INSULATING LINING, USE OF AN ALUMINA-BASED PART, REACTOR FOR HYDROCARBON REFORMING AND PROCESS FOR HYDROCARBON REFORMING

Abstract

The invention refers to an insulating lining, a use of an alumina-based part, a reactor for hydrocarbon reforming and a process for hydrocarbon reforming.

Claims

1. An insulating lining (1) for insulating a reducing high-temperature atmosphere (6), comprising the following features: 1.1 a plurality of layers (2, 3, 4, 5), wherein said plurality of layers (2, 3, 4, 5) are 1.1.1 running parallel and 1.1.2 adjacent to each other; wherein 1.2 said plurality of layers (2, 3, 4, 5) comprise a first layer (2) and at least one second layer (3, 4, 5); wherein 1.3 said at least one second layer (3, 4, 5) 1.3.1 is comprised of high temperature resistant material and 1.3.2 comprises at least two layers; wherein 1.4 said first layer (2) 1.4.1 comprises alumina-based parts (101, 201), wherein 1.4.2 said alumina-based parts (101, 201) comprise at least one hollow alumina-based part (101), said at least one hollow alumina-based part (101) comprising at least one cavity (108), wherein 1.4.3 said alumina-based parts (101, 201) form a masonry and wherein 1.4.4 said alumina-based parts (101) provide a tongue-and-groove system.

2. The insulating lining (1) according to claim 1, wherein the alumina content of said at least one hollow alumina-based part (101) is at least 60% by mass, relative to the mass of said at least one hollow alumina-based part (101).

3. The insulating lining (1) according to claim 1, wherein said at least one cavity (108) has a volume of at least 5% by volume, relative to the volume of said at least one hollow alumina-based part (101).

4. The insulating lining (1) according to claim 1, wherein said high temperature resistant material is refractory material.

5. The insulating lining (1) according to claim 1, wherein said high temperature resistant material is based on alumina.

6. Use of a hollow alumina-based part (101), comprising at least one cavity (108), in an insulating lining (1) according to claim 1 for insulating a reducing high-temperature atmosphere (6).

7. The use according to claim 6, wherein said reducing high-temperature atmosphere (6) is a reducing high-temperature atmosphere of a hydrocarbon reforming process, preferably a secondary hydrocarbon reforming process.

8. A reactor (301) for a hydrocarbon reforming process, comprising the following features: 8.1 a chamber (302); 8.2 means (303) for providing a reducing high-temperature atmosphere (6) for a hydrocarbon reforming process within said chamber (302); 8.3 a wall (304) enclosing said chamber (302); wherein 8.4 said wall (304) comprises said insulating lining (1) according to claim 1.

9. A hydrocarbon reforming process, comprising the following steps: A. providing a reactor (301) according to claim 8; B. providing a reducing high-temperature atmosphere (6) for a hydrocarbon reforming process within said chamber (302); C. carrying out a hydrocarbon reforming process within said chamber (302).

Description

[0087] The figures show in

[0088] FIG. 1 a sectional view, perpendicular to the course of the layers, of an exemplary embodiment of a lining according to the invention;

[0089] FIG. 2 a sectional view of an exemplary embodiment of a reactor according to the invention, the chamber of which comprises the insulating lining according to FIG. 1;

[0090] FIG. 3 a perspective view of a hollow alumina-based part of the first layer of the insulating lining according to FIG. 1;

[0091] FIG. 4 a perspective view of an alumina-based part of the first layer of the insulating lining according to FIG. 1; and

[0092] FIG. 5 a perspective view of a part of the first layer of the lining in detail.

[0093] FIG. 1 shows a cross-sectional view of a highly schematized embodiment of an insulating lining according to the invention, the section being perpendicular to the course of the layers of the lining. In its entirety, the insulating lining in FIG. 1 is identified by the reference sign 1.

[0094] The insulating lining 1 comprises a total of four layers 2, 3, 4, 5, namely a first layer 2 and three second layers 3, 4, 5. The four layers 2, 3, 4, 5 run parallel and adjacent to each other.

