Methods and systems for separating C.sub.3 hydrocarbons from lighter hydrocarbons, carbon monoxide, carbon dioxide, and water are provided. In certain embodiments, the methods include feeding a gaseous mixture including C.sub.1, C.sub.2, and C.sub.3 hydrocarbons and benzene solvent to the absorber column where benzene solvent selectively absorbs C.sub.3 hydrocarbons. The methods can further include removing a first stream comprising benzene solvent and absorbed C.sub.3 hydrocarbons from the absorber column, and feeding the first stream to a stripper column where benzene solvent is separated from C.sub.3 hydrocarbons, and removing a second stream comprising C.sub.3 hydrocarbons from the stripper column.

Methods and systems for separating C.sub.3 hydrocarbons from lighter hydrocarbons, carbon monoxide, carbon dioxide, and water are provided. In certain embodiments, the methods include feeding a gaseous mixture including C.sub.1, C.sub.2, and C.sub.3 hydrocarbons and benzene solvent to the absorber column where benzene solvent selectively absorbs C.sub.3 hydrocarbons. The methods can further include removing a first stream comprising benzene solvent and absorbed C.sub.3 hydrocarbons from the absorber column, and feeding the first stream to a stripper column where benzene solvent is separated from C.sub.3 hydrocarbons, and removing a second stream comprising C.sub.3 hydrocarbons from the stripper column.

A method for quenching a pyrolysis product, including: supplying a discharge stream from a liquid decomposition furnace to a first quench tower; supplying an upper discharge stream from the first quench tower to a second quench tower; supplying a discharge stream from a first gas decomposition furnace to the second quench tower; and supplying a discharge stream from a second gas decomposition furnace to the second quench tower.

A method for quenching a pyrolysis product, including: supplying a discharge stream from a liquid decomposition furnace to a first quench tower; supplying an upper discharge stream from the first quench tower to a second quench tower; supplying a discharge stream from a first gas decomposition furnace to the second quench tower; and supplying a discharge stream from a second gas decomposition furnace to the second quench tower.

Disclosed herein are scavenging and antifouling compositions useful in applications relating to the production, transportation, storage, and separation of crude oil and natural gas. Also disclosed herein are methods of using the compositions as scavengers and antifoulants, particularly in applications relating to the production, transportation, storage, and separation of crude oil and natural gas.

This method comprises passing a residual stream into a flash drum to form a gaseous overhead flow and liquid bottom flow, and feeding the bottom flow into a distillation column,

It comprises cooling the overhead flow in a heat exchanger to form a cooled overhead flow.

It comprises the extraction of a gaseous overhead stream at the head of the distillation column, and the formation of at least one effluent stream from the overhead stream and/or from the top stream.

The separation of the cooled overhead flow flow comprises passing the cooled overhead flow into an absorber, and injecting a methane-rich stream into the absorber to place the cooled overhead flow in contact with the methane-rich stream.

This method comprises passing a residual stream into a flash drum to form a gaseous overhead flow and liquid bottom flow, and feeding the bottom flow into a distillation column,

It comprises cooling the overhead flow in a heat exchanger to form a cooled overhead flow.

It comprises the extraction of a gaseous overhead stream at the head of the distillation column, and the formation of at least one effluent stream from the overhead stream and/or from the top stream.

The separation of the cooled overhead flow flow comprises passing the cooled overhead flow into an absorber, and injecting a methane-rich stream into the absorber to place the cooled overhead flow in contact with the methane-rich stream.

A method for separating a hydrogen-containing hydrocarbon mixture (C2minus), which in addition to the hydrogen essentially contains hydrocarbons with two carbon atoms and methane, using a distillation column (10). Fluid (a, c, e) of the hydrocarbon mixture (C2minus) is cooled stepwise at a first pressure level, during which time first condensates (b, d) are separated from the fluid (a, c, e). Fluid (e) from the hydrocarbon mixture (C2minus) which remains gaseous after this is fed at the first pressure level into a C2 absorber (7), to which a liquid reflux (r) is added at the top, while a second condensate (f) is drawn off from the sump of the C2 absorber (7) and a gaseous top stream (g) containing predominantly methane and hydrogen is drawn off at the top of the C2 absorber (7). Fluid of the above-mentioned gaseous top stream (g) from the top of the C2 absorber (7) is cooled to a third temperature level and transferred at the first pressure level into a hydrogen separator (8) in which a methane-rich third condensate (i) is separated from the fluid of the gaseous top stream (g), leaving behind a gaseous, hydrogen-rich stream (h). Fluid of the first condensates (b, d) and fluid of the second condensate (f) is depressurized from the first pressure level to a second pressure level below the first pressure level and fed into the distillation column (10) which is operated at the second pressure level. Fluid (e) of the third condensate (i) which is separated in the hydrogen separator (8) from the fluid of the gaseous top stream (g) from the top of the C2 absorber is used as the reflux (r) added at the top of the C2 absorber (7) and transferred from the hydrogen separator to the C2 absorber solely by gravity. The invention also relates to a corresponding separating unit and a corresponding olefin apparatus.

A method for separating a hydrogen-containing hydrocarbon mixture (C2minus), which in addition to the hydrogen essentially contains hydrocarbons with two carbon atoms and methane, using a distillation column (10). Fluid (a, c, e) of the hydrocarbon mixture (C2minus) is cooled stepwise at a first pressure level, during which time first condensates (b, d) are separated from the fluid (a, c, e). Fluid (e) from the hydrocarbon mixture (C2minus) which remains gaseous after this is fed at the first pressure level into a C2 absorber (7), to which a liquid reflux (r) is added at the top, while a second condensate (f) is drawn off from the sump of the C2 absorber (7) and a gaseous top stream (g) containing predominantly methane and hydrogen is drawn off at the top of the C2 absorber (7). Fluid of the above-mentioned gaseous top stream (g) from the top of the C2 absorber (7) is cooled to a third temperature level and transferred at the first pressure level into a hydrogen separator (8) in which a methane-rich third condensate (i) is separated from the fluid of the gaseous top stream (g), leaving behind a gaseous, hydrogen-rich stream (h). Fluid of the first condensates (b, d) and fluid of the second condensate (f) is depressurized from the first pressure level to a second pressure level below the first pressure level and fed into the distillation column (10) which is operated at the second pressure level. Fluid (e) of the third condensate (i) which is separated in the hydrogen separator (8) from the fluid of the gaseous top stream (g) from the top of the C2 absorber is used as the reflux (r) added at the top of the C2 absorber (7) and transferred from the hydrogen separator to the C2 absorber solely by gravity. The invention also relates to a corresponding separating unit and a corresponding olefin apparatus.

A method and apparatus for continuously treating acid gases including recovering absorbent chemicals by introducing streams leaving a regenerator and/or leaving an absorber into a static mixing zone wherein supplemental washing water is added to recover absorbent chemicals. Improvements to the prior art methods are provided where one or more absorbent chemical recovery units are included to increase the amount of recovered absorbent chemicals exiting the regenerator and/or exiting the absorber are increased and/or maximized. Absorbent chemical recovery units can include mixing units where liquid is added to the stream of sour gas and absorbent chemical to mix with and absorb the absorbent chemical from the stream.