A process is provided for control of an ammoxidation reactor. More specifically, the process includes controlling an amount of oxygen added to the reactor, steam temperature and linear velocity to minimize reactor temperature deviations.

A novel mixed oxide material is disclosed which contains molybdenum, vanadium, tellurium and niobium and the use of the molybdenum mixed oxide material as catalyst for the oxidative dehydrogenation of ethane to ethene or the oxidation of propane to acrylic acid and a process for producing the mixed oxide material.

A novel mixed oxide material is disclosed which contains molybdenum, vanadium, tellurium and niobium and the use of the molybdenum mixed oxide material as catalyst for the oxidative dehydrogenation of ethane to ethene or the oxidation of propane to acrylic acid and a process for producing the mixed oxide material.

A novel mixed oxide material is disclosed which contains molybdenum, vanadium, tellurium and niobium and the use of the molybdenum mixed oxide material as catalyst for the oxidative dehydrogenation of ethane to ethene or the oxidation of propane to acrylic acid and a process for producing the mixed oxide material.

A process for producing unsaturated nitrile comprising a reaction step of subjecting hydrocarbon to a vapor phase catalytic ammoxidation reaction in a fluidized bed reactor to produce the corresponding unsaturated nitrile, wherein, in the reaction step, a powder is fed to a dense zone in the fluidized bed reactor using a carrier gas, and a ratio of a linear velocity LV1 of the carrier gas at a feed opening to feed the powder to the fluidized bed reactor to a linear velocity LV2 of a gas in the dense zone (LV1/LV2) is not less than 0.01 and not more than 1200.

A process for producing unsaturated nitrile comprising a reaction step of subjecting hydrocarbon to a vapor phase catalytic ammoxidation reaction in a fluidized bed reactor to produce the corresponding unsaturated nitrile, wherein, in the reaction step, a powder is fed to a dense zone in the fluidized bed reactor using a carrier gas, and a ratio of a linear velocity LV1 of the carrier gas at a feed opening to feed the powder to the fluidized bed reactor to a linear velocity LV2 of a gas in the dense zone (LV1/LV2) is not less than 0.01 and not more than 1200.

The present invention relates to a preheating process and a start-up process for the ammoxidation reaction. The preheating process or the start-up process at least includes the step of heating the catalyst bed in the ammoxidation reactor while controlling the reactor operation linear speed to 0.03-0.15 m/s. The start-up process of the present invention has the advantages such as the significantly reduced launch time compared with the prior art and the operation safety.

The present invention relates to a preheating process and a start-up process for the ammoxidation reaction. The preheating process or the start-up process at least includes the step of heating the catalyst bed in the ammoxidation reactor while controlling the reactor operation linear speed to 0.03-0.15 m/s. The start-up process of the present invention has the advantages such as the significantly reduced launch time compared with the prior art and the operation safety.

An oxide catalyst to be used for gas-phase catalytic ammoxidation reaction of propane or isobutane, the oxide catalyst comprising a composite oxide, wherein the composite oxide comprises a catalytically active species to be isolated from the composite oxide using a hydrogen peroxide solution, and the catalytically active species has an average composition represented by the following formula (1) in STEM-EDX measurements;

Formula:

Mo.sub.1V.sub.aSb.sub.bNb.sub.cW.sub.dX.sub.eO.sub.n   (1) wherein X represents at least one selected from the group consisting of Te, Ce, Ti, and Ta; a, b, c, and d satisfy relations represented by a formulae of 0.050≤a≤0.200, 0.050≤b≤0.200, 0.100≤c≤0.300, 0≤d≤0.100, 0≤e≤0.100, and a≤c; and n represents a number determined by valences of the other elements.

An oxide catalyst to be used for gas-phase catalytic ammoxidation reaction of propane or isobutane, the oxide catalyst comprising a composite oxide, wherein the composite oxide comprises a catalytically active species to be isolated from the composite oxide using a hydrogen peroxide solution, and the catalytically active species has an average composition represented by the following formula (1) in STEM-EDX measurements;

Formula:

Mo.sub.1V.sub.aSb.sub.bNb.sub.cW.sub.dX.sub.eO.sub.n   (1) wherein X represents at least one selected from the group consisting of Te, Ce, Ti, and Ta; a, b, c, and d satisfy relations represented by a formulae of 0.050≤a≤0.200, 0.050≤b≤0.200, 0.100≤c≤0.300, 0≤d≤0.100, 0≤e≤0.100, and a≤c; and n represents a number determined by valences of the other elements.