A packed bed for a heat exchanger may comprise a frame and a first fin layer disposed within the frame. A second fin layer may be disposed within the frame. A first perforated sheet may be disposed between the first fin layer and the second fin layer. A sorbent material may be disposed within a volume of at least one of the first fin layer or the second fin layer.

A highly efficient combined cooling, heating, and power (CCHP) system is capable of providing 100% utilization of an energy generator used by the system by distributing thermal and electrical outputs of the energy generator to loads and/or other storage apparatuses. The CCHP system includes an energy generator, which can be a fuel cell and a waste heat recovery unit that assists in recovering thermal energy from the energy generator and returning it to the energy generator, and/or providing it to a thermal load, or a storage as needed or desired.

Solar thermal units and methods of operating solar thermal units for the conversion of solar insolation to thermal energy are provided. In some examples, solar thermal units have an inlet, and a split flow of heat absorbing fluid to either side of the solar thermal unit, along a first fluid flow path and a second fluid flow path. Optionally, one or more photovoltaic panels can be provided as part of the solar thermal unit, which may convert solar insolation to electric power that may be used by a system connected to the solar thermal unit.

A method of operating a water electrolysis system including a water electrolysis stack discharging moisture-containing hydrogen gas, a plurality of dehumidification devices including a regenerative adsorbent removing moisture from the moisture-containing hydrogen gas discharged from the water electrolysis stack, temperature and pressure sensors detecting an internal temperature and pressure of each of the plurality of dehumidification devices, and a heating device heating the plurality of dehumidification devices, and in which the plurality of dehumidification devices are connected in parallel to a hydrogen gas supply pipe connecting the water electrolysis stack and the plurality of dehumidification devices and a hydrogen gas discharge pipe discharging moisture-reduced hydrogen gas from the plurality of dehumidification devices and are alternately used to remove moisture from the moisture-containing hydrogen gas, and the hydrogen gas supply pipe and the hydrogen gas discharge pipe are provided with a plurality of inlet valves and outlet valves.

Consumed energy and cost relating to control of a carbon dioxide concentration is reduced. Each of CO.sub.2 concentration control systems (100 to 105) includes a measuring unit (20) that measures a CO.sub.2 concentration, a CO.sub.2 absorption unit (30) that has a CO.sub.2 absorption material (31) for absorbing CO.sub.2 at a rate depending on the temperature thereof, and a control unit (10) that controls the temperature of the CO.sub.2 absorption material (31) by using exhaust heat of a power system (40), so as to control a CO.sub.2 absorption rate of the CO.sub.2 absorption material (31).

Provided herein are water harvesting systems, as well as methods of making and using such systems, for capturing water from surrounding air using a design that reduces overall energy costs of the systems and improve water harvesting cycle efficiency. The systems and methods use sorbent materials, such as metal-organic frameworks, to adsorb water from the air. The systems and methods desorb this water in the form of water vapor, and the water vapor is condensed into liquid water and collected. The liquid water is suitable for use as drinking water.

This disclosure is related to systems, methods, apparatuses, and techniques for generating water using waste heat. In certain embodiments, a system includes a water generating unit and a waste-heat-generating-system. The water generating unit can be configured to generate the water and comprises a desiccation device and a condenser coupled to the desiccation device. The waste-heat-generating-system can generate the waste heat when operating or is use. The water generating unit can be configured to use waste heat generated by the waste-heat-generating-system to generate the water.

A system for reducing carbon dioxide emissions from a flue gas is provided. The system includes a carbonator, and a calciner. The carbonator receives the flue gas and lean sorbent particles such that the lean sorbent particles absorb gaseous carbon dioxide from the flue gas and become loaded sorbent particles. The calciner includes a drum that defines a cavity having a first opening and a second opening. The first opening is fluidly connected to the carbonator such that the loaded sorbent particles flow into the cavity from the carbonator. The drum rotates such that at least some of the loaded sorbent particles are mixed with heat-transferring particles so as to release the absorbed gaseous carbon dioxide and exit the drum via the second opening as lean sorbent particles.

A gas desorption apparatus includes a central desorption chamber defining an interior portion adapted for heating, an inlet airlock coupled to chamber, a pump system coupled to each interior portion of the chamber and the inlet airlock and operable to create a pressure equivalency between the interior portions, and a channel disposed between the interior portion of the desorption chamber and an adsorbate storage chamber. The inlet airlock includes an exit port allowing passage from the interior portion of the inlet airlock into the interior portion of the central desorption chamber, an egress port allowing passage from an exterior portion of the inlet airlock into the interior portion of the inlet airlock and a toggleable door at each of the egress port and the ingress port sealing the interior portion of the inlet airlock when each said toggleable door is in a closed position.

Some embodiments of the disclosure correspond to, for example, a system for scrubbing a mixture of gases and/or contaminants from indoor air from an enclosed space to remove at least one gas and/or contaminant from the mixture of gases and/or contaminants. The system may include one or more adsorbent materials configured to be cycled between adsorption and regeneration of at least one of gas and/or contaminant from the mixture of gases and/or contaminants via a temperature swing adsorption cycle (for example), regeneration means configured to regenerate one or more adsorbent materials. The regeneration means may be configured at a regeneration temperature to regenerate the one or more adsorbent materials.