INDUCTIVE HEATING OF A STEAM REFORMER FURNACE

Abstract

A furnace and method for steam reforming of a hydrocarbon-containing feed stream, which particularly comprises methane, with: a combustion chamber, at least one reactor tube, which in portions extends in the combustion chamber and is designed for receiving a catalyst and for passing the feed stream through, and at least one burner, which is designed to burn a fuel in the combustion chamber for heating the at least one reactor tube is disclosed. It is provided that the at least one reactor tube has a portion of tube running above and outside the combustion chamber, an inductor which is designed for inductively heating the portion of tube being arranged on the portion of tube.

Claims

1. A furnace for steam reforming of a hydrocarbon-containing feed stream, with: a combustion chamber, at least one reactor tube, which in portions extends in the combustion chamber and is designed for receiving a catalyst and for passing the feed stream through, and at least one burner, which is designed to burn a fuel in the combustion chamber for heating the at least one reactor tube, characterized in that the at least one reactor tube has a portion of tube running above and outside the combustion chamber and an inductor which is designed for inductively heating the portion of tube being arranged on the portion of tube.

2. The furnace according to claim 1, characterized in that the inductor has a coil, which is wound around the said portion of tube.

3. The furnace according to claim 1, characterized in that the said portion of tube is designed to receive the catalyst, or in that the portion of tube is filled with the catalyst.

4. A method for steam reforming in a furnace wherein a hydrocarbon-containing and steam-comprising feed stream is passed through at least one reactor tube of the furnace and reacted there in the presence of a catalyst arranged in the at least one reactor tube to yield a stream of raw synthesis gas, the feed stream being passed in the at least one reactor tube through a combustion chamber, in which a fuel is burned for heating the feed stream, characterized in that the feed stream in the at least one reactor tube is at least temporarily additionally heated by the at least one reactor tube being inductively heated, or in that instead of heating the feed stream by burning the fuel, the at least one reactor tube is at least temporarily inductively heated.

5. The method according to claim 4, characterized in that the at least one reactor tube has a portion of tube running above and outside the combustion chamber.

6. The method according to claim 4, characterized in that the inductor has a coil, which is wound around the said portion of tube.

7. The method according to claim 4, characterized in that the said portion of tube is designed to receive the catalyst, or in that the portion of tube is filled with the catalyst.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Further features and advantages of the present invention are to be explained in the description of exemplary embodiments on the basis of the FIGURE, in which:

[0031] The FIGURE shows a perspective representation of a furnace according to the invention in the form of a cutout.

DETAILED DESCRIPTION OF THE INVENTION

[0032] The FIGURE shows a furnace 1 according to the invention for steam reforming a hydrocarbon-containing feed stream E, which particularly comprises methane. The furnace 1 has a combustion chamber 10, which has a radiation zone 11 and a convection zone 12. In the radiation zone 11, burners 30, which are designed to burn a fuel in the presence of oxygen in the combustion chamber 10 or radiation zone 11, are provided for example on an upper horizontal wall 13 of the combustion chamber 10, the resultant heat being transferred to a plurality of reactor tubes 20 (or at least one reactor tube 20, see above), just three of which are shown here for the sake of simplicity. The reactor tubes 20 respectively extend along a vertical longitudinal axis z through the radiation zone 11 of the combustion chamber 10. A catalyst K is provided in the reactor tubes 20. This catalyst is provided here in a portion of tube 20b of the respective reactor tube 20 that runs inside the combustion chamber 10 and also in a portion of tube 20a of the respective reactor tube 20 that is respectively provided above and outside the combustion chamber 10.

[0033] The heat generated in the radiation zone 11 is set in particular such that the feed stream E introduced into the reactor tubes 20, which has in particular previously been preheated in the convection zone 12 of the furnace 1 or the combustion chamber 10, is reacted by steam reforming in the reactor tubes 20 using said heat to yield a stream of raw synthesis gas R which comprises CO and H.sub.2.

[0034] The reactor tubes 20 open here into a manifold 21, which is provided under the combustion chamber 10 and via which the stream of raw synthesis gas R which has been produced can be drawn off from the furnace 1 or the reactor tubes 20.

[0035] The reformed gas R leaves the radiation zone 11 of the reformer furnace 1 generally for example in a temperature range of 780 C. to 1050 C., preferably 820 C. to 950 C. The pressure range of the gas is preferably in the range from 10 bar to 50 bar, preferably 15 to 40 bar.

[0036] According to the invention, the furnace 1 then has in addition to the burners 30 inductors 23, which are arranged on the upper portions of tube 20a and are configured for inductively heating the portions of tube 20a. For this purpose, the inductors may have electrically conducting coils 23, which are respectively wound around an assigned portion of tube 20a, the individual inductors or coils 23 being connected to an energy source 2, which produces in the inductors 23 a flow of current that generates an alternating magnetic field, which in turn produces in the portions of tube 20a eddy currents that lead to the heating of the respective portion of tube 20a.

[0037] According to the invention, electrical energy may thus be used instead of the fuel or in addition to the fuel for heating the feed stream E. The electrical energy is preferably surplus energy or particularly inexpensive energy.

[0038] The furnace 1 according to the invention is particularly suitable for carrying out the method according to the invention. In this respect, the technical teaching of the present invention makes it possible that, in addition to the firing, the feed stream E in the reactor tubes 20 can for example be temporarily heated by an electrical eddy current being inductively generated by means of the inductors or coils 23 in each case in the way described above in the portions of tube of the reactor tubes 20 that are likewise filled with catalyst. Furthermore, instead of the firing, the said portions of tube 20a of the reactor tubes 20 may in particular be temporarily inductively heated respectively for heating the feed stream E. The invention consequently advantageously makes it possible for amounts of energy that are in particular surplus to requirements, and possibly particularly inexpensive electrical energy, to be included in a steam reforming process.

TABLE-US-00001 List of reference signs 1 Furnace 2 Energy source 10 Combustion chamber 11 Radiation zone 12 Convection zone 13 Wall 20 Reactor tube 20a, 20b Portion of tube 21 Manifold 23 Inductor (for example coil) R Stream of raw synthesis gas Z Longitudinal axis