The invention relates to a method (100) for the recovery of a separation product which contains predominantly hydrocarbons with two carbon atoms, with the use of a separation feedstock which contains predominantly methane, hydrogen and hydrocarbons with two carbon atoms, wherein the methane content of the separation feedstock is up to 20%, and the separation feedstock is provided in a gaseous state. It is provided that, at a first pressure level, the separation feedstock is partially condensed in a single step by cooling from a first temperature level to a second temperature level, thereby obtaining precisely one first liquid fraction and precisely one first gaseous fraction; at least one part of the first gaseous fraction is partially condensed in a single step through further cooling from the second temperature level to a third temperature level, thereby obtaining precisely one second liquid fraction and precisely one second gaseous fraction; at least one part of the second gaseous fraction at the second pressure level is subjected to a contraflow absorption in the contraflow to an absorption liquid containing predominantly methane, thereby obtaining precisely one third liquid fraction and precisely one third gaseous fraction; the first, the second and the third liquid fraction are at least partially combined and, at least partially, at a second pressure level above the first pressure level, subjected to a low-temperature rectification, thereby obtaining a sump liquid and an overhead gas; at least one part of the overhead gas at the second pressure level is partially condensed in a single step through further cooling from the second temperature level to the third temperature level, thereby obtaining a fourth liquid fraction and a fourth gaseous fraction; and the absorption liquid containing predominantly methane is formed through further cooling of at least a part of the fourth gaseous fraction to a fourth temperature level. A corresponding plant also forms the subject matter of the invention.

The invention relates to a method (100) for the recovery of a separation product which contains predominantly hydrocarbons with two carbon atoms, with the use of a separation feedstock which contains predominantly methane, hydrogen and hydrocarbons with two carbon atoms, wherein the methane content of the separation feedstock is up to 20%, and the separation feedstock is provided in a gaseous state. It is provided that, at a first pressure level, the separation feedstock is partially condensed in a single step by cooling from a first temperature level to a second temperature level, thereby obtaining precisely one first liquid fraction and precisely one first gaseous fraction; at least one part of the first gaseous fraction is partially condensed in a single step through further cooling from the second temperature level to a third temperature level, thereby obtaining precisely one second liquid fraction and precisely one second gaseous fraction; at least one part of the second gaseous fraction at the second pressure level is subjected to a contraflow absorption in the contraflow to an absorption liquid containing predominantly methane, thereby obtaining precisely one third liquid fraction and precisely one third gaseous fraction; the first, the second and the third liquid fraction are at least partially combined and, at least partially, at a second pressure level above the first pressure level, subjected to a low-temperature rectification, thereby obtaining a sump liquid and an overhead gas; at least one part of the overhead gas at the second pressure level is partially condensed in a single step through further cooling from the second temperature level to the third temperature level, thereby obtaining a fourth liquid fraction and a fourth gaseous fraction; and the absorption liquid containing predominantly methane is formed through further cooling of at least a part of the fourth gaseous fraction to a fourth temperature level. A corresponding plant also forms the subject matter of the invention.

Processes for recovering electrical power from a process unit waste heat steam generation system are described. A power-recovery turbine reduces the pressure of a stream of superheated steam to a pressure lower than that needed by the steam reboiler for use in other process units or equipment in the plant.

Processes for recovering electrical power from a process unit waste heat steam generation system are described. A power-recovery turbine reduces the pressure of a stream of superheated steam to a pressure lower than that needed by the steam reboiler for use in other process units or equipment in the plant.

A low cost and efficient design is used to convert a propane recovery process based on low nitrogen content feed gas to an ethane recovery process based on a high nitrogen feed gas while achieving over 95 mole % ethane recovery while maintaining a 99% propane recovery, and achieved without additional equipment.

Rich natural gas is first compressed, and then cooled by a series of heat exchangers and an ambient air cooler. The cooled mixture of natural gas, natural gas liquid (NGL), and water is first separated in a high-pressure three-phase separator. NGL flows through a depressurization valve and NGL is separated from gas in a second separator for storage and transport such as in a conventional propane tank. A resulting lean natural gas is suitably conditioned for internal combustion, compressed natural gas processing, or liquid fuel processing.

A low cost and efficient design is used to convert a propane recovery process based on low nitrogen content feed gas to an ethane recovery process based on a high nitrogen feed gas while achieving over 95 mole % ethane recovery while maintaining a 99% propane recovery, and achieved without additional equipment.

Contemplated plants for flexible ethane recovery and rejection by allowing to switch the top reflux to the demethanizer from residue gas to the deethanizer overhead product and by controlling the flow ratio of feed gas to two different feed gas exchangers. Moreover, the pressure of the demethanizer is adjusted relative to the deethanizer pressure for control of the ethane recovery and rejection.

Rich natural gas is first compressed, and then cooled by a series of heat exchangers and an ambient air cooler. The cooled mixture of natural gas, natural gas liquid (NGL), and water is first separated in a high-pressure three-phase separator. NGL flows through a depressurization valve and NGL is separated from gas in a second separator for storage and transport such as in a conventional propane tank. A resulting lean natural gas is suitably conditioned for internal combustion, compressed natural gas processing, or liquid fuel processing.