Papers by Keyword: Mixture

Abstract: Biomass waste is one of the promising resource for the production of bio oil. In this study, a mixture of biomass waste will be pyrolyzed in the presence of activated carbon and zeolite as the catalyst. The catalyst concentrations were varied at 2%, 4%, 6%, respectively. While, the pyrolysis process was carried out at 500°C, for 60 minutes, with a nitrogen flow of 3 L/min. The highest bio oil yield was obtained the pyrolysis process by using zeolite with 35% at 4% w/w of the catalyst concentration. The lowest acid number obtained was 42.92 on 4% zeolite catalyst with rice husk biomass as the raw material, the best viscosity was obtained on 4% activated carbon multi feedstock with a viscosity value of 4.96 cP. The best density was obtained in multi feedstock with 4% zeolite catalyst and rice husk with 4% zeolite of 0.996 g/mL.

Abstract: Since ancient times, lime, lime pozzolanic, lime-cement, lime-clay binders, the compositions of which our ancestors found empirically, widely and everywhere used in construction. Even in the first half of the XX century, these binders occupied a significant place in the construction practice. The development of production and the relative availability of cement led to a significant reduction in demand for many clinker-free, including lime (Portland) binders. Today, the priorities of scientific and applied technological developments of both traditional building materials and materials of new generations are determined by the actualization of the concept and criteria of resource saving and energy efficiency.

Abstract: In the framework of the research project of the Technology Agency of the Czech Republic TA 02011350 “Investigation of properties of diatomaceous clays and methods for improving their structure", clay properties have been investigated depending on the content of diatoms. To investigate the effects of diatom microfossil content on the index properties of clay soils, measuring tests were performed on cohesive soils with different diatom microfossils content.

Abstract: Two series of experiments on the formation of convective flows in multicomponent liquid and gaseous mixtures are considered. In the first series, the convective structures arising during the diffusion of a binary aqueous solution of salt and sugar in an aqueous solution of pure salt were studied using the schlieren method. The observed behavior of convective cells corresponds to the instability similar to the "finger structures". In the second series, the experiments were conducted to determine the effective diffusion coefficients as a function of pressure in gas mixtures 0.5504 CH₄ + 0.4496 Ar – N₂ and 0.5994 H₂ + 0.4006 Ar – N₂. Our experiments have shown that the onset of convective flows both in liquid and gaseous multicomponent mixtures is due to the difference in the interdiffusion coefficients of the components. The experimental data for the ternary gas mixtures are described in the framework of the linear theory of stability.

Abstract: For many recycled plastics, materials with different rheological properties and melting points are usually mixed together, and can not be separated. For this situation, the block of die-plate holes can be regarded as an important factor that must be taken into consideration in pelleting process. This paper discusses pelleting process in die-plate and reasons of die hole’s blocking. Finite element simulation is calculated to analyze the relationship between operation factors of pelleting process and blocking situation of die holes. Furthermore, block self-healing is realized by changing the velocity of polymer-melt in die-hole.

Abstract: At present, SMA mixture generally to the use of SBS modified asphalt, especially in the area of expressway construction in our country, but in recent years, the use of SBS modified asphalt has some problems, for example: SBS of storage stability of modified asphalt is a difficult problem, because SBS and asphalt compatibility between components of the difference, the modified agent and asphalt separation, reduces the performance of SBS modified asphalt; SBS modified asphalt in the stored procedure, the performance will decay, even if not stop stirring, decay cannot avoid, also influence the effect of the use of SBS modified asphalt.

Abstract: An experimental setup for indirect contact sensible heat TES was built. Air was chosen as the heat transfer fluid to flow inside the tubes and carry heat, while the mixture in the tank contacts the outside of the tubes. The results were also compared with pure sand filler material. It can be found that and the TES efficiency of mixture increased by 18% compared with pure sand, what’s more, its temperature gradient along the radical direction was also lower, while its temperature gradient along the axial direction was higher, so the mixture was better. Under various air inlet temperature (60-70°C), TES performances were similar, but for real power generation, further work on optimism temperature range was needed. Air velocity was also important to TES tank, lower velocity can not only increase the TES efficiency, but also enlarge the thermocline temperature gradient.

Abstract: This paper presents results of exploration related to C2 and C6 crushed-stone-and-sand ready mixtures strengthened with limestone powder used in road pavement layers. Limestone powder is an industrial waste, which in Ararat region is in big volumes. The samples were taken composed of different fractions of crushed-stone and two types of sand produced from crushed basalt and crushed gravel, and were tested. The composition of ready mixtures meets the requirements of corresponding standard on grain size. To these mixtures limestone powder was added of the percentage range 0-30% of the mixture mass. The main purposes of experimental exploration were to determine the influence of different percentages of limestone powder on compression strength of crushed-stone-and-sand ready mixtures and optimal content of powder. The change of the influence grade was studied by applying different types of sands. Three cylindrical samples were made for each percentage of limestone powder according to a standard method. Compressive strengths of samples have been determined. It was concluded, that the applying limestone powder in C2 and C6 ready mixtures contributes to the cohesion of stone grains as well as to obtaining high indicators of compaction in road pavement layers. The received results allow to arrive to a conclusion that applying limestone powder according to the optimal range distinctly increases the strength characteristics of crushed-stone-sand ready mixtures which in tur contributes the effective implementation of the compacting process. Especially the influence grade is considerable in C6 ready mixtures containing a large amount of crushed stone, as well as in mixtures using sands with smaller fineness modulus.

Abstract: Half of the urea is produced by complete circulation of aqueous solution processing in China. The mixing between the gas and liquid is the key of the technology. This paper presents an improvement of the complete circulation of aqueous solution processing by premixing and atomizing liquid NH₃ and Methylamine. And a novel atomizer was developed for the high pressure and limited space. We proposed a new model based on the two innovations and predicted the performance of the suggested processing. The modeling prediction agreed well with the experimental results. For the same urea synthesis tower structure, the conversion rate increased 3~5%. This indicates this technology is competitive to retrofit the existed units.

Abstract: The noble variety of the Boa Vista bentonites became scarce, originating fluids which do not answer the Petrobras specifications. The utilization of a blending with available samples have been used in industry successfully. Thus, the present work aims to use the mixture modeling methodology with design in simplex-centroid network and further purification by hydrocycloning, trying to optimize rheological properties of dispersions prepared with little noble clays, obtaining drilling fluids that attend the normative requirements. Initially, the rheological behavior of dispersions on each of the five clays, activating them in proportions of 50, 75, 100, 125 e 150 meq of Na₂CO₃/100 g of dry clay. After result analyzing, the mixtures were formulated, using experimental planning with the five clays, but with activation in proportions of 100 and 125 meq of Na₂CO₃/100 g of dry clay.