Methods for operating solar-thermochemical processes
View Patent ↗Methods for controlling or operating solar thermochemical reactions process that maximize the two-step thermochemical energy cycle efficiency by a combination of pressure and temperature swing are disclosed.
1. A method for determining an operating oxidation temperature in a thermochemical reactor process, comprising:
(a) selecting a thermal reduction temperature for a reactive oxide;
(b) selecting an operating pressure in the thermal reduction step in a containment vessel;
(c) selecting a solid-solid and a gas-gas recuperation efficiency;
(d) selecting an initial oxidation temperature for a feed stream having a heat requirement for oxidizing the feed stream;
(e) iterating/repeating steps (a)-(d) to develop a performance/efficiency map as a function of reduction temperature, temperature swing, pressure swing, and recuperation efficiencies;
(f) embedding the performance/efficiency map into a solar collection and heating system model to determine the operating oxidation temperature; and
(g) utilizing the determined operating oxidation temperature in the thermochemical reactor process which comprises thermal reduction, solid-solid heat exchange in a thermal recuperator, H 2 production and steam pre-heating by employing solar radiation to heat and thermally reduce the reactive oxide in a thermal reduction chamber of the reactor, moving the reactive oxide through the recuperator and into an H 2 production chamber of the reactor, where the H 2 production chamber is operated at the determined operating oxidation temperature by exposing the H 2 production chamber to pre-heated steam in a countercurrent flow arrangement, producing H 2 .
2. The method of claim 1 , wherein the thermal reduction temperature is based on materials limitations of the reactive material or containment vessel.
3. The method of claim 1 , wherein the thermal reduction temperature is based on thermal receiver performance.
4. The method of claim 1 , wherein the thermochemical reactor process is a water splitting process.
5. The method of claim 1 , wherein heat requirements for achieving the thermal reduction temperature and the oxide temperature are equal.
6. The method of claim 1 , wherein the solar collection and heating system model includes at least one parameter selected from a group consisting of the solar field, receiver, and secondary concentrators.
7. The method of claim 1 , wherein the operating pressure is oxygen partial pressure at the thermal reduction temperature.
8. A method for determining an operating oxidation temperature in a thermochemical reactor process, comprising:
(a) selectLng a thermal reduction temperature for a reactive oxide;
(b) selecting an operating pressure in the thermal reduction step in a containment vessel;
(c) selecting a solid-solid and a gas-gas recuperation efficiency;
(d) selecting an initial oxidation temperature for a feed stream having a heat requirement for oxidizing the feed stream;
(e) iterating/repeating steps (a)-(d) to develop a performance/efficiency map as a function of reduction temperature, temperature swing, pressure swing, and recuperation efficiencies;
(f) embedding the performance/efficiency map into a system cost model to determine a configuration of process system components that result in the largest amount of stored chemical energy per unit of capital cost;
wherein the operating oxidation temperature is determined at a temperature at which the largest amount of stored chemical energy per unit capital cost is achieved; and
(g) utilizing the determined operating oxidation temperature in the thermochemical reactor process which comprises thermal reduction, solid-solid heat exchange in a thermal recuperator, H 2 production and steam pre-heating by employing solar radiation to heat and thermally reduce the reactive oxide in a thermal reduction chamber of the reactor, moving the reactive oxide through the recuperator and into an H 2 production chamber of the reactor, where the H 2 production chamber is operated at the determined operating oxidation temperature by exposing the H 2 production chamber to pre-heated steam in a countercurrent flow arrangement, producing H 2 .
9. The method of claim 7 , wherein the process system components comprise thermal recuperation components.
10. The method of claim 7 , wherein the thermal reduction temperature is based on materials limitations of the reactive material or containment vessel.
11. The method of claim 7 , wherein the thermal reduction temperature is based on thermal receiver performance.
12. The method of claim 7 , wherein the thermochemical reactor process is a water splitting process.
13. The method of claim 7 , wherein heat requirements for achieving the thermal reduction temperature and the oxide temperature are equal.
14. The method of claim 7 , wherein the operating pressure is oxygen partial pressure at the thermal reduction temperature.