Determination of the dye penetration rate in porous aluminum oxide using Raman spectroscopy

Oxidised aluminum coatings are useful in various high technology applications to protect surfaces from negative environmental effects. In this study, aluminum discs and foils of industrial alloys were anodised in a sulphuric acid/oxalic acid electrolyte. Scanning electron microscopy was used to determine the pore diameter, distribution and surface porosity. The anodising procedure was adapted to produce near‐hollow templates on aluminium foil, onto which aqueous solutions of commercial chromium‐complexed anionic azodyes were dropped. Raman spectroscopy was used to detect the penetration of dye compounds based on the most intensive vibrational modes. Each dye was successfully monitored to assess its penetration rate and behaviour in the anodised coating. This method could be applied to characterise newly developed organic dyes for aluminum colouring.     

Continuous preparation of activated carbon supported zinc acetate catalyst and industrial synthesis of vinyl acetate from acetylene

A continuous manufacturing method of an activated carbon supported zinc acetate catalyst has been established. Based on the dipping of a crushed activated palm carbon into a zinc acetate aqueous solution, the catalyst is prepared for the synthesis of vinyl acetate from acetylene in an industrial fluidized reaction vessel. The relationship between the supported amount of zinc acetate and various factors has been studied. Based on these results, an empirical formula was developed. Using this formula, the continuous manufacturing apparatus was designed and constructed for the purpose of preparing the optimum supported fluidized catalyst. To minimize the activated carbon loss due to crushing and wearing, a vibrating conveyor system was employed. This continuous manufacturing process produced a uniform catalyst with an activated carbon feed rate of 0.25 m³ h^?1. Using this catalyst, a series of operational tests of the vinyl acetate synthesis was performed for investigating the optimum reaction conditions. These operational tests were carried out using an industrial fluidized reaction vessel of 3.28 m diameter and 50 tons day^?1 vinyl acetate production capacity. Based on these test results, the reaction rate constant and the deterioration rate constant were newly introduced, and the optimum operation conditions were then determined.     

The Isolation of Yellow Mustard Oil Using Water and Cyclic Ethers

An aqueous extraction process (AEP) was developed for dehulled yellow mustard flour with the aim of producing yellow mustard oil for industrial applications, as a by-product of food protein production. During AEP, most of the oil extracted was bound in a stable oil-in-water emulsion that must be destabilized to recover free oil. The oil distribution after aqueous extraction and the composition of the emulsion produced were determined. The emulsion was solubilized in organic solvents including tetrahydrofuran (THF) and 1,4-dioxane to fully recover the oil in a single-phase oil–solvent-water miscella. Over 97 and 95% of the oil in the emulsion was successfully recovered using 4:1 THF:oil and 9:1 dioxane:oil weight ratios, respectively. The oil recovery from the emulsion was optimized, based on experimentally prepared ternary phase diagrams of THF/oil/water and dioxane/oil/water. The results suggest that this technically viable approach can successfully recover essentially all of the oil from the emulsion, equivalent to an overall free oil recovery of ~63% from dehulled yellow mustard flour.     

Removal of organic impurities with activated carbons for ultra-pure hydrogen peroxide preparation

The aim of this research was to select suitable activated carbon (AC) for effective removal of organic impurities from industrial aqueous hydrogen peroxide solution to produce ultra-pure hydrogen peroxide. The