The production of NH.sub.3, Urea, UAN, and DAP, starting from inherently intermittent renewable energy, such as photovoltaic and wind power, is made economical by use of molten salt thermal energy storage (ESS) and water electrolyzer (WE) concentrated oxygen. The process inputs and equipment apply air; hydrogen-containing fuel, such as biomass; WE (concentrated O.sub.2 and H.sub.2 producing); thermal ESS equipped with a turbine and generator to steady the electricity input to the WE; and an ammonia plant. The thermal ESS enables minimally sized process equipment including, the WE, the air separation unit and less hydrogen storage. The concentrated oxygen from the water electrolyzer uniquely enables high-temperature thermal ESS input, water and CO2 collection and other fertilizer products, including Urea, UAN and DAP. DAP production is facilitated by using WE high-purity O.sub.2 oxidation and ammonium nitrate is similarly facilitated by anhydrous NH.sub.3 oxidation.

Plant and method for producing hydrogen at cryogenic temperature, in particular liquefied hydrogen, comprising: an electrolyzer having an oxygen outlet and a hydrogen outlet; a hydrogen circuit to be cooled, comprising an upstream end connected to the hydrogen outlet and a downstream end to be connected to a member for collecting cooled and/or liquefied hydrogen, the plant also comprising a set of heat exchanger(s) in heat exchange with the hydrogen circuit to be cooled, the plant further comprising at least one cooling device in heat exchange with at least a portion of the set of heat exchanger(s), the hydrogen circuit to be cooled comprising a system for expanding the hydrogen stream and at least one hydrogen compressor upstream of the hydrogen stream expansion system, the hydrogen stream expansion system comprising at least one expansion turbine, wherein said at least one expansion turbine and said at least one compressor are coupled to the same rotating shaft to transfer expansion work from the pressurized hydrogen stream to the compressor in order to compress the hydrogen stream upstream of the turbine.

A system and method for supplying an energy grid with energy from an intermittent renewable energy source having a production unit for producing Hydrogen, Nitrogen, and Oxygen. The production unit is operated by using energy provided by the renewable energy source. An Oxygen storage receives and stores Oxygen produced by the production unit, a mixing unit receives and mixes the Hydrogen and the Nitrogen produced by the production unit to form a Hydrogen-Nitrogen-mixture, an Ammonia source receives and processes the Hydrogen-Nitrogen-mixture for generating a gas mixture containing Ammonia, an Ammonia power generator generates energy for the energy grid. The Ammonia power generator is fluidly connected to the Ammonia storage vessel, is configured to combust the received Ammonia in a combustion chamber to generate the energy, and is fluidly connected to the Oxygen storage to introduce Oxygen into the combustion chamber for combustion of Ammonia.

A cryogenic technology for the cost-efficient capture of each known component of emissions, such as carbon dioxide, sulfur oxides, nitrogen oxides, carbon monoxide, any other acid vapor, mercury, steam, in a liquefied or frozen/solidified form, and unreacted nitrogen (gas) from industrial plants, such that each of the components is captured separately with minimum use of energy and is industrially useful.

The production of NH.sub.3, Urea, UAN, and DAP, starting from inherently intermittent renewable energy, such as photovoltaic and wind power, is made economical by use of molten salt thermal energy storage (ESS) and water electrolyzer (WE) concentrated oxygen. The process inputs and equipment apply air; hydrogen-containing fuel, such as biomass; WE (concentrated O.sub.2 and H.sub.2 producing); thermal ESS equipped with a turbine and generator to steady the electricity input to the WE; and an ammonia plant. The thermal ESS enables minimally sized process equipment including, the WE, the air separation unit and less hydrogen storage. The concentrated oxygen from the water electrolyzer uniquely enables high-temperature thermal ESS input, water and CO.sub.2 collection and other fertilizer products, including Urea, UAN and DAP. DAP production is facilitated by using WE high-purity O.sub.2 oxidation and ammonium nitrate is similarly facilitated by anhydrous NH.sub.3 oxidation.

A novel concept for a high energy and material efficient nitric acid production process and system is provided, wherein the nitric acid production process and system, particularly integrated with an ammonia production process and system, is configured to recover a high amount of energy out of the ammonia that it is consuming, particularly in the form of electricity, while maintaining a high nitric acid recovery in the conversion of ammonia to nitric acid. The energy recovery and electricity generation process comprises pressurizing a liquid gas, such as air, oxygen and/or N.sub.2, subsequently evaporating and heating the pressurized liquid gas, particularly using low grade waste heat generated in the production of nitric acid and/or ammonia, and subsequently expanding the evaporated pressurized liquid gas over a turbine. In particular, the generated electricity is at least partially used to power an electrolyzer to generate the hydrogen needed for the production of ammonia. The novel concepts set out in the present application are particularly useful in the production of nitric acid based on renewable energy sources.

In an aspect, a system comprises a water stream in fluid communication with an electrolyzer; the electrolyzer comprising an anode and a cathode side chamber; a deep space oxygen radiator in fluid communication with the anode side chamber of the electrolyzer; a cryogenic heat exchanger comprising an oxygen storage tank in fluid communication with the deep space oxygen radiator; an electrochemical hydrogen compressor in fluid communication with the cathode side chamber; a hydrogen storage tank in fluid communication with the electrochemical hydrogen compressor via a cooled hydrogen stream; wherein at least a portion of the cooled hydrogen stream is in a first fluid communication with an expansion valve and the cryogenic heat exchanger; wherein the hydrogen storage tank is in a second fluid communication with the electrochemical hydrogen compressor via a warmed hydrogen stream; and wherein the cryogenic heat exchanger is in fluid communication with the warmed hydrogen stream.

A cryogenic cooling system for an aircraft includes a first air cycle machine, a second air cycle machine, and a means for collecting liquid air. The first air cycle machine is operable to output a cooling air stream based on a first air source. The second air cycle machine is operable to output a chilled air stream at a cryogenic temperature based on a second air source cooled by the cooling air stream of the first air cycle machine. An output of the second air cycle machine is provided to the means for collecting liquid air.

A system for an aircraft includes an engine bleed source of a gas turbine engine. The system also includes a means for chilling an engine bleed air flow from the engine bleed source to produce a chilled working fluid. The system further includes a means for providing the chilled working fluid for an aircraft use.

A propulsion system includes an electric fan propulsion motor with a plurality of propulsion motor windings. The propulsion system also includes a means for controlling a flow rate of a working fluid through a cryogenic working fluid flow control assembly to the propulsion motor windings.