Patent ID: 7022307

Claim:
A method for carrying out a reaction selected from oxidation of propylene or propane to acrolein and/or acrylic acid, oxidation of naphthalene or o-xylene to phthalic anhydride, oxidation of benzene or butane to maleic anhydride, Fischer Tropsch synthesis of hydrocarbons and or oxygenates from carbon monoxide and hydrogen, gas phase clorination or oxychlorination of hydrocarbons, gas phase hydrogenation of organic compounds, fluid catalyst cracking of oil, fluid catalytic reforming of naphtha and other hydrocarbons, reforming of hydrocarbons to synthesis gas, hydrocracking of heavy oil by effecting gas-solid contact in a bubbling fluidized bed reactor said method comprising: (a) introducing into a reactor with bed length to bed diameter ratio below about 5.0, a primary gas consisting essentially of reactant(s) of the reaction to be carried out in the bed of solid particles through a primary gas distributor located at the reactor bottom at a superficial gas velocity U p , which is very close or equivalent to the minimum fluidization velocity U mf , required for achieving the incipient fluidization of the solid particles in the bed to obtain an emulsion phase consisting essentially of the solid particles and the primary gas with little or no formation of gas bubbles to achieve incipient fluidization or liquid-like behaviour of fluidizable solid particles; (b) forming gas bubbles in the incipiently fluidized bed by introducing through a secondary gas distributor located immediately above the primary gas distributor a secondary gas, selected from one of the reactants which is used in excess of that required for the reaction stoichiometry, steam, an inert or a mixture of two or more thereof at a superficial gas velocity, U s , which is related to the superficial velocity of the primary gas such that a ratio of the superficial velocity of the secondary gas to the superficial velocity of the primary gas U s /U p , is in the range from about 0.5 to about 10.0.