The devices, systems, and methods of the present disclosure are generally directed to using an increase in gas pressure (e.g., through an increase in heat) to move an actuator that at least partially defines a volume containing a feed fluid in fluid communication with a membrane. As the increase in gas pressure moves the actuator, pressure on the feed fluid in the volume may increase beyond a threshold pressure sufficient to move the feed fluid through the membrane. Movement of the feed fluid through the membrane may reduce a volumetric concentration of one or more components of the feed fluid to form a permeate. For example, the increase in pressure may drive the actuator to increase pressure on salt-water in the volume and, ultimately, move the salt-water through the membrane to form the permeate as part of a reverse osmosis process achieved without the use of a mechanical pump.

Solar collectors can provide power for electricity, thermal propulsion, and material processing (e.g., mining asteroids). In one aspect, a rocket propulsion system is configured to produce thrust for a spacecraft and includes: one or more optical elements configured to receive solar energy. The optical elements include: a first window configured to allow energy to enter the rocket propulsion system and form a concentrated energy beam, and a second window positioned to allow the concentrated energy beam to pass to the heat exchanger. The second window is spaced away from the first window to form a pressurized plenum chamber therebetween. The system further includes: a heat exchanger configured to receive the energy and use it to heat and pressurize a propulsion gas, and a rocket nozzle configured to expel the pressurized propulsion gas.

A system includes a containment vessel configured to receive and hold one or more pieces of personal protection equipment to be heated and decontaminated during a decontamination process. The system also includes a solar collection device configured to heat the containment vessel based on received solar energy. The solar collection device includes a body having a first portion and a second portion. The first portion includes a solar aperture configured to receive the solar energy. The second portion is configured to receive the containment vessel within the body of the solar collection device. The solar collection device also includes louvered slats across the solar aperture. The louvered slats are configured to be rotated in order to control an amount of solar energy passing through the solar aperture into the body of the solar collection device.

A solar energy powered Stirling duplex cooler is presented which includes a Stirling engine and a Stirling cooler. The Stirling engine drives the Stirling cooler to produce cold temperatures for refrigeration or air conditioning. The Stirling duplex cooler includes a solar concentrator to focus high temperature solar radiation upon the Stirling engine expansion space. The Stirling duplex cooler further includes a thermal storage tank to receive and store heat rejected from the cooler expansion space. This stored heat is used to operate the cooler at night. A flywheel connected operatively to engine and cooler expansion space pistons and a crankshaft connected operatively to engine and cooler compression space pistons actuate the pistons to move a working fluid between the expansion and compression spaces.

A solar energy powered Stirling duplex cooler is presented which includes a Stirling engine and a Stirling cooler. The Stirling engine drives the Stirling cooler to produce cold temperatures for refrigeration or air conditioning. The Stirling duplex cooler includes a solar concentrator to focus high temperature solar radiation upon the Stirling engine expansion space. The Stirling duplex cooler further includes a thermal storage tank to receive and store heat rejected from the cooler expansion space. This stored heat is used to operate the cooler at night. A flywheel connected operatively to engine and cooler expansion space pistons and a crankshaft connected operatively to engine and cooler compression space pistons actuate the pistons to move a working fluid between the expansion and compression spaces.

Devices, systems, and methods relating to providing a portable, rechargeable vessel for collecting, storing, and recovering thermal energy are provided. In one aspect, vessel includes a structure defining a well and an open-top portion at the top of the well; a phase-change material, wherein the phase-change material is disposed in the well, the phase-change material being configured to change phase at temperature in the range of 110-700° C.; one or more thermally-conductive fins interleaved in the phase-change material; and a thermally-conductive heat transfer plate disposed at and substantially covering the open-top portion of the structure, in direct thermal contact with the one or more fins, thereby allowing the transfer plate to directly exchange thermal energy with the phase change material.

Devices, systems, and methods relating to providing a portable, rechargeable vessel for collecting, storing, and recovering thermal energy are provided. In one aspect, vessel includes a structure defining a well and an open-top portion at the top of the well; a phase-change material, wherein the phase-change material is disposed in the well, the phase-change material being configured to change phase at temperature in the range of 110-700° C.; one or more thermally-conductive fins interleaved in the phase-change material; and a thermally-conductive heat transfer plate disposed at and substantially covering the open-top portion of the structure, in direct thermal contact with the one or more fins, thereby allowing the transfer plate to directly exchange thermal energy with the phase change material.

Methods and systems for making calcium oxide (CaO), carbon dioxide (CO.sub.2) and/or calcium hydroxide (Ca(OH).sub.2) from aragonite, for example, oolitic aragonite, are provided. The method can include applying solar energy, for example, by focusing one or more mirrors in one or more heliostats, to heat a reactant mixture in a vessel. The reactant mixture includes oolitic aragonite and can be heated to a temperature from 500° C. to 950° C. The system can include a vessel and a means for applying solar energy to heat a supply of oolitic aragonite disposed inside the vessel. Methods of converting the CO.sub.2 to ethanol, ethylene, graphene, and/or methane are also provided.

Methods and systems for making calcium oxide (CaO), carbon dioxide (CO.sub.2) and/or calcium hydroxide (Ca(OH).sub.2) from aragonite, for example, oolitic aragonite, are provided. The method can include applying solar energy, for example, by focusing one or more mirrors in one or more heliostats, to heat a reactant mixture in a vessel. The reactant mixture includes oolitic aragonite and can be heated to a temperature from 500° C. to 950° C. The system can include a vessel and a means for applying solar energy to heat a supply of oolitic aragonite disposed inside the vessel. Methods of converting the CO.sub.2 to ethanol, ethylene, graphene, and/or methane are also provided.

A system for reclaiming carbon fiber from carbon fiber containing material using solar energy includes a sunlight focusing system, a sample platform for placement of carbon fiber containing material to be treated by focused sunlight from the sunlight focusing system, the sample platform being provided with a gas absorption pipe, and a waste gas treatment system connected with the gas absorption pipe.