In accordance with the present invention, disclosed herein is a method comprising the steps for separating syngas and methane from C2-C4 hydrocarbons. Also disclosed herein, are systems utilized to separate syngas and methane from C2-C4 hydrocarbons.

The present invention concerns a process for the treatment of a hydrocarbon feed containing hydrogen and hydrocarbons including C.sub.1 to C.sub.4 hydrocarbons, employing a first and a second recontacting step and in which the gaseous effluent obtained from the second recontacting step is recycled to the first recontacting step. The process is of particular application to the treatment of a hydrocarbon feed obtained from catalytic reforming with a view to recovering hydrogen and C.sub.3 and C.sub.4 hydrocarbons.

The present invention concerns a process for the treatment of a hydrocarbon feed containing hydrogen and hydrocarbons including C.sub.1 to C.sub.4 hydrocarbons, employing a first and a second recontacting step and in which the gaseous effluent obtained from the second recontacting step is recycled to the first recontacting step. The process is of particular application to the treatment of a hydrocarbon feed obtained from catalytic reforming with a view to recovering hydrogen and C.sub.3 and C.sub.4 hydrocarbons.

The present subject matter relates generally to processes for propylene recovery. More specifically, the present subject matter relates to processes for enhanced recovery of propylene and liquid petroleum gas (LPG) from the fuel gas produced in fluid catalytic cracking (FCC) units by minimizing the light ends and propylene in the unstabilized gasoline which is used as lean oil for the primary absorber of the FCC gas concentration unit.

Processes and systems for upgrading a hydrocarbon. In some embodiments, the process for upgrading a hydrocarbon, can include contacting a gas that can include one or more C.sub.1-C.sub.4 hydrocarbons and carbonyl sulfide with a sorbent under conditions sufficient to cause at least a portion of the carbonyl sulfide to sorb onto the sorbent to produce a treated gas lean in carbonyl sulfide and a sorbent rich in carbonyl sulfide. The process can also include contacting the sorbent rich in carbonyl sulfide with a regenerating gas that can include molecular hydrogen, one or more C.sub.1-C.sub.4 hydrocarbons, or a mixture thereof to produce a regenerated sorbent and a desorb effluent that can include a sulfur-based contaminant. The process can also include introducing at least a portion of the desorb effluent into a pyrolysis zone of a steam cracker and recovering a steam cracker effluent from the pyrolysis zone.

A system for hydrogenation C.sub.3 and C.sub.4 acetylenes contained within a hydrocarbon stream generated in a stream cracker unit where a debutanizer is placed upstream of a depropanizer for more economical processing of the hydrocarbon stream to produce lighter hydrocarbons, where the system requires only one stripper tower downstream of hydrogenation to remove residual hydrogen.

A method for recovering C2 components in a methane-containing industrial gas includes the steps of (1) cooling a compressed methane-containing industrial gas and performing gas-liquid separation; (2) absorbing C2 components in the gas phase by using an absorbent to obtain an absorption rich liquid; (3) returning the absorption rich liquid to the compression in step (1) or mixing the absorption rich liquid with the liquid phase obtained in step (1) to obtain a mixed liquid, and depressurizing the mixed liquid or the absorption rich liquid; (4) performing methane desorption on the depressurized stream to obtain a rich absorbent, or performing second gas-liquid separation on the depressurized stream, followed by methane desorption on the second liquid phase to obtain a rich absorbent; and (5) desorbing and separating the rich absorbent to obtain a lean absorbent and an enriched gas, and recycling and reusing the lean absorbent.

A process and system for recovering natural gas liquids (NGL) using a combination of J-T cooling and membrane separation. The process involves compressing, separating, and cooling a flare gas stream comprising at least methane and C.sub.3+ hydrocarbons prior to being introduced to a J-T valve. The cooled stream exiting the J-T valve is further separated, producing a NGL product stream and an uncondensed gas stream. The uncondensed gas stream is directed to a membrane separation step, which results in a C.sub.3+ hydrocarbon enriched stream and a C.sub.3+ hydrocarbon depleted stream. The C.sub.3+ hydrocarbon enriched stream may be recycled back to the process to recover more NGL.

The invention relates to membrane gas separation, in particular to a method of fractionating mixtures of low molecular weight hydrocarbons based on the capillary condensation of the mixture components in the pores of microporous membranes having uniform porosity and a pore diameter of 5 to 250 nm, wherein, for capillary condensation, the temperature of the membrane and the pressure on the permeate side are kept below the temperature and the pressure of the feed mixture. The method provides significantly increasing membrane permeability with respect to condensable components, and also component separation factors, while also allowing to avoid deep cooling of the gas stream fed to a membrane module, and to carry out gas separation under insignificant cooling of the membrane on the permeate side (down to -50? C.). The invention provides for energy-efficient fractionation of hydrocarbon mixtures, including separation and drying of natural and associated petroleum gases.

A process and apparatus for oxidizing thiol compounds from an alkaline stream. The process includes passing a thiol rich alkaline stream and an oxygen containing gas to a low pressure oxidizing zone to oxidize at least a portion of the thiol compounds to disulfide compounds. A liquid stream comprising the alkali containing the disulfide compounds is passed through a pump to increase the pressure and form a pressurized alkaline stream. The pressurized alkaline stream and a sulfur lean liquid light hydrocarbon stream are introduced to a high pressure disulfide separation vessel to form a sulfur lean alkaline stream and a sulfur rich liquid light hydrocarbon stream.