Disclosed is an absorbent containing an amine for absorption of an acid gas in a biogas, and a biogas purification system using the same.

Disclosed herein are scavenging compounds and 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 compounds and compositions as scavengers, particularly in applications relating to the production, transportation, storage, and separation of crude oil and natural gas.

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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A method for generating Renewable Natural Gas (RNG) from raw biogas is disclosed, in which carbon dioxide is removed from biogas to generate pipeline specification RNG by a combination of absorption and membrane processes. The absorption process provides for the initial bulk carbon dioxide removal. The membrane process provides for the simultaneous removal of carbon dioxide and water vapors to pipeline specification. The method is characterized by a reduced separation energy consumption as compared to stand-alone membrane and absorption unit separations for biogas upgrading.

Provided are a process and a system for treating both a high-pressure (HP) and a low-pressure (LP) acid gas-containing gas streams. The system includes a HP absorber unit, a flash drum coupled downstream of the HP absorber unit, and a LP absorber unit coupled downstream of the flash drum. The process includes introducing a HP rich amine solution from a HP absorber unit into a flash drum, operating the flash drum such that a flashed sour gas and a flash drum rich amine solution are produced, and introducing the flashed sour gas and the LP acid gas-containing gas stream into a LP absorber unit.

An integrated system for the conversion of biomass to renewable natural gas and then to methanol and other value-added products is provided. The integrated system includes a compressor that receives biomass gases from a biomass source and a series of purification stations that produce purified gas from the biomass gases. Characteristically, the purified gas has an enhanced amount of methane. A gas-to-liquids plant converts the purified gas to a product blend that includes methanol.

A method of managing foam in a gas processing system includes flowing a gas processing solution through a processing line and flowing an antifoaming agent through a treatment line into a mixed fluid line to form a fluid mixture, determining a foam level of the fluid mixture at a foam controller disposed along the mixed fluid line, automatically controlling a valve disposed along the treatment line to control a flow rate at which the antifoaming agent is flowed into the mixed fluid line to achieve a target dose of the antifoaming agent to be mixed with the gas processing solution in the mixed fluid line based on the foam level determined at the foam controller, and flowing the fluid mixture containing the target dose of the antifoaming agent into a system component to prevent an amount of the foam in the gas processing system from exceeding a threshold amount.

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.

Disclosed is an adsorbent containing a metal oxide for adsorption of hydrogen sulfide in biogas, and a biogas purification system using the same.

A process for recovering sulfur and carbon dioxide from a sour gas stream, the process comprising the steps of: providing a sour gas stream to a membrane separation unit, the sour gas stream comprising hydrogen sulfide and carbon dioxide; separating the hydrogen sulfide from the carbon dioxide in the membrane separation unit to obtain a retentate stream and a first permeate stream, wherein the retentate stream comprises hydrogen sulfide, wherein the permeate stream comprises carbon dioxide; introducing the retentate stream to a sulfur recovery unit; processing the retentate stream in the sulfur recovery unit to produce a sulfur stream and a tail gas stream, wherein the sulfur stream comprises liquid sulfur; introducing the permeate stream to an amine absorption unit; and processing the permeate stream in the amine absorption unit to produce an enriched carbon dioxide stream.