Abstract: A method of carbon-capture sorbent regeneration is provided. The method includes obtaining a sorbent that includes adsorbed carbon dioxide. Magnetic nanoparticles are introduced to the sorbent and adsorbed carbon dioxide to form a mixture. A magnetic field is applied to the mixture. The magnetic nanoparticles generate heat which releases carbon dioxide from the sorbent, thereby regenerating the sorbent. The magnetic nanoparticles include iron oxides, doped ferrites, functionalized iron oxides, functionalized ferrites, and composite materials that are combinations of these. The sorbent includes liquid and solid sorbents, and the regenerated sorbent may be utilized for further carbon capture.

Abstract: A medium for energy storage includes a plurality of capsules. Each capsule contains a phase changing material (PCM) configured to undergo a liquid-solid phase transition at a solidification temperature, TS. The PCM undergoes a relative volume change due to the phase transition. A shell is filled with the PCM. The shell contains a first heat-conducting material, and is configured to comply to the relative volume change. The relative volume change is configured to cause a buoyancy force, which acts on the capsule when the capsule is disposed in water at a water temperature, TW, to be larger than the capsule's weight for Tw>Ts, and equal to or smaller than the capsule's weight for Tw<Ts. The Ts can be within ±5° F. of a design water temperature To at the outlet of a water tank. The capsule can be neutrally buoyant in water at To.