Provided is a natural gas liquefaction system including a natural gas storage unit, a liquefied natural gas storage unit, body, a pumping unit, a sub-cooling unit, and a first distributing and conveying unit.

The present disclosure provides a method for separating a feed stream in a distillation tower. The method may include forming solids in a controlled freeze zone section of the distillation tower; emitting radiation from a first radiation source in the controlled freeze zone section while the controlled freeze zone section forms no solids; detecting radiation emitted by the first radiation source as a first radiation level; detecting radiation emitted by the first radiation source as a second radiation level after detecting the first radiation level; and determining whether the solids adhered to at least one of on and around a first mechanical component included in the controlled freeze zone section based on the first radiation level and the second radiation level.

A method of constructing a plate fin heat exchanger includes joining a first side bar formed from a nickel-iron alloy to a first end of a fin element formed from a nickel-iron alloy through a first nickel-iron alloy bond, and joining a second side bar formed from a nickel-iron alloy to a second end of the fin element through a second nickel-iron alloy bond to create a first layer of the plate fin heat exchanger. The fin element defines a fluid passage.

Hydrogen is liquefied through a process utilizing refrigeration from hydrogen at one, two, or three different pressures as well as a nitrogen refrigeration cycle. One or more stages of catalyst are used to convert ortho-hydrogen to para-hydrogen as the hydrogen is cooled and liquefied. Subcooled liquid hydrogen feeds the final stage of ortho-hydrogen to para-hydrogen conversion to reduce or eliminate vaporization of the hydrogen during the exothermic ortho-hydrogen to para-hydrogen conversion.

An equipment safety management device for managing safety of equipment capable of holding fluid is provided. The equipment safety management device includes: a safety means configured to be in fluid communication with an outlet of the equipment, the safety means being brought into a released state when pressure of the equipment reaches a previously set pressure, the safety means delivering the fluid to a flare pipe, which is fluidly communicated; and, as the flare pipe, at least one first flare pipe allowing a low-temperature fluid to flow therethrough and at least one second flare pipe allowing an aqueous fluid to flow therethrough. The safety means can deliver the fluid to both the first flare pipe and the second flare pipe.

A system and method for liquefaction of a natural gas stream utilizing a plurality of asymmetric parallel pre-cooling circuits. The use of asymmetric parallel cooling circuits allows for greater control over each refrigerant stream during the cooling process and simplifies process control by dedicating heat exchangers to performing similar duties.

A LNG liquefaction plant includes a propane recovery unit including an inlet for a feed gas, a first outlet for a LPG, and a second outlet for an ethane-rich feed gas, an ethane recovery unit including an inlet coupled to the second outlet for the ethane-rich feed gas, a first outlet for an ethane liquid, and a second outlet for a methane-rich feed gas, and a LNG liquefaction unit including an inlet coupled to the second outlet for the methane-rich feed gas, a refrigerant to cool the methane-rich feed gas, and an outlet for a LNG. The LNG plant may also include a stripper, an absorber, and a separator configured to separate the feed gas into a stripper liquid and an absorber vapor. The stripper liquid can be converted to an overhead stream used as a reflux stream to the absorber.

A method for supplementing condenser heat rejection in natural gas processing including passing unprocessed gas through a gas-to-chilling fluid heat exchanger, transferring cooled and condensed gas to a vapor liquid separator, sending the chilling fluid to a chilling fluid reservoir, directing the chilling fluid to a refrigeration sub-system, circulating refrigerant throughout the refrigeration sub-system, touting vapor refrigerant through a refrigeration compressor, sending the vapor refrigerant to a refrigeration condenser, routing the liquid refrigerant to an accumulator tank and through an expansion valve, muting the reduced-pressure liquid refrigerant to the evaporator, and passing at least a portion of the processed vapor to a processed vapor-to-refrigerant heat exchanger via an actuated valve controlled by a processor to remove heat from the liquid refrigerant before the liquid refrigerant is sent to the expansion valve. The refrigeration sub-system includes an evaporator that is configured to transfer heat from the chilling fluid to the refrigerant.

A system and method for integrated heavy hydrocarbon removal in a liquefaction system having a lean natural gas source. An economizer located between a main cryogenic heat exchanger and a reflux drum is provided to cool an overhead vapor stream against a partially condensed stream. In addition, pressure of the natural gas feed stream is maintained into a scrub column. A pressure drop is provided by a valve located between the economizer and the reflux drum on a partially condensed stream withdrawn from the cold end of the warm section of the main cryogenic heat exchanger.

Systems, devices, and methods for recovering mixed refrigerant and/or nitrogen within liquefaction systems are provided. The systems, devices, and methods facilitate recovering mixed refrigerant (MR) and/or nitrogen vapor that can leak from a compressor, separating the MR from the nitrogen, and reusing the MR and/or the nitrogen within the liquefaction system. Recovering and reusing MR and/or nitrogen can minimize loss of MR and nitrogen which can lower the total operating cost of a liquefaction system. Additionally, recovering the MR, rather than burning it, can reduce environmental emissions by reducing the amount of MR that is burned.