP=0.5 bar, 500° C.)

Experimental Example 2: Examination of Operating Efficiency of Separation Membrane Reactor of the Present Invention

[0106] The reforming of natural gas and hydrogen separation process were performed simultaneously using the tube-type separation membrane module manufactured in Example 2 above, and subsequently, the operating efficiency was examined.

[0107] The experimental conditions were as follows.

[0108] GHSV=3500/h, S/C (steam to carbon ratio)=3.0, reaction temperature: 500° C..fwdarw.equilibrium methane conversion rate=approx. 42% at 1 bar

[0109] The results thereof are shown in Table 2 below.

TABLE-US-00002 TABLE 2 Pressure Methane difference Operating conversion CO concentration (bar) pressure rate (%) (%) H.sub.2/CO ratio 1.0 2.0 36 1.2 40.5 1.5 2.0 53 1.5 42.2 1.0 3.0 68 1.7 42.1 2.5 3.5 77 1.9 41.4

[0110] When comparing Examples 1 and 2, it can be confirmed that a similar or higher methane conversion rate can be observed even at low temperature as the hydrogen permeability and selectively increase.