This invention relates to a method of continuously preparing acrylic acid and an apparatus using the same, the method including: (1) subjecting a feed including propane, oxygen, water vapor and carbon dioxide to partial oxidation using a catalyst, thus obtaining an acrylic acid-containing mixed gas, (2) separating the acrylic acid-containing mixed gas into an acrylic acid-containing solution and a gas byproduct, (3) separating an acrylic acid solution from the separated acrylic acid-containing solution, and (4) recycling the separated gas byproduct into the feed.

This invention relates to a method of continuously preparing acrylic acid and an apparatus using the same, the method including: (1) subjecting a feed including propane, oxygen, water vapor and carbon dioxide to partial oxidation using a catalyst, thus obtaining an acrylic acid-containing mixed gas, (2) separating the acrylic acid-containing mixed gas into an acrylic acid-containing solution and a gas byproduct, (3) separating an acrylic acid solution from the separated acrylic acid-containing solution, and (4) recycling the separated gas byproduct into the feed.

The present invention provides a chromatographic separation process for recovering a polyunsaturated fatty acid (PUFA) product, from a feed mixture, which process comprises introducing the feed mixture to a simulated or actual moving bed chromatography apparatus having a plurality of linked chromatography columns containing, as eluent, an aqueous alcohol, wherein the apparatus has a plurality of zones comprising at least a first zone and a second zone, each zone having an extract stream and a raffinate stream from which liquid can be collected from said plurality of linked chromatography columns, and wherein (a) a raffinate stream containing the PUFA product together with more polar components is collected from a column in the first zone and introduced to a nonadjacent column in the second zone, and/or (b) an extract stream containing the PUFA product together with less polar components is collected from a column in the second zone and introduced to a nonadjacent column in the first zone, said PUFA product being separated from different components of the feed mixture in each zone.

A process and an apparatus for the purification of a crude acrylic acid composition containing maleic anhydride as an impurity comprising the following steps: (a) carrying out at least one dynamic melt crystallization stage (14, 14a, 14b, 14c, 14d) with the crude acrylic acid composition to prepare a first purified acrylic acid composition and a first residue containing at least 3.5% by weight maleic anhydride, (b) adding a solvent (26) which is capable of dissolving maleic anhydride to the first residue in an amount that the weight ratio of the solvent to the maleic anhydride is 0.3 or more to prepare a ratio-adjusted residue and (c) carrying out at least one further dynamic melt crystallization stage and/or at least one static melt crystallization stage (18, 18a, 18b) with the ratio-adjusted residue to prepare a second purified acrylic acid composition and a second residue.

A process and an apparatus for the purification of a crude acrylic acid composition containing maleic anhydride as an impurity comprising the following steps: (a) carrying out at least one dynamic melt crystallization stage (14, 14a, 14b, 14c, 14d) with the crude acrylic acid composition to prepare a first purified acrylic acid composition and a first residue containing at least 3.5% by weight maleic anhydride, (b) adding a solvent (26) which is capable of dissolving maleic anhydride to the first residue in an amount that the weight ratio of the solvent to the maleic anhydride is 0.3 or more to prepare a ratio-adjusted residue and (c) carrying out at least one further dynamic melt crystallization stage and/or at least one static melt crystallization stage (18, 18a, 18b) with the ratio-adjusted residue to prepare a second purified acrylic acid composition and a second residue.

A process and an apparatus for the purification of a crude acrylic acid composition containing maleic anhydride as an impurity comprising the following steps: (a) carrying out at least one dynamic melt crystallization stage (14, 14a, 14b, 14c, 14d) with the crude acrylic acid composition to prepare a first purified acrylic acid composition and a first residue containing at least 3.5% by weight maleic anhydride, (b) adding a solvent (26) which is capable of dissolving maleic anhydride to the first residue in an amount that the weight ratio of the solvent to the maleic anhydride is 0.3 or more to prepare a ratio-adjusted residue and (c) carrying out at least one further dynamic melt crystallization stage and/or at least one static melt crystallization stage (18, 18a, 18b) with the ratio-adjusted residue to prepare a second purified acrylic acid composition and a second residue.

The present invention relates to a process suitable for adoption to large scale manufacture of 1-isopropyl-3-{5-[1-(3-methoxypropyl)piperidin-4-yl]-[1,3,4]oxadiazol-2-yl}-1H-indazole oxalate of formula (I), which is a selective 5-HT.sub.4 receptor ligand intended for the symptomatic treatment of Alzheimer's disease and other disorders of memory and cognition like Attention deficient hyperactivity, Parkinson's and Schizophrenia.

The present invention relates to a process suitable for adoption to large scale manufacture of 1-isopropyl-3-{5-[1-(3-methoxypropyl)piperidin-4-yl]-[1,3,4]oxadiazol-2-yl}-1H-indazole oxalate of formula (I), which is a selective 5-HT.sub.4 receptor ligand intended for the symptomatic treatment of Alzheimer's disease and other disorders of memory and cognition like Attention deficient hyperactivity, Parkinson's and Schizophrenia.

The present invention relates to a process suitable for adoption to large scale manufacture of 1-isopropyl-3-{5-[1-(3-methoxypropyl)piperidin-4-yl]-[1,3,4]oxadiazol-2-yl}-1H-indazole oxalate of formula (I), which is a selective 5-HT.sub.4 receptor ligand intended for the symptomatic treatment of Alzheimer's disease and other disorders of memory and cognition like Attention deficient hyperactivity, Parkinson's and Schizophrenia.

A novel salt of treprostinil and methods of its preparation and use are disclosed.