[0095] The insulating lining 1 comprises two opposite, outer layers, namely the (in FIG. 1 left) outer first layer 2 and the (in FIG. 1 right) outer second layer 5. Between these outer layers 2, 5 are arranged the further two layers 3, 4, the second layer 3 being arranged immediately adjacent to the first layer 2 and the second layer 4 being arranged immediately adjacent to the second layer 5, and the second layers 3, 4 in turn being arranged immediately adjacent to one another.

[0096] The insulating lining 1 is arranged such that, when the insulating lining 1 is in use, a reducing high-temperature atmosphere 6 is in direct contact with the first layer 2. Accordingly, the second layer 5 is arranged on the opposite, outer and thus cold side of the insulating lining 1.

[0097] The first layer 2 comprises the alumina-based parts 101, 201 shown in FIGS. 3, 4.

[0098] The alumina-based parts 101, 201 of the first layer 2 comprise the hollow alumina-based parts 101 as shown in FIG. 3. The alumina-based parts 101, 201 are provided as prefabricated bricks, manufactured by pressing, firing and then provided for the manufacture of the insulating lining 1.

[0099] The hollow alumina-based parts 101 have a substantially cuboid outer contour with a back side 102, an opposing front side 103, a top side 106, an opposing bottom side 107, a left side 104, and an opposing right side 105. Each hollow alumina-based part 101 includes a cavity 108. The cavity 108 is substantially channel-shaped and has a substantially rectangular cross-sectional area, perpendicular to the longitudinal axis of the channel or cavity 108. The cavity 108 extends through the hollow alumina-based part 101 between the opposing top and bottom surfaces 106, 107 and is open to each of the top and bottom surfaces 106, 107. The cavity 108 has a volume of about 0.67 dm.sup.3, which is about 15% by volume of the volume of the hollow alumina-based part 101.

[0100] The hollow alumina-based parts 101 are made of sintered fused magnesia and have the following chemical composition, determined according to ISO 12677 (fired substance at 1,025 C.), relative to the total mass of the hollow alumina-based part 101: [0101] Al.sub.2O.sub.3: 99.3% by mass [0102] Other: 0.7% by mass

[0103] Each oxide other than Al.sub.2O.sub.3 is present in a proportion below 0.3% by mass.

[0104] The hollow alumina-based parts 101 have an open porosity (according to ISO 5017) of 17.5% by volume and a thermal conductivity (according to EN 821-2) at 1,200 C. of 3.15 W/m K.

[0105] In the embodiment shown, the cavity 108 is filled with ceramic fibers (not shown in the figures). The ceramic fibers are alumina-based fibers having a chemical composition with 96% by mass Al.sub.2O.sub.3.

[0106] In addition to the hollow alumina-based parts 101, the first layer 2 further comprises the alumina-based parts 201. The alumina-based parts 201 are made of the same material as the hollow alumina-based parts 101 and thus have the same chemical and physical properties as the hollow alumina-based parts 101. The alumina-based parts 201 have a substantially cuboid outer contour.

[0107] The hollow alumina-based parts 101 have grooves 109 and tongues 110 on their surfaces. The alumina-based parts 201 also have grooves 202 and tongues 203 on their surfaces.

[0108] In FIGS. 3 and 4, the hollow alumina-based parts 101 and the alumina-based parts 201 are not shown in their use position, i.e., in the position used in the insulating lining 1. The use-position is shown in FIG. 5.

[0109] FIG. 5 shows in detail a part of the first layer 2 of the insulating lining 1. As shown in FIG. 5, in the first layer 2, the alumina-based parts 201 and the hollow alumina-based parts 101 form a jointless masonry structure. The grooves 109 and tongues 110 of the hollow alumina-based parts 101 and the grooves 202 and tongues 203 of the alumina-based parts 201 of adjacent alumina-based parts 101, 201 interlock in such a way that a mechanically stable, jointless masonry is provided. In the embodiment shown, the hollow alumina-based parts 101 are arranged in five rows one above the other, wherein within each of the five rows hollow alumina-based parts 101 are arranged one beside the other. The five rows are arranged one above the other, each offset by half the width of the front side 103 of the hollow alumina-based parts 101, giving the masonry additional stability. On top row of the five rows of the hollow alumina-based parts 101, alumina-based parts 201 are arranged in such a way that the cavities 108 are closed on the top surface 106 by the alumina-based parts 201.

