Abstract: Proposed according to the invention are a process and a plant for producing carbon dioxide-based methanol and synthesis gas, wherein the produced synthesis gas may be utilized process-internally for methanol synthesis. Hydrocarbons which are present in a carbon dioxide input gas stream as an impurity and are inert under the conditions of the methanol synthesis are chemically utilized through integration of a reforming unit, in particular a POX unit. This is done by supplying a purge gas stream diverted from the methanol synthesis loop to said reforming unit in which the hydrocarbons are converted into synthesis gas. In a preferred embodiment the purge gas stream is supplied to a hydrogen recovery unit, in particular a membrane unit. The hydrocarbons-enriched purge gas stream produced on the retentate side is subsequently supplied to the reforming unit.

Abstract: The present invention relates to a process for removing carbon dioxide from synthesis gas using a hygroscopic, physical absorption medium. The process includes cooling the absorption medium and the synthesis gas; water is at least partially removed from the synthesis gas by condensation; carbon dioxide is removed from the cooled synthesis gas via the cooled absorption medium in a physical absorption step at elevated pressure; laden absorption medium is treated in a plurality of serially arranged flash stages, wherein co-absorbed carbon monoxide and hydrogen are removed from the laden absorption medium in at least one first flash stage, and carbon dioxide is removed from the laden absorption medium in a flash stage arranged downstream of the first flash stage. The process features a high rate of separated carbon dioxide and a pure and dry (anhydrous) carbon dioxide product. The invention further relates to a plant for performing the process.

Abstract: 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.

Abstract: The present invention relates to a gas scrubbing process and a plant for removing carbon dioxide (CO2) and water (H2O) from synthesis gas, wherein the synthesis gas includes at least hydrogen (H2), carbon dioxide (CO2) and water (H2O), The invention features a dedicated circuit for water removal which comprises a scrubbing apparatus for removal of water by means of the physical absorption medium used in the gas scrubbing process. The absorption medium supplied to the scrubbing apparatus is withdrawn from a thermal separation apparatus for separation of water and absorption medium. The circuit is arranged such that water entrained via synthesis gas to be purified cannot pass into the main absorption medium circuit which is formed inter alia by an absorption apparatus and a regeneration apparatus. The energy cost and the apparatus complexity especially in respect of the thermal separation apparatus is thus reduced.

Abstract: 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.

Abstract: 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.

Abstract: The present invention relates to a process for removing carbon dioxide from synthesis gas using a hygroscopic, physical absorption medium. The process includes cooling the absorption medium and the synthesis gas; water is at least partially removed from the synthesis gas by condensation; carbon dioxide is removed from the cooled synthesis gas via the cooled absorption medium in a physical absorption step at elevated pressure; laden absorption medium is treated in a plurality of serially arranged flash stages, wherein co-absorbed carbon monoxide and hydrogen are removed from the laden absorption medium in at least one first flash stage, and carbon dioxide is removed from the laden absorption medium in a flash stage arranged downstream of the first flash stage. The process features a high rate of separated carbon dioxide and a pure and dry (anhydrous) carbon dioxide product. The invention further relates to a plant for performing the process.

Abstract: The present invention relates to a process for producing hydrogen and for separating carbon dioxide from synthesis gas using a physical absorption medium. The process comprises the steps where the synthesis gas and the absorption medium are cooled; carbon dioxide is removed from the cooled synthesis gas via the cooled absorption medium in a physical absorption step at elevated pressure; laden absorption medium is treated in a plurality of flash stages, wherein co-absorbed carbon monoxide, hydrogen and carbon dioxide are separately removed from the laden absorption medium; hydrogen is separated from synthesis gas freed of carbon dioxide in a physical separation step, wherein hydrogen as product gas and an offgas comprising hydrogen, carbon monoxide and carbon dioxide are obtained; product gas hydrogen and carbon dioxide are discharged from the process. The invention further relates to a plant for performing the process.

Abstract: 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.

Abstract: In a process for separating a mixture containing carbon monoxide, hydrogen and carbon dioxide, the mixture cooled in a heat exchanger is contacted by a stream of liquid methanol at a temperature below ?40° C. to produce carbon dioxide enriched methanol and a carbon dioxide depleted gas relative to the cooled mixture, the carbon dioxide depleted gas is cooled in the heat exchanger and is sent to a separation unit to produce a carbon monoxide enriched stream and a hydrogen enriched stream and the streams enriched in carbon monoxide and hydrogen are heated in the heat exchanger by exchanging heat with the mixture.

Abstract: Disclosed herein is a process and a plant for recovering ammonia from a mixture including ammonia, acid gas containing H2S and/or CO2 and low-boiling water-soluble organic components. To avoid an enrichment of volatile organic compounds in the acid gas absorber, a partial stream of the liquid phase is withdrawn from an acid gas absorber and processed such that gaseous ammonia with a reduced content of volatile organic components is obtained, which is recirculated into the acid gas absorber.

Abstract: Disclosed herein is a process and a plant for recovering ammonia from a mixture including ammonia, acid gas containing H2S and/or CO2 and low-boiling water-soluble organic components. To avoid an enrichment of volatile organic compounds in the acid gas absorber, a partial stream of the liquid phase is withdrawn from an acid gas absorber and processed such that gaseous ammonia with a reduced content of volatile organic components is obtained, which is recirculated into the acid gas absorber.

Abstract: Ammonia is recovered from waste water containing NH3, at least one acid gas (CO2, H2S) and inert gases. Firstly, the waste water is passed through a pretreatment column and then, at least in part, into a total stripping column. The top product from the total stripping column is cooled in a condenser, and an aqueous NH3-containing condensate coming from the condenser is fed to an NH3 stripping column. The top product from the NH3 stripping column is brought into direct contact with circulating aqueous NH3-containing condensate in a wash column, and NH3 is recovered from the top product from the wash column. Some of the bottom product from the wash column is fed back into the NH3 stripping column. The temperature in the bottom region of the pretreatment column is set to from less than 30 to 200° C., a sub-stream of the waste water is introduced into the upper region of the pretreatment column, and a second sub-stream of the waste water is fed into the pretreatment column below the first sub-stream.

Abstract: Phenols are extracted from a phenol-containing waste water by means of two solvents A and B. The waste water is first of all passed through a first extraction zone, and then through a second extraction zone. To the first extraction zone a mixture of the solvents A and B is supplied, and into the second extraction zone at least one of the two solvents is introduced. From the first extraction zone, solvent-mixture loaded with phenols is withdrawn, phenols am separated therefrom, and the solvents are used again in at least one of the extraction zones. Solvent B is lower-boiling and has a lower water solubility at a temperature in the range from 10.degree. to 60.degree. C. than solvent A. Solvent B has a water solubility at 40.degree. C. of up to 2 wt.-% and a boiling point at 1 bar of 50.degree. to 100.degree. C., and it is miscible with solvent A. Solvent A has a boiling point at 1 bar of not more than 172.degree. C. and a water solubility at 40.degree. C. of not more than 5 wt.-%.