International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

The paper proposes a reconstruction of the distillation of caprolactam for more complete removal of water from the finished product, removing the droplet phase during the process in thin-film evaporators, will improve the final product performance by eliminating the inappropriate indicators alkali content and the optical density of the final product and to ensure its stable high quality. The relevance of the work presented directions for improving the process of production of caprolactam – raw ingredient for the preparation of polymeric materials used in various sectors of the economy. Describes the causes affecting the quality characteristics of the finished products produced from caprolactam. the implementation the liquid distributor and the centrifugal separator would reduce 5 – 6 times droplet entrainment to ensure complete removal of moisture from the final product, will reduce the alkali content in the final product, reduce the rate of optical density and thus bring trademark caprolactam by indicators «alkalinity» and «optical density» to the level of the highest quality product.

Natural gas in Republic of Croatia is being produced from three main regions: Sjeverni Jadran, Duboka Podravina and Međimurje. The natural gas produced from Međimurje region has been taken as an example for modelling the dehydration process because, compared to natural gas from Duboka Podravina region, it contains higher amount of acid gases. The associated gas with much smaller content of acid gases, currently being flared at region site called Istočna Hrvatska, has been taken as a second example. The comparison of these two cases has shown the effect of acid gases to the dehydration process efficiency. In both cases, absorption by triethylene glycol is chosen. Due to a large discrepancy in acid gas content, water content difference observation is much easier. Modelling of the dehydration process has been made in Aspen Hysys software.

The investigation of influence of modified conditions on formation of complex materials based on tetragonal zirconia doped by d-elements of I group (Cu or Ag) was carried out, in particular the routes of synthesis and type of dopant. The kinetic parameters of separated stage of NPs formation (drying of hydrogel under MW irradiation, dehydration and crystallization of amorphous zirconia NPs) were estimated. It was shown, the dehydration of tetragonal zirconia hydrogel in conditions of MW irradiation occurs due in two stage. In contrast for Cu (or Ag) –modified hydrogels only one stage dehydration is observed. The dehydration and crystallization of unmodified and modified xerogel is studied by DSC method. It was shown that the kinetic parameters of dehydration depend as from nature of zirconium salts that were using for synthesis and type of dopant. For crystallization processes the some parameters (crystallization temperature, enthalpy) are saved features of dependence on route of synthesis for unmodified and modified systems. However, the behaviour of dependence of activation energy on route of synthesis is contrast for unmodified and modified systems.