Reactors for conducting thermochemical processes with solar heat input, and associated systems and methods

1. A method for processing a hydrogen donor, comprising:

determining a level of radiant energy, the radiant energy detected from a radiant energy sensor;

in response to a determination that the detected radiant energy is equal to or greater than a threshold,

i) positioning a solar concentrator to direct concentrated radiant energy to a reaction zone positioned at a focal area of the solar concentrator, and

ii) dissociating, at the reaction zone, a hydrogen donor into dissociation products via the concentrated radiant energy, wherein the dissociation products include at least one of: (a) a structural building block based on at least one of carbon, nitrogen, boron, silicon, a transition metal, and sulfur; and (b) a hydrogen-based fuel; and

in response to a determination that the detected radiant energy is less than the threshold,

positioning the solar concentrator to disperse heat from the reaction zone positioned at the focal area of the solar concentrator.

2. The method of claim 1 wherein the hydrogen donor includes methane, and wherein providing includes providing hydrogen and at least one of carbon, carbon dioxide and carbon monoxide.

3. The method of claim 1 wherein the hydrogen donor includes a hydrocarbon.

4. The method of claim 1 wherein the hydrogen donor includes a nitrogenous compound.

5. The method of claim 1 , further comprising operating a radiation control structure positioned between the solar concentrator and the focal area by:

positioning a first surface of the radiation control structure having a first radiant energy absorptivity and a first radiant energy emissivity to face toward the solar concentrator when the radiant energy is equal to or greater than a threshold value; and

positioning a second surface of the radiation control structure having a second radiant energy absorptivity less than the first radiant energy absorptivity and a second radiant energy emissivity greater than the first radiant energy emissivity to face toward the focal area when the radiant energy is less than the threshold value.

6. The method of claim 1 , further comprising:

in response to a determination that the radiant energy is equal to or greater than the threshold level,

pointing the solar concentrator toward the sun; and

in response to a determination that the radiant energy is less than the threshold level,

placing at least one of the structural building block and the hydrogen-based fuel in thermal communication with the focal area, wherein dispersing heat at the focal area includes positioning the solar concentrator away from the sun and to another location having relatively little radiant energy to cool the at least one of the structural building block and the hydrogen-based fuel.

7. The method of claim 6 wherein placing at least one of the structural building block and the hydrogen-based fuel in thermal communication with the focal area includes:

aligning a heat exchanger with the focal area; and

directing a heat exchange fluid from the heat exchanger to the at least one of the structural building block and the hydrogen-based fuel.

8. A system for processing a hydrogen donor, comprising:

a solar concentrator positionable to direct radiant energy to a focal area;

a reactor having a reaction one positioned at the focal area of the solar concentrator;

a reactant source coupled in fluid communication with the reaction zone of the reactor;

a radiant energy sensor detecting a level of radiant energy;

an actuator coupled to the solar concentrator to move the solar concentrator relative to the sun; and

a controller operatively coupled to the actuator and the radiant energy sensor, the controller configured to:

a) in response to a determination that the detected radiant energy is equal to or greater than a threshold,

i) causing the actuator to position a solar concentrator to direct-concentrated radiant energy to the reaction zone, and

ii) dissociate, at the reaction zone, a hydrogen donor into dissociation products via the concentrated radiant energy, wherein the dissociation products include at least one of: (a) a structural building block based on at least one of carbon, nitrogen, boron, silicon, a transition metal and sulfur; and (b) a hydrogen-based fuel; and

b) in response to a determination that the detected radiant energy is less than the threshold,

causing the actuator to position the solar concentrator to disperse heat from the reaction zone positioned at the focal area of the solar concentrator.

9. The system of claim 8 wherein the hydrogen donor includes a hydrocarbon.

10. The system of claim 8 wherein the hydrogen donor includes methane.

11. The system of claim 8 wherein the hydrogen donor includes a nitrogenous compound.

12. The system of claim 8 , further comprising:

a radiation control structure positioned between a surface of the solar concentrator and the focal area, wherein the controller is further configured to:

causing the actuator to position a first surface of the radiation control structure having a first radiant energy absorptivity and a first radiant energy emissivity to face toward the solar concentrator when the radiant energy is equal to or greater than a threshold value; and

causing the actuator to position a second surface of the radiation control structure having a second radiant energy absorptivity less than the first radiant energy absorptivity and a second radiant energy emissivity greater than the first radiant energy emissivity to face toward the focal area when the radiant energy is less than the threshold value.

13. The system of claim 8 , wherein the controller is further configured to:

in response to a determination that the radiant energy is equal to or greater than the threshold level,

causing the actuator to point the solar concentrator toward the sun; and

in response to a determination that the radiant energy is less than the threshold level,

place at least one of the structural building block and the hydrogen-based fuel in thermal communication with the focal area wherein dispersing heat at the focal area includes positioning the solar concentrator away from the sun and to another location having relatively little radiant energy to cool the at least one of the structural building block and the hydrogen-based fuel.

14. The system of claim 13 wherein the controller is configured to place at least one of the structural building block and the hydrogen-based fuel in thermal communication with the focal area includes the controller configured to:

align a heat exchanger with the focal area; and

direct a heat exchange fluid from the heat exchanger to the at least one of the structural building block and the hydrogen-based fuel.