Dehydrogenation of 1-butene into butadiene

Dumez and Froment [19] studied the dehydrogenation of 1-butene into butadiene in the temperature range 480 to 630°C on a chromia-alumina catalyst containing 20 wt % CrjOs and having a surface area of 57 mVg. The investigation concerned the kinetics of both the main reaction and of the coking. 

The kinetics of the main reaction were determined in a differential reactor. The rates in the absence of coke deposition, r were obtained by extrapolation to 

Tc is the initial coking rate, a function of the partial pressures and temperature that reduces to a constant for a given experiment in the microbalance. Several 

Note that the deactivation function is expressed in terms of the coke content of the catalyst, not in terms of time as has been done frequently indeed, time is not the true variable for the deactivation, as discussed earlier. Substitution of the deactivation function into Eq. (b) and integration with respect to time yields, respectively, 

For the majority of the 50 experiments = exp(—aCJ turned out to give the best lit. An explanation based on a pore blocking mechanism has been attempted (Beeckman and Froment, to be published). The parameter a was found to be identical for coking from either butene or butadiene and independent of the operating variables, as was concluded from the partial correlation coefficients between a and T, pg, pg, and po, respectir y, and the t-test values for the zero hypothesis for the partial correlation coefficient 

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Dumez, F.J. and G.F. Froment, "Dehydrogenation of 1-Butene into Butadiene. Kinetics, Catalyst Coking, and Reactor Design", Ind Eng. Chem. Proc. Des. Devt., 15,291-301 (1976). 

The oxidation of olefins has also been investigated on a-Mo03 supported on carbon the mild oxidation of propene into acrolein takes place mainly on the (100) face of a-Mo03 while total oxidation occurs on the (010) face (425fg). Similar results have been obtained for the oxidative dehydrogenation of 1-butene into butadiene (425h). 

Example 23.d.l-l Model discrimination in the dehydrogenation of 1-butene into butadiene... 

Dumez and Froment studied the dehydrogenation of 1-butene into butadiene on a chromium-aluminium oxide catalyst in a differential reactor [57]. This work is probably the first in which the experimental program was actually and uniquely based on a sequential discrimination procedure. The reader is also referred to a more detailed treatment, Dumez, Hosten, and Froment [58]. The following mechanisms were considered to be plausible ... 

Example 5.3.3.B Application to Industrial Processes Rigorous Kinetic Equations for Catalyst Deactivation by Coke Deposition in the Dehydrogenation of 1-Butene into Butadiene... 

COKE FORMATION IN THE DEHYDROGENATION OF 1-BUTENE INTO BUTADIENE... 

Cyclohexane is rly easily dehydrogenated into benzene, and even at very low extents of reaction, stoichiometry reaction (6) can be replaced by the secondary stoichiometry reaction (12). For cyclohexane, the constituents are (apart from cyclohexane) hydrogen, methane, ethane, ethylene, acetylene, propene, 1-butene, 1,3-butadiene, cydohexene, and benzene [3]. However, one can check that the equations written are independent, using the Jouguet [IS] criterion, (t.e., if/ = n-o)). In this criterion, the number of the independent constituents, 1//, for a chemical system is equal to the required constituents. n, (i e., H3, Cl, C3, CsHe, Q, C4, Cj. c-Q, CaJ, subtracting the number of independent stoichiometric equations. q>. 

Butene Dehydrogenation into Butadiene Example 11.9.l.G Influence of Internal Diffusion Limitations in Gatalytic Reforming... 

SIMULATION OF AN INDUSTRIAL REACTOR FOR 1-BUTENE DEHYDROGENATION INTO BUTADIENE... 

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