| abstract |
The invention relates to a process for the oxidative dehydrogenation of n-butenes to butadiene, which comprises two or more production steps (i) and at least one regeneration step (ii), in whichn (i) in one production step, a starting gas mixture comprising n-butenes is mixed with an oxygen-comprising gas and brought into contact with a multimetal oxide catalyst which comprises at least molybdenum and a further metal and is arranged in a fixed catalyst bed in a fixed-bed reactor at a temperature of from 220 to 490° C.,n nand, before the relative decrease in conversion at constant temperature is >25%,n (ii) in a regeneration step, the multimetal oxide catalyst is regenerated by passing an oxygen-comprising regeneration gas mixture at a temperature of from 200 to 450° C. over the fixed catalyst bed and burning off the carbon deposited on the catalyst,n nwhere a regeneration step (ii) is carried out between two production steps (i),n nwherein from 2 to 50% by weight of the carbon deposited on the catalyst is burnt off per regeneration step (ii). |