[0110] In the first layer 2, the hollow alumina-based parts 101 are each arranged such that the front side 103 faces the reducing high-temperature atmosphere 6 and the top side 106 faces upward.

[0111] The second layer 5 of the insulating lining 1, which is opposite the first layer 2, consists of a refractory ceramic castable of hydraulically bonded fireclay, lightweight raw materials of the following chemical composition (determined in accordance with ISO 12677 on substance fired at 1,025 C.): [0112] Al.sub.2O.sub.3: 65.0% by mass [0113] SiO.sub.2: 24.7% by mass [0114] CaO: 8.2% by mass [0115] Other: 2.1% by mass

[0116] Each oxide other than Al.sub.2O.sub.3, SiO.sub.2 and CaO is present in a proportion below 0.8% by mass.

[0117] Layer 4, adjacent to the second layer 5, also consists of a refractory ceramic castable of hollowsphere fused alumina of the following chemical composition (determined according to ISO 12677 on substance fired at 1,025 C.): [0118] Al.sub.2O.sub.3: 92.0% by mass [0119] CaO: 6.6% by mass [0120] Other: 1.4% by mass

[0121] Each oxide other than Al.sub.2O.sub.3 and CaO is present in a proportion below 0.6% by mass.

[0122] The thermal conductivity according to Dr. Klasse (Klasse, F.; Heinz, A.; Hein, J.: Vergleichsverfahren zur Ermittlung der Wrmeleitfhigkeit keramischer Werkstoffe. Ber. DKG 34 (1957), S. 183-189) at 1,200 C. is 0.89 W/mK.

[0123] Layer 3, located between layer 4 and the first layer 2, consists of ceramic-bonded bricks of hollowsphere fused alumina. The bricks of layer 3 have the following chemical composition according to ISO 12677 (fired substance at 1,025 C.): [0124] Al.sub.2O.sub.3: 99.0% by mass [0125] Other: 1.0% by mass

[0126] Each oxide other than Al.sub.2O.sub.3 is present in a proportion below 0.7% by mass.

[0127] The thermal conductivity at 1,200 C. according to ASTM C182 is 1.17 W/mK.

[0128] The insulating layer only has a small thickness, with a thickness of the first layer 2 of 175 mm, the thickness of layer 3 of 116 mm, the thickness of layer 4 of 136 mm, and the thickness of layer 5 of 150 mm.

[0129] The insulating lining 1 shown in the embodiment is used to insulate a reducing high-temperature atmosphere of an autothermal reforming process (ATR). A reactor for carrying out such an autothermal reforming process is shown in highly schematized form in FIG. 2.

[0130] The reactor 301 according to FIG. 2 comprises a chamber 302 and means 303 by which a reducing high temperature atmosphere 6 can be provided for carrying out an autothermal reforming process in the chamber 302. The chamber 302 is enclosed by a wall 304. The wall 304 comprises an insulating lining 1 according to the embodiment shown in FIGS. 1, 3 and 4. The insulating lining 1 is arranged such that the first layer 2 faces the chamber 302 or a reducing high temperature atmosphere 6 formed in the chamber 302, such that the first layer 2 directly contacts the reducing high temperature atmosphere 6 during operation of the reactor 301.

[0131] According to the embodiment, a reducing high temperature atmosphere 6 is provided in the chamber 302 by means 303. The temperature of this atmosphere is about 1,250 C. The atmosphere is a reducing atmosphere based on synthesis gas, namely, a mixture of gases based on carbon monoxide (CO) and hydrogen (H.sub.2).

[0132] This reducing high temperature atmosphere 6 could be excellently isolated by the insulating lining 1. The temperature at the side of the first layer 2 facing layer 3 was only 943 C. The temperature at the outer surface of the outer layer 5 was only 148 C. At the same time, the insulating lining 1 proved to be mechanically stable, with the first layer 2 proving to withstand the reducing high-temperature atmosphere 6.