Abstract:
Disclosed is a method for producing a catalyst containing vanadium, phosphorus, and oxygen, which is used for oxidizing the gas phase of a hydrocarbon having at least four carbon atoms to maleic anhydride. According to the inventive method, a corresponding catalyst precursor which contains vanadium, phosphorus, and oxygen and is provided with particles having an average diameter of at least 2 mm is converted into a catalytically active form by means of calcination, and a flow of the catalyst precursor is transported on a conveyor belt across at least one calcination area over a distance ln at an essentially steady speed in order to be calcinated. The variation over time of the gas temperature in relation to the set point value amounts to
Abstract:
The invention relates to a method for producing maleic anhydride by the heterogeneous catalytic gas phase oxidation of hydrocarbons comprising at least four carbon atoms with gases containing oxygen, in the presence of a volatile phosphorus compound, on a catalyst containing vanadium, phosphor and oxygen in a multitube flow reactor unit with at least one reaction zone that is cooled by a heat-transfer medium, at a temperature ranging between 350 and 500 °C. In the first reaction zone, in relation to the educt supply, the supply temperature and/or the supply quantity is set in such a way that the average temperature of the heat transfer medium in the first reaction zone TSB(1st zone), said temperature being produced by the average value formation of the supply temperature and the drainage temperature of the heat-transfer medium, fulfils the formulas (I) and (II): (I) TSB(1st zone)
Abstract:
Disclosed is a method for producing a catalyst containing vanadium, phosphorus, and oxygen, which is used for oxidizing the gas phase of a hydrocarbon having at least four carbon atoms to maleic anhydride. According to the inventive method, a corresponding catalyst precursor which contains vanadium, phosphorus, and oxygen and is provided with particles having an average diameter of at least 2 mm is converted into a catalytically active form by means of calcination, and a flow of the catalyst precursor is transported on a conveyor belt across at least one calcination area over a distance ln at an essentially steady speed in order to be calcinated. The variation over time of the gas temperature in relation to the set point value amounts to
Abstract:
The invention relates to a vanadium-, phosphorus- and oxygen-containing catalyst that is used for producing maleic anhydride by heterogeneous catalytic gas phase oxidation of a hydrocarbon carrying at least four carbon atoms in which the ratio of phosphorus/vanadium is 0.9 to 1.5. Said catalyst comprises particles with an average diameter of at least 2 mm and the composition has a x-ray powder diffraction pattern, obtained by irradiation with CuK alpha radiation ( lambda = 1.54 10 m), that produces in the 2 theta range of 10 DEG to 70 DEG a signal/noise ratio of
Abstract:
A process for the production of maleic acid anhydride by heterogeneous catalytic gas phase oxidation of hydrocarbons having at least four carbon atoms with oxygen-containing gas in the presence of a volatile phosphorus compound at a vanadium, phosphorus and oxygen-containing catalyst in a tubular reactor unit having at least one reaction zone cooled by a heat exchange medium at 350-500 degreesC. A process for the production of maleic acid anhydride by heterogeneous catalytic gas phase oxidation of hydrocarbons having at least four carbon atoms with oxygen-containing gas in the presence of a volatile phosphorus compound at a vanadium, phosphorus and oxygen-containing catalyst in a tubular reactor unit having at least one reaction zone cooled by a heat exchange medium at 350-500 degreesC. With respect to the addition of reactants to the first reaction zone, the addition temperature and/or addition amount of the heat exchange medium are such that the average temperature of the heat exchange medium in the first reaction zone (TSB(1. zone)) is described by formula (1) and (2). TSB(1.zone) at most TD(1.zone)-TSafety(1.zone) (1) TSB,Amax(1.zone)-TA(1.zone) at most TSB(1.zone) at most TSB,Amax(1.zone)+TB(1.zone) (2) TD(1.zone) = through temperature