Apparatus and process for preparing acetylene and synthesis gas

Abstract

An apparatus (10) for preparation of acetylene and synthesis gas by partial oxidation of hydrocarbons with oxygen is proposed, comprising a reactor (12). The reactor (12) has a burner block (14) with a firing space for acetylene preparation, a secondary space (18) formed within the burner block (14), and an annular space (20) surrounding the secondary space (18). The burner block (14) has holes (22) for supply of a stream of a mixture of hydrocarbons and oxygen to the firing space and holes (24) for supply of a stream of auxiliary oxygen to the firing space. The holes (24) for supply of a stream of auxiliary oxygen to the firing space are connected to the secondary space (18). The secondary space (18) is connected to the annular space (20). There is a further proposal of a process for preparing acetylene and synthesis gas by partial oxidation of hydrocarbons with oxygen.

Claims

1. An apparatus, comprising a reactor, wherein the reactor has a burner block with a firing space for acetylene preparation, a secondary space formed within the burner block, and an annular space surrounding the secondary space, wherein the burner block has holes for supply of a stream of a mixture of hydrocarbons and oxygen to the firing space and holes for supply of a stream of auxiliary oxygen to the firing space, wherein the holes for supply of a stream of auxiliary oxygen to the firing space are connected to the secondary space, wherein the secondary space is connected to the annular space, wherein the secondary space is separated from the annular space by a wall, said wall having orifices to connect the holes for supply of a stream of auxiliary oxygen to the annular space, wherein the annular space is connected to at least one feed for supply of auxiliary oxygen.

2. The apparatus according to claim 1, wherein the annular space concentrically surrounds the secondary space.

3. The apparatus according to claim 1, wherein the annular space is essentially circular.

4. The apparatus according to claim 1, wherein the orifices are distributed homogeneously in the wall along a circumference of the burner block.

5. The apparatus according to claim 1, wherein the orifices have a greater cross-sectional area than the holes for supply of a stream of auxiliary oxygen to the firing space with the annular space.

6. The apparatus according to claim 1, wherein ratio of a sum total of cross-sectional areas of the orifices to a cross-sectional area of the annular space is from 0.05 to 1.

7. The apparatus according to claim 1, wherein the holes for supply of a stream of auxiliary oxygen to the firing space are arranged in a regular or irregular pattern in the burner block.

8. The apparatus according to claim 1, wherein a ratio of a sum total of cross-sectional areas of the holes for supply of a stream of auxiliary oxygen to the firing space to a cross-sectional area of the burner block is from 0.0001 to 0.1.

9. A process for preparing acetylene and synthesis gas by partial oxidation of hydrocarbons with oxygen, the process comprising: first preheating separately, starting gases, which comprise a hydrocarbonaceous stream and an oxygenous stream; then heating the starting gases in a mixing zone, flowing the starting gases through a burner block; and then reacting the starting gases in a firing space and subsequently cooling rapidly, wherein holes and a secondary space are formed in the burner block, wherein the secondary space is connected to the holes and an annular space surrounding the secondary space, wherein the secondary space is formed such that a stream of auxiliary oxygen from the annular space is fed to the firing space in homogeneous distribution through the holes.

10. The process according to claim 9, wherein the annular space concentrically surrounds the secondary space.

11. The process according to claim 9, wherein the annular space is connected to the secondary space via a plurality of orifices such that the auxiliary oxygen from the annular space is fed to the secondary space in homogeneous distribution.

12. The process according to claim 9, wherein the annular space is connected to the secondary space via a plurality of orifices, which are arranged such that the auxiliary oxygen from the annular space is fed into the secondary space in radial direction.

13. The process according to claim 9, wherein the annular space is fed from at least one feed for supply of auxiliary oxygen.

Description

(1) The figure shows:

(2) FIG. 1 a perspective cross-sectional view of an inventive apparatus for preparing acetylene and synthesis gas by partial oxidation of hydrocarbons with oxygen.

EMBODIMENTS OF THE INVENTION

(3) FIG. 1 shows a cross-section view of an apparatus 10 for preparing acetylene and synthesis gas by partial oxidation of hydrocarbons with oxygen. The apparatus 10 comprises a reactor 12.

(4) The reactor 12 has a burner block 14 with a firing space, not shown in detail, for acetylene preparation. The burner block is cylindrical in shape, and so it has a center line 16 corresponding to a cylinder axis of the cylindrical shape. The reactor 12 also has a secondary space 18. The secondary space 18 is formed within the burner block 14. The reactor 12 also has an annular space 20. The annular space 20 surrounds the secondary space 18. For example, the annular space 20 surrounds the secondary space 18 concentrically. The annular space 20, in the working example shown in FIG. 1, is essentially circular, based on the section diagram in FIG. 1. In fact, the annular space 20 is cylindrical when viewed in three dimensions. The section in FIG. 1 runs at right angles to the center line 16 through the burner block 14. The firing space in the section diagram in FIG. 1 is beneath the plane of the drawing, and so it is hidden by the burner block 14 and therefore cannot be seen in FIG. 1.

