A method of cooling a boil-off gas (BOG) stream from a liquefied gas tank comprising at least the step of heat exchanging the BOG stream with a first refrigerant in a heat exchanger, the heat exchanger having an entry port and a warmer exit port, and comprising at least the steps of: (a) passing the first refrigerant into the entry port of the heat exchanger and into a first zone of the heat exchanger to exchange heat with the BOG stream, to provide a first warmer refrigerant stream; (b) withdrawing the first warmer refrigerant stream from the heat exchanger at an intermediate exit port between the entry port and the warmer exit port; (c) admixing the first warmer refrigerant stream with an oil-containing refrigerant stream to provide a combined refrigerant stream; (d) passing the combined refrigerant stream into the heat exchanger through an entry port located in a second zone of the heat exchanger that is warmer than the first zone; (e) passing the combined refrigerant stream out of the heat exchanger through the warmer exit port. The present invention is a modification of a refrigerant cycle for BOG cooling, and LNG re-liquefaction in particular, that allows the use of a cost-efficient oil-injected screw compressor in the refrigerant system. The present invention is also able to accommodate the possibility of different flows or flow rates of the first refrigerant stream and the oil-containing refrigerant stream, such that there is reduced or no concern by the user of the process in relation to possible oil freezing and clogging of the heat exchanger caused by variation of the flow or flow rate of the oil-containing refrigerant stream.

Methods and systems for removing contaminants, such as water and/or carbon dioxide, from a gas stream, such as a natural gas stream or a flue gas stream. One or more solid-tolerant heat exchangers are employed to chill the gas stream to a temperature at which the contaminants solidify. The solidified contaminants may then be separated and removed from the gas stream. In one or more aspects, the one or more solid-tolerant heat exchangers may include a scraped heat exchanger.

The invention primarily concerns a facility for storing and cooling a liquefied gas, for example a liquefied natural gas, the facility comprising at least one tank configured to contain the liquefied gas, a closed cooling circuit configured to be supplied with liquefied gas in the liquid state coming from the tank, at least one injection member configured for reinjecting cooled liquefied gas into the tank, the facility being characterized in that it comprises at least one connection line configured to recover a cooled gas from at least one remote container that is separate and independent from the facility.

A heat exchanger having a first and second mixing devices having at least one lateral channel configured in order for a first phase of the first fluid to flow from at least one first inlet; a series of longitudinal channels extending in the longitudinal direction and each configured in order for a second phase of the first fluid to flow from a second inlet to a second outlet, the longitudinal channels succeeding each other in a lateral direction orthogonal to the longitudinal direction; and at least one opening fluidly connecting the at least one lateral channel to at least one longitudinal channel such that the first and second mixing devices are configured to distribute a mixture of the first phase and the second phase via the second outlets of their respective longitudinal channels.

A system for condensing and phase separating a refrigerant fluid includes a condenser inlet header configured to receive a stream of refrigerant vapor. A condenser is in fluid communication with the condenser header and is configured to receive vapor and produce a mixed phase fluid stream. An elongated manifold separator including multiple mixed phase inlets is configured to separate mixed phase fluid received from the condenser. Resulting vapor and liquid streams exit vapor and liquid outlets of the manifold separator.

The present invention is a modification of a typical single mixed refrigerant (SMR) cycle for LNG re-liquefaction in particular, that allows the use of a cost-efficient oil-injected screw compressor in the mixed refrigerant system. In comparison with the typical arrangement, the present innovation allows for reduced complexity, fewer pieces of equipment, and reduced capital cost. There is shown a method of cooling a boil-off gas (BOG) stream from a liquefied gas tank using a single mixed refrigerant (SMR) comprising at least the step of heat exchanging the BOG stream with the SMR in a liquefaction heat exchanger system to provide a cooled BOG stream, wherein the SMR is provided in an SMR recirculating system comprising at least the steps of: (a) compressing the SMR using at least one oil-injected screw compressor to provide a post-compression SMR stream; (b) separating the post-compression SMR stream to provide an oil-based stream and a first SMR vapour stream; (c) passing the first SMR vapour stream into the liquefaction heat exchanger system to cool the first SMR vapour stream and provide a cooled first SMR vapour stream; (d) withdrawing the cooled first SMR vapour stream from the liquefaction heat exchanger system; (e) separating the cooled first SMR vapour stream to provide a liquid-phase SMR stream and an oil-free SMR vapour stream; (f) passing the oil-free SMR vapour stream through the liquefaction heat exchanger system to provide a condensed SMR stream; and (g) expanding the condensed SMR stream to provide an expanded lowest-temperature SMR stream to pass through the liquefaction heat exchanger system for heat exchange against the BOG stream.

A process for the production of a liquid oxygen stream and a liquid hydrocarbon-rich stream by the cryogenic rectification of an inlet air stream, including dividing the inlet air stream into a first portion, and a second portion. Cooling the first portion, and the second portion against a cooled multicomponent refrigerant circuit, thereby producing a first cooled portion, and a second cooled portion. Condensing the first cooled portion, thereby producing a condensed first portion, then introducing the condensed first portion into one or more distillation columns. Expanding the second cooled portion in a turbo-expander, thereby producing an expanded second portion, then introducing the expanded second portion within the one or more distillation columns. Producing within the one or more distillation columns at least a waste nitrogen stream, a nitrogen enriched stream, and an oxygen enriched stream.

A hybrid process of air separation and gas liquefaction, including dividing a compressed multicomponent refrigerant stream into a first portion and a second portion, introducing the first portion into a gas liquefaction system, thereby producing a first multicomponent refrigerant return stream, and introducing the second portion into an air separation system, thereby producing a second multicomponent refrigerant return stream. Wherein the first multicomponent refrigerant return stream and the second multicomponent refrigerant return are recompressed in a common compression system, thereby producing the compressed multicomponent refrigerant stream.

A method and apparatus for producing liquefied natural gas. A pretreated natural gas stream is compressed in at least two serially arranged compressors to a pressure of at least 1,500 psia and cooled. The resultant cooled compressed natural gas stream is expanded in at least one work producing natural gas expander to a pressure less than 2,000 psia and no greater than the pressure to which natural gas stream has been compressed, thereby forming a chilled natural gas stream that is separated into a refrigerant stream and a non-refrigerant stream. The refrigerant stream is warmed in a heat exchanger through heat exchange with one or more process streams associated with pretreating the natural gas stream, thereby generating a warmed refrigerant stream. The warmed refrigerant stream and the non-refrigerant stream are then liquefied.

Systems and methods are provided for increasing the efficiency of liquefied natural gas production and heavy hydrocarbon distillation. Air within an LNG production facility can be utilized as a heat source to provide heat to HHC liquid for distillation in a HHC distillation system. The mechanism of heat transfer from the air can be natural convection. Heat provided by natural gas, or compressed natural gas, can be also used for HHC distillation. Various other liquids can further be used to transfer heat to HHC liquid for distillation.