In a propane dehydrogenation (PDH) process, the purpose of the deethanizer and chilling train systems is to separate the cracked gas into a methane-rich tail gas product, a C2, and a C3 process stream. By the use of staged cooling, process-to-process inter-change against propane feed to the reactor and use of high efficiency heat exchangers and distributed distillation techniques, refrigeration power requirements are reduced and a simple and reliable design is provided by the process described herein.

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.

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 is described herein for removing high freeze point hydrocarbons, including benzene compounds, from a mixed feed gas stream. The process involves cooling process streams in one or more heat exchangers and separating condensed compounds in multiple separators to form a methane-rich product gas stream. Select solvent streams from a fractionation train and/or separate solvent streams are employed to lower the freeze point of one or more streams that contain high freeze point hydrocarbons. A corresponding system also is disclosed.

Method and system for removing high freeze point components from natural gas. Feed gas is cooled in a heat exchanger and separated into a first vapor portion and a first liquid portion. The first liquid portion is reheated using the heat exchanger and separated into a high freeze point components stream and a non-freezing components stream. A portion of the non-freezing components stream may be at least partially liquefied and received by an absorber tower. The first vapor portion may be cooled and received by the absorber tower. An overhead vapor product which is substantially free of high freeze point freeze components and a bottoms product liquid stream including freeze components and non-freeze components are produced using the absorber tower.

A system and method for removing nitrogen from natural gas using two fractionating columns, that may be stacked, and a plurality of separators and heat exchangers, with horsepower requirements that are 50-80% of requirements for prior art systems. The fractionating columns operate at different pressures. A feed stream is separated with a vapor portion feeding the first column to produce a first column bottoms stream that is split into multiple portions at different pressures and first column overhead stream that is cooled and separated into vapor and liquid portions to control subcooling of the vapor portion prior to feeding the second column. Heat exchange between first column and second column streams provides first column reflux and reboil heat for a second column ascending vapor stream. Three sales gas streams are produced, each at a different pressure.

A process and apparatus integrate a deethanizer column with a cryogenic heat exchanger by reboiling the deethanizer column with a refrigerant stream and/or cooling a deethanizer overhead line in the cryogenic heat exchanger. A single stage separator and a single deethanizer column may be used to obtain high purity hydrogen in the net gas stream and an ethane rich off-gas stream, whereas conventionally a dual stage separator and two deethanizer columns were necessary for equivalent purity, respectively.

A process and apparatus reboil a propylene splitter bottoms by heat exchange and/or a deethanizer bottoms stream with a compressed propylene splitter overhead stream. Use of single splitter compressor and operation of the propane-propylene splitter column at lower pressure are enabled, whereas conventionally two splitter compressors and higher splitter pressure were necessary to provide a propylene product stream and a propane recycle stream of equivalent quality.

A process and plant for natural gas liquids (NGL) recovery includes a main heat exchanger, a cold gas/liquid separator, a separation or distillation column, and an overhead gas heat exchanger. A pressurized residue gas generated from an overhead gas stream removed the top of the separation or distillation column is expanded and used as a cooling medium in the overhead gas heat exchanger and the main heat exchanger. The expanded residue gas, used as a cooling medium, is then compressed up to a pressure to be combined with the overhead stream from the separation or distillation column.

This specification relates to operating industrial facilities, for example, crude oil refining facilities or other industrial facilities that include operating plants that process natural gas or recover natural gas liquids.