(5) The burner block 14 has holes 22 for supply of a stream of a mixture of hydrocarbons and oxygen to the firing space. The holes 22 for supply of a stream of a mixture of hydrocarbons and oxygen to the firing space are arranged in a regular pattern in the burner block 14. In the working example shown in FIG. 1, the holes 22 for supply of a stream of a mixture of hydrocarbons and oxygen to the firing space are arranged around the center line 16 analogously to the corners of a square, such that the center line 16 runs through the center of the square. This arrangement is elucidated in detail by way of example for the four innermost holes 22 for supply of a stream of a mixture of hydrocarbons and oxygen to the firing space, with respect to the center line 16. The centers of these four innermost holes 22 form a square, with the center line 16 running through the center of the square. Accordingly, the distance between the centers of two immediately adjacent holes 22, i.e. holes 22 at the ends of an edge of the square is a factor of √2 greater than that distance between the centers of two holes 22 opposite one another with the center of the square between them, i.e. holes 22 at the ends of a diagonal of the square. The other holes 22 are arranged analogously, such that the centers of four holes 22 always form a corresponding square.

(6) The burner block 14 also has holes 24 for supply of a stream of auxiliary oxygen to the firing space. The holes 24 for supply of a stream of auxiliary oxygen to the firing space are connected to the secondary space 18. The holes 24 for supply of a stream of auxiliary oxygen to the firing space are likewise arranged in a regular pattern in the burner block 14. Alternatively, the holes 24 for supply of a stream of auxiliary oxygen to the firing space may be arranged in an irregular pattern. In the working example shown in FIG. 1, the holes 24 for supply of a stream of auxiliary oxygen to the firing space are arranged in gaps between the holes 22 for supply of a stream of a mixture of hydrocarbons and oxygen to the firing space. The innermost hole 24 with respect to the center line 16 is arranged such that the center line 16 runs through the center of the innermost hole 24. The holes 24 are arranged analogously to the corners of a square, with the holes 22 for supply of a stream of a mixture of hydrocarbons and oxygen to the firing space between them. This arrangement is elucidated in detail, by way of example, four holes 24. The centers of these four holes 24 form a square, the center of the hole 22 coinciding with the center of the square. Accordingly, the distance between the centers of two immediately adjacent holes 24, i.e. holes 24 at the ends of one edge of the square is greater by a factor of √2 than the distance between the centers of two holes 24 opposite one another with the center of the hole 22 or of the square between them, i.e. holes 24 at the ends of a diagonal of the square. The other holes 24 are arranged analogously, such that the centers of four holes 24 always form a corresponding square.

(7) The secondary space 18 is connected to the annular space 20. For example, the secondary space 18 is separated from the annular space 20 by a wall 26. The wall 26 has orifices 28 for connection of the holes 24 for supply of a stream of auxiliary oxygen to the annular space 20. For example, the orifices 28 are arranged in the wall 26 in homogeneous distribution about the center line 16 along a circumferential direction of the burner block 14. In the working example shown in FIG. 1, four orifices 28 are provided, which are arranged with homogeneous spacing along a circumferential direction of the burner block 14, i.e. at a separation of 90° based on the circular form of the annular space 20. The orifices 28 are, as shown in FIG. 1, arranged such that auxiliary oxygen can be fed from the annular space 20 into the secondary space 18 in radial direction based on the center line 16. The orifices 28 have a greater cross-sectional area than the holes 24 for supply of auxiliary oxygen to the firing space. The cross-sectional area of the holes 24 for supply of auxiliary oxygen to the firing space is the surface area of the holes 24 for supply of auxiliary oxygen to the firing space at right angles to the center line 16 or parallel to the plane of the drawing of FIG. 1. The cross-sectional area of an orifice 28 is the surface area of the orifice 28 parallel to the center line 16 or at right angles to the plane of the drawing of FIG. 1 or at right angles to the flow direction of oxygen fed in through the orifice 28. The ratio of the sum total of the cross-sectional areas of the orifices 28 to the cross-sectional area of the annular space 20 may be from 0.05 to 1, preferably from 0.1 to 0.4 and even more preferably from 0.1 to 0.2, for example 0.15. The cross-sectional area of the annular space 20 is the surface area of the annular space 20 parallel to the center line 16 or at right angles to the plane of the drawing of FIG. 1 or at right angles to the flow direction of oxygen flowing through the annular space 20. The ratio of the sum total of the cross-sectional areas of the holes 24 for supply of a stream of auxiliary oxygen to the firing space 16 to the cross-sectional area of the burner block 14 may be from 0.0001 to 0.1, preferably from 0.05 to 0.01 and even more preferably from 0.02 to 0.01, for example 0.015. The cross-sectional area of the burner block 14 is the surface area of the burner block 14 at right angles to the center line 16 or parallel to the plane of the drawing of FIG. 1.

