Abstract: Disclosed is a fluidized bed reactor wherein the average cross-sectional area occupied by a cooling coil, a dummy pipe and/or a cyclone leg is 10% or more of the average cross-sectional area of said reactor in a dense-phase fluidized catalyst bed region. The fluidized bed reactor in the present invention allows an improved fluidization of catalyst and thus allows an efficient reaction of a hydrocarbon with an oxygen-containing gas in the presence of a catalyst.

Abstract: Disclosed is a process for the production of maleic anhydride, which comprises: reacting a hydrocarbon with an oxygen-containing gas in the presence of a catalyst; recovering maleic anhydride from the reaction gas; recovering unreacted hydrocarbon from the remaining gas; and returning the hydrocarbon thus recovered to the reactor for re-use, wherein said reaction is effected under the conditions such that the hydrocarbon concentration X (vol %) and oxygen concentration Y (vol) in all the gases to be fed into the reactor, the hydrocarbon conversion Z (t) in the reactor and the oxygen concentration W (vol %) in all the effluent gases from the reactor satisfy the following relationships: Y≧20, X+Y≦70, 1≦Y/X≦5, and 20(Y−10)/X≦Z≦25Y/X or 2≦W≦10.

Abstract: Disclosed is a process for the preparation of maleic anhydride which comprises subjecting an aliphatic hydrocarbon having four or more carbon atoms to gas phase oxidation reaction in the presence of a catalyst, wherein supposing that the function of reaction product gas composition is FL and the function of temperature and pressure of reaction product gas is FR, the safety index F satisfies the following relationship (1): F=FL−FR>0  (1) According to the present invention, it is possible that the loss of unreacted hydrocarbon and maleic anhydride as reaction product due to non-catalytic oxidation reaction is prevented while effecting the reaction in a stable manner, whereby the yield of maleic anhydride can be kept maximum while assuring safety.

Abstract: Disclosed is a process for the production of maleic anhydride, which comprises: reacting a hydrocarbon with an oxygen-containing gas in the presence of a catalyst; recovering maleic anhydride from the reaction gas; recovering unreacted hydrocarbon from the remaining gas; and returning the hydrocarbon thus recovered to the reactor for re-use, wherein said reaction is effected under the conditions such that the hydrocarbon concentration X (vol %) and oxygen concentration Y (vol) in all the gases to be fed into the reactor, the hydrocarbon conversion Z (t) in the reactor and the oxygen concentration W (vol %) in all the effluent gases from the reactor satisfy the following relationships:

Abstract: Disclosed is a process for the production of maleic anhydride, which comprises: reacting a hydrocarbon with an oxygen-containing gas in the presence of a catalyst; recovering maleic anhydride from the reaction gas; recovering unreacted hydrocarbon from the remaining gas; and returning the hydrocarbon thus recovered to the reactor for re-use, wherein said reaction is effected under the conditions such that the hydrocarbon concentration X (vol %) and oxygen concentration Y (vol %) in all the gases to be fed into the reactor, the hydrocarbon conversion Z (%) in the reactor and the oxygen concentration W (vol %) in all the effluent gases from the reactor satisfy the following relationships: Y≧20, X+Y≦70, 1≦Y/X≦5, and 20(Y−10)/X≦Z≦25Y/X or 2≦W≦10.

Abstract: A method for a gas phase catalytic oxidation reaction of a hydrocarbon, which comprises: subjecting an alkane having a carbon number ranging from 3 to 8 and/or an alkene having a carbon number ranging from 2 to 8 to a gas phase catalytic oxidation reaction to produce a vapor phase oxidation product in the presence of a mixed metal oxide catalyst, wherein the reacion is conducted in the presence of particles substantially inert to the reaction in an amount within a range of the same amount as the amount of catalyst to 99 wt. % in all particles.

Abstract: A process for producing maleic anhydride is described, which comprises (i) reacting a hydrocarbon with oxygen in a vapor phase in the presence of a catalyst to yield a reaction mixture gas containing maleic anhydride, (ii) bringing the reaction mixture gas into contact with an organic solvent to collect the maleic anhydride in the organic solvent, (iii) separating at least part of the maleic anhydride from the organic solvent, (iv) washing with an aqueous alkali solution at least part of the organic solvent from which maleic anhydride has been separated, and (v) reusing the resultant washed organic solvent and the residual organic solvent for contact with the reaction mixture gas.

Abstract: A catalyst for the production of a nitrile from an alkane, which satisfies the following conditions 1 and 2:1 the catalyst is represented by the empirical formula:Mo.sub.a V.sub.b Te.sub.c X.sub.x O.sub.n (1)wherein X is at least one element selected from the group consisting of Nb, Ta, W, Ti, Al, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ni, Pd, Pt, Sb, Bi, B and Ce,when a=1,b=0.01 to 1.0,c=0.01 to 1.0,x=0.01 to 1.0,and n is a number such that the total valency of the metal elements is satisfied; and2 the catalyst has X-ray diffraction peaks at the following angles of 2.theta. in its X-ray diffraction pattern:Diffractionangles of 2.theta. (.degree.)22.1.+-.0.328.2.+-.0.336.2.+-.0.345.2.+-.0.350.0.+-.0.3.

Abstract: A process for preparing a catalyst useful for producing a nitrile by a gas phase catalytic oxidation reaction of an alkane with ammonia, which comprises drying a solution or slurry containing molybdenum, vanadium and tellurium by a spray drying method or a freeze-drying method and heat-treating the resulting dried product.

Abstract: A process for producing a nitrile, which comprises subjecting an alkane and ammonia in the gaseous state to catalytic oxidation in the presence of a catalyst which satisfies the following conditions of (1) and (2):(1) the catalyst is represented by the empirical formula:Mo.sub.a V.sub.b Te.sub.c X.sub.x O.sub.n (1)wherein X is at least one element selected from the group consisting of Nb, Ta, W, Ti, Al, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ni, Pd, Pt, Sb, Bi, B and Ce,______________________________________ when a = 1, b = 0.01 to 1.0, c = 0.01 to 1.0, x = 0.01 to 1.0, ______________________________________and n is a number such that the total valency of the metal elements is satisfied; and(2) the catalyst has X-ray diffraction peaks at the following angles of 2.theta. in its X-ray diffraction pattern: ______________________________________ Diffraction angles of 2.theta. (.degree.) ______________________________________ 22.1 .+-. 0.3 28.2 .+-. 0.3 36.2 .+-. 0.3 45.2 .+-. 0.3 50.0 .+-. 0.3.