One or more specific embodiments disclosed herein includes a method for separating hydrogen from an olefin hydrocarbon rich compressed effluent vapor stream, employing a single heat exchanger, multiple gas-liquid separators, multiple expander/compressor sets, and a rectifier attached to a liquid product drum.

A process for recovering hydrogen from dehydrogenation reactor effluent is disclosed. A feed stream comprising hydrocarbons and hydrogen to a dehydrogenation reactor maintained at dehydrogenation conditions to provide a dehydrogenation reactor effluent. The dehydrogenation reactor effluent is passed to a cold box separation unit to provide a liquid hydrocarbon product stream and a recycle hydrogen stream. A return portion of the recycle hydrogen stream is passed to the reactor effluent compressor. The subject matter disclosed improved process and apparatus which enables the paraffin dehydrogenation reactor to run at reduced H.sub.2/HC ratio without requiring an investment in a resized compressor or resized turboexpanders or separators in the cold box.

A method for operating a heat exchanger, in which a first operating mode is carried out in first time periods, and a second operating mode is carried out in second time periods that alternate with the first time periods; in the first operating mode a first fluid flow is formed at a first temperature, is fed into the heat exchanger in a first region at the first temperature, and is partially or completely cooled in the heat exchanger; in the first operating mode a second fluid flow is formed at a second temperature, is fed into the heat exchanger in a second region at the second temperature, and is partially or completely heated in the heat exchanger; and in the second operating mode the feeding of the first fluid flow and of the second fluid flow into the heat exchanger is partially or completely halted.

A method for operating the liquid air energy storage (LAES) includes production of the storable liquid air through consumption of a low-demand power and recovery the liquid air for co-production of an on-demand power and a high-grade saleable cold thermal energy which may be used, say, for liquefaction of the delivered natural gas; in so doing zero carbon footprint is provided both for fueled augmentation of the LAES power output and for LNG co-production at the LAES facility.

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.

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.

One or more specific embodiments disclosed herein includes a method for separating hydrogen from an olefin hydrocarbon rich compressed effluent vapor stream, employing a integrated heat exchanger, multiple gas-liquid separators, external refrigeration systems, and a rectifier attached to a liquid product drum.

Integrated systems are provided for the production of higher hydrocarbon compositions, for example liquid hydrocarbon compositions, from methane using an oxidative coupling of methane system to convert methane to ethylene, followed by conversion of ethylene to selectable higher hydrocarbon products. Integrated systems and processes are provided that process methane through to these higher hydrocarbon products.

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.

A method for producing liquid nitrogen using a residual gas stream derived from a flue gas of a power plant is provided. The residual gas stream is purified in a front-end purification unit to remove freezable components and then the purified stream is compressed. Following compression, the stream can be divided into a first portion and a second portion, wherein the first portion is cooled and sent to a distillation column, wherein oxygen and argon are separated, thereby leaving an essentially pure gaseous nitrogen stream. The gaseous nitrogen stream can then be liquefied using refrigeration provided by expanding the second portion of the purified stream. In a preferred embodiment, the second portion is expanded in two turbines, and the gaseous nitrogen is compressed in a cold nitrogen booster, which is powered by one of the two turbines. In an additional embodiment, after warming, the expanded second portion of the purified stream can be used to regenerate the front-end purification unit.