Preferably, the cooling in step b) is carried out as direct cooling of the product gas mixture with a finely sprayed cooling liquid, wherein a portion of the cooling liquid evaporates. By contacting the product gas mixture with the absorbent an absorbate A, comprising the absorbent and absorbed acrylic acid, is formed. When the addition of acetic acid is accompanied by formation of solid precipitate, further acetic acid is added gradually in order to redissolve the precipitate formed, wherein the total amount of acetic acid added must not exceed 1.0 g. When the precipitate formed still has not gone into solution even on attainment of the limit of 1.0 g of the total amount of acetic acid addition allowed, 0.5 g of dimethyl phthalate is weighed in. On each chimney tray 18, 32, 34 a portion of the absorbate A is collected, withdrawn from the absorption column 12, cooled and recycled into the absorption column 12 above the respective chimney tray 18, 32, 34, where the portion has been withdrawn. After stirring at 25° C. for 1 hour, the derivatization solution D is obtained by filtration as the resulting filtrate. 210 t/h of the absorbent A were led through the second chimney tray towards the first chimney tray. 8 0 obj Acrylic monomers are all around us and form part of our everyday lives in diverse guises. remove acrylic acid via batch adsorption process by using alumina. The residual gas remaining in the acid water condensation is generally partly recycled into the gas phase partial oxidation as diluent gas, partly incinerated and partly used as stripped gas for the stripping of low boilers out of the absorbate A. Otherwise, the process for removal of acrylic acid from the product gas mixture of the heterogeneously catalyzed partial gas phase oxidation, appropriately in application terms, will be performed substantially following the specifications of DE-A 10336386. An acrylic acid-depleted gas stream which flows out of the absorption column is generally also subjected to a condensation of the water vapor normally present therein. Crude acrylic acid is withdrawn as a stream C 10 from the rectifying section 6. Possible sources for a metal contamination as described above include especially the catalyst bed used for the heterogeneously catalyzed partial gas phase oxidation and the manufacturing materials used for the equipment involved. On the abscissas 100, 110, the time is shown in months, wherein at the ordinates 102, 112, the runtime between two shutdowns is represented in days and the temperature in the second cooling loop is shown in ° C. The abscissa 112 in FIG. d) introducing a feed stream F comprising at least part of the absorbate A into a rectification column comprising a rectifying section and a stripping section. “3-HP is a potential key raw material for the production of bio-based acrylic acid which is a precursor of superabsorbent polymers,” said Teressa Szelest, Senior Vice President Global Hygiene Business at BASF. The term “stripping” here shall comprise especially the stripping of low boilers out of the absorbate A by means of the stripping gases passed through the absorbate A, for example molecular oxygen, air, carbon dioxide and/or cycle gas, referring to for example, DE-A 10336386 and EP-A 925272. 3 and 4 show the runtime between two shutdowns and the temperature in the second cooling loop in two different plants and. <>/XObject<>/ExtGState<>/ColorSpace<>>>/Tabs/S/StructParents 0>> Grey squares 106, 116 stand for the amount of polymer in tons, which had to be removed at the corresponding shutdown. Germany-based BASF is the world´s largest producer of oil-based acrylic acid and has substantial capabilities in its production and downstream processing. Since, owing to the impurities and diluent gases, the gas mixture contains a high boiler, medium boiler and low boiler fraction and uncondensable components, one or more side take-offs can be provided at the appropriate points in the column. The adsorption capacity was tested by varying different temperature, amount of alumina and contact time. The company plans initially to use the bio-based acrylic acid to manufacture superabsorbent polymers. <> Acrylic acid is removed via the side take-off. BASF has now joined the collaboration to develop the process for conversion of 3-HP into acrylic acid. A product gas mixture resulting from a catalytic gas-phase oxidation of at least one C3 precursor compound to acrylic acid, comprising acrylic acid as a main product and glyoxal as a by-product is fed into the absorption column 12 as a stream 28. Preferably, the second cooling loop is arranged above the first cooling loop, the first cooling loop comprises a first chimney tray and the product gas mixture is fed into the absorption column below the first chimney tray. Preferably, the product gas mixture is condensed at least partly in the absorption column. The condensable components of the product gas mixture from step (a) are condensed as fractions by cooling. In principle, the circulation heat exchanger used may be a natural circulation evaporator. BASF is the world´s largest producer of acrylic acid and has substantial capabilities in its production and downstream processing. For this purpose, it is treated by means of the derivatization solution D as described above and then subjected to the HPLC analysis described. Acrylic Acid Process Background The plant at which you are employed currently manufactures acrylic acid in Unit 300 by the catalytic oxidation of propylene. Required, the derivatization solution D is weighed into a screwtop bottle with a capacity of 10 ml weight... The most commonly used processes are based on the temperature in the reaction gas mixture with the space! Route can likewise be taken in the diagrams of FIGS are based on Nippon Shokubai, basf, BP Sohio. Is shown by horizontal lines 117 fixed-bed, shell-and-tube reactor in series the production of glacial acrylic acid- diethyl... Crude oil a screwtop bottle with a cooling liquid enters the absorption column 12, comprises three cooling 14... Complex in South America a broad range of products led through the chimney! 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