The present invention relates to a process and a system for supplying a backup gas at a higher pressure from a source gas at a lower pressure. The backup gas at the lower pressure is at least partially condensed against a backup liquid at a higher pressure in a reprocessing heat exchanger and as a result, the backup liquid is at least partially vaporized. The backup liquid at the higher pressure is formed from boosting liquefied backup gas at the lower pressure. A backup vaporizer is disposed downstream of the reprocessing heat exchanger to completely vaporize the backup liquid at a higher pressure before it was delivered to the customer. The present invention eliminates the use of costly gas compressor and mitigates associated safety risks, in particular when the backup gas is oxygen.

A moderate pressure nitrogen and argon producing cryogenic air separation unit is provided that includes a three distillation column system and turbine air stream bypass arrangement or circuit. The turbine air stream bypass arrangement or circuit is configured to improve argon and nitrogen recoveries in select operating modes by optionally diverting a portion of the turbine air stream to a nitrogen waste stream circuit drawn from the lower pressure column of the cryogenic air separation unit such that the diverted portion of the turbine air stream bypasses the distillation column system.

In a method for reheating an atmospheric vaporizer, a cryogenic liquid is vaporized by heat exchange with ambient air in the atmospheric vaporizer and to reheat the vaporizer, a gas is sent thereto at a temperature of at least 0° C., this gas originating from a cryogenic distillation air separation unit.

A system for natural gas cooling using nitrogen. The system can include a nitrogen liquefier and a natural gas cooler. The nitrogen liquefier can provide liquid nitrogen to the natural gas cooler. One or more heat exchangers of the natural gas cooler can include a gaseous nitrogen output that is in fluid communication with the nitrogen liquefier. In response to receiving gaseous nitrogen at the nitrogen liquefier, from the one or more heat exchangers, a production rate of the the nitrogen liquefier is adjusted.

A method and system for liquefying a natural gas feed stream and removing nitrogen therefrom.

Liquefier arrangements configured for flexible co-production of both liquid natural gas (LNG) and liquid nitrogen (LIN) are provided. Each liquefier arrangement comprises separate and independent nitrogen recycle circuits or loops, including a warm recycle circuit and a cold recycle circuit with a means for diverting nitrogen refrigerant between the two recycle circuits or loops. The warm recycle circuit includes a booster loaded warm turbine, a warm booster compressor and warm recycle compression whereas the cold recycle circuit includes a booster loaded cold turbine, a cold booster compressor and a separate cold recycle compression.

A method and apparatus for reducing heat bumps following regeneration of adsorbers in an air separation unit is provided. Certain embodiments of the current invention utilize the two waste streams available at very different temperatures from the two main exchangers (low-pressure and high-pressure core exchangers) for regeneration of the front-end purification adsorbers in the air separation unit (ASU) to reduce its energy consumption without compromising the stability of process. Certain embodiments help to eliminate/minimize high air temperature disturbance (heat bump) for the process downstream of the front-end purification unit during the transition from offline to online.

A method for temperature-controlled delivery of the gaseous product at temperatures at or below ambient in the event of an air separation unit failure. In one embodiment, a first portion of a stored cryogenic liquid product is sent to the back-up vaporizer and heated to ambient conditions, and a second portion of stored cryogenic liquid product, which is at the cryogenic storage temperature, bypasses the back-up vaporizer using a bypass line controlled by a bypass valve and is mixed with the vaporized gas. This mixed stream will then preferably go through a static mixer in order to get to an homogenous temperature that is below the ambient temperature. A temperature control loop can be used to adjust the opening of the by-pass valve in order to reach the desired product temperature.

Process for the combined production of a mixture of hydrogen and nitrogen, and of carbon monoxide by cryogenic distillation and cryogenic scrubbing, wherein a methane-rich liquid is introduced at a first intermediate level of a scrubbing column as first scrubbing liquid and at least one nitrogen-rich liquid is introduced at a level higher than the first level of the scrubbing column as second scrubbing liquid and a mixture of hydrogen and nitrogen is drawn off as overhead gas from the scrubbing column.

A liquefier device which may be a retrofit to an air separation plant or utilized as part of a new design. The flow needed for the liquefier comes from an air separation plant running in a maxim oxygen state, in a stable mode. The three gas flows are low pressure oxygen, low pressure nitrogen, and higher pressure nitrogen. All of the flows are found on the side of the main heat exchanger with a temperature of about 37 degrees Fahrenheit. All of the gasses put into the liquefier come out as a subcooled liquid, for storage or return to the air separation plant. This new liquefier does not include a front end electrical compressor, and will take a self produced liquid nitrogen, pump it up to a runnable 420 psig pressure, and with the use of turbines, condensers, flash pots, and multi pass heat exchangers. The liquefier will make liquid from a planned amount of any pure gas oxygen or nitrogen an air separation plant can produce.