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The results of studying the convective drying of cylindrical granules of a support for a nickel catalyst using mathematical modeling techniques have been presented. A mathematical model for intensive heat and mass transfer in a granule has been formulated that makes it possible to choose the efficient regimes of convective drying. The specific feature of the mathematical model is the analytical calculation of local mass transfer coefficients for a liquid taking into account the sorption properties of a material, a permeability coefficient, the local values of the moisture content, and temperature. Comparison of the results of mathematical modeling of heat and mass transfer in granules and the data of a laboratory experiment has shown that they are in satisfactory agreement.

Abstract:The dynamics and kinetics of drying of intermediate product for nickel catalyst are studied. The unity of mass transfer mechanism in this material at different drying temperatures is shown. The temperature intervals of drying rational from the perspective of preserving the technological properties of the finished product and labor protection are determined. It is shown that the kinetics of drying of the studied object affects the hydrodynamic conditions in the machine. The influence of the size of dried granules on the kinetics of the drying process is researched. The possibility of an intensification of the drying process by decreasing the size of the drying object, by increasing temperature with the allowable attrition and the quality requirements of the finished product is shown.The aim of the research is the selection of drying operating parameters of a typical capillary-porous material -intermediate product of nickel catalyst used in chemical technology, in particular for the conversion of methane. Drying of the intermediate Product Producing Catalyst (PPC) is important in providing the desired properties of the finished catalyst, and therefore the determination of operating parameters of rational drying PPC is of considerable interest.Intermediate product of nickel catalyst -PPC is a typical capillary-porous body having micro pores and transient pores, transfer of moisture in which is carried out by combined mechanisms of mass transfer typical of capillary-porous materials (capillary transfer, membrane flow, tight vapor diffusion, and others.) [1 -3]. PPC in its composition comprises kaolin, magnesium oxide, nitrate and nickel carbonate (apparent density of the material -1250 kg/m 3 , the true density -1920 kg/m 3 ). As it was shown in the researches of PPC total pore volume is 0.28 cm 3 /g, pore volume with a radius of 100 Å is 0.03 cm 3 /g, and the rest volume (0.25 cm 3 /g) -is finer pores. It is important to have information about the fields of moisture content of the drying facility for the technology-related research, in particular, when selecting drying. It gives an idea of some of the laws governing the internal moisture transfer.