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 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.

An object of the present invention is to provide a process for producing an oxide catalyst used in a vapor-phase catalytic oxidation or vapor-phase catalytic ammoxidation reaction of propane or isobutene, which enables a catalyst demonstrating favorable yield to be stably produced. According to the present invention, there is provided a process for producing an oxide catalyst used in a vapor-phase catalytic oxidation or vapor-phase catalytic ammoxidation reaction of propane or isobutane, comprising the steps of: (i) preparing a catalyst raw material mixture containing Mo, V and Nb and satisfying the relationships of 0.1≦a≦1 and 0.01≦b≦1 when atomic ratios of V and Nb to one atom of Mo are defined as a and b, respectively; (ii) drying the catalyst raw material mixture; and (iii) calcining a particle, in which a content of the particle having a particle diameter of 25 μm or less is 20% by mass or less and a mean particle diameter is from 35 to 70 μm, in an inert gas atmosphere.

The present invention relates to a high-performance polyoxometalate catalyst and a method of preparing the same. More particularly, the present invention provides a high-performance polyoxometalate catalyst, the activity and selectivity of which may be improved by controlling the content of vanadium and the like and which has superior reproducibility and may unsaturated carboxylic acid from unsaturated aldehyde in a high yield for a long time, a method of preparing the same, and the like.

The invention relates to a process for treating a catalyst for alkane oxidative dehydrogenation and/or alkene oxidation, which catalyst is a mixed metal oxide catalyst containing molybdenum, vanadium and niobium, wherein the process comprises: contacting the catalyst with a gas mixture comprising an inert gas and oxygen (O.sub.2), wherein the amount of oxygen is of from 10 to less than 10,000 parts per million by volume (ppmv), based on the total volume of the gas mixture, at an elevated temperature.

Mixed metal oxide catalysts having an amorphous content of not less than 40 wt. % are prepared by calcining the catalyst precursor fully or partially enclosed by a porous material having a melting temperature greater than 600° C. in an inert container including heating the catalyst precursor at a rate from 0.5 to 10° C. per minute from room temperature to a temperature from 370° C. to 540° C. under a stream of pre heated gas chosen from steam and inert gas and mixtures thereof at a pressure of greater than or equal to 1 psig having a temperature from 300° C. to 540° C. and holding the catalyst precursor at that temperature for at least 2 hours and cooling the catalyst precursor to room temperature.

Provided in this disclosure are oxidative dehydrogenation catalysts that include a mixed metal oxide having the empirical formula:
Mo.sub.1.0V.sub.0.12-0.49Te.sub.0.05-0.17Nb.sub.0.10-0.20O.sub.d
wherein d is a number to satisfy the valence of the oxide. The oxidative dehydrogenation catalyst is characterized by having XRD diffraction peaks (2θ degrees) at 22±0.2, 27±0.2, 28.0±0.2, and 28.3±0.1. The disclosure also provides methods of making the catalysts that include wet ball milling.

This document relates to oxidative dehydrogenation catalysts that include molybdenum, vanadium, and oxygen.

This document relates to oxidative dehydrogenation catalysts that include molybdenum, vanadium, and oxygen.

The invention relates to a process for preparing a catalyst for alkane oxidative dehydrogenation and/or alkene oxidation, which catalyst is a mixed metal oxide catalyst containing molybdenum, vanadium, niobium and optionally tellurium, wherein the process comprises: a) preparing a catalyst precursor containing molybdenum, vanadium, niobium and optionally tellurium; b) optionally contacting the catalyst precursor obtained in step a) with oxygen and/or an inert gas at an elevated temperature; c) contacting the catalyst precursor obtained in step a) or step b) with a gas mixture comprising ammonia and water, which gas mixture further comprises oxygen and/or an inert gas, at an elevated temperature; and d) optionally contacting the catalyst precursor obtained in step c) with an inert gas at an elevated temperature. Further, the invention relates to a catalyst obtainable by said process and to a process of the oxidative dehydrogenation of an alkane containing 2 to 6 carbon atoms and/or the oxidation of an alkene containing 2 to 6 carbon atoms wherein said catalyst is used.