Batch Extractive Distillation in a Column with a Middle Vessel

Batch extractive distillation was studied in a column with a middle vessel. The process was simulated by a constant holdup model and solved by two point implicit method. Acetone and methanol mixture was separated in such a setup using water as solvent. The simulation agrees well with experimental results. The experimental and simulation results show that the solvent at the bottom and the product at the top of the column can be withdrawn simultaneously for a long period of time. It needs more time for the solvent to reach high purity than that required for the more volatile component to reach high purity, so that the time to withdraw solvent from the bottom is delayed.     

Lending a Hand to Recyclers with a Low—Density Adhesive

研究在一般EVA热熔胶中用聚丁烯取代20％～50％的松香酯，使胶的密度从0．975降至0．936～0．970范围，结果表明不影响热熔胶性能．但成本可下降，尤其较易在纸浆工序中清除。     

Low pressure ethylene oligomerization with a nickel-PÔ complex

Summary The oligomerization of ethylene catalyzed by nickel-PÔ complexes at room temperature and low pressure (5 to 30 bar) yields butenes, hexenes and octenes. The molecular weight distribution can be manipulated by variation of ethylene pressure and by addition of triphenylphosphine. An unexpected linear dependence between the growing factor of the Schulz-Flory type distribution and the pressure has been observed. The equation: =6.2 (PPh₃/Ni)^1.2-[0,17 P(PPh₃/Ni)^1.2] allows to predict the composition of the -olefins formed under different reaction conditions.     

Oil–water pre-separation with a novel axial hydrocyclone

A novel hydrocyclone with guide vanes, named as axial hydrocyclone(AHC), is designed to tackle the problem of oil–water separation faced by most mature oilfields. Optimal design of the AHC is carried out by using numerical methods. The effects of guide vanes, cone angle, tapered angle and overflow pipe on the oil–water separation are discussed in this paper. The results show that a double swirling flow is generated in the tapered section where oil–water separation occurs. Both the cylindrical and the tapered section have important influences on AHC performance. On the basis of single factor results, response surface methodology is employed to optimize the AHC design. The experimental results indicate that the novel AHC has an excellent performance for the oil–water separation.     

Petroleum isoprenanes with a non-regular “head-to-head” link

• 1.1. A homological series of C₂₉-C₃₉ isoprenanes having a non-regular “head-to-head” link has been found in oil of the North-Tol'kin field (West Siberia). The structure of the hydrocarbons has been demonstrated by chromato-mass spectrometry and synthesis of a standard C₃₃ hydrocarbon.
• 2.2|It has been shown that the hydrocarbons under examination were formed by means of bacterial combination of pristane radicals and different regular C₁₀-C₂₀ isoprenoids.
• 3.3|The mass spectra and retention indices of the isoprenanes identified are given.

     

Synthesis of solid resorcinol–formaldehyde resin modified with styrene with the use of a shale phenol fraction with a boiling temperature higher than 270°C

The synthesis of modified solid resorcinol–formaldehyde resins based on resorcinol and a fraction of water-soluble shale alkylresorcinols (T_b > 270°C) was studied. Styrene was used as a modifier. Data on the quality of the target products depending on a molar ratio between the initial components were acquired.     

‘All twisted up’: a dinuclear helicate with a highly contorted pyridazine bridge

Two homotopic homostranded dinuclear helicates displaying tripodal coordination at each metal atom were synthesised by reaction of bis-3,6-(di-2-pyridylmethyl)pyridazine with M(BF₄)₂ salts (where M=Ni, Cu), and characterised by single crystal X-ray crystallography. The structures represent closely related examples of this class of helicate, possess a very compact overall size and differ primarily in the coordination geometry of the metal atom. In the nickel helicate the ligand strands adopt a highly contorted bridging geometry which is relieved in the corresponding square pyramidal copper helicate by releasing one of the metal–nitrogen interactions.     

Fluidization Characteristics of Silicon Particles with a Wide Size Distribution

Fluidization characteristics of silicon particle system are studied by the pressure fluctuation method. The existence of fine particles in the system can improve fluidization. Silicon particles with a wide size distribution, preferably with some fines, behave as Group A particles according to Geldart classification, although the system belongs to Group B actually. The system is also approved to be suitable for organochlorosilane monomer production using a fluidized bed reactor. Experimental data obtained in this work are important for the design and operation of commercial fluidized bed reactors for the production of organochlorosilane monomers.     

Local Measurement of Gas-Liquid Bubbly Flow with a Double-Sensor Probe

A double-sensor probe was used to measure local interfacial parameters of a gas-liquid bubbly flow in a horizontal tube. The parameters included void fraction, interfacial concentration, bubble size distribution, bubble frequency and bubble interface velocity. The authors paid special attention to the probe design and construction for minimizing measurement errors. Measures were also taken in the design of sensor ends for preventing corrosions in the flow. This is an effort to improve the current double-sensor probe technique to meet the ever-increasing needs to local varameter measurements in gas-liquid two-phase flows.     

