A method describing the integration of a nitrogen liquefier and letdown of natural gas for the production of liquid nitrogen and lower pressure natural gas is provided. The method may include: providing a nitrogen liquefier having a nitrogen refrigeration cycle, wherein the nitrogen liquefier comprises a nitrogen compressor, a nitrogen recycle compressor, a heat exchanger, and at least a first turbine booster and introducing a nitrogen gas stream to the nitrogen liquefier under conditions effective for liquefying the nitrogen to produce a liquid nitrogen product. The refrigeration needed to liquefy the nitrogen is provided for by the nitrogen refrigeration cycle and letdown of a high pressure natural gas stream.

A method for the integration of a nitrogen liquefier and liquefaction of natural gas for the production of liquefied natural gas and liquid nitrogen is provided. The method may include providing a nitrogen liquefaction unit and providing a natural gas liquefaction unit. Liquefaction of the nitrogen can be achieved via a nitrogen refrigeration cycle within the nitrogen liquefaction unit. Liquefaction of the natural gas can be achieved through the use of natural gas letdown and a second nitrogen refrigeration cycle. The two liquefaction units can be integrated via a common nitrogen recycle compressor, thereby providing significant capital savings.

A facility for recovering carbon dioxide from a feed gas flow, including a unit for treating the feed gas flow in order to produce, from feed gas flow, a carbon dioxide-rich gas flow and a nitrogen-rich gas flow, a compression stage for compressing the feed gas flow, an expansion stage capable of outputting mechanical energy generated by the expansion of the nitrogen-rich gas flow, a thermal device arranged to enable heat transfers to take place between the gas flow leaving the compression stage and the nitrogen-rich gas flow prior to expansion, and a device for utilising the mechanical energy output by the expansion stage.

A method and an apparatus for a cooling of an electroyzer unit is described. The apparatus receives a temperature value associated with ambient air in proximal to the electrolyzer unit. The apparatus compares the temperature value with a predefined temperature threshold. The apparatus controls a supply of a liquid air stream from an air separation unit to a first heat exchanger unit based on the comparison. The apparatus control the first heat exchanger unit to mix the liquid air stream with the ambient air. The mixing of the liquid air stream and the ambient air causes transfer of heat therebetween. The apparatus controls a cooling of the electrolyzer unit based on the mixing.

Hydrogen liquification includes three streams of refrigerant at between 320 to 425 degrees F. A fourth stream has ambient temperature and pressure between 150 to 650 PSIA. Fourth stream cooling flows are cooled by heat exchangers to between 320 to 270 degrees F. A first flow of these cooling flows is reduced across a valve to a two-phase mixture directed to fourth warming flows. A separate fifth stream has ambient temperature and pressure of between 700 and 1200 PSIA. Fifth stream cooling flows have a first flow portion removed by a splitter at between 0 and 60 degrees F., and a second flow portion removed at between 160 and 100 degrees F. The first flow portion and a cooled flow of the second flow portion are feed into expanders that power fifth compressors to reduce a temperature of the fifth stream to serve as the first and second flow portions.

An air separation unit including: a main heat exchanger, a medium-pressure rectification column, a low-pressure rectification column, a crude argon column, a nitrogen condenser, a crude argon condenser, an oxygen turbine, a nitrogen compressor, and a nitrogen turbine. The nitrogen turbine expands nitrogen gas supplied from the nitrogen compressor. The air separation unit includes an inlet temperature of the oxygen turbine is lower than an inlet temperature of the nitrogen turbine.

A process for cryogenic air separation and liquefaction, including purifying and compressing an inlet air stream, thereby producing a compressed inlet air stream, dividing the compressed inlet air stream into an ASU portion and a liquefaction portion, introducing the ASU portion into an air separation unit, thereby producing a gaseous oxygen steam and a gaseous nitrogen stream, and introducing the liquefaction portion, the gaseous oxygen steam and the gaseous nitrogen stream into a liquefaction unit, thereby producing a liquid nitrogen stream and a liquid oxygen stream. Wherein, the air separation unit is located more than 200 meters from the liquefaction unit, and there is no compression driven by external energy within 200 meters of the liquefaction unit.

Methods and systems providing a process for cooling and liquefying a purified gaseous hydrogen feed stream to a liquid hydrogen stream that may be stored in a liquid hydrogen storage tank, as well as a system wherein ortho-hydrogen (o-H2) contained in the purified gaseous hydrogen feed stream may be converted to para-hydrogen (p-H2) through serial low-temperature catalytic converters along the cooling process from normal ambient temperature (300K) to the liquefied temperature about (20K) of the hydrogen.

A process for separating carbon dioxide from a waste gas of a fluid catalytic cracking installation including converting at least a portion of the carbon monoxide of the waste gas into carbon dioxide to form a flow enriched in carbon dioxide, separating at least a portion of the flow enriched in carbon dioxide to form a gas enriched in carbon dioxide and depleted in nitrogen and a gas rich in nitrogen and depleted in carbon dioxide, and at least a portion of the gas enriched in carbon dioxide and depleted in nitrogen is separated by way of separation at a temperature of less than 0 C. to form a fluid rich in carbon dioxide and a fluid depleted in carbon dioxide and sending a gas containing at least 90% oxygen to combustion.

Methods and systems providing a process for cooling and liquefying a purified gaseous hydrogen feed stream to a liquid hydrogen stream that may be stored in a liquid hydrogen storage tank, as well as a system wherein ortho-hydrogen (o-H2) contained in the purified gaseous hydrogen feed stream may be converted to para-hydrogen (p-H2) through serial low-temperature catalytic converters along with cooling process from normal ambient temperature (300K) to the liquefied temperature (about 20K) of the hydrogen.