A method of producing a fuel additive includes passing a feed stream comprising C4 hydrocarbons through a butadiene extraction unit producing a first process stream; passing the first process stream through a methyl tertiary butyl ether unit producing a second process stream and a methyl tertiary butyl ether product; passing the second process stream through a hydration unit producing the fuel additive and a recycle stream; passing the recycle stream through a hydrogenation unit; and recycling the recycle stream to a steam cracker unit and/or to the feed stream

Methods and systems for operating and NGL recovery process are provided. In an exemplary method, an absorber column upstream of a fractionator column is operated at a higher pressure than a pressure in the fractionator column. An NGL (C.sub.3 plus) stream is taken from the bottom of a fractionator column and then ethylene/ethane stream is taken from the top of the fractionator column. A differential pressure between the absorber column and the fraction are column is controlled based, at least in part, on a flow rate of the fractionator feed stream from the absorber column to the fractionator column.

The present disclosure includes systems and methods that integrate a flare gas recovery process with a gas sweetening process used in oil and gas refining. A flare gas recovery system includes a primary gas sweetening unit and a liquid-driven ejector in continuous fluid communication with the primary gas sweetening unit. The ejector includes an inlet configured to receive a motive fluid including a regenerable amine solvent in a lean state from the primary gas sweetening unit, a gas inlet configured to receive a suction fluid including a gas, and a fluid outlet configured to either directly or indirectly discharge to the primary gas sweetening unit a two-phase fluid including a mixture of the suction fluid and the amine solvent in a rich state.

Natural gas may be purified by removing C.sub.3+ hydrocarbons and CO.sub.2 in respective one or more separation units to yield conditioned gas lower in C.sub.3+ hydrocarbons and CO.sub.2 in comparison to the un-conditioned natural gas. Notably, the feed gas need not be subjected to joule-thomson expansion and molecular sieve dehydration performed by conventional processes. Rather, any water-rich reject stream from the separation unit(s) is dried downstream with a smaller compressor and smaller molecular sieve or gas separation membrane dehydration unit before it may be re-injected deep underground or deep under the sea bed.

A gas stream comprising LPG and naphtha hydrocarbons is absorbed with a sponge absorbent to recover LPG and naphtha hydrocarbons. The gas stream may comprise stripper off gas and/or PSA tail gas. An absorbent stream may be a stripped stream. The stripper off gas stream and the stripped stream may be obtained from a stripper that is downstream of a hydroprocessing unit.

A process for removing C.sub.5-C.sub.8-hydrocarbons and acid gases from a fluid stream is described, where a) the fluid stream is brought into contact with an absorption medium comprising at least one amine in an absorption zone to obtain a deacidified fluid stream and an acid-gases-laden absorption medium, b) the laden absorption medium is heated in a first heat exchanger and decompressed into a decompression zone to a pressure of from 5 to 10 bar to obtain a C.sub.5-C.sub.8-hydrocarbons-comprising gas phase and a hydrocarbon-depleted laden absorption medium, c) the hydrocarbon-depleted laden absorption medium is heated in an optional second heat exchanger and passed into a stripper in which at a pressure of 1 to 2.5 bar the acid gases are at least partially liberated by supplying heat to obtain a regenerated absorption medium and an acid-gas-comprising stream, and d) the regenerated absorption medium is recycled into the absorption zone.

Disclosed is method for removing carbonyl sulphide and/or carbon disulphide from a sour gas stream. The method comprises subjecting the gas stream to simultaneous contact with an absorption liquid, such as an aqueous amine solution, and with a catalyst suitable for hydrolyzing carbonyl sulphide and/or carbon disulphide. To this end, the invention also provides a reactor system wherein both an absorption liquid and a catalyst are present. In a preferred embodiment, the catalyst is a heterogeneous catalyst present on or in an absorption column, either coated on the trays of a column with trays, or contained in the packing of a packed column.

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.

Disclosed in the present disclosure are a low energy consumption anhydrous CO.sub.2 phase change absorption agent, and a regeneration method and an application thereof, the absorption agent using a unitary diamine with a primary amine (NH.sub.2) and a tertiary amine (N), and not containing any other organic solvent, water, and ionic liquid; two alkyl branches are linked to a nitrogen atom of the tertiary amine, forming a certain hydrophobicity; after absorbing the CO.sub.2, the diamine changes from a liquid phase to a solid phase, undergoing liquid-solid phase change to form white amino formate crystals.

A membrane contactor for separating components from a feed gas stream comprises a housing, a feed gas inlet for receiving the feed gas stream at a first pressure, and a liquid inlet or receiving a stream of liquid at a second pressure, the liquid containing an absorbent for reacting components of the gas stream and a slip gas outlet. The contactor also includes a plurality of fibers with pore channels in contact with the feed gas incoming from the gas inlet on a first side, and in contact with liquid incoming from the liquid inlet on a second side, producing a gas-liquid interface at the pore channels. Liquid is prevented from wetting the pore channels by maintaining the first pressure of the gas stream higher than the liquid stream, and a portion of the gas stream bubbles through as slip gas into the liquid stream due to the elevated pressure.