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.

A process for producing water-absorbing polymer particles, comprising the steps of thermal cracking of bionaphtha in the presence of steam, removing propene and at least some of the propane, gas phase oxidation to give acrylic acid and polymerization to give water-absorbing polymer particles.

A process for producing water-absorbing polymer particles, comprising the steps of thermal cracking of bionaphtha in the presence of steam, removing propene and at least some of the propane, gas phase oxidation to give acrylic acid and polymerization to give water-absorbing polymer particles.

A process for producing water-absorbing polymer particles, comprising the steps of thermal cracking of bionaphtha in the presence of steam, removing propene and at least some of the propane, gas phase oxidation to give acrylic acid and polymerization to give water-absorbing polymer particles.

The invention relates to a process for preparing a shaped catalyst for alkane oxidative dehydrogenation and/or alkene oxidation, which comprises: a) preparing a mixed metal oxide catalyst containing molybdenum, vanadium, niobium and optionally tellurium; b) mixing the catalyst obtained in step a), a binder and optionally water, wherein the binder has a surface area greater than 100 m.sup.2/g and a water loss upon heating at a temperature of 485° C. which is greater than 1 wt. %; c) shaping the mixture obtained in step b) to form a shaped catalyst by means of tableting; and d) subjecting the shaped catalyst obtained in step c) to an elevated temperature. Further, the invention relates to a catalyst obtainable by said process and to a process of alkane oxidative dehydrogenation and/or alkene oxidation wherein said catalyst is used.

The invention relates to a process for preparing a shaped catalyst for alkane oxidative dehydrogenation and/or alkene oxidation, which comprises: a) preparing a mixed metal oxide catalyst containing molybdenum, vanadium, niobium and optionally tellurium; b) mixing the catalyst obtained in step a), a binder and optionally water, wherein the binder has a surface area greater than 100 m.sup.2/g and a water loss upon heating at a temperature of 485° C. which is greater than 1 wt. %; c) shaping the mixture obtained in step b) to form a shaped catalyst by means of tableting; and d) subjecting the shaped catalyst obtained in step c) to an elevated temperature. Further, the invention relates to a catalyst obtainable by said process and to a process of alkane oxidative dehydrogenation and/or alkene oxidation wherein said catalyst is used.

A method of production of malic acid includes treating a first intermediate product to form a second intermediate product. The treating includes substantially removing impurities from the first intermediate product to obtain a treated intermediate product by gas stripping the crude maleic anhydride, or subjecting a mixture of one or more of the crude maleic acid, the crude fumaric acid, and the vent gas scrubber solution obtained from a phthalic anhydride production process or a maleic anhydride production process to crystallization, passing an aqueous solution of the treated intermediate product through a carbon column to substantially remove retained impurities to form the second intermediate product, obtaining a feed that includes the second intermediate product, and causing the feed to undergo hydration reaction in a tubular reactor or a continuous stirred tank reactor to produce malic acid.

A method of production of malic acid includes treating a first intermediate product to form a second intermediate product. The treating includes substantially removing impurities from the first intermediate product to obtain a treated intermediate product by gas stripping the crude maleic anhydride, or subjecting a mixture of one or more of the crude maleic acid, the crude fumaric acid, and the vent gas scrubber solution obtained from a phthalic anhydride production process or a maleic anhydride production process to crystallization, passing an aqueous solution of the treated intermediate product through a carbon column to substantially remove retained impurities to form the second intermediate product, obtaining a feed that includes the second intermediate product, and causing the feed to undergo hydration reaction in a tubular reactor or a continuous stirred tank reactor to produce malic acid.

The present disclosures and inventions relate to methods for the preparation of acetic acid via the oxidation of ethane, including the preparation of high purity acetic acid that comprises very low concentrations of formic acid impurity. More specifically, described herein are methods for producing acetic acid comprising: a. producing a crude acetic acid composition comprising formic acid from ethane via ethane oxidation; and then b. purifying the crude acetic acid composition by crystallization to remove formic acid to achieve a purified acetic acid composition; wherein the formic acid is present in the purified acetic acid composition in an amount less than 0.2% by weight, based on the total weight of the purified acetic acid composition.

The present disclosures and inventions relate to methods for the preparation of acetic acid via the oxidation of ethane, including the preparation of high purity acetic acid that comprises very low concentrations of formic acid impurity. More specifically, described herein are methods for producing acetic acid comprising: a. producing a crude acetic acid composition comprising formic acid from ethane via ethane oxidation; and then b. purifying the crude acetic acid composition by crystallization to remove formic acid to achieve a purified acetic acid composition; wherein the formic acid is present in the purified acetic acid composition in an amount less than 0.2% by weight, based on the total weight of the purified acetic acid composition.