regenerator

A regenerator is a device or process that restores a degraded medium, material, or energy stream to a usable state. In engineering and science, regenerators are used to recover heat or chemical energy, extend the life of sorbents or solvents, or convert and store energy that would otherwise be wasted.

In heat-transfer equipment, a regenerator or regenerator bed is a thermal energy storage medium that alternately contacts hot and cold gas streams. It transfers heat from exhaust or hot gas to incoming fluid, thereby improving efficiency. Common examples are regenerator heat exchangers used in Stirling engines and high-temperature industrial furnaces.

In gas-turbine and power systems, regenerators (often called recuperators) recover heat from the engine exhaust to preheat compressed air or fuel. This reduces fuel consumption and emissions and is a key feature in some stationary and microturbine designs.

In chemical processing and environmental engineering, regenerators restore spent materials to usable form. They are used to desorb captured species from sorbents, regenerate activated carbons, or reheating and reactivating catalysts and ion-exchange resins. They enable repeated use of adsorbents and catalysts in adsorption and chromatography processes.

In energy storage and transportation, the term regenerator may refer to systems that capture kinetic or potential energy for storage, such as regenerative braking in electric or hybrid vehicles, where electrical energy is stored rather than dissipated as heat.

See also: heat exchanger, regenerator bed, recuperator, regenerative braking, sorbent regeneration.