A system and method for cryogenic purification of a hydrogen, nitrogen, methane and argon containing feed stream to produce a methane free, hydrogen and nitrogen containing synthesis gas and a methane rich fuel gas, as well as to recover an argon product stream, excess hydrogen, and excess nitrogen is provided. The disclosed system and method are particularly useful as an integrated cryogenic purifier in an ammonia synthesis process in an ammonia plant. The excess nitrogen is a nitrogen stream substantially free of methane and hydrogen that can be used in other parts of the plant, recovered as a gaseous nitrogen product and/or liquefied to produce a liquid nitrogen product.

A method and main heat exchange system for use in a cryogenic air separation plant in which down-flow and thermosiphon heat exchangers are employed to partially vaporize an oxygen-rich liquid produced in a lower pressure column and to condense the nitrogen-rich vapor in a higher pressure column. A greater proportion of the oxygen-rich liquid can be partially vaporized in the down-flow heat exchangers than in the thermosiphon heat exchangers and the nitrogen-rich vapor condensed in the thermosiphon heat exchangers can have a higher oxygen content than the nitrogen-rich vapor condensed in the down-flow heat exchangers. This allows the higher pressure column to operate at a lower pressure than would otherwise be possible. A central conduit can extend from the higher pressure column into the lower pressure column to introduce the nitrogen-rich vapor into at least the down-flow heat exchangers for purposes of reducing pressure drop and column height.

A process for cooling a tube side stream in a main heat exchanger is described. The process comprises: a) supplying a first mass flow of a tube side stream to a first zone of individual tubes in the tube bundle; b) supplying a second mass flow of the tube side stream to a second zone of individual tubes in the tube bundle, the second zone being offset from the first zone; c) supplying a refrigerant stream on the shell side for cooling the first and second mass flows; d) removing the evaporated refrigerant stream from the warm end of the main heat exchanger; and, e) adjusting the first mass flow of the tube side stream relative to the second mass flow of the tube side stream to maximise the temperature of the removed evaporated refrigerant stream.

This heat exchanger can include parallel plates which define liquid-refrigerant passages following a longitudinal direction, andfins extending in each passage in a lateral direction orthogonal to the longitudinal direction, each fin having orifices for the flow of the liquid refrigerant. At least one lower portion of at least one fin defines, with the plate secured to this lower portion, a distribution channel for channeling the liquid refrigerant in the lateral direction. The orifices in said at least one fin are formed by overflow openings in the upper portion. The liquid refrigerant flows through the overflow openings when the or each distribution channel is full of liquid refrigerant.

An LNG plant comprises a cold box and a refrigeration unit fluidly coupled with a plurality of heat exchanger passes in the cold box. The refrigeration unit is configured to provide a first refrigerant stream to a first heat exchanger pass of the plurality of heat exchanger passes at a first pressure, a second refrigerant stream to a second heat exchanger pass at a second pressure, and a third refrigerant stream to a third heat exchanger pass at a third pressure. The second refrigerant stream comprises a first portion of the first refrigerant stream, and the third refrigerant stream comprises a second portion of the first refrigerant stream. The second pressure and the third pressure are both below the first pressure. The cold box is configured to produce LNG from a natural gas feed stream to the cold box using a refrigeration content from the refrigeration unit.

An LNG plant comprises a cold box and a refrigeration unit fluidly coupled with a plurality of heat exchanger passes in the cold box. The refrigeration unit is configured to provide a first refrigerant stream to a first heat exchanger pass of the plurality of heat exchanger passes at a first pressure, a second refrigerant stream to a second heat exchanger pass at a second pressure, and a third refrigerant stream to a third heat exchanger pass at a third pressure. The second refrigerant stream comprises a first portion of the first refrigerant stream, and the third refrigerant stream comprises a second portion of the first refrigerant stream. The second pressure and the third pressure are both below the first pressure. The cold box is configured to produce LNG from a natural gas feed stream to the cold box using a refrigeration content from the refrigeration unit.

A fuel gas conditioning unit includes a brazed aluminum heat exchanger including a plurality of parting sheets defining a plurality of separate flow channels positioned between the plurality of parting sheets, a plurality of fin sheets positioned in the plurality of flow channels, a feed inlet configured to receive a raw feed stream, a cooled feed outlet configured to discharge a cooled feed stream formed from the raw feed stream, a fuel outlet configured to discharge a finished fuel gas stream, and a liquids outlet configured to discharge a finished liquids stream, an expansion device coupled to the heat exchanger and configured to receive a cooled fuel stream from the heat exchanger and discharge an expanded fuel stream formed from the cooled fuel stream, and a feed separator where the heat exchanger is configured to form the finished fuel gas stream and the finished liquids stream.

A system and method for the concurrent condensation of a nitrogen-rich vapor and vaporization of an oxygen-rich liquid in a distillation column based air separation unit is provided. The disclosed system includes a condenser-reboiler heat exchanger located between a lower pressure column and a higher pressure column and configured to condense a nitrogen-rich vapor from the higher pressure column and partially vaporize an oxygen-rich liquid from the lower pressure column. Within the condenser-reboiler heat exchanger, the nitrogen-rich vapor flows in an upward direction such that any non-condensables present in the nitrogen-rich vapor will accumulate proximate the upper portion or top of the condenser-reboiler modules where they can be easily removed through venting by means of a venting apparatus having a plurality of perforated tubes.

A process for liquefying a tube side stream in a main heat exchanger is described. The process comprises the steps of: a) providing a first mass flow to the warm end of a first subset of individual tubes, b) providing a second mass flow to the warm end of a second subset of individual tubes, c) evaporating a refrigerant stream on the shell side; d) measuring an exit temperature of the first mass flow; e) measuring an exit temperature of the second mass flow; and, f) comparing the exit temperature of the first mass flow measured in step d) to the exit temperature of the second mass flow measured in step e), the process characterized in that at least one of the first and second mass flows is adjusted to equalize the exit temperature of the first mass flow with the exit temperature of the second mass flow.

A system and method for the concurrent condensation of a nitrogen-rich vapor and vaporization of an oxygen-rich liquid in a distillation column based air separation unit is provided. The disclosed system includes a condenser-reboiler heat exchanger located between a lower pressure column and a higher pressure column and configured to condense a nitrogen-rich vapor from the higher pressure column and partially vaporize an oxygen-rich liquid from the lower pressure column. Within the condenser-reboiler heat exchanger, the nitrogen-rich vapor flows in an upward direction such that any non-condensables present in the nitrogen-rich vapor will accumulate proximate the upper portion or top of the condenser-reboiler modules where they can be easily removed through venting.