Abstract:
PROBLEM TO BE SOLVED: To remove a part of a face which is in the shadow region of a reflux sprayed and inhibited in polymerization of the internal structure included in a separating column suitable for a thermal separation method from the shadow region by using a method as simple as possible without a high cost, and also without a spraying nozzle to be used. SOLUTION: The problem is solved by the separating column which includes a continuity of a substance exchanging tray in which a covered double-T support and/or a covered U-shaped support are incorporated as a supporting element. COPYRIGHT: (C)2010,JPO&INPIT
Abstract:
The invention relates to a method for separating a raw acrylic acid from a product gas mixture comprising glyoxal as auxiliary product of a heterogeneously catalyzed partial gas phase oxidation of at least one C3-precursor compound, comprising the absorption of the acrylic acid in a high-boiling absorption agent and the rectificative processing of the resulting absorbent, and wherein, in a distillation unit, an absorption agent contained in the sump fluid that has been removed from the sump chamber of the absorption column is distilled and is fed back into the absorption before remaining high-boiling components are removed, and wherein the glyoxal content of the raw acrylic acid is reduced by limiting the duration of the high-boiling components in the distillation unit.
Abstract:
A method is disclosed for transferring heat to a liquid F containing dissolved monomeric acrylic acid, acrylic acid oligomers obtained by Michael addition, and acrylic acid polymer with the help of an indirect heat exchanger to which the liquid F is fed at a temperature TF = 150°C and a heat transfer fluid W is fed at a temperature Tw > TF. In said method, gas bubbles or thin layers of liquid F bordering a gas phase are generated in the liquid F while said liquid F flows through the heat exchanger.
Abstract:
Separating acrylic acid, contained as main constituent and glyoxal, contained as by-product from a gaseous product mixture of a partial gas phase oxidation of 3C-precursor compound of acrylic acid comprises producing a liquid phase containing at least 70 wt.% of acrylic acid and at least 200 mol.ppm of glyoxal in relation to the contained molar quantity of acrylic acid and separating glyoxal from the acrylic acid by crystallization from the liquid phase, where the acrylic acid is formed in crystallite form and the glyoxal is enriched in the mother liquor remained after crystallization.
Abstract:
A process for transferring heat to a liquid F comprising dissolved monomeric acrylic acid, Michael acrylic acid oligomers, and acrylic acid polymer with the aid of an indirect heat exchanger to which are supplied the liquid F with a temperature TF of >=150° C. and a fluid heat carrier W with a temperature of TW>TF, wherein the formation of gas bubbles and/or of thin layers of liquid F adjoining a gas phase is brought about in the liquid F during the flow through the heat exchanger.
Abstract:
Process for transferring heat to a liquid mixture comprising at least one (meth)acrylic monomer with the aid of an indirect heat exchanger comprises introducing the liquid mixture simultaneously into the primary side of the heat exchanger by a liquid heat carrier and secondary side of the heat exchanger, where: the liquid mixture comprising at least one (meth)acrylic monomer contains at least one added active compound other than (meth)acrylic monomers from tertiary amine or salts formed from a tertiary amine and Bronsted acid, and quaternary ammonium compounds. Process for transferring heat to a liquid mixture comprising at least one (meth)acrylic monomer with the aid of an indirect heat exchanger comprises introducing the liquid mixture simultaneously into the primary side of the heat exchanger by a liquid heat carrier and secondary side of the heat exchanger, where: the liquid mixture comprising at least one (meth)acrylic monomer contains at least one added active compound other than (meth)acrylic monomers from tertiary amine or salts formed from a tertiary amine and Bronsted acid, and quaternary ammonium compounds, with proviso that none of the tertiary and quaternary nitrogen atoms in the active compound bears a phenyl group, but at least partly contains an alkyl group.
