A nitrogen producing cryogenic air separation unit with an excess air circuit is provided. The nitrogen producing cryogenic air separation unit is capable of producing high pressure gaseous nitrogen without the use of a nitrogen product compressors and is also capable of producing high rates of liquid nitrogen without adding additional compression stages in the main air compressor and/or without a nitrogen recycle compressor.

A dual-mode LNG liquefier arrangement that is configurable to operate in a first mode broadly characterized as a low pressure, liquid nitrogen add LNG liquefier without turbo-expansion or a second mode broadly characterized as a low pressure, liquid nitrogen add LNG liquefier with turbo-expansion.

A process for producing liquid oxygen, including, a first operating mode, and a second operating mode. During the first operating mode, the distillation column produces a first flowrate of product liquid oxygen, and a first flow rate of liquid nitrogen product. During the second operating mode, the distillation column produces a second flowrate of product liquid oxygen, and a second flow rate of liquid nitrogen product. Wherein, the second flowrate of product liquid oxygen is greater than the first flowrate of product liquid oxygen.

A system and method for liquefaction of natural gas using two distinct refrigeration circuits having compositionally different working fluids and operating at different temperature levels is provided. The turbomachinery associated with the liquefaction system are driven by a single three-pinion, three-turbine integral gear machine with customized pairing arrangements. The system and method of natural gas liquefaction further includes the conditioning of a lower pressure natural gas containing feed stream to produce a purified, compressed natural gas stream at a pressure equal to or above the critical pressure of natural gas and substantially free of heavy hydrocarbons to be liquefied.

A system and method for liquefying a hydrogen gas feed stream uses a high-pressure hydrogen stream from a storage source to provide refrigeration to the system. After providing refrigeration to the system, the hydrogen from the high-pressure storage source is at a pressure not lower than the pressure of a cold box feed stream of the system, where the cold box feed stream includes the hydrogen gas feed stream and at least one recycle stream, and is not recycled back through the system but instead exits the system.

The invention relates to a method and a device for generating electrical energy in a combined system consisting of a power plant and an air handling system. The power plant comprises a first gas expansion unit connected to a generator. The air handling system comprises an air compression unit, a heat exchange system, and a fluid tank. In a first operating mode, feed air is compressed in the air compression unit and cooled in the heat exchange system. A storage fluid is generated from the compressed and cooled feed air and is stored as cryogenic fluid in fluid tank. In a second operating mode, cryogenic fluid is removed from fluid tank and is vaporized, or pseudo-vaporized, at superatmospheric pressure. The gaseous high pressure storage fluid generated is expanded in the gas expansion unit. Gaseous natural gas is introduced into the heat exchange system (21) to be liquefied.

A method and apparatus for liquefying a feed gas stream comprising natural gas and carbon dioxide. A method includes compressing an input fluid stream to generate a first intermediary fluid stream; cooling the first intermediary fluid stream with a first heat exchanger to generate a second intermediary fluid stream, wherein a temperature of the second intermediary fluid stream is higher than a carbon dioxide-freezing temperature for the second intermediary fluid stream; expanding the second intermediary fluid stream to generate a third intermediary fluid stream, wherein the third intermediary fluid stream comprises solid carbon dioxide; separating the third intermediary fluid stream into a fourth intermediary fluid stream and an output fluid stream, wherein the output fluid stream comprises a liquefied natural gas (LNG) liquid; and utilizing the fourth intermediary fluid stream as a cooling fluid stream for the first heat exchanger.

An expander and motor-compressor unit is disclosed. The unit includes a casing and an electric motor arranged in the casing. A compressor is arranged in the casing and drivingly coupled to the electric motor through a central shaft. Furthermore, a turbo-expander is arranged for rotation in the casing and is drivingly coupled to the electric motor and to the compressor through the central shaft.

Described herein are systems and processes of removing contaminants in a liquid nitrogen (LIN) stream used to produce liquefied natural gas (LNG). Greenhouse gas contaminants are removed from the LIN using a greenhouse gas removal unit. The LNG is compressed prior to being cooled by the LIN.

A technology liquefies natural gas. The natural gas liquefaction method pre-cools treated natural gas by ethane evaporation, sub-cools liquefied gas using cooled nitrogen as a refrigerant, reduces liquefied gas pressure, separates non-liquefied gas and diverts liquefied natural gas. Before pre-cooling the natural gas is compressed, ethane is evaporated during the multi-stage pre-cooling of liquefied gas with simultaneous evaporation of ethane using cooled ethane as a refrigerant. Ethane generated by evaporation is compressed, condensed and used as a refrigerant during the cooling of liquefied gas and nitrogen, with nitrogen being compressed, cooled, expanded and fed to the natural gas sub-cooling stage. The natural gas liquefaction unit contains a natural gas liquefaction circuit, an ethane circuit and a nitrogen circuit. The natural gas liquefaction circuit includes a natural gas compressor, a cooler unit, ethane vaporizers, a closed-end subcooling heat exchanger, and a separator, connected in series.