A method for efficiently reducing the energy required to convert natural gas from a natural gas pressure letdown facility at high pressure and pipeline/wellhead temperature to liquid natural gas in close proximity to/collocation with a natural gas pressure letdown/regulation facility using Non-Freezing Vortex Tubes (U.S. Pat. No. 5,749,231) in arrangement with indirect contact heat exchangers. The Non-Freezing Vortex Tubes separate the inlet natural gas into hot flow and cold flow outlet natural gas flows. One portion of the natural gas flow from the high-pressure transmission line/gas wellhead is directed through the Non-Freezing Vortex Tube and the cold outlet flow of the natural gas is directed to the indirect contact heat exchanger(s) to act as the cooling medium. The liquid natural gas plant's required natural gas flow is directed at the existing pipeline/wellhead gas pressure through the heat exchanger and cooled. The already cooled natural gas flow is directed to a turbo expander and refrigeration cold box system where it is further chilled and converted into liquid natural gas at −162° C.

Provided herein are systems and methods for the processing of exhaust gases of industrial processes in order to reduce or eliminate emission of pollutants (including carbon dioxide) and store energy in the form of cryogenic liquids. Advantageously, the provided systems and methods utilize advanced heat exchanger systems to reduce or eliminate the net power required for operation. The heat exchangers are used both to reduce effluent gases to liquid temperatures as well as reheat previously cooled and separated gases, which can generate electricity via a turbo generator. The described systems and method may also produce cryogenic liquid products (Argon, Krypton, liquid Oxygen, liquid Nitrogen, etc.).

A method to recover olefins and C.sub.2.sup.+ fractions from refineries gas streams. The traditional recovery methods employed at refineries are absorption with solvents and cryogenic technology using compression and expansion aided by external refrigeration systems. In contrast to known methods, there is provided first a pre-cooling heat exchanger on a feed line feeding the gas stream to a in-line mixer, secondly by injecting and mixing a stream of LNG to condense the C.sub.2.sup.+ fractions upstream of the fractionator. The temperature of the gas stream entering the fractionator is monitored downstream of the in-line mixer. A LNG stream is temperature controlled to flow through the injection inlet and mix with the feed gas at a temperature which results in the condensation of the C.sub.2.sup.+ fractions before entering the fractionator. A LNG reflux stream is temperature controlled to maintain fractionator overhead temperature. The fractionator bottoms temperature is controlled by a circulating reboiler stream.

A CO2 separation and liquefaction system such as might be used in a carbon capture and sequestration system for a fossil fuel burning power plant is disclosed. The CO2 separation and liquefaction system includes a first cooling stage to cool flue gas with liquid CO2, a compression stage coupled to the first cooling stage to compress the cooled flue gas, a second cooling stage coupled to the compression stage and the first cooling stage to cool the compressed flue gas with a CO2 melt and provide the liquid CO2 to the first cooling stage, and an expansion stage coupled to the second cooling stage to extract solid CO2 from the flue gas that melts in the second cooling stage to provide the liquid CO2.

The present disclosure relates generally to a system for removing fuel from a mixture of air and fuel vapor in an ullage space of an aircraft fuel tank. The system includes a compressor for drawing the mixture of air and fuel vapor from the ullage space and directing the mixture of air and fuel vapor through a heat exchanger where the mixture of air and fuel vapor is cooled. The system also includes a turbine configured to be driven by the mixture of air and fuel from the heat exchanger. Power from the turbine can be transferred back toward the compressor to assist in driving rotation of the compressor. The system further includes a separator for receiving the mixture of air and fuel vapor from the turbine and separating at least some liquid fuel from the mixture of air and fuel vapor. From the separator, a separated liquid fuel and a mixture of air and fuel vapor with reduced concentration of fuel vapor are returned to the aircraft fuel tank.

A liquefaction system is capable of sequentially or simultaneously liquefying multiple feed streams of hydrocarbons having different normal bubble points with minimal flash. The liquefying heat exchanger has separate circuits for handling multiple feed streams. The feed stream with the lowest normal boiling point is sub-cooled sufficiently to suppress most of the flash. Feed streams with relatively high normal boiling points are cooled to substantially the same temperature, then blended with bypass streams to maintain each product near its normal bubble point. The system can also liquefy one stream at a time by using a dedicated circuit or by allocating the same feed to multiple circuits.

In a process for treating a carbon dioxide-rich gas (1) containing water, the treatment by compression and/or washing and/or drying of the gas produces acidified water (W1, W2, W3, W4, W7) which is sent to a cooling circuit (W8, W10).

A system and method for capturing and separating carbon dioxide from mixed gas streams. The gas stream is processed in a structure including a compression module comprising a plurality of compressors, intercoolers and inter-stage condensate separators. The flow path from the compression module includes a plurality of flow separators, gas stream splitters, heat exchangers and at least a first mixer and a first expander. The gas stream is sequentially compressed and cooled to form process condensate and separate it from the compressed gas stream. The gas stream is further dried and cooled to liquefy carbon dioxide and separate it from the non-condensable portion. Selective expansion of liquid carbon dioxide streams provides cooling for the system, and further energy efficiency is achieved by selective recycling of portions of gas streams, allowing for compact equipment and economical operation, while providing for high purity product streams of carbon dioxide.

Carbon dioxide is recovered from an exhaust gas in the form of liquid carbon dioxide or supercritical carbon dioxide utilizing a rotary separator. Nitrogen gas recovered from the rotary separator can be expanded to provide cooling for carbon dioxide in a closed-loop CO2 power cycle that is used to cool the exhaust gas upstream of the rotary separator. The recovery can power itself and can produce excess electricity from waste heat.

One or more specific embodiments disclosed herein includes a method for separating hydrogen from an olefin hydrocarbon rich compressed effluent vapor stream, employing a integrated heat exchanger, multiple gas-liquid separators, external refrigeration systems, and a rectifier attached to a liquid product drum.