Solar Receivers for Use in Solar-Driven Thermochemical Processes

Abstract

Solar receivers which produce heat at very high temperatures (in excess of 1000° C.) are described herein. The receiver produces the high temperature heat and radiates the heat to a containment element (e.g., pipe) that contains a heat transfer fluid which absorbs the heat. The fluid is preferably a material which is thermally and chemically stable at the temperatures involved. The heat transfer fluid absorbs the heat and can deliver it to a reactor system to drive an endothermic reaction, such as thermochemical water splitting, CO 2 capture, and/or syngas production. Alternatively, the heat can be used to directly generate electricity through a high temperature heat engine such as a Brayton or combined Brayton+Rankine cycle.

I claim: 
     
         1 . A solar receiver for converting electromagnetic energy to thermal energy, the collector comprising a cavity and a heat transfer fluid, wherein the heat transfer fluid comprises a liquid material which is stable at temperatures greater than 1000° C. 
     
     
         2 . The receiver of  claim 1 , wherein the liquid material is selected from the group consisting of liquid metals, liquid metal oxides or mixed metal oxides, molten salts, glasses, liquid organic materials, and combinations thereof. 
     
     
         3 . The receiver of  claim 2 , wherein liquid metal or liquid organic material is chemically and thermally stable at a temperature greater than about 1100° C. 
     
     
         4 . The receiver of  claim 2 , wherein liquid metal or liquid organic material is chemically and thermally stable at a temperature greater than about 1200° C. 
     
     
         5 . The receiver of  claim 2 , wherein liquid metal or liquid organic material is chemically and thermally stable at a temperature greater than about 1300° C. 
     
     
         6 . The receiver of  claim 2 , wherein liquid metal or liquid organic material is chemically and thermally stable at a temperature greater than about 1400° C. 
     
     
         7 . The receiver of  claim 2 , wherein liquid metal or liquid organic material is chemically and thermally stable at a temperature of about 1500° C. 
     
     
         8 . The receiver of  claim 2 , wherein the metal is selected from the group consisting of tin, aluminum, gallium, sodium, lead, lithium, bismuth, and combinations thereof. 
     
     
         9 . The receiver of  claim 2 , wherein the liquid organic material is graphite. 
     
     
         10 . The receiver of  claim 1 , wherein the heat transfer fluid is contained within a containment material that is chemically and thermally stable at temperatures about 1000° C. 
     
     
         11 . The receiver of  claim 10 , wherein the containment element comprises one or more materials selected from the group consisting of aluminum oxide, zirconia, magnesia, metals, metal carbides, nitrides, borides, and/or silicides, graphite, and combinations thereof. 
     
     
         12 . A solar absorption system comprising a plurality of solar collectors and the receiver of  claim 1 . 
     
     
         13 . The system of  claim 12 , wherein the collectors are heliostats. 
     
     
         14 . The system of  claim 13 , wherein the mirrors on the heliostats are coated with polymer solar cells to convert the highest frequency photons first at higher efficiency and then reflect the remaining photons. 
     
     
         15 . The system of  claim 12 , wherein the collectors are parabolic mirrors which couple the light to fiber optic cables. 
     
     
         16 . A method for thermochemical power generation, the method comprising collecting and concentrating solar energy to heat a heat transfer fluid to a temperature of at least about 1000° C. and using the heat radiated from the heat transfer fluid to drive an endothermic chemical reaction which produces one or more gaseous products from the conversion of thermal energy to chemical energy. 
     
     
         17 . The method of  claim 1 , wherein the gaseous products are stored for power generation. 
     
     
         18 . The method of  claim 16 , wherein the endothermic reaction is water splitting. 
     
     
         19 . A system for thermochemical power generation, the system comprising the solar absorption system of  claim 1 , one or more reactors for converting thermal energy to chemical energy, one or more gas storage containers for storing gases that are the product of the conversion of thermal energy to chemical energy, and one or more power generation units for processing the stored product gases into electrical power.