A process and an apparatus are disclosed for separation of a hydrocarbon gas stream containing methane and heavier hydrocarbons and significant quantities of nitrogen and carbon dioxide. The gas stream is cooled and expanded, then fractionated in a first distillation column into a first overhead vapor and a hydrocarbon liquid stream containing the majority of the carbon dioxide. The hydrocarbon liquid stream is fractionated into a hydrocarbon vapor stream and a less volatile fraction comprised of heavier hydrocarbons. The first overhead vapor is cooled, expanded, and separated into vapor and liquid streams. Both streams are cooled and expanded before feeding a second distillation column that produces a second overhead vapor that is predominantly nitrogen and a bottom liquid that is predominantly methane. The bottom liquid is vaporized and combined with the hydrocarbon vapor stream to form a volatile residue gas fraction containing the majority of the methane.

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.

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.

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.

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.

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.

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.

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.

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.

Certain implementations of natural gas liquid fractionation plant waste heat conversion to simultaneous cooling capacity and potable water using Kalina Cycle and modified multi-effect distillation system can be implemented as a system. The system includes first waste heat recovery heat exchanger configured to heat a first buffer fluid stream by exchange with a first heat source in a natural gas liquid fractionation plant. The system includes a water desalination system comprising a first train of one or more desalination heat exchangers configured to heat saline by exchange with the heated first buffer fluid stream to generate fresh water and brine.