Abstract:
Process for transferring heat to a liquid mixture comprising at least one (meth)acrylic monomer with the aid of an indirect heat exchanger comprises introducing the liquid mixture simultaneously into the primary side of the heat exchanger by a liquid heat carrier and secondary side of the heat exchanger, where: the liquid mixture comprising at least one (meth)acrylic monomer contains at least one added active compound other than (meth)acrylic monomers from tertiary amine or salts formed from a tertiary amine and Bronsted acid, and quaternary ammonium compounds. Process for transferring heat to a liquid mixture comprising at least one (meth)acrylic monomer with the aid of an indirect heat exchanger comprises introducing the liquid mixture simultaneously into the primary side of the heat exchanger by a liquid heat carrier and secondary side of the heat exchanger, where: the liquid mixture comprising at least one (meth)acrylic monomer contains at least one added active compound other than (meth)acrylic monomers from tertiary amine or salts formed from a tertiary amine and Bronsted acid, and quaternary ammonium compounds, with proviso that none of the tertiary and quaternary nitrogen atoms in the active compound bears a phenyl group, but at least partly contains an alkyl group.
Abstract:
Separating acrylic acid from the product gas mixture of a heterogeneously catalyzed partial gas phase oxidation of at least one 3C-precursor compound to acrylic acid comprises: (a) cooling the product gas mixture in a direct cooler by directly cooling with a finely sprayed cooling liquid, where a portion of the cooling liquid is evaporated and (b) providing the cooled product gas mixture together with evaporated and non-evaporated cooling liquid into an absorption column of a sump region. Method for separating acrylic acid from the product gas mixture of a heterogeneously catalyzed partial gas phase oxidation of at least a 3C-precursor compound to acrylic acid, where the mixture, in addition to acrylic acid, comprises water vapor, glyoxal, low boiling, average boiling, high boiling and highly condensable compounds that are different from the above, as by-products, comprises: (a) cooling the product gas mixture in a direct cooler by directly cooling with a finely sprayed cooling liquid, where a portion of the cooling liquid is evaporated; (b) providing the cooled product gas mixture together with evaporated and non-evaporated cooling liquid into an absorption column of a sump region, where between the absorption room of the absorption column a chimney plate having at least one chimney, is present and connected; (c) providing the cooled product gas mixture and evaporated cooling liquid into the soil absorption column through the chimney of the chimney plate, which forms descending high-boiling absorption medium, where the chimney plate contains a absorbate, which absorbs acrylic acid; (d) removing the acrylic acid from the absorbate; (e) contacting one portion of absorbate filled in the absorption column to the sump room of the absorption column for forming a sump fluid in the sump region, optionally cooling another portion of the absorbate and recycling the chimney plate into the absorption column; (f) contacting the residual quantity in the absorbate or the absorbate in a rectification column with reinforcing and stripping section; (g) enriching the stripping section of the rectification column with the absorbate and feeding out the stripping section of absorption agent with an acrylic acid weight portion of >= 1 wt.%; (h) enriching the rectification section of the rectification column with acrylic acid and feeding out the reinforcing section of a raw acrylic acid, where the weight portion of the acrylic acid is = 90 wt.%; (i) extracting the obtained sump liquid from the sump region of the absorption column, feeding one portion of the obtained sump liquid, as cooling liquid, into the direct cooler and feeding the remaining portion of the liquid into the bottom of a distillation unit comprising a distillation column and a circulating heat exchangers; (j) separating the sump liquid in the distillation column of the distillation unit in exhaust vapors, whose weight portion in the absorption agent is greater than the weight portion of the sump fluid at absorption agent, and into liquid concentrate, whose weight portion is high, when the absorption agent of the boiling components is greater than the high boiling components of the sump liquid; (k) recycling water vapor, possibly its cooling and/or condensation in an indirect heat exchanger and above the chimney plate in the absorption column; (l) leading out a mass flow from the bottom of the distillation column in the standing height of the liquid concentrate with the temperature T 1>from the distillation column; (m) discharging a partial stream of the mass flow from the procedure of the separation of acrylic acid from the product gas mixture; and (n) recycling the residual stream of the mass flow over the circulation heat exchanger with a temperature (T 2>>= T 1>) of absorbed mass flow from the distillation column, into the distillation column; where the average retention time of the components of the partial stream in the distillation unit is = 40 hours.