Dehydrogenation of propane–isobutane mixture in a fluidized bed reactor over Cr2O3/Al2O3 catalyst: Experimental studies and mathematical modelling

An influence of propane addition to the inlet feed on the performance of industrial fluid bed reactor for isobutane dehydrogenation was experimentally and numerically studied. Experiments on dehydrogenation of propane–isobutane mixture in a pilot fluidized and in a lab fixed bed reactors were performed over Cr2O3/Al2O3 industrial catalyst. Adding C3H8 to the reactor inlet was found to increase experimental conversion of C3–C4 mixture and the total process selectivity to olefins. Results of the mathematical modelling of the industrial-scale fluidized bed reactor show some benefits of C3H8 addition. Selectivity to i-C4H8 was found to be high enough and grows slightly from 86 to 89% on increasing inlet C3H8 fraction from 0 to 60 wt%. Inlet concentrations of C3H8 up to 20 wt% lead to the apparent selectivity to C3H6 exceeding 100%. Coke yield rises slowly allowing safe industrial fluid bed reactor operation.

► We study C3H8 addition to the inlet of isobutane dehydrogenation reactor.
► Cr2O3/Al2O3 industrial catalyst is used.
► Experiments in a pilot fluidized and in a lab fixed bed reactors were performed.
► Mathematical modelling of the industrial-scale fluidized bed reactor was carried out.
► Some benefits of C3H8 addition were shown.