Catalytic solar reactor
A catalytic solar reactor useful in chemical processes, more particularly, useful in endothermic chemical processes. The reactor comprises a reaction pathway defined by an exterior wall and an interior wall, the exterior wall comprising a solar radiation receiver capable of converting solar radiation into heat and transmitting the heat to the reaction pathway. Further, the reaction pathway has disposed therein, in alternating fashion, a plurality of catalytic elements and a plurality of heat transfer elements. Optionally, a supplementary heater, such as a conventional fossil fuel burner, is disposed in a plenum located within the interior of the reactor. The heater is employed as a supplemental source of heat, for example, when solar radiation is unavailable.
1. A catalytic solar reactor comprising a reaction pathway having a reactor inlet and a reactor outlet, the reaction pathway defined by an exterior wall and an interior wall; wherein the exterior wall comprises a solar radiation receiver disposed in thermal communication with the reaction pathway; and further wherein the reaction pathway has disposed therein the following structures:
(a) a plurality of catalytic elements, each catalytic element comprising a porous material having a catalyst supported thereon, each catalytic element further comprising a first flowpath from a first inlet side to a first outlet side;
(b) a plurality of heat transfer elements directly attached to said exterior wall, each heat transfer element comprising at least one porous, thermally-conductive material substantially lacking catalytic activity; each heat transfer element further comprising a second flowpath from a second inlet side to a second outlet side; and
(c) further such that the plurality of catalytic elements and the plurality of heat transfer elements are disposed within the reaction pathway in an alternating configuration defining a fluid flowpath from each element inlet side to each element outlet side.
2. The catalytic solar reactor of claim 1 wherein under operating conditions, the reactor functions via passive thermal conduction from the solar radiation receiver to the reaction pathway.
3. The catalytic solar reactor of claim 1 wherein under operating conditions, the reactor operates essentially isothermally within the plurality of catalytic elements.
4. The catalytic solar reactor of claim 1 wherein each of the plurality of catalytic elements is independently selected from metallic and ceramic materials.
5. The catalytic solar reactor of claim 4 wherein each of the plurality of catalytic elements is provided in the form of a mesh.
6. The catalytic solar reactor of claim 5 wherein the mesh has an ultra-short-channel-length ranging from 25 microns to 500 microns.
7. The catalytic solar reactor of claim 5 wherein the mesh comprises from 100 to 1,000 flow channels per square centimeter.
8. The catalytic solar reactor of claim 4 wherein each of the plurality of catalytic elements comprises a structured material having from 5 to 80 pores per inch.
9. The catalytic solar reactor of claim 1 wherein each of the plurality of catalytic elements independently comprises a set of from 1 to 5 catalytic elements.
10. The catalytic solar reactor of claim 1 wherein the catalyst is selected from a dry reforming catalyst or a Fisher-Tropsch catalyst.
11. The catalytic solar reactor of claim 1 wherein each of the plurality of heat transfer elements is independently selected from monolithic honeycombs and ultra-short-channel-length meshes.
12. The catalytic solar reactor of claim 11 wherein the monolithic honeycomb has a channel length ranging from 50 microns to 25 millimeters; or alternatively, the ultra-short-channel-length mesh has a channel length ranging from 25 microns to 500 microns.
13. The catalytic solar reactor of claim 1 wherein each of the plurality of heat transfer elements is constructed from a metallic composition.
14. The catalytic solar reactor of claim 1 wherein each of the plurality of heat transfer elements independently comprises a set of from 1 to 5 heat transfer elements.
15. The catalytic solar reactor of claim 1 wherein each of the plurality of heat transfer elements comprises no catalyst; or alternatively, comprises a catalyst in an amount less than 0.5 percent, based on total weight of the heat transfer element plus catalyst, so as to facilitate less than 1 percent additional conversion or yield under operating conditions.
16. The catalytic solar reactor of claim 1 wherein a thickness of each catalytic element ranges from 1 percent to 100 percent of a thickness of each heat transfer element.
17. The catalytic solar reactor of claim 1 wherein a total length occupied by the plurality of catalytic elements ranges from 1 percent to 50 percent of a total length of the sum of the catalytic elements plus the heat transfer elements.
18. The catalytic solar reactor of claim 1 wherein a thickness of a set of catalytic elements ranges from 75 microns to 6.3 millimeters, and a thickness of a set of heat transfer elements ranges from 75 microns to 25 millimeters.
19. The catalytic solar reactor of claim 1 wherein the solar radiation receiver is capable of receiving from 100 to 500 kW/m 2 solar irradiance, based on a planar receiver area normal to the direction of direct or reflected solar irradiance.
20. The catalytic solar reactor of claim 1 wherein the solar radiation receiver is capable of adsorbing from 50 percent to 100 percent of irradiated energy.
21. The catalytic solar reactor of claim 1 wherein the solar radiation receiver is constructed with planar dimensions, normal to direct or reflected solar irradiance, of from 1 m 2 to 200 m 2 .
22. The catalytic solar reactor of claim 1 wherein a supplemental heater is disposed within an interior plenum of the catalytic solar reactor.
23. The catalytic solar reactor of claim 22 wherein the supplemental heater is a fossil fuel burner.