(8) The annular space 20 is connected to a feed 30 for supply of auxiliary oxygen. The feed 30 is fed, for example, from a reservoir, not shown in detail, which may take the form of an oxygen line. For example, the reservoir is an oxygen line installed in a fixed manner from an air separation plant. In this way, in the case of supply of auxiliary oxygen from the annular space 20 to the secondary space 18, it is not possible for more auxiliary oxygen from the annular space 20 to escape into the secondary space 18 than passes from the reservoir through the feed into the annular space 20. This particular geometric configuration thus avoids pressure variations in the annular space 20. It is emphasized explicitly that it is also possible for more than one feed 30 to be connected to the annular space 20.

(9) Consequently, the auxiliary oxygen from the annular space 20 is first fed to the secondary space 18, where the auxiliary oxygen is distributed homogeneously, since, in contrast to the known apparatuses from the prior art, it is not conducted in lines. Since the orifices 28 each have a greater cross-sectional area than the holes 24 for supply of auxiliary oxygen to the firing space, in the case of supply of auxiliary oxygen from the secondary space 18 through the holes 24 for supply of auxiliary oxygen to the firing space into the firing space, it is not possible for more auxiliary oxygen from the secondary space 18 to escape into the firing space than passes from the annular space 20 through the orifices 28 into the secondary space 18. This particular geometric configuration thus avoids pressure variations in the secondary space 18.

(10) The secondary space 18 is thus designed, in terms of flow mechanics, such that it ensures homogeneous distribution between the holes 24 for supply of auxiliary oxygen to the firing space which are supplied by the secondary space 18. Accordingly, variations in the pressure are avoided and the flame stability and the desired yield are improved.

(11) A process according to the invention for preparing acetylene and synthesis gas by partial oxidation of hydrocarbons with oxygen will now be described hereinafter. The underlying process is based on the BASF-Sachsse-Bartholomé acetylene process, and therefore details in this regard will not be addressed in detail, reference instead being made to the abovementioned publications, the contents of which with regard to the process for preparing acetylene and synthesis gas by partial oxidation of hydrocarbons with oxygen are incorporated herein by reference.

(12) The starting gases comprise a hydrocarbonaceous stream, for example a stream of natural gas, and an oxygenous stream, for example a stream of pure oxygen. These starting gases are first preheated separately from one another. Subsequently, the preheated starting gases are heated in a mixing zone, which is not shown in detail. The already heated and mixed starting gases flow through the burner block 14 through the holes 22 for supply of a stream of a mixture of hydrocarbons and oxygen to the firing space, and thus pass into the firing space. In addition, the annular space 20 is fed by the feed 30 with auxiliary oxygen from the reservoir. The auxiliary oxygen then flows through the orifices 28 in the wall 26 into the secondary space 18. Since a plurality of orifices 28 distributed in the wall 26 are provided, the auxiliary oxygen is fed to the secondary space 18 from a plurality of directions. Since the auxiliary oxygen, in contrast to the known prior art apparatuses, is not conducted in lines, the auxiliary oxygen is distributed homogeneously in the secondary space 18. This is also promoted by the orifices 28, which are arranged such that the auxiliary oxygen from the annular space 20 is fed into the secondary space 18 in radial direction based on the center line 16. The auxiliary oxygen then flows out of the secondary space 18 through the holes 24 for supply of auxiliary oxygen to the firing space into the firing space. After flowing through the burner block 14, the starting gases are reacted in the firing space and then cooled rapidly by a quench unit. In addition, the auxiliary oxygen is fed through the feed 30 into the annular space 20, such that it is fed permanently when auxiliary oxygen is withdrawn from the annular space 20 into the secondary space 18.

(13) Consequently, the auxiliary oxygen is thus first fed from the annular space 20 to the secondary space 18, where the oxygen is distributed homogeneously. Through the holes 24 formed in the burner block 14, the oxygen is introduced into the firing space. The secondary space 18 is designed, in terms of flow mechanics, such that it ensures homogeneous distribution between the holes 24 that it supplies. Accordingly, variations in the pressure are avoided and the flame stability and the desired yield are improved.

LIST OF REFERENCE NUMERALS

(14) 10 apparatus 12 reactor 14 burner block 16 center line 18 secondary space 20 annular space 22 holes 24 holes 26 wall 28 orifices 30 feed