摘要:
An absorption medium for the removal of acid gases from a fluid stream comprises an aqueous solution a) of at least one amine and b) at least one phosphonic acid, wherein the molar ratio of b) to a) is in the range from 0.0005 to 1.0. The phosphonic acid is, e.g., 1-hydroxyethane-1,1-diphosphonic acid. The absorption medium exhibits a reduced regeneration energy requirement compared with absorption media based on amines or amine/promoter combinations, without significantly decreasing the absorption capacity of the solution for acid gases.
摘要:
A process for removing carbon dioxide from a fluid comprises the steps of: (a) treating the fluid by bringing it into countercurrent contact with a liquid absorbent in a first absorption zone and thereafter in a second absorption zone to absorb at least part of the carbon dioxide contained in the fluid into the absorbent; (b) depressurizing the loaded absorbent to release a first stream of carbon dioxide and yield a partially regenerated absorbent; (c) recycling a first stream of the partially regenerated absorbent into the first absorption zone; (d) heating a second stream of the partially regenerated absorbent to release a second stream of carbon dioxide and yield a regenerated absorbent; (e) recycling the regenerated absorbent into the second absorption zone; (f) condensing water vapor entrained in the second stream of carbon dioxide by cooling the second stream of carbon dioxide and transferring at least part of the heat recovered to the partially regenerated absorbent by indirect heat exchange. The invention provides a two-stage carbon dioxide recovery process wherein the overall energy required for carbon dioxide recovery is reduced and/or wherein at least part of the carbon dioxide is recovered at a pressure higher than atmospheric pressure so as to reduce the energy required for compression of the carbon dioxide, e.g., for sequestration. Also disclosed is a plant for removing carbon dioxide from a fluid.
摘要:
An absorption medium for removing acid gases from a fluid stream comprises an aqueous solution (A) of an alkali metal salt of an N,N-di-C1-C4-alkylaminocarboxylic acid and (B) N-hydroxyethylpiperazine. The absorption medium has a low vapor pressure and an increased resistance to oxygen. Preferred fluid streams are combustion exhaust gases or biogas.
摘要:
Processes comprising: providing an alkanolic reaction mixture, the alkanolic reaction mixture comprising: at least one alkoxycarbonylaminotriazine; at least one carbonic ester; at least one C1-C13-alkanol, which alkanol may further comprise up to two ether-bound oxygen atoms and may further comprise a substituent selected from the group consisting of C1-C4-alkyls and hydroxyls; and at least one alkali metal alkoxide or alkaline earth metal alkoxide; and subjecting the alkanolic reaction mixture to extraction with a polar extractant such that at least a portion of polar/ionic components present in the reaction mixture are removed, wherein the polar extractant is less than entirely miscible with an organic phase of the reaction mixture, to form an alkanolic phase comprising the at least one alkoxycarbonylaminotriazine and a polar phase comprising the polar extractant and the portion of polar/ionic components; and wherein the extraction is carried out with one or more selected from the group consisting of mixer/settler units, columns, centrifugal field separation extractors, and combinations thereof.
摘要:
A process for removing carbon dioxide from a fluid comprises the steps of: (a) treating the fluid by bringing it into countercurrent contact with a liquid absorbent in a first absorption zone and thereafter in a second absorption zone to absorb at least part of the carbon dioxide contained in the fluid into the absorbent; (b) depressurizing the loaded absorbent to release a first stream of carbon dioxide and yield a partially regenerated absorbent; (c) recycling a first stream of the partially regenerated absorbent into the first absorption zone; (d) heating a second stream of the partially regenerated absorbent to release a second stream of carbon dioxide and yield a regenerated absorbent; (e) recycling the regenerated absorbent into the second absorption zone; (f) condensing water vapour entrained in the second stream of carbon dioxide by cooling the second stream of carbon dioxide and transferring at least part of the heat recovered to the partially regenerated absorbent by indirect heat exchange. The invention provides a two-stage carbon dioxide recovery process wherein the overall energy required for carbon dioxide recovery is reduced and/or wherein at least part of the carbon dioxide is recovered at a pressure higher than atmospheric pressure so as to reduce the energy required for compression of the carbon dioxide, e.g., for sequestration. Also disclosed is a plant for removing carbon dioxide from a fluid.
摘要:
The invention relates to a process for preparing free-flowing, pulverulent alkoxycarbonylaminotriazine from an alkanolic reaction mixture which is obtained in the preparation of alkoxycarbonylaminotriazines and comprises at least one alkoxycarbonylaminotriazine, at least one cyclic and/or acyclic carbonic ester, at least one C1-C13-alkanol which optionally comprises one or two oxygen atoms in the form of ether bonds and is optionally substituted by C1-C4-alkyl and/or hydroxyl, and also at least one alkali metal or alkaline earth metal alkoxide, with or without melamine and with or without catalyst, by atomizing and drying the reaction mixture in a spray drier.
摘要:
A process for preparing acrylic acid, in which an acrylic acid-comprising product gas mixture obtained by catalytic gas phase partial oxidation of a C3 precursor of acrylic acid is fractionally condensed in a condensation column provided with internals ascending into itself with side draw removal of crude acrylic acid and with liquid phase draw removal of acrylic acid-comprising acid water, and acrylic acid present in acid water is taken up into an extractant and then removed from the extractant and recycled into the condensation column, or taken up in aqueous metal hydroxide, or sent to further purification of the crude acrylic acid.