In a method for separating air by cryogenic distillation using a column system consisting of a higher pressure column operating at a first pressure and a lower pressure column operating at a second pressure, a first air flow constituting between 75% and 98% of the air sent to the column system compressed to a third pressure above the first pressure, is sent to the higher pressure column, a second air flow constituting between 5% and 25% of the air sent to the column system is compressed to a fourth pressure above the second pressure but lower than the third pressure, is sent to the lower pressure column, a third column separates an argon-enriched flow and the air sent to the lower pressure column constitutes between 10% and 25% of the total air sent to the column system.

There is provided a system and method for producing liquefied natural gas (LNG). An exemplary method includes flowing a high-pressure stream of LNG through a first series of liquid turbines. The exemplary method also includes generating electricity by reducing the pressure of the high-pressure stream of LNG to form a low-pressure stream of LNG. The exemplary method additionally includes bypassing any one the liquid turbines that has a failure while continuing to produce electricity from the first series.

A plant for energy storage, comprises: a basin (2) for a work fluid having a critical temperature (T.sub.c) lower than 0°; a tank (3) configured to store the work fluid in at least partly liquid or super-critical phase with a storage temperature (T.sub.s) close to the critical temperature (T.sub.c); an expander (4); a compressor (5); an operating/drive machine (6) operatively connected to the expander (4) and to the compressor (5); a thermal store (8) operatively interposed between the compressor (5) and the tank (3) and between the tank (3) and the expander (4). The plant (1) is configured for actuating a Cyclic Thermodynamic Transformation (TTC) with the work fluid, first in a storage configuration and then in a discharge configuration. The thermal store (8), in the storage configuration, is configured for absorbing sensible heat and subsequently latent heat from the work fluid and, in the discharge configuration, it is configured for transferring latent heat and subsequently sensible heat to the work fluid.

A marine vessel and method for carbon capture and sequestration are described. The marine vessel includes a buoyant hull, a cryogenic storage tank within the hull, and a gaseous carbon dioxide loading manifold. The marine vessel also includes a carbon dioxide liquefaction system in fluid communication with the cryogenic storage tank downstream of the carbon dioxide liquefaction system and with the gaseous carbon dioxide loading manifold upstream of the carbon dioxide liquefaction system. Finally, the marine vessel includes a carbon dioxide supercritical system in fluid communication with the cryogenic storage tank. In operation, the marine vessel moves between multiple locations, where gaseous carbon dioxide is onboarded, liquified and stored. Thereafter, the marine vessel transports the liquified carbon dioxide to a location adjacent an offshore geological reservoir. The liquefied carbon dioxide is then pressurized to produce supercritical carbon dioxide, which is then injected directly into the reservoir from the marine vessel.

The present invention relates to a system for treating and cooling a hydrocarbon stream, comprising—a gas treatment stage comprising a pre-cooler to cool at least part of the hydrocarbon feed against cooling water, —a first cooling stage comprising one or more first water coolers, —a second cooling stage comprising one or more second water coolers. The system comprises a cooling water unit arranged to receive a stream of cooling water and supply a first part of the stream of cooling water to a chilling unit to obtain a stream of chilled cooling water and pass the stream of chilled cooling water to a selection of the at least one pre-cooler, the one or more first water coolers and the one or more second water coolers.

An anaerobic digester is provided. The anaerobic digester includes a biogas storage container comprising a semi-permeable membrane separating the biogas storage container into a first space and a second space, such that the first space is configured to be methane enriched and the second space is configured to be CO.sub.2 enriched. The anaerobic digester further includes a cover positioned over the biogas storage container for protecting the biogas storage container against the elements.

Disclosed techniques include gas liquefaction using hybrid processing. A gas is compressed adiabatically to produce a compressed gas at a first pressure. The compressing a gas adiabatically is accomplished using one or more compressing stages. Heat is extracted from the compressed gas at a first pressure. The heat that is extracted is collected in a thermal store. The compressed gas at a first pressure is further compressed. The further compressing is accomplished using a first liquid piston compressor. The further compressing produces a compressed gas at a second pressure. The first liquid piston compressor is cooled using a liquid spray. The compressed gas at a second pressure is cooled using a heat exchanger. The cooling accomplishes liquefaction of the compressed gas at a second pressure. The gas that was liquefied is stored for future use. The gas that was liquefied is used to perform work.

A method and system for liquefying a methane-rich high-pressure feed gas stream using a first heat exchanger zone and a second heat exchanger zone. The feed gas stream is mixed with a refrigerant stream to form a second gas stream, which is compressed, cooled, and directed to a second heat exchanger zone to be additionally cooled below ambient temperature. It is then expanded to a pressure less than 2,000 psia and no greater than the pressure to which the second gas stream was compressed, and then separated into a first expanded refrigerant stream and a chilled gas stream. The first expanded refrigerant stream is expanded and then passed through the first heat exchanger zone such that it has a temperature that is cooler, by at least 5° F., than the highest fluid temperature within the first heat exchanger zone.

A method of co-producing liquid hydrogen and ammonia, including a hydrogen generator, a nitrogen generator, and a HLU is presented. The method includes pressurizing a hydrogen stream from the hydrogen generator in a hydrogen compressor, dividing the pressurized hydrogen into at least a first portion and a second portion, wherein the first portion includes at least part of the flow of a first refrigeration cycle in the HLU, and the second part comprises at least part of the feed to an ammonia plant. The method also includes pressurizing a nitrogen stream from the nitrogen generator in a HP nitrogen compressor, dividing the pressurized nitrogen stream into at least a first part and a second part, wherein the first part comprises at least part of the flow of a second refrigeration cycle in the HLU, and the second part comprises at least part of the feed to the ammonia plant.

A system and method for removing nitrogen and producing a high pressure methane product stream and an NGL product stream from natural gas feed streams where at least 90%, and preferably at least 95%, of the ethane in the feed stream is recovered in the NGL product stream. The system and method of the invention are particularly suitable for use with feed streams in excess of 5 MMSCFD and up to 300 MMSCFD and containing around 5% to 80% nitrogen. The system and method preferably combine use of strategic heat exchange between various process streams with a high pressure rectifier tower and the ability to divert all or a portion of a nitrogen rejection unit feed stream to optionally bypass a nitrogen fractionation column to reduce capital costs and operating expenses.