Abstract: This invention relates to a process for the purification of acrylic acid from a mixture containing acrylic acid and acetic acid, comprising the following steps: extraction of the mixture containing acrylic acid and acetic acid with an extractant stream, whereby a raffinate stream and an extract stream are obtained, distillation of the extract stream, whereby an acrylic acid stream and a return stream are obtained, wherein the return stream contains acetic acid and is recirculated into the extraction. Furthermore, the invention may include a plant for carrying out this process.

Abstract: This invention relates to a process for the purification of acrylic acid from a mixture containing acrylic acid and acetic acid, comprising the following steps: extraction of the mixture containing acrylic acid and acetic acid with an extractant stream, whereby a raffinate stream and an extract stream are obtained, distillation of the extract stream, whereby an acrylic acid stream and a return stream are obtained, wherein the return stream contains acetic acid and is recirculated into the extraction. Furthermore, the invention may include a plant for carrying out this process.

Abstract: A slurry bubble column reactor with a gas distribution arrangement comprising an upper sparger, a lower sparger, and an open-ended tube. Gas from the lower sparger enters the tube and lowers the density of slurry in the tube. The difference in slurry density causes the slurry in the tube to rise, causing slurry outside the tube to move down, maintaining circulation and flushing catalyst from the vessel wall.

Abstract: A process for recovering solid reaction products during partial oxidation of hydrocarbons in a liquid solvent as a reaction medium by multi-stage evaporative crystallization includes determining a final temperature of the multi-stage evaporative crystallization based on a melting point of the solvent. The pressure and temperature of the solvent is reduced in steps via successive crystallization stages until the final temperature is reached. Each of the crystallization stages includes a compressor configured to perform the reducing of the pressure and to withdraw vapors formed. The vapors from the compressor of a lower expansion pressure crystallization stage are introduced into a vapor discharge conduit of a next successive higher expansion pressure crystallization stage upstream of the compressor of the higher expansion pressure crystallization stage.

Abstract: A slurry bubble column reactor with a gas distribution arrangement comprising an upper sparger, a lower sparger, and an open-ended tube. Gas from the lower sparger enters the tube and lowers the density of slurry in the tube. The difference in slurry density causes the slurry in the tube to rise, causing slurry outside the tube to move down, maintaining circulation and flushing catalyst from the vessel wall.

Abstract: A process for recovering solid reaction products during partial oxidation of hydrocarbons in a liquid solvent as a reaction medium by multi-stage evaporative crystallization includes determining a final temperature of the multi-stage evaporative crystallization based on a melting point of the solvent. The pressure and temperature of the solvent is reduced in steps via successive crystallization stages until the final temperature is reached. Each of the crystallization stages includes a compressor configured to perform the reducing of the pressure and to withdraw vapors formed. The vapors from the compressor of a lower expansion pressure crystallization stage are introduced into a vapor discharge conduit of a next successive higher expansion pressure crystallization stage upstream of the compressor of the higher expansion pressure crystallization stage.

Abstract: Process for generating a homogeneous gas mixture of o-xylene and air for the production of phthalic anhydride wherein o-xylene is completely evaporated in the absence of oxygen, superheated and then mixed with air and supplied to a phthalic anhydride reactor.

Abstract: To improve the columns used so far for producing phthalic anhydride, and to make them less expensive and easier to install, it is proposed that in the column for concentrating phthalic anhydride two distillation stages are arranged, wherein the removal of the low-boiling components of the crude phthalic anhydride by distillation is effected in the first distillation stage (2) and the separation of the high-boiling components from the pure phthalic anhydride is effected in the second distillation stage (3), both distillation stages being arranged side by side and being separated from each other by a vertical wall (4), and that the bottom (7) of the first distillation stage (2) is connected with the bottom (10) of the second distillation stage (3).

Abstract: To improve the columns used so far for producing phthalic anhydride, and to make them less expensive and easier to install, it is proposed that in the column for concentrating phthalic anhydride two distillation stages are arranged, wherein the removal of the low-boiling components of the crude phthalic anhydride by distillation is effected in the first distillation stage (2) and the separation of the high-boiling components from the pure phthalic anhydride is effected in the second distillation stage (3), both distillation stages being arranged side by side and being separated from each other by a vertical wall (4), and that the bottom (7) of the first distillation stage (2) is connected with the bottom (10) of the second distillation stage (3).

Abstract: Process for generating a homogeneous gas mixture of o-xylene and air for the production for the production of phthalic anhydride wherein o-xylene is completely evaporated in the absence of oxygen, superheated and then mixed with air and supplied to a phthalic anhydride reactor.