For PP catalytic cracking

Zhou, Jainhua, Wang, Shieyu, and Jiang, Weisun. A steady-state mathematical model for a catalytic cracking riser, Chemical Engineering Industry (in Chinese), vol. 39, No. 4, pp. 461-468 (1988). 

Lee, L.L., Chen, Y.W., Huang, T.N. and Pan, W.Y. 1989, Four-Lump Kinetic Model for Fluid Catalytic Cracking Process, The Canadian Journal of Chem. Engng., 67, pp. 615-619. 

Figure 13 The apparent flow regime diagram calculated with EMMS-based multiscale CFD and the intrinsic flow regime diagram for the air-FCC system (fluid catalytic cracking particle, dp = 54 m, pp = 930 kg/m3) calculated by using the EMMS model without CFD. The intrinsic flow regime diagram is independent of the riser height (Wang et al., 2008).

Another approach for overcoming the problems posed by conventional cracking catalysts has been disclosed recently by Reverse et al. [101]. In this case, direct cracking is performed by using as catalyst a molten bed of pure metal or a metal mixture (mainly lead, zinc, tin) at a temperature of 460-550°C wherein the waste polymer is loaded inside the reactor at a certain depth. The authors point out that the products are indeed a result of the combination of both thermal and catalytic cracking. The catalyst composition may also include some acidic component such as metal silicates, metal carbonates and their mixtures. The process can be applied to pure and mixed polymers (PE, PET, PP, PVC), as well as to the plastic fraction of municipal solid wastes. 

The components of products from thermal and catalytic cracking of HDPE, LDPE, LP, PP, PS were analyzed [48], and the results are shown in Table 28.2 and Table 28.3. The products from thermal cracking of HDPE, LDPE and LP (linear polyethylene) are mainly wax-like substances at normal temperamre. The fraction under 200°C recovered from HDPE accounts for 16% of the total cracking products, while that from LP accounts for 23%. Compared with tlie products of PE, PP produces less solid residue, but more liquid components, and PS produces the highest proportion of liquid fraction, which is 99.17% by thermal cracking and 99.56% by catalytic cracking. 

I Pitault, D Nevicato, M Forissier, J R Bernard. Kinetic model based on a molecular description for catalytic cracking of vacuum gas oil. Chemical Engineering, 49 (1994) 24A, pp. 4249-4262... 

Galtier PA, Pontier RJ, Patureaux TE. Near full-scale cold flow model for the R2R catalytic cracking process. In Girace JR, Shemilt LW, Bergougnou MA, eds. Fluidization VI. New York Engineering Foundation, 1989, pp 17-24. 

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