in the first reaction zone corresponding to the average temperature of the heat exchange medium at which a 1 degreesC increase in the average temperature of the heat exchange medium results in a 5 degreesC increase of the hot spot temperature of the first reaction zone THS(1.zone); TSB(1.zone) = average temperature of the heat exchange medium; TSafety(1.zone) = safety temperature of the first reaction zone and is 1 degreesC; TSB,Amax(1.zone) = average temperature of the heat exchange medium in the first reaction zone in the region TSB(1.zone) of no greater than T (1.zone) corresponding to the maximum yield of maleic acid anhydride; T (1.zone) = 20 degreesC; T (1.zone) = 10 degreesC
Abstract:
A vanadium-, phosphorus- and oxygen-containing catalyst for the preparation of maleic anhydride by heterogeneously catalyzed gas-phase oxidation of a hydrocarbon of at least four carbon atoms has a phosphorus/vanadium ratio of from 0.9 to 1.5, comprises particles having a mean diameter of at least 2 mm and has a composition which, using CuKalpha radiation (lambda=1.54.10- m), gives a powder X-ray diffraction pattern which, in the 2theta range from 10° to 70°, has a signal/background ratio of
Abstract:
The invention relates to a vanadium-, phosphorus- and oxygen-containing catalyst that is used for producing maleic anhydride by heterogeneous catalytic gas phase oxidation of a hydrocarbon carrying at least four carbon atoms in which the ratio of phosphorus/vanadium is 0.9 to 1.5. Said catalyst comprises particles with an average diameter of at least 2 mm and the composition has a x-ray powder diffraction pattern, obtained by irradiation with CuK alpha radiation ( lambda = 1.54 10 m), that produces in the 2 theta range of 10 DEG to 70 DEG a signal/noise ratio of
Abstract:
Production of maleic anhydride by gas-phase oxidation of C4+ hydrocarbons with oxygen in the presence of a volatile phosphorus compound and a heterogeneous vanadium/phosphorus/oxygen catalyst comprises performing the oxidation in a shell-and-tube reactor comprising at least two sequential cooled reaction zones, in which the first zone is at 350-450 deg C, the second and subsequent zones are at 350-480 and the temperature difference between the hottest and coolest zones is at least 2 deg C. An Independent claim is also included for apparatus for carrying out the process, comprising: a unit for the metered supply of hydrocarbon, oxygen-containing gas and optionally the phosphorus compound; a shell-and-tube reactor comprising at least two sequential cooled reaction zones with independent temperature control; and a unit for separating maleic anhydride and optionally oxygenated hydrocarbon by-products.
Abstract:
A process for preparing a vanadium, phosphorus, and oxygen catalyst precursor for preparing maleic anhydride by heterogeneously catalyzed gas-phase oxidation of a hydrocarbon having at least four carbon atoms, which comprises (a) reacting vanadium pentoxide with from 102 to 110% strength phosphoric acid in the presence of a primary or secondary, noncyclic or cyclic, unbranched or branched, saturated alcohol having from 3 to 6 carbon atoms in a temperature range from 80 to 160° C.; (b) isolating the precipitate formed; (c) setting an organic carbon content of
Abstract:
Disclosed is a method for producing a catalyst containing vanadium, phosphorus, and oxygen, which is used for oxidizing the gas phase of a hydrocarbon having at least four carbon atoms to maleic anhydride. According to the inventive method, a corresponding catalyst precursor which contains vanadium, phosphorus, and oxygen and is provided with particles having an average diameter of at least 2 mm is converted into a catalytically active form by means of calcination, and a flow of the catalyst precursor is transported on a conveyor belt across at least one calcination area over a distance 1 n at an essentially steady speed in order to be calcinated. The variation over time of the gas temperature in relation to the set point value amounts to n /2 of the calcination area, while the local difference in the gas temperature between any positions in the area of the flow of the catalyst precursor, which is located within the second half 1 n /2 of the calcination area, amounts to