Chemical reactors with annularly positioned delivery and removal devices, and associated systems and methods

1. A chemical reactor, comprising:

a reactor vessel having a light-transmissible surface proximate to a reaction zone;

a movable reactant delivery system positioned within the reactor vessel;

a product removal system positioned within the reactor vessel and positioned annularly inwardly or outwardly from the delivery system wherein the product removal system is positioned in close thermal communication with the reactant delivery system to transfer heat to the reactant delivery system; and

a solar concentrator positioned to direct solar radiation through the light transmissible surface to the reaction zone.

2. The reactor of claim 1 wherein the reactant delivery system includes a rotatable screw having an outwardly-extending helical thread positioned to convey reactants to the reaction zone.

3. The reactor of claim 2 wherein the screw is extended along and rotatable about a rotation axis, and wherein a pitch of the helical thread varies as a function of position along the rotation axis.

4. The reactor of claim 2 wherein the screw is extended along and rotatable about a rotation axis, and wherein a radial width of the helical thread varies as a function of position along the rotation axis.

5. The reactor of claim 1 wherein the product removal system includes a rotatable screw having an outwardly-extending helical thread positioned to convey products from the reaction zone.

6. The reactor of claim 1 wherein the reactant delivery system includes a piston that is incrementally movable toward the reaction zone.

7. The reactor of claim 1 , further comprising:

a combustor operatively coupled to the reaction zone to direct heat to the reaction zone;

a sensor positioned to detect incident solar radiation; and

a controller operatively coupled to the combustor and the sensor to activate the combustor when the incident solar radiation falls below a threshold level.

8. The reactor of claim 1 , further comprising a source of solid reactants, and wherein the product delivery system extends between the source and the reaction zone.

9. The reactor of claim 1 , further comprising a source of gaseous reactants, and wherein the product delivery system extends between the source and the reaction zone.

10. The reactor of claim 1 , further comprising a source of hydrocarbon reactants, and wherein the product delivery system extends between the source and the reaction zone.

11. The reactor of claim 1 , further comprising a source of reactants, and wherein the source includes nitrogen.

12. A chemical reactor, comprising:

a cylindrical reactor vessel having a light-transmissible surface proximate to and bounding a reaction zone positioned within the vessel;

a reactant delivery system positioned within the reactor vessel, the reactant delivery system including a first screw shaft having an outwardly extending first spiral thread and being rotatable about a rotation axis, the first spiral thread having a volume between neighboring threads that is smaller proximate to the reaction zone than distal from the reaction zone, the first screw shaft extending to the reaction zone and having a first axial opening extending along the rotation axis;

a product removal system positioned within the reactor vessel, the product removal system including a second screw shaft positioned concentrically within the first axial opening of the first screw shaft in close thermal communication with the first screw shaft, the second screw shaft having an outwardly extending second spiral thread and being rotatable about the rotation axis, the second screw shaft extending to the reaction zone and having a second axial opening extending along the rotation axis, the second screw shaft further having perforations at the reaction zone to receive gaseous products from the reaction zone;

a combustor zone operatively coupled to the reaction zone to direct heat to the reaction zone;

a gas supply conduit positioned in the second axial opening of the second screw shaft to deliver at least one of a fuel and an oxidant to the combustor zone via the perforations of the second screw shaft;

a solar concentrator positioned to direct solar radiation through the light transmissible surface to the reaction zone;

a sensor positioned to detect incident solar radiation; and

a controller operatively coupled to the combustor and the sensor to activate the combustor when the incident solar radiation falls below a threshold level.

13. The reactor of claim 12 wherein a radial width of the spiral thread decreases as a function of position along the rotation axis.

14. The reactor of claim 12 wherein a pitch of the spiral thread decreases as a function of position along the rotation axis.