The system is provided with: a first heat exchanger which is interposed at an intersection between a rich solution supply line and a lean solution supply line, which has absorbed CO.sub.2 and H.sub.2S extracted from a bottom portion of an absorber, and a regenerated absorbent; a second heat exchanger which is interposed at an intersection between a semi-rich solution supply line and a branch line branched at the branch portion C from the lean solution supply line, and the lean solution; a merging portion which merges a branch line configured to supply the lean solution after heat exchange with the lean solution supply line; and a flow rate adjusting valve which is interposed in the lean solution supply line to adjust the distribution amount of the lean solution.

A carbon dioxide adsorbent includes a porous metal oxide represented by Chemical Formula 1, the porous metal oxide having a specific surface area of greater than or equal to about 30 m.sup.2/g, and an average pore size of greater than or equal to about 2 nm.

The present invention relates to a CO.sub.2 selective gas separation membrane and a method for preparing the gas separation membrane and the use thereof. The CO.sub.2 selective gas separation membrane comprises a gas permeable or porous support layer; and at least one gas permeable polymer layer, which is surface modified with polymer chains having CO.sub.2 philic groups, wherein the gas permeable polymer layer has a spatially controlled distribution of the CO.sub.2 philic groups on the surface thereof. The method of preparing the CO.sub.2 selective gas separation membrane, comprises the steps of: depositing at least one gas permeable polymer layer on a porous or gas permeable support layer to form a dense membrane, and surface modifying the dense membrane with polymer chains having CO.sub.2 philic groups, to obtain spatially controlled distribution of the CO.sub.2 philic groups on the surface thereof.

A method for separating at least one hydrocarbon from a feed containing a mixture of at least one hydrocarbon and nitrogen, comprising contacting the feed with an adsorbent comprising a porous support wherein the porous support comprises exchangeable cations and at least a portion of the exchangeable cations are organic cations.

A method for operating an adsorption-based system for removing water and potentially other components from a feed stream. The system includes at least two dehydration units each comprising an adsorption bed. The method includes the steps of: i) obtaining process data from one or more sensors at a predetermined time resolution, the sensors at least comprising at least one moisture sensor at a specified location in each of the dehydration units; ii) dehydrating the feed stream by operating the adsorption-based system in regenerative mode, wherein at least one active unit of the at least two dehydration units is in an adsorption cycle, and wherein at least another one of the at least two dehydration units is being regenerated; iii) estimating an adsorption bed water adsorption capacity during every adsorption cycle; and iv) using the process data to update the estimated adsorption bed water adsorption capacity.

The present invention relates to a composite separation membrane that is applicable to carbon dioxide separation and recovery processes. The composite separation membrane includes a coating layer composed of graphene oxide and a bile acid or its salt on a porous polymer support. The composite separation membrane of the present invention, which includes a coating layer composed of graphene oxide and a bile acid or its salt, has both high carbon dioxide permeability and high selectivity for carbon dioxide over nitrogen, hydrogen or methane gas, is free of surface defects, and maintains a stable structure without deterioration of its performance even after long-term use. Due to these advantages, the composite separation membrane of the present invention can be applied to industrial fields involving carbon dioxide separation and recovery processes. The present invention also relates to a method for manufacturing the composite separation membrane.

This disclosure relates to the adsorption and separation of nitrogen in a feed stream (e.g., natural gas) using zeolite ITQ-55 as the adsorbent. A process is disclosed for removing impurities such as nitrogen while producing a high pressure hydrocarbon product. The process involves passing the feed stream through a bed of an adsorbent comprising zeolite ITQ-55 to adsorb nitrogen from the feed stream, thereby producing a product stream depleted in nitrogen at pressure as feed condition without need of recompression. The zeolite ITQ-55 has a mean crystal particle size within the range of from about 0.01 microns to about 40 microns. The feed stream is exposed to the zeolite ITQ-55 at effective conditions for performing a kinetic separation, in which the kinetic separation exhibits greater kinetic selectivity for nitrogen than for methane. The system and method of this disclosure are particularly suitable for use with feed streams utilizing rapid cycle PSA operations.

A process and/or system for producing fuel that includes providing biogas, removing carbon dioxide from the biogas, transporting the upgraded biogas to a hydrogen plant; providing the transported upgraded biogas and fossil-based natural gas as feedstock for hydrogen production. The carbon intensity of the fuel is less than 11 gCO.sub.2-eq/MJ, at least in part because carbon dioxide removed from the biogas and carbon dioxide from hydrogen production is captured and stored.

A system and method for treating natural gas, including producing natural gas from a subterranean formation via a wellhead system to a nonthermal plasma (NTP) catalytic unit, converting by the NTP unit carbon dioxide (CO.sub.2) and hydrogen sulfide (H.sub.2S) in the natural gas into carbon monoxide (CO), elemental sulfur (S), and hydrogen (H.sub.2), and removing the elemental sulfur as liquid elemental sulfur to give treated natural gas. The NTP unit may convert methane (CH.sub.4) in the natural gas to heavier hydrocarbons.

This disclosure relates to membranes containing a polymer containing crown ether monomer units and a guest compound capable of binding thereto. This disclosure also relates to methods for making the membranes, and to methods for using the membranes for gas separation applications.