A process for removal of acid gases from fluid stream, wherein the fluid stream is brought into contact with an absorbent to obtain a treated fluid stream and a laden absorbent, the absorbent comprising a diluent and a compound of the general formula (I) wherein R.sup.1 is selected from C.sub.1-C.sub.8-alkyl and C.sub.2-C.sub.8-hydroxyalkyl; R.sup.2 is selected from hydrogen and C.sub.1-C.sub.8-alkyl; R.sup.3 is selected from hydrogen and C.sub.1-C.sub.8-alkyl; R.sup.4 is selected from hydrogen and C.sub.1-C.sub.8-alkyl; R.sup.5 is C.sub.1-C.sub.8-alkyl; with the proviso that at least one of the following conditions (i) and (ii) is met: (i) R.sup.5 is C.sub.3-C.sub.8-alkyl bound to the nitrogen atom via a secondary or tertiary carbon atom; (ii) when R.sup.4 is hydrogen, R.sup.3 is C.sub.1-C.sub.8-alkyl; or when R.sup.4 is C.sub.1-C.sub.8-alkyl, at least one of R.sup.2 and R.sup.3 is C.sub.1-C.sub.8-alkyl; and n is an integer from 0 to 6. Further provided is an absorbent for the absorption of acid gases from a fluid stream, comprising a diluent and a compound of the general formula (I) as defined above, as well as the use of a compound of the general formula (I) as defined above for removal of acid gases from a fluid stream. The absorbents are useful for the selective removal of hydrogen sulfide from fluid streams and have high acid gas loading capacity, high stability, and low volatility.

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The present invention relates to methods for selective binding, selective membrane transport and storage of carbon dioxide (CO.sub.2) in aqueous media. The method of the present invention comprises providing an aqueous acceptor solution containing at least one acceptor compound having a free guanidino and/or amidino group, which is contacted with a gas containing carbon dioxide to bind the carbon dioxide in the acceptor solution. The acceptor solutions containing bound carbon dioxide obtained thereby are useful for storing carbon dioxide in aqueous media, for again releasing the carbon dioxide, and for use in electrochemical processes, such as electrodialysis, to selectively transport bound carbon dioxide through separation membranes into aqueous media. The present invention further relates to the preparation of carbonates starting from acceptor solutions containing bound carbon dioxide.

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.

The present disclosure relates to systems and methods for separation of sulfurous material(s) from a multi-component feed stream. The systems and methods can comprise contacting the multi-component feed stream with a solvent in a contacting column so that at least a portion of the sulfurous material(s) is transferred from the multi-component feed stream to the solvent. A stream of a substantially purified gas can thus be provided along with a liquid stream comprising at least a majority of the sulfurous material. In particular, the solvent can comprise liquid carbon dioxide, which can be particularly beneficial for removing sulfurous materials from multi-component feed streams.

A natural gas pretreatment system includes: a carbon dioxide removal unit configured to remove carbon dioxide from the natural gas by bringing an absorption liquid and the natural gas into contact with each other; and a water removal unit configured to remove water by causing the natural gas to flow through a packed bed containing a water adsorbent. The packed bed contains a carbon dioxide adsorbent for adsorbing and removing the carbon dioxide that has not been completely removed in the carbon dioxide removal unit, and a concentration of the carbon dioxide contained in the natural gas is measured by an outlet-side carbon dioxide measurement unit on an outlet side of the water removal unit.

The present invention is directed to the removal of mercury in a gas dehydration process using thermally table chemical additives.

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 invention relates to a system, method and apparatus for removing heavies from natural gas. Natural gas and an external rich reflux gas feed are processed in a single column refluxed absorber. A bottoms stream is routed to a first heat exchanger and then to a stabilizer column where an overhead stream from the stabilizer column is routed through a condenser for partial separation into an overhead stream. A rich solvent may be introduced to the stabilizer column. The overhead stream is routed through a condenser for partial separation into a stabilizer reflux and a second overhead stream lights. The second overhead stream lights is routed to a heat exchanger and then routed to a partial condenser where the stream is separated into a heavies rich reflux stream, a distillate stream and heavies treated natural gas stream. The rich reflux is routed through a heat exchanger and the rich reflux is pumped to the single column refluxed absorber to be introduced into the single column refluxed absorber as the external rich reflux gas feed.

Implementations described and claimed herein provide systems and methods for processing liquefied natural gas (LNG). In one implementation, a solvent is injected into a feed of natural gas at a solvent injection point. A mixed feed is produced from a dispersal of the solvent into the feed of natural gas. The mixed feed contains heavy components. A chilled feed is produced by chilling the mixed feed. The chilled feed includes a vapor and a condensed liquid. The condensed liquid contains a fouling portion of the heavy components condensed by the solvent during chilling. The liquid containing the fouling portion of the heavy components is separated from the vapor. The vapor is directed into a feed chiller heat exchanger following separation of the liquid containing the fouling portion of the heavy components from the vapor, such that the vapor being directed into feed chiller heat exchanger is free of freezing components.

Various illustrative embodiments of a system and process for recovering high-quality biomethane and carbon dioxide product streams from biogas sources and utilizing or sequestering the product streams are provided. The system and process synergistically yield a biomethane product which meets gas pipeline quality specifications and a carbon dioxide product of a quality and form that allows for its transport and sequestration or utilization and reduction in greenhouse gas emissions. The system and process result in improved access to gas pipelines for products, an improvement in the carbon intensity rating of the methane fuel, and improvements in generation of credits related to reductions in emissions of greenhouse gases.