The invention provides a process to purify a gas stream by using an adsorbent bed and a secondary device to remove heavy hydrocarbons with a recycle stream then sent first to a vessel containing an amine solvent to remove acid gases including carbon dioxide and hydrogen sulfide and then in most embodiments of the invention sending the treated gas stream to a dehydration unit such as an adsorbent bed or to a triethylene glycol absorbent to remove water. The invention further provides improved integration of the process streams to allow for smaller amine solvent and dehydration units as compared to the prior art.

Systems, devices and methods for submarine CO.sub.2 scrubbing are disclosed. The system may comprise an assembly including a sorbent, a scrubbing inlet configured to receive a first airflow during an adsorption mode. The first airflow may comprise air received from a cabin of a submarine. The assembly may be configured to flow the first airflow over and/or through the sorbent during the adsorption mode such that the sorbent removes a portion of CO.sub.2 entrained in the first airflow. The system may also include a scrubbing outlet configured to expel the scrubbed first airflow from the assembly into the cabin. The system may include an outside air inlet configured to receive a second airflow comprising outside air during a regeneration mode. The system may include a regeneration air outlet in configured to expel the second airflow after the second airflow has flowed over and/or through the sorbent during the regeneration mode.

Disclosed are processes, apparatuses, and systems that can be used in natural gas pipelines to significantly reduce the CO2 emissions of the natural gas pipelines, by capturing combusted flue gas which is normally wasted and putting it back to the pipelines, which can also be monetized (e.g., carbon credits). One example process may include producing a captured CO2 stream from a combustion gas of a gas turbine in a natural gas pipeline, compressing the captured CO2 stream, and combining the compressed CO2 stream with natural gas transported in the natural gas pipeline.

The invention relates to regenerative, solid sorbent for adsorbing carbon dioxide from a gas mixture, with the sorbent including a modified polyamine and a nano-structured solid support. The modified polyamine is the reaction product of an amine and an aldehyde. The sorbent provides structural integrity, as well as high selectivity and increased capacity for efficiently capturing carbon dioxide from gas mixtures, including the air. The sorbent is regenerative, and can be used through multiple operations of absorption-desorption cycles.

The present invention relates to an apparatus and method for recovering carbon dioxide (hereinafter also referred to as “CO.sub.2”) contained in a combustion exhaust gas, and more specifically relates to: an apparatus and method for reactively absorbing CO.sub.2 contained in a combustion exhaust gas into an amine compound-containing absorption liquid; an apparatus and method for desorbing CO.sub.2 contained in an amine compound-containing absorption liquid from the amine compound-containing absorption liquid; an apparatus and method for evaporating and separating impurities from the amine compound-containing absorption liquid containing the impurities; an apparatus and method for performing a pretreatment such as desulfurization, dust removal, and cooling on a combustion exhaust gas; and a carbon dioxide-recovering apparatus and method utilizing the above apparatuses and methods.

Sweep-based gas separation processes for reducing carbon dioxide emissions from gas-fired power plants. The invention involves at least two compression steps, a combustion step, a carbon dioxide capture step, a power generate step, and a sweep-based membrane separation step. One of the compression steps is used to produce a low-pressure, low-temperature compressed stream that is sent for treatment in the carbon dioxide capture step, thereby avoiding the need to expend large amounts of energy to cool an otherwise hot compressed stream from a typical compressor that produces a high-pressure stream, usually at 20-30 bar or more.

A system for use in recovering carbon dioxide from a stream of gas includes an absorption unit configured to receive the stream of gas and a stream of liquid absorbent. The gas includes carbon dioxide and vaporized water, and the liquid absorbent is chemically reactive with the carbon dioxide to form a solidified carbon dioxide-rich absorbent material. The gas and the liquid absorbent are mixed in the absorption unit such that a slurry that includes the solidified carbon dioxide-rich absorbent material and condensed water is formed therein. The system also includes a transport mechanism coupled in communication with the absorption unit, wherein the transport mechanism is configured to channel the slurry downstream from the absorption unit.

The present disclosure concerns a method and detector (10) for detecting an analyte (1) in a sample volume (2), such as nitrosamine in an amine solvent. The method comprises measuring a resonance Raman spectrum (I1) with a first light beam (PI) matching an electronic transition of the analyte (1). The detection of the analyte is enhanced by measuring an off-resonance Raman spectrum (12) using a second light beam (P2) that is shifted in wavelength at least 10 nm away from the electronic resonance. The resonance Raman signal (S1) of the analyte (1) is isolated from the background (Q1, Q2) by a difference analysis between the resonance and off-resonance Raman spectra (I1, I2). The method and detector (10) can be employed for detecting nitrosamine in a carbon capture process or plant (20) that employs an amine solvent.

The system includes: an absorber which brings an introduction gas into contact with an absorbent that absorbs CO.sub.2 and H.sub.2S; an absorbent regenerator which releases CO.sub.2 or the like to regenerate the absorbent; a second supply line which returns a regenerated absorbent to the absorber from the regenerator; a third supply line which extracts a semi-rich solution from the vicinity of a middle stage of the absorber, and introduces the semi-rich solution to the vicinity of the middle stage of the regenerator; and a semi-rich solution heat exchanger which is interposed at an intersection between the third supply line and the second supply line to perform the heat exchange between the semi-rich solution and the lean solution.

The present invention relates to an aqueous alkanolamine solution demonstrating low volatility comprising 2-di-methylamino-2-hydroxymethyl-1, 3-propanediol useful for removing acid gases from gaseous mixtures. Said aqueous alkanolamine solution may further comprise one or more of an acid or acid-forming compound, another amino compound, an activator, a physical solvent, or one or more other compounds used in gal-liquid treatment practices. Further, the present invention relates to a process for removing acid gases from a gaseous mixture, preferably hydrogen sulfide, comprising the step of contacting the gaseous mixture with said aqueous alkanolamine solution. Examples of the gaseous mixtures include natural gas, synthesis gas, tail gas, and refinery gas.