METHOD AND DEVICE FOR PRODUCING HYDROGEN AND PYROLYTIC CARBON FROM HYDROCARBONS

Abstract

A process for producing hydrogen and pyrolytic carbon from hydrocarbons may involve converting hydrocarbons into hydrogen and carbon in a reactor at temperatures of 1000° C. or more. The reactor may include two electrodes spaced apart from one another in a flow direction of the hydrocarbons. In a region of the reactor between the electrodes an inert gas component is supplied over an entire reactor cross section. The reactor contains carbon particles in the region between the two electrodes. By introducing an inert gas component over the entire reactor cross section, deposition of carbon in this region of the reactor inner wall is prevented, thus effectively inhibiting the formation of conductivity bridges on the reactor inner wall.

Claims

1.-19. (canceled)

20. A process for producing hydrogen and pyrolytic carbon from hydrocarbons, the process comprising: converting the hydrocarbons into hydrogen and carbon in a reactor at a temperature of 1000° C. or more, wherein the reactor includes two electrodes spaced apart from one another in a flow direction of the hydrocarbons and carbon particles in a region between the two electrodes; and supplying in the region between the two electrodes an inert gas component over an entire reactor cross section.

21. The process of claim 20 wherein the hydrocarbons are methane.

22. The process of claim 20 wherein the inert gas component is nitrogen or hydrogen.

23. The process of claim 20 wherein the reactor comprises a reaction zone that is arranged vertically in a reactor space, wherein the hydrocarbons pass through the reaction zone from bottom to top and the carbon particles pass through the reaction zone from top to bottom.

24. The process of claim 20 wherein the inert gas component has a temperature of less than 1000° C.

25. The process of claim 20 comprising supplying as the inert gas component a portion of a product gas that is generated by the process.

26. The process of claim 20 comprising introducing the inert gas component into the reactor at an angle of between 30° to 60° relative to the flow direction of the hydrocarbons.

27. The process of claim 20 comprising maintaining a temperature in a reaction zone of the reactor in a range from 1000° C. to 1800° C.

28. The process of claim 20 comprising feeding the hydrocarbons into the reactor at a flow rate in a range from 0.001 m/s to 10 m/s.

29. The process of claim 20 comprising feeding the inert gas into the reactor at a flow rate in a range from 0.001 m/s to 100 m/s.

30. The process of claim 20 comprising passing the carbon particles through the reactor counter to the flow direction of the hydrocarbons.

31. The process of claim 30 wherein the carbon particles are fed into the reactor at a flow rate in a range from 0.5 m/h to 100 m/h.

32. An apparatus for pyrolytic conversion of hydrocarbons into hydrogen and carbon, the apparatus comprising: a reactor having a reactor space that comprises two electrodes that are spaced apart from one another in a flow direction of the hydrocarbons, by means of which the reactor may be resistance-heated; and a feeding apparatus for an inert gas installed in a region between the two electrodes that extends over an entire reactor cross section.

33. The apparatus of claim 32 wherein the feeding apparatus is configured such that the reactor cross section narrows above and/or below a gas entry opening.

34. The apparatus of claim 32 wherein the feeding apparatus is configured such that the reactor cross section is uniform in the region between the two electrodes except at an outlet for the inert gas from the feeding apparatus.

35. The apparatus of claim 32 wherein the feeding apparatus is configured to supply the inert gas to the reactor via a slot with a height, wherein the height of the slot is configured to cause a pressure drop that ensures distribution of the inert gas over the entire reactor cross section while the inert gas is flowing.

36. The apparatus of claim 32 wherein the feeding apparatus is configured such that the inert gas is introducible into the reactor at an angle of 30° to 60° relative to the flow direction of the hydrocarbons.

37. The apparatus of claim 32 comprising a discharge conduit for product gas formed in the reactor, wherein the discharge conduit comprises a diversion conduit by way of which a portion of the product gas is returnable to the reactor via the feeding apparatus for the inert gas.

38. The apparatus of claim 37 comprising a compressor in a region of the diversion conduit.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0043] FIG. 1 shows a reactor 1 configured according to the invention comprising two electrodes 2 spaced apart from one another and a carbon bed 3 extending beyond both electrodes. In FIG. 1 the reactor wall 4 comprises a distributor structure for inert gas 5, from which inert gas is passed into the reactor via a slot 9. Below and above the distributor structure 5 the reactor cross section narrows 6, 7. As a result an elevated gas velocity is realized in these narrowed regions, thus reducing the probability density of carbon particles in this region. In the area below the distributor structure for inert gas 7 the narrowing also acts as a deflection means for gas flowing through. A pyrolytic carbon layer 8 is formed on the reactor inner wall in the course of the process.

[0044] FIG. 2 shows different variants of the feed conduit for inert gas into the reactor space, wherein the variants A and B are configured with narrowings of the reactor cross section in the region above and below the feed conduit for the inert gas while variant C features a feed conduit configured such that the reactor cross section is uniform in the region between the electrodes with the exception of the outlet for inert gas from the feeding apparatus.

[0045] FIG. 3 shows a gas distributor construction according to the invention, wherein H1 indicates the slot height through which the gas flows from the distributor space into the reactor space. P1 denotes the distributor pressure, P2 the reactor pressure and Δp the pressure drop between the distributor pressure and the reactor pressure.

[0046] FIG. 4 shows a scheme of an apparatus according to the invention comprising a reactor 1, a feed conduit for hydrocarbon starting material 10, a feed conduit for carbon particles 11, a discharge conduit for carbon particles 12 and a discharge conduit for product gas 13. Provided in the region of the discharge conduit for product gas is a diversion 14, by means of which a portion of the product gas may be passed into a compressor 15 and from there passed back into the reactor.

LIST OF REFERENCE NUMERALS

[0047] 1 Reactor [0048] 2 Electrodes [0049] 3 Carbon bed [0050] 4 Reactor wall [0051] 5 Distributor structure for inert gas [0052] 6 Upper narrowing of reactor cross section [0053] 7 Lower narrowing of reactor cross section [0054] 8 Pyrolytic carbon layer [0055] 9 Feed slot for inert gas [0056] 10 Feed conduit for hydrocarbon starting material [0057] 11 Feed conduit for carbon particles [0058] 12 Discharge conduit for carbon particles [0059] 13 Discharge conduit for product gas [0060] 14 Diversion [0061] 15 Compressor