Fuel Combustion in Combustion Chambers of a Gas–Turbine Engine with a Rotating Injector

Specific features of combustion in combustion chambers of a gasturbine engine with a rotating injector are considered. The region of the combustion site and the temperature field are found. A method for threedimensional simulation of heat and mass transfer is described. The calculation results are compared with the temperature fields of real engines.     

The drug release from a coated planar matrix with a sub-saturation loading in the core

A model was proposed for the drug release from a coated matrix system.To validate thismodel,5-Fu/EVAL matrices coated with various polymeric materials with different diffusivities wereprepared and characterized.These coated systems were experimentally investigated and graphically andquantitatively compared with theoretical values.The results show a good correlation between theoryand experiment.     

Performance of lithium-ion cells with a γ-ray radiated electrolyte

Lithium-ion cells are potential energy storage devices in planetary exploration due to their high energy density and long lifespan. The high intensity of γ-ray radiation in outer space poses a great challenge to lithium-ion cells. In this study, radioactive Co-60 was applied as the radiation source to investigate the performance of lithium-ion cells with the electrolyte radiated by γ-rays. Two kinds of cathode (LiMn₂O₄, LiNi_0.8Co_0.15Al_0.05O₂) and three kinds of anode (Li, graphite, Li₄Ti₅O₁₂) were examined. There are two new mechanisms in the cells with a radiated electrolyte which affect the cell voltage and cycling performance: (i) erosion of the lithium electrode in the radiated electrolyte in the cases of half cells and lithium symmetrical cells; and (ii) electrochemical reaction between carboxyl species and the lithium extracted from the cathode in the case of full cells.     

A Study on a Gas Agitated Extractor with Static Mixer

1 INTRODUCTIONMany chemical engineering operations involve the mass and heat transfer between two liquidphases in reactions.Mechanically agitated liquid-liquid extractor can be one of the examples forsuch operations.It has been well developed and used in the nuclear energy,petrochemical andother chemical industries.However,not much attention has been paid to the gas agitated liquid-     

Synthesis of a gold(I) complex with a (thio)phosphine-modified β-cyclodextrin

A gold(I) complex with the bidentate ligand 6^A-S-[2-(diphenylphosphino)-ethyl]thio-β-cyclodextrin has been prepared. The complex has been studied by mass spectrometry as well as IR and NMR spectroscopy. The influence of the ligand:metal ratio on the coordination mode has also been examined.     

CFD modeling of a headbox with injecting dilution water in a central step diffusion tube☆

For engineering applications of water dilution controlling system,the fluid dynamics of a mixed flow was studied with computational fluid dynamics(CFD) simulations and self-designed experimental set-up.In order to examine the predictability of CFD model for the headbox in industrial scale,two pulp suspensions before mixing were treated as homogeneous flows separately.Standard k-ε turbulence models with the mass diffusion in turbulent flows-species transport approach were applied in the simulations.A numerical simulation of this headbox model was analyzed with semi-implicit method for pressure linked equations scheme with pressure–velocity coupling.Results show that the model can predict hydrodynamic characteristics of headbox with injecting dilution water in a central diffusion tube,and the distribution of water content at the outlet of the slice lip is ideally normal at different speeds.     

Multiobjective Optimization of a Micromixer with Convergent–Divergent Sinusoidal Walls

A multiobjective optimization of a micromixer with convergent–divergent sinusoidal walls has been conducted using flow and mixing analyses, surrogate modeling, and multiobjective genetic algorithm. The ratios of amplitude to wavelength of the sinusoidal walls, throat width to depth of the convergent–divergent sections, and diameter of the inner circular wall to wavelength were chosen as the design variables for optimization. The full-factorial method was used to discretize the design space. The mixing index and nondimensional pressure loss were selected as objective functions. Radial basis neural network functions were used to train the objective functions. The optimization was carried out at a Reynolds number of 30. A concave Pareto-optimal front representing the trade-off between the two objective functions was obtained. The analysis of representative designs along the Pareto-optimal front showed significant variation in the ratio of throat width to depth of the convergent–divergent sections, whereas the ratio of amplitude to wavelength of the sinusoidal walls maintained a nearly constant value. The concept of mixing effectiveness was used to select the most efficient designs considering both the mixing performance and pressure drop.     

Flame Propagation in a Variable–Section Channel with Gas Filtration

A one–dimensional unsteady model is proposed, which describes gas–flame propagation in a narrow variable–section channel with a gas counterflow and takes into account heat propagation over the channel walls. The case of the channel cross section changing slowly at a distance of the order of the thermal thickness of the combustion wave is considered. It is shown that various regimes of flame propagation are possible in such a system: a regime of flame propagation with a high velocity (of the order of the burning velocity of the flame), a regime of flame propagation with a low velocity as in the case of filtrational gas combustion in a porous medium, and an intermittent regime of combustion, where the flame has a high velocity in the wide section of the channel and a low velocity in the narrow section. A simple analytical model of flame oscillations in such a system is constructed. The possibility of these oscillations was predicted by numerical simulation results. The simple model considered is an attempt to take into account the large–scale inhomogeneity of the porous medium in simulation of filtrational combustion of gases.