Controlling aerosol production during absorption in ammonia-based desulfurization. The absorption reaction temperature, the oxygen content and water content of the process gas may be controlled, and an absorption circulating liquid containing ammonium sulfite may be used for removing sulfur dioxide in flue gas, so as to control aerosol production during absorption in the ammonia-based desulfurization.

Provided is an acetic acid production method including an absorption step that enables efficient and energy-saving separation of methyl iodide in a downstream step, when provided, of separating methyl iodide from a solution after the absorption of methyl iodide. The acetic acid production method according to the present invention includes an absorption step in an acetic acid production process. In the absorption step, at least a portion of offgases formed in the process is fed to an absorption column, is brought into contact with an absorbent including an organic acid having a higher boiling point as compared with acetic acid to allow the absorbent to absorb an iodine compound from the offgas, and a gas having a lower iodine compound concentration as compared with the offgas, and a solution containing the absorbent and the iodine compound are thereby to be separated.

A method is provided in which a carbon dioxide containing flue gas is provided by combusting a carbonaceous fuel in a high pressure steam generating unit using combustion air, and in which the carbon dioxide in the flue gas is at least partially captured and compressed in a carbon dioxide capture and compression unit having a carbon dioxide scrubber operated with an absorbing liquid which is regenerated using low pressure steam. The combustion air used in the high pressure steam generating unit is at least partially heated using sensible heat of the flue gas and/or the steam used for regenerating the absorption liquid of the carbon dioxide scrubber is at least partially generated using sensible heat of the flue gas. A corresponding system is also described herein.

A method for producing aqueous hydrochloric acid from flue gases is provided. The method comprises conveying water to a first scrubber (102, 202, 302, 402, 502, 602, 702) or to a line (112b, 212b, 312b, 412b, 512b, 712b, 712c) to use the water in a scrubbing liquid of the first scrubber. The method also comprises providing flue gas containing chlorides into the first scrubber (102, 202, 302, 402, 502, 602, 702) and scrubbing the flue gas containing chlorides with the scrubbing liquid by contacting the flue gas with the scrubbing liquid in the first scrubber (102, 202, 302, 402, 502, 602, 702). Dilute hydrochloric acid and a flue gas derivate (104, 204, 304, 404, 504, 704) are produced. The method comprises letting out at least some of the dilute hydrochloric acid from the first scrubber (102, 202, 302, 402, 502, 602, 702) as a scrubber bleed, separating solids suspended by the scrubber bleed in a solids separator (192, 592, 692), conveying the scrubber bleed from the solids separator (192, 592, 692) into an evaporation vessel (194, 594, 694) and concentrating the scrubber bleed in the evaporation vessel (194, 594, 694) to produce hydrochloric acid vapor having a concentration of 5-22 wt-%. A corresponding system is also provided.

The present disclosure is related to systems and methods for the biological processing of hydrocarbon-containing substances. In particular embodiments, the systems and methods herein relate to pre-digestion of hydrocarbon containing substances and further processing of the same to produce hydrocarbon fuels, fertilizer, and other products.

The present invention concerns a process and system for producing and isolating a fraction of monocyclic aromatic compounds from a gasification gas. The process comprises (a) contacting the gas with a catalyst capable of converting ethylene and possibly other unsaturated hydrocarbons into monocyclic aromatic compounds; and (b) isolating monocyclic aromatic compounds from the gas originating from step (a). The present invention is ideally suited for treatment of gas from coal, biomass or waste gasification, which comprises substantial amounts of ethylene as well as monocyclic aromatic compounds. Treatment according to the invention first converts the ethylene into further monocyclic aromatic compounds, and the entire fraction of monocyclic aromatic compounds is isolated to obtain a valuable product.

A carbonator reactor includes a cylindrical body, a nozzle for supplying a gas stream, inside the carbonator reactor and above the surface of a liquid phase and where the nozzle is located at the top of the reactor body, an inlet, an outlet, means for regulating the temperature and the pressure, a stirring system and at least one baffle regulating the stirring of the liquid phase and the mass transfer of the gas into the liquid surface, at least one impeller having inclined blades that make an angle from 5° to 60° with respect to the vertical axis. The reactor prepares sodium carbonate and has a configuration for the mass transfer of a gas phase in a liquid phase. A method for the preparation of sodium carbonate by means of the carbonator reactor by capturing CO.sub.2 in an NaOH aqueous solution, directly on the free surface of the liquid phase.

The invention relates to a process and a plant for removing thiols from synthesis gas. Thiols and optionally thiophene and carbon disulfide are absorbed in a dedicated absorption stage with methanol as physical absorption medium. Methanol laden with at least thiols is freed of thiols in a stripping stage with methanol vapours as stripping gas and the methanol vapours-containing thiols are freed of methanol in a scrubbing stage. The process according to the invention minimizes methanol losses and the amounts of coolant required for the process.

The present invention relates to a process for removing carbon dioxide from a synthesis gas having at least hydrogen and carbon dioxide in which the synthesis gas is at least partially freed of carbon dioxide in an absorption apparatus by physical absorption at elevated absorption pressure. The carbon dioxide is subsequently desorbed by pressure reduction relative to the absorption pressure in a plurality of serially arranged flash stages and an at least partially regenerated absorption medium is withdrawn from the last of the plurality of serially arranged flash stages, recompressed to absorption pressure and recycled into the absorption apparatus for use as absorption medium. It is also provided according to the invention that a partially regenerated absorption medium from a flash stage upstream of the last of the plurality of serially arranged flash stages is recompressed to absorption pressure and recycled into the absorption apparatus for use as absorption medium.

A method and system are provided to recover water and carbon dioxide from combustion emissions. The recovery includes, among other things, electrolysis and carbon dioxide capture in a suitable solvent. The recovered water and carbon dioxide are subject to reaction, such as a catalytic methanation reaction, to generate at least methane.