A process and a plant for purifying a crude gas stream containing sulfur components and hydrocarbons by gas scrubbing using a scrubbing medium which is selective for sulfur components in an absorption column. Heavy hydrocarbons and heavy mercaptans are removed from the crude gas in a lower section of the absorption column and the resulting, loaded scrubbing medium stream is fed separately from the other loaded scrubbing medium streams to a hot regeneration column. A vapor stream enriched in water, hydrocarbons and sulfur components is obtained as overhead product from the hot regeneration column and this stream is cooled to below its dew point and is separated in a gas-liquid-liquid phase separation apparatus. The resulting, organic liquid phase contains heavy hydrocarbons and heavy mercaptans and can thus be discharged from the process or the plant, as a result of which accumulation thereof in the scrubbing medium is prevented.

The invention relates to a gas scrubbing process and a corresponding plant for removal of acidic gas constituents from crude synthesis gas which make it possible by treatment of shifted and of unshifted crude synthesis gas in the gas scrubbing process and by combination of the thus-obtained partial product streams to produce a plurality of gas products having different compositions. In addition, the invention ensures that the flash gases obtained during decompression of the laden scrubbing medium are utilized materially and/or energetically in advantageous fashion.

In one embodiment, a carbon dioxide capturing system includes an absorber configured to include a first contact portion that brings a combustion exhaust gas containing carbon dioxide into contact with an absorbing liquid containing an amine compound, cause the absorbing liquid to absorb at least a portion of the carbon dioxide in the combustion exhaust gas at the first contact portion, and release the combustion exhaust gas. The system further includes a washing apparatus configured to include a second contact portion that brings the combustion exhaust gas released from the first contact portion of the absorber into contact with a washing liquid, and configured such that the combustion exhaust gas and the washing liquid are individually fed to an upstream side of the second contact portion.

A method for capturing carbon dioxide includes contacting a carbon dioxide lean gas mixture with water. One or more acid gas impurities may pass from the carbon dioxide lean gas mixture to the water to form a gas mixture and an aqueous effluent. The gas mixture is passed to a pressure swing adsorption system or a temperature swing adsorption system to increase a concentration of carbon dioxide in the gas mixture to form a carbon dioxide enriched gas mixture. The carbon dioxide enriched gas mixture is contacted with the aqueous effluent in a carbon dioxide scrubber. Carbon dioxide passes from the carbon dioxide enriched gas mixture to the aqueous effluent to form a stripped gas and acid gas enriched water. The acid gas enriched water is passed to a reactive rock formation. The one or more acid gas impurities and carbon dioxide are mineralized and permanently sequestered.

One variation of a method for carbon sequestration includes: mixing ambient air including carbon dioxide and secondary gases with a working fluid to generate a first mixture; conveying the first mixture through a compressor to pressurize the first mixture from a first pressure to a second pressure greater than the first pressure to promote absorption of carbon dioxide into the working fluid; depositing the first mixture in a high-pressure vessel to generate an exhaust stream of secondary gases and a second mixture including carbon dioxide dissolved in the working fluid; conveying the second mixture through a turbine configured to extract energy and reduce pressure of the second mixture, from the second pressure to the first pressure, to promote desorption of carbon dioxide from the working fluid; transferring the second mixture into the low-pressure vessel; and releasing carbon dioxide, desorbed from the working fluid, from the low-pressure vessel for collection.

A carbon dioxide (CO.sub.2) capture and utilization system captures CO.sub.2 from flue gas and utilizes the same to enhance algae or cyanobacteria growth. The system generally comprises a CO.sub.2 capture unit and a utilization unit that is in fluid communication with the CO.sub.2 capture unit. The CO.sub.2 capture unit includes a membrane CO.sub.2 absorber that captures CO.sub.2 from incoming flue gas to produce a CO.sub.2-rich solvent. The utilization unit processes the CO.sub.2-rich solvent to produce a product stream that includes CO.sub.2 and NH.sub.3 in a predetermined CO.sub.2:NH.sub.3 ratio. The product stream is delivered to a cultivation subsystem of the utilization of the unit including one or more species of algae or cyanobacteria. A method for capturing and utilizing CO.sub.2 is also provided herein.

A process for recovering by-products of a substituted aromatic hydrocarbon oxidation reaction, comprising cooling one or more of a vapor stream directed to a high-pressure absorber (380), a solvent-rich scrubbing stream (381) directed to a high-pressure absorber (380), and a water-rich liquid stream (383) directed to a solvent recovery zone, by heat exchange with a cooled spent scrubbing liquid withdrawn from a low-pressure scrubber (430).

The present invention describes methods for absorbing a targeted chemical compound from a gas stream into a scrubbing solution for various uses and with various benefits. Methods are described to produce a gas stream that can be further processed with operational benefits, such as through condensing and wastewater treatment with a lower load on the wastewater treatment system. Methods are described for adsorbing the targeted compound with reduced condensation of water from the gas stream. Methods are described for producing a liquid stream comprising an absorbed form of the targeted compound for use as a saleable product, such as adsorbing ammonia for the production of a fertilizer, wherein the concentration of the absorbed form may be increased through reduced condensation from the gas stream. Methods are described for producing a lower volume liquid waste stream from the absorption process through the use of reduced condensation of the gas stream.

A method of capturing CO.sub.2 and converting the captured CO.sub.2 into useful byproducts includes providing a material including a material matrix holding an ionic liquid, exposing the material to a source of thermal energy to capture CO.sub.2 within the material, removing the material from exposure to the source of thermal energy, and washing the material with a solution to convert the captured CO.sub.2 and wash the converted, captured CO.sub.2 from the material as filtrate. Materials and systems for capturing CO.sub.2 and converting the captured CO.sub.2 into useful byproducts are also provided.

A method for recovering sulfur within a gas processing system is described herein. The method includes contacting a natural gas stream including an acid gas with a solvent stream within a co-current contacting system to produce a sweetened natural gas stream and a rich solvent stream including an absorbed acid gas. The method also includes removing the absorbed acid gas from the rich solvent stream within a regenerator to produce a concentrated acid gas stream and a lean solvent stream. The method further includes recovering elemental sulfur from hydrogen sulfide (H.sub.2S) within the concentrated acid gas stream via a sulfur recovery unit.