Endothermic reactions heated by resistance heating
A reactor system for carrying out an endothermic reaction of a feed gas, including: a structured catalyst arranged for catalyzing the endothermic reaction of a feed gas, the structured catalyst including a macroscopic structure of electrically conductive material, the macroscopic structure supporting a ceramic coating, wherein the ceramic coating supports a catalytically active material; a pressure shell housing the structured catalyst; heat insulation layer between the structured catalyst and the pressure shell; at least two conductors electrically connected to the electrically conductive material and to an electrical power supply placed outside the pressure shell, wherein the electrical power supply is dimensioned to heat at least part of said structured catalyst to a temperature of at least 200° C. by passing an electrical current through the electrically conductive material. Also, a process for performing an endothermic reaction of a feed gas.
1. A reactor system for carrying out an endothermic reaction of a feed gas, said reactor system comprising:
a structured catalyst arranged for catalyzing said endothermic reaction of said feed gas, said structured catalyst comprising a macroscopic structure of electrically conductive material, said macroscopic structure supporting a ceramic coating, wherein said ceramic coating supports a catalytically active material;
a pressure shell housing said structured catalyst;
a heat insulation layer between said structured catalyst and said pressure shell; and
at least two conductors electrically connected to said structured catalyst and to an electrical power supply placed outside said pressure shell, wherein said electrical power supply is dimensioned to heat at least part of said structured catalyst to a temperature of at least 200° C. by passing an electrical current through said electrically conductive material,
wherein the pressure shell comprises an inlet at a first end of the pressure shell for letting in process gas and an outlet at a second end of the pressure shell for letting out product gas, and wherein the at least two conductors are connected to the structured catalyst at a position closer to the inlet than to the outlet.
2. The reactor system according to claim 1 , wherein the pressure shell has a design pressure of between 2 and 30 bar.
3. The reactor system according to claim 1 , wherein the pressure shell has a design pressure of between 30 and 200 bar.
4. The reactor system according to claim 1 , wherein the resistivity of the electrically conductive material is between 10 −5 Ω·m and 10 −7 Ω·m.
5. The reactor system according to claim 1 , where said at least two conductors are led through the pressure shell in a fitting so that the at least two conductors are electrically insulated from the pressure shell.
6. The reactor system according to claim 5 , wherein said pressure shell further comprises one or more inlets, including the inlet, close to or in combination with at least one fitting in order to allow a cooling gas to flow over, around, close to, or inside at least one conductor within said pressure shell.
7. The reactor system according to claim 1 , wherein the reactor system further comprises an inner tube in heat exchange relationship with but electrically insulated from the structured catalyst, said inner tube being adapted to withdraw the product gas from the structured catalyst so that the product gas flowing through the inner tube is in heat exchange relationship with gas flowing over the structured catalyst.
8. The reactor system according to claim 1 , wherein the connection between the structured catalyst and said at least two conductors is a mechanical connection, a welded connection, a brazed connection or a combination thereof.
9. The reactor system according to claim 1 , wherein the electrically conductive material comprises an 3D printed or extruded and sintered macroscopic structure, said macroscopic structure is supporting a ceramic coating, wherein said ceramic coating supports a catalytically active material.
10. The reactor system according to claim 9 , wherein said macroscopic structure has a plurality of parallel channels, a plurality of non-parallel channels and/or a plurality of labyrinthic channels.
11. The reactor system according to claim 10 , wherein said reactor system further comprises a third catalyst material in the form of catalyst pellets, extrudates or granulates loaded into the channels of said macroscopic structure.
12. The reactor system according to claim 1 , wherein the structured catalyst comprises an array of macroscopic structures electrically connected to each other.
13. The reactor system according to claim 1 , wherein the reactor system further comprises a bed of a second catalyst material upstream said structured catalyst within said pressure shell.
14. The reactor system according to claim 1 , wherein said reactor system further comprises a control system arranged to control the electrical power supply to ensure that the temperature of the gas exiting the pressure shell lies in a predetermined range and/or to ensure that the conversion of the feed gas lies in a predetermined range.
15. The reactor system according to claim 1 , wherein the structured catalyst within said reactor system has a ratio between the area equivalent diameter of a horizontal cross section through the structured catalyst and the height of the structured catalyst in the range from 0.1 to 2.0.
16. The reactor system according to claim 1 , wherein the height of the reactor system is between 0.5 and 7 m.
17. The reactor system according to claim 16 , wherein the height of the reactor system is between 0.5 and 3 m.
18. The reactor system according to claim 1 , further comprising electrically insulating parts provided in the structured catalyst and positioned between the at least two conductors.