Ten-lump model

Ten lump kinetic scheme (as shown in figure 2) developed by Jacob et al. (1976) is used with some modifications. Since Jacob et al. (1976) lumped coke and gas together, regenerator model can not be integrated with its present form. In this case, gas yield was predicted from correlation available in Gary and Hadwerk (1994) and hence ten lump model was made suitable. This model has also been tuned for an industrial application. Since hydrodynamics and detailed design were idealised, it was necessary to tune the model to match with industrial performance. 

Modified ten lump model is used, since feed composition is allowed to change in this problem. Appropriate bounds on the decision variables are specified and the constraints specified in problem 1 are applied. Also an additional constraint is specified to ensure CO emission within some limit. 

Mobil s ten-lump model for catalytic cracking of gasoil. From Jacob et al. [1976], Weekman [1979], Froment [1986]. 

The ten-lump model has shown success in adequately describing selectivity and conversion behaviour in pilot plant and commercial risers for a wide variety of feeds without modification of the rate constants. However, the simplicity of kinetic representations such as the ones for the three-lump model are partially lost. In using higher lumping models where the number of parameters is significantly increased means that greater amounts of experimental data are also required. 

Figure 13, A ten lump model for the kinetics of catalytic cracking...

Selection of an appropriate lumping scheme was one of the most important issues in this modelling exercise. Ten lump kinetic scheme developed by Jacob et al. (1976) and five lump kinetic model proposed by Ancheyta et al. (1999) were examined closely. The virtue of more detailed lumping scheme over other less detailed models is that rate constants is that rate constants are independent of feed composition. But utilisation of these models are limited by two problems i.e. detailed characterisation of streams is not available on a regular basis and elaborate kinetic information is scarcely available. Thus, a balance between kinetic description required and cost of laboratory analysis often decides selection of lumping strategy. 

Fluidized Bed Reactor. Two-Phase Model with Ten Lump Reaction Scheme... 

Mosby et al. reported a seven-lump residue hydroconversion model. Lumped models for steam cracking of naphtha and gas oils can be found in Dente and Ranzi s review. The literature aboimds with FCC kinetic models, with the number of lumps being three four °, five, six , eight, ten °. 

In linear chromatography, these last two linear kinetic models are particular cases of the model used by Lapidus and Amundson [85] (Eq. 2.22). By contrast, the different lumped kinetic models give different solutions in nonlinear chromatography. Investigations of the properties of these models and especially of the relationship between the band profiles and the value of the kinetic constant have been carried out for many single-component problems. Numerous studies of the influence of the mass transfer kinetics on the separation of binary mixture have been published in the last ten years. These results are discussed in Chapters 14 and 16, respectively. 

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