Study of Thermochemical Transformations of Hydrolytic Lignin and the Properties of the Produced Active Carbons

There has been studied the influence of the conditions of heat treatment of hydrolytic lignin and its mixtures with oil slime on the yield, structure and adsorption properties of active carbons (AC). With the increase in the temperature of lignin processing from 400 to 900 ˚C, the yield of active carbon decreases, and its specific surface area and sorption activity reach the maximum values at 800 ˚C. The mutual influence of the components of the mixture of hydrolytic lignin and oil slime during the thermochemical transformations, becomes apparent in the variation of the yield and the porous structure of AC. As for the oil slime, it acts as a binding and structure forming component

DIFFUSION MODEL OF CREAMY- AND VEGETABLE SPREADS MIXING

Summary .A mathematical model of the process of mixing cream- and vegetable spread was developed. In modeling the diffusion understanding of the nature of the process were used, allowing escape from the apparatus geometry. After turning on the mixer the mixing process begins. Its duration can be determined by the behavior of the tracer particles introduced into the agitated medium in a predetermined quantity through the free liquid surface within a short period of time. If tracer particles have the same density with the surrounding bulk liquid phase, then the path of movement of the particles and the fluid are identical. The degree of homogeneity of the composition can be stirred calculated by the coefficient of variation, which is identified by the local concentrations of tracer particles in the volume of stirred medium. The task of a one-dimensional particle transport in the plane layer of the mixed liquid is solved for their calculation. The calculated ratios obtained allow us to calculate the particle concentration at any point in the volume being mixed at random times. Based on the experiment effective mixing coefficients are identified and relations for their assessment, depending on the Reynolds number of the mixer in the range studied variations of process are offered. Using the time dependence of the variation coefficient characterizing the homogenity of the system being mixed, it is possible to determine the duration of mixing to obtain the product with the desired uniformity and homogeneity of the product under the definition of a predetermined duration of the mixing process. The variation coefficient %, indicating a sufficiently good uniformity of the spread composition was found for the spread №1, being mixed with a stirrer rotating at a speed of n=150 rev / min, and the dimensionless length of the process Fo =0,0935 for obtaining estimated relations. Using the proposed calculation algorithm one can estimate the homogeneity of the product at any time

Spectroscopy and crystal chemical properties of NaCa2[Si4O10]F natural agrellite with tubular structure

Agrellite is a rare inosilicate, having a crystal structure characterized by SiO4-tetrahedral tubes located between continuous wall layers formed by edge-sharing Ca-polyhedra. A detailed crystal chemical and physical study of agrellite specimens is carried out by means of electron probe microanalysis, Fourier transform infrared spectroscopy, electron-paramagnetic resonance, and single crystal X-ray diffraction. Additionally, the electronic structures of agrellite was calculated. Luminescence due to 5d-4f transition in Ce3+ ions is observed in both investigated samples. EPR analysis points out the Mn2+ replaces Ca2+ ion in Ca(1A) and Ca(2B) positions, coordinated by two F sites

Experimental Development of Approaches to Reduce the Slagging and Corrosive Activity of Salty Coal

The problems of reducing the slagging ability and corrosiveness of coal with a high content of low-melting salts (the so-called salty coal (SC) in the processes of its combustion) are considered. Salty coal is considered to be the coal, the ash of which contains Na2O>2 %. The object of study is the salty coal of Donbass and ways of solving the problems of its use. The influence of low-melting salts on the formation of ash deposits and the development of corrosion of the metal surface during the combustion of salty coal from different fields was determined.A noticeable decrease in the slagging ability and corrosiveness of the test coal was noted during the removal of salts by water extraction. The composition of corrosive compounds (oxides Fe2O3, Fe3O4 and iron sulfide FeS) has been determined, formed during the combustion of native coal, and their absence in the case of desalinated coal.Artificial fuel mixtures produced from more reactive salty and conventional low reactive coal have been studied. To create a mixed fuel, long-flame salty coal (low stage of metamorphism) from the Northern Donbas and unsalty lean coal (high stage of metamorphism) from Kuzbas were used. A significant deviation (to 9 %) was noted for the release of ash during the combustion of mixtures from the additivity, indicating a chemical interaction between the mineral components of the mixture. The formation of new refractory mineral phases of ash (nepheline, ultramarine, combeite) during the combustion of composite fuel from coals of different metamorphism and salinity was established.The obtained results will be useful in the development of recommendations for the preparation of model fuel mixtures and their accident-free combustion in industrial boiler units. Experimental data on the determination of new mineral compounds in the case of composite fuels can be used to create a general theory of slagging in the combustion of salty coal of different origin

Study of Thermochemical Transformations of Hydrolytic Lignin and the Properties of the Produced Active Carbons

There has been studied the influence of the conditions of heat treatment of hydrolytic lignin and its mixtures with oil slime on the yield, structure and adsorption properties of active carbons (AC). With the increase in the temperature of lignin processing from 400 to 900 ˚C, the yield of active carbon decreases, and its specific surface area and sorption activity reach the maximum values at 800 ˚C. The mutual influence of the components of the mixture of hydrolytic lignin and oil slime during the thermochemical transformations, becomes apparent in the variation of the yield and the porous structure of AC. As for the oil slime, it acts as a binding and structure forming component

Badanie równowag ekstrakcji w reakcji zasadowej hydrolizy aktywowanych estrów aminokwasów

Correlation between observed kinetic effects of phase-transfer catalytic reaction of the alkaline hydrolysis of 4-nitrophenyl ester of N-benzyloxycarbonylglycine-4 in the two-phase system chloroform-borate buffer pH = 10 and a content of ionic forms of catalyst was investigated. The phosphonium salts QX (X = Cl¯, Br¯, I¯) shows high catalytic reactivity. Dependence of the reaction kinetics discussed in the framework of the extraction mechanism with a competitive extraction of a nucleophile ОН¯, nucleofuge 4-NO2C6H4O¯ and anion X¯ of the phase-transfer catalyst.Zbadano korelację pomiędzy obserwowanym efektem kinetycznym przejścia fazowego katalitycznej reakcji zasadowej hydrolizy estru 4-nitrofenylowego N-benzyloksycarbonylglycyny-4 w dwufazowym układzie chloroform-bufor boranowy, pH = 10, z zawartością jonowych form katalizatora. Sole fosfoniowe QX (X = Cl¯, Br¯, I¯) wykazują wysoką aktywność katalityczną. Zależności kinetyki reakcji przeanalizowano w ramach mechanizmu ekstrakcji z konkurencyjną ekstrakcją nukleofilu ОН¯, grupą odchodzącą 4-NO2C6H4O¯ i anionem X¯ katalizatora przejścia fazowego

Crystal Chemistry, Isomorphism, and Thermal Conversions of Extra-Framework Components in Sodalite-Group Minerals

Isomorphic substitutions of extra-framework components in sodalite-group aluminosilicate minerals and their thermal conversions have been investigated using infrared, Raman, electron spin resonance (ESR), as well as ultraviolet, visible and near infrared (UV–Vis–near IR) absorption spectroscopy methods and involving chemical and X-ray diffraction data. Sodalite-related minerals from gem lazurite deposits (haüyne, lazurite, and slyudyankaite) are characterized by wide variations in S-bearing extra-framework components including SO42− and various polysulfide groups (S2●−, S3●−, S4●− radical anions, and S4 and S6 neutral molecules) as well as the presence of CO2 molecules. Heating at 700 °C under reducing conditions results in the transformation of initial S-bearing groups SO42− and S3●− to a mixture of S2−, HS−, S2●−, and S4●− and transformation of CO2 to a mixture of CO32− and C2O42− or HC2O4− anionic groups. Further heating at 800 °C in air results in the decomposition of carbonate and oxalate groups, restoration of the SO42− and S3●− groups, and a sharp transformation of the framework. The HS− anion is stable only under reducing conditions, whereas the S3●− radical anion is the most stable polysulfide group. The HS−-dominant sodalite-group mineral sapozhnikovite forms a wide solid-solution series with sodalite. The conditions required for the formation of HS−- and CO20-bearing sodalite-group minerals are discussed