STUDIES ON CYANATION OF O-HALOGENATED AZO DYES(Ⅰ)IDENTIFICATION OF THE PRODUCTS OF THE CYANATION

The molecular structures of the products of the cyanation of 2,6-bromo-4-nitro-4′-(N,N-diethy1)-azo dye withCuCN were analyzed and identified.Mechanism of the formation of the by-products was also discussed.     

THE SWELLING BEHAVIOR OF (W/O)/W LIQUID SURFACTANT MEMBRANE(Ⅰ)MODELING OF THE PERMEATION-SWELLING PROCESS

Water transfer through the organic phase of kerosene containing surfactant Span 80,L113B and certain carrier wasstudied theoretically and experimentally in(W/O)/W liquid surfactant membranes.The process of swelling owing to os-motic pressure can be pictured as solubilization of water in membrane phase caused by surfactant and certain carriers andthen diffusion of it through the membrane between the two aqueous phases due to the gradient of chemical potential.Amathematical model for estimating the permeation-swelling rate has been developed.This mathematical model does notcontain any adjustable parameters and the predicted values agree well with the experimental data of Fujinawa et al.,Xinsheng Ma and Yajun Shi and the authors.Using an apparatus developed for measuring the solubility of water in membrane phase,data for solubilization ofwater in oil caused by some surfactants and carrier were measured.     

THE SWELLING BEHAVIOR OF (W/O)/W LIQUID SURFACTANT MEMBRANE (Ⅰ) ADSORPTION OF SURFACTANT AT THE INTERFACE AND THE SWELLING CAUSED BY EMULSIFICATION

The concept of effective concentration of surfaetant in membrane phase has been proposed,considering the high ad-sorption density of the surfactant at the droplet interfaces in LSM system.The effective concentration of surfactant,C_2,can be estimated by Eq.(7)—(9).The swelling caused by emulsification during the initial dispersion process was investigated.The swelling rate wasmeasured by a density method.A model for estimating the“Emulsification”swelling rate,F_(se),has been proposed,basedon a mechanism of swelling due to the entrainment of water resulted from the interracial turbulence and emulsification inthe initial dispersion process.It has been found that Eq.(26)gives excellent fit to the experimental data of Fujinawa,etal.and of the authors.     

STUDIES ON THE RELATIONSHIP BETWEEN THE NETWORK STRUCTURE AND THE MECHANICAL PROPERTIES OF RUBBER VULCANIZATES (H) THE REINFORCEMENT OF ELASTOMERS BY CARBON BLACK FILLERS AND ITS CHARACTERIZATION

A satisfactory account of reinforcement of rubber through the application of the theory of elasticity forits vulcanizates with carbon black fillers has been obtained. A statistical theory of reinforcement by carbonblack fillers and its characterization was developed. Three methods for     

COBALT–NICKEL SEPARATION: THE EXTRACTION OF COBALT(II) AND NICKEL(II) WITH BIS(2-ETHYLHEXYL) PHOSPHINIC ACID (PIA-8) IN TOLUENE

The extraction behaviour of cobalt(II) and nickel(II) from sulfate solutions with bis(2-ethylhexyl) phosphinic acid (PIA-8) in toluene has been studied. Quantitative extraction of Co(II) was observed at pH 5.0–5.9 while that of Ni(II) at pH 6.8–7.0 with 0.03 M PIA-8 in toluene. The difference in pH_0.5 for Co(II) and Ni(II) was 1.9. The stoichiometry of the extracted species were determined by slope analysis method. The extraction reaction proceeds by cation exchange mechanism and the extracted species were Co · R₂(HR)₂ and Ni · R₂ · 2(HR)₂. Temperature dependance of the extraction equilibrium constants were determined to estimate the apparent thermodynamic functions (ΔG, ΔS and ΔH). The method was used for separation of cobalt(II) and nickel(II). Cobalt(II) was separated from nickel even at 1:20 (Co:Ni) ratio. The separation of cobalt(II) from nickel(II) was favoured with the increase in temperature.     

STUDIES ON “THE THREE CRITICALS AND THE TWO OPTIMUMS”IN MEMBRANE GAS SEPARATION PROCESSES ( I ) “THE THREE CRITICALS”AND THEIR RELATIONSHIPS

提出了“三临二优”（系指临界操作压力比R~-、临界选择系数α~-、临界进料浓度x_f~-和最优操作压力比R~+、最优选择系数α~+）新概念,通过计算、分析和优化等手段,在x_f≥0.40、R≤100、a≤100范围内获得如下通用回归公式R~-=2+B/（α~-+A）,式中A、B仅与临界进料浓度x_f~-有关,并对他们分别进行了回归。此外,还在R≤1000、a≤1000范围内给出了x_f~-=0.95和0.50时的回归公式。     

A NEW CORRELATION FOR THE TRANSPORT DISENGAGING HEIGHT (TDH) OF FLUIDIZED BED

In designing fluidized-bed equipment, it is important to determine the TDH (Transport Disengaging Height) for the dilute-phase zone. Until the present time, the empirical curve developed by Zenz and Weil in 1958 has been widely used. In the present paper, on the basis of the equation for the motion of single particle, methods for calculating gas velocity, particle velocity, and particle stagnation time and rising height in gas-solid flow, have been developed through theoretical analysis, resulting in an eight-parameter expression, Eq. (14), for computing TDH. This equation, which contains more parameters than those in any previous work, gives closer fit to experimental results, and is thus recommended for design.     

STUDIES ON THE RELATIONSHIP BETWEEN THE NETWORK STRUCTURE AND THE MECHANICAL PROPERTIES OF RUBBER VULCANIZATES (Ⅰ) THEORY OF ELASTICITY FOR RUBBER VULCANIZATES WITH CARBON BLACK FILLERS IN LARGE DEFORMATION

A model structure formed by the combination of crosslinked, trapped entanglement and carbon black-polymer chain networks has been developed for rubber vulcanizates with carbon black fillers. Based on thisstructure and the proposed mechanism of large deformation, the elastic free energy     

THE MASS TRANSFER BEHAVIORS OF FE(Ⅲ), CO(Ⅱ) AND NI(Ⅱ) IN SULFURIC ACID WITH CYANEX302 BY USINGMICROPOROUS HOLLOW FIBER

In this paper the mass transfer behaviors of Fe(Ⅲ), Co(Ⅱ) and Ni(Ⅱ) with Cyanex302(bis(2,4,4- trimethylpentyl)monothiophosphinic acid) from sulfate medium by using hollow fiber membrane in counter-currently circulating operation were studied. The effect of acidity in aqueous solution and the extractant concentration on the mass transfer coefficient (Kw) was discussed. The reaction mechanism of membrane extraction was considered as a false one series reaCtion and the rate controlling step was membrane resistance. When the value of Kw arrived at 1.0 × 10-6 m/s, △pH:CoFe equaled tO 6.225, and △pH:NiFe was bigger than △p HCoFe.     

STUDIES ON VAPOR-LIQUID AND LIQUID-LIQUIDVAPOR EQUILIBRIA FOR THE TERNARY SYSTEM METHANOL-METHYL METHACRYLATEWATER (Ⅱ) TERNARY SYSTEM

Isothermal P-x data for homogeneous, and P-x'-x" data for partially miscible mixtures for the ternary system methanol-methyl methacrylate-water have been determined at 25, 35, 45, 55 and 60℃. By using a modified UNIQUAC model and binary parameters only, the predicted ternary phase equilibrium data were found to be in good agreement with the experimental results, indicating the adequacy of using binary model parameters in computing vapor-liquid and liquid-liquid-vapor equilibria covering pressures ranging from reduced to atmospheric.     

THE EXTRACTION OF CATIONIC RUTHENIUM COMPLEXES FROM AQUEOUS MEDIA BY α-TIN(IV) HYDROGEN PHOSPHATE

ABSTRACT

The ruthenium species [Ru(NH₃)₆]³⁺ was adsorbed by the surface of (α-Sn(HPO₄)₂.2H₂O [SnP]) α-tin(IV) hydrogen phosphate. The ruthenium(II)-containing cation [Ru(NH₃)₆]²⁺, however, has been directly intercalated into (SnP). Since the corresponding ruthenium(III) complex cation was not so intercalated, a new self-catalysed intercalation mechanism involving labile ammonia ligands from the ruthenium(II) has been proposed. At high loadings, guest ruthenium(II) species were oxidised to ruthenium(III).     

EQUILIBRIUM AND KINETIC STUDIES FOR THE ADSORPTION OF MN(II) AND CO(II) FROM AQUEOUS MEDIUM USING AGAR–AGAR AS SORBENT

An extensive increase in industrial activities and environmental accidents in recent years have greatly contributed to increasing metal pollution in water resources, thereby causing threats to terrestrial as well as aquatic life. The toxicity of metal pollution is slow and long lasting, as these metal ions are nonbiodegradable. The most appropriate solution for controlling the biogeochemistry of metal contaminants to produce high-quality treated effluents from polluted wastewaters is sorption technique. Agar–agar, a readily available seaweed, was used as sorbent for the removal of Mn(II) and Co(II) from aqueous media. Batch experiments were performed to study adsorption as a function of process parameters: sorption time, initial pH, concentration of sorbate and sorbent. The Freundlich model fitted best with the experimental equilibrium data between the two adsorption isotherm models tested. The kinetic data correlated well with the Lagergren pseudo-second-order kinetic model for the sorption of both Mn(II) and Co(II) using agar–agar. Adsorbed metal ions were quantitatively recovered from the spent adsorbent using 5.0 mol L^?1 HCl. The efficiency of agar–agar for decontaminating Mn(II) and Co(II) from electroplating effluent has also been evaluated. The results proved agar–agar to be a favorable adsorbent to remove and recover Mn(II) and Co(II) from waste effluent for further use in diversified industrial applications.     

ON THE MURPHREE EFFICIENCIES IN THE SIMULATION OF MULTICOMPONENT DISTILLATION COLUMN:THE BIZARRE BEHAVIOUR AND THE ESTIMATION METHODS

The composition profiles in an I.D.30mm Oldershaw distillation column with 6 plates at total reflux weremeasured for two ternary systems,ethanol/chloroform/n-hexane and cyclohexane/n-heptane/toluene.Somecomponent effieiencies exhibit the bizarre behaviour,exceeding the normal range(0,1),at the plates near theextreme points of the concentration profiles of the components.The possible relationship between the extremeof the profiles and the bizarre values of component efficiencies has been analysed,and the feasibility and availa-bility of some approaches for the estimation of the component efficiencies are discussed.     

TWO-PHASE FLOW AND HEAT TRANSFER IN VERTICAL U-SHAPED TUBES(Ⅰ)FLOW PATTERN TRANSITIONS IN THE BEND

1 .Introduetion The vertiealU一shaPed boiling tubes are widely usedi一飞waste heat boilers,nuelear reaetorsteam generators,evaPorators and heat exehangers.Fo一instanee,waste heat boilers withU一shaPed tube are used in synthetie ammonia fertilizer Plants w     

STUDIES ON VAPOR-LIQUID AND LIQUID-LIQUID-VAPOR EQUILIBRIA FOR THE TERNARY SYSTEM METHANOL-METHYL METHACRYLATEWATER (Ⅰ) THREE BINARY SYSTEMS

Isothermal P-x data tor the binary systems methanol-methyl methacrylate and methanol-water, and isothermal P-x'-x" data for the binary system methyl methacrylate-water have been determined at 25, 35, 45, 55 and 60℃. Based on the maximum likelihood principle, the modified UNIQUAC model pa rameters for these binary systems were obtained by fitting the experimental data. Vapor compositions were then calculated, and the results were compared with literature data.     

EFFECT OF SELECTED β-DIKETONES ON THE SYNERGICEXTRACTION OF COBALT(II) BY TRIPHENYL-PHOSPHINE OXIDE IN BENZENE

Abstract

Synergic extraction of Co(ll) by thenoyltrifluoroacetone (HTTA), Pivaroyltrilluoioacetone (HPvTA) or hexafiuoroacetylacetone (HHFA) mixed with triphenyiphosphine oxide (ph₃PO) in benzene from perchlorate media has been investigated. It ’ was found that in all the systems studied, Co(ll) is synergistically extracted as CoL₂.ph₃PO, where L stands for the different chelating ligands. The obtained equilibrum constants for the chelating and adduct systems indicated that: i- the weaker the acidity of the chelating ligand, the higher the overall aqueous phase formation constant of the metal chelate (β₂ ), ii- the sequence of the extraction constants (K_2,1 ) and the organic phase formation constants for the adduct ( β_2,1) as related to the chelating ligands is TTA> HFA > PvTA, iii- the stability of the adduct is related to both the structure and the pK_avalues of the chelating ligands.     

ON THE MINLP APPROACH FOR OPTIMAL DESIGN OF CHEMICAL ENGINEERING SYSTEMS(Ⅱ)SYNTHESIS OF DISTILLATION SEQUENCES

In this paper the MINLP method proposed in Part(Ⅰ)is illustrated by applying it tothe synthesis problem of non-sharp distillation sequences.A MINLP formulation for the synthesis ofdistillation sequences with non-sharp separation is proposed.In this formulation the recoveries of thekey components are introduced as optimization variables and this makes it possible to synthesize adistillation sequence with specified component recoveries,and at the same time,renders the MINLPproblem nonconvex.The solution procedure is illustrated with three example problems.