Mathematical Modelling Method Application for Optimisation of Catalytic Reforming process

The application of mathematical modelling method monitoring of catalytic reforming unit of Komsomolsk oil-refinery is proposed. The mathematical model-based system “Catalyst's Control” which takes into account both the physical and chemical mechanisms of hydrocarbon mixture conversion reaction as well as the catalyst deactivation was used for catalytic reforming installation monitoring. The models created can be used for optimization and prediction of operating parameters (octane number, reactors outlet temperature and yield) of the reforming process. It is shown, that the work on the optimal activity allows increasing product output with a constant level of production costs, and get the information about Pt-Re catalyst work efficiency

Effect of an electric field on nucleation and growth of crystals

The effect of the electric field strength on nucleation and growth of the crystals of ammonium halides and alkali metal sulfates has been studied. The optimal electric field strength for NH[4]Cl and NH[4]Br crystals was found to be 15 kV/cm, and for NH[4]I, it equaled 10 kV/cm. No effect of the electric field strength on the crystal growth was found for alkali metal sulfates. This difference is analyzed in terms of the crystal growth thermodynamics. In case, when the electric field is small and the Gibbs energy is of a significant value, the influence of the electric field at the crystal growth is negligible. A method to estimate the critical radius of homogeneous nucleation of the crystal is suggested

Determination of glass transition temperature for polymers by methods of thermoactivation spectroscopy

For rapid determination of glass transition temperature for polymers, we propose a method of thermally stimulated luminescence. The experiments were carried for epoxy polymers dyed and undyed with organic dyes. It is shown that glass transition temperature depends on curing temperature and concentration of the dye. The comparison with the thermogravimetric analysis showed coincidence of the results obtained

Effect of ion irradiation on the properties multi-element plasma coatings

The paper presents the results of the study of ion irradiation on the properties of multi-element plasma coatings. The coatings were bombarded by argon ions using heavy current ion source with a hollow cathode. After ion irradiation, the structure and physical properties of the coatings change, however, the nature of the changes is different for different coatings. To predict the behavior of the coating exposed to irradiation is virtually impossible. Therefore, structural studies and investigation of physical properties of the coatings to determine their functional characteristics are to be conducted

Radiation Hardening of Ni-Ti Alloy Under Implantation of Inert Gases Heavy Ions

The consistent patterns of changes in nano- and micro-hardness of Ni-Ti alloy with the shape memory effect after implantation of [40]Ar{8+} and [84]Kr{15+} ions depending on phase composition and implantation parameters have been experimentally studied. It has been shown that softening by 4 and 14% near the surface of the two-phase Ni-Ti alloy after implantation of [40]Ar{8+} and [84]Kr{15+} ions is connected with the differences in the nanostructure. Hardening of the near-surface layer of this alloy maximum by 118% at h=~3 pm and single-phase alloy in the entire region of the [40]Ar{8+} and [84]Kr{15+} ions range and in the out-range (h>R[p]) area have been detected. The role of the current intensity of the ions beam in the change of nanohardness for the two-phase Ni-Ti alloy has been established

Effect of an electric field on nucleation and growth of crystals

The effect of the electric field strength on nucleation and growth of the crystals of ammonium halides and alkali metal sulfates has been studied. The optimal electric field strength for NH[4]Cl and NH[4]Br crystals was found to be 15 kV/cm, and for NH[4]I, it equaled 10 kV/cm. No effect of the electric field strength on the crystal growth was found for alkali metal sulfates. This difference is analyzed in terms of the crystal growth thermodynamics. In case, when the electric field is small and the Gibbs energy is of a significant value, the influence of the electric field at the crystal growth is negligible. A method to estimate the critical radius of homogeneous nucleation of the crystal is suggested

Hydrogenation of furanic compounds over heterogeneous catalysts

Substituted furans are valuable platform chemicals that can be derived from biomass feedstock. Thanks to the rich functionality, they can be chemically transformed into a variety of useful products. Currently, hydrogenation of furanic compounds calls a lot of attention of researchers as the furans can be upgraded by lowering the number of oxygen atoms into the molecule. In spite of a number of publications in this area, the challenges of designing of active, selective, cheap and environmentally friendly catalysts for furan hydrogenation still exist. Moreover, understanding the mechanism and kinetics of these reactions on the catalyst surface is still missing, mostly because of the rich chemistry of substituted furans and the great number of the species involved. The present dissertation reports a study on alkaline earth metal oxide catalysts for furfural hydrogenation by means of hydrogen transfer using methanol as a hydrogen donor. Interestingly, low surface area CaO and SrO pretreated at the optimal conditions show remarkable activity in the transformation of furfural to furfuryl alcohol, with nearly 100% selectivity. The careful analyses of the catalyst samples indicate that there is no correlation between the number and strength of base sites and their catalytic activity. Whereas DRIFT measurements confirm that the interaction of methanol with the catalyst surface and its subsequent activation play an important role in promoting furfural hydrogenation.Mechanistic and kinetic studies of the hydrogenation of furfural and furfuryl alcohol over conventional Ru/C using molecular hydrogen show that at lower temperature the hydrogenation of the furan ring is favored, whereas at higher temperatures the hydrogenation of functional groups goes first with the subsequent hydrogenation of the furan ring. The selectivity of reactions is also influenced by the specificity of the functional group attached to the furan ring. Applying the detailed kinetic modeling to furfural and furfuryl alcohol hydrogenation, we confirmed that the interaction of the substrate with the catalyst surface differs depending on the exact functional group attached to the furan ring that also determines the main reaction route.The study was extended to include 5-hydroxymethylfurfural as a substrate in hydrogenation over Ru/C as well as Ni/C. For both catalysts the importance of the first step, hydrogenation of the aldehyde group, is confirmed by providing mechanistic and kinetic studies. Here we also see the different reaction selectivities depending on the substrate’s functional groups, either both alcohol and aldehyde groups are attached to the furan ring or twice an alcohol group. In case of Ni/C used as a catalyst the main product of 5-hydroxymethylfurfural hydrogenation is 2,5-dimethylfuran, whereas in case of Ru/C 2,5-dimethylfuran acts as an intermediate and the kinetically favored product is 2,5-dimethyltetrahydrofuran. Therefore, understanding the nature of substrate – catalyst interaction and the kinetics of the process, it becomes possible to selectively upgrade the substituted furans to valuable products