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Since the beginning of 90s of last century both the petroleum industry and petrochemical industry have operated in difficult circumstances. In particularly, margins of petroleum and petrochemical industry were exacerbated during global economic crisis in 2008-2009 years. At that time, as one option that could be the solution, the global analysts had started to more intense investigate the benefits of Refining-Petrochemical Integration. Shortly afterwards, more and more petroleum refineries and petrochemical manufacturers began to see the future in this kind of operational, managerial, marketing and commercial connection. This paper evaluates, in particular, the achieved level of integration of refinery and petrochemical businesses in Central and South-Eastern Europe. And specifically, the paper identifies current capabilities and future chances of linking this kind of integration between Serbian refining and petrochemical players. The viability of integration between possible actors and benefits of every single refining-petrochemical interface in Serbia depend on many factors, and therefore each integrated system is unique and requires prior serious Cost Benefit Analysis.

The process of drying of porous polymer powder (polypropylene) intended to remove the solvent (heptane) is analyzed. The dryer consists of two stages (apparatus) with multizone fluidized bed. The mathematical model of the process in multizone fluidized bed is proposed. The rate-limiting step, depending on diameter of polymer particles, is determined. It was found that in relatively large particles (>200 μm) the rate of drying is limited by intraparticle diffusion. A way to decrease the energy consumption in drying has been also discussed and verified in experiments.

The charge percolation mechanism (CPM) of olefin polymerization in the presence of transition metal compounds has been applied to explain the polymerization of ethylene by silica supported chromium oxide. In the previous work of this series, the fundamental issues and mechanism of this polymeri­zation were presented. In this work the compatibility of the CPM with the em­pirical findings is confirmed. The CPM has been applied to explain: the appea­rance of an induction period; the deactivation of active centers and the forma­tion of oligomers; the effects of chromium concentration on the silica surface, the silica surface discontinuity and the pore size of silica on polymerization and the formation of the structure of polyethylene. A mathematical model has been derived to explain the effects of the CrOx/SiO2 ratio on the productivity of Phil­lips catalysts in the polymerization of ethylene. The empirical findings have also been confirmed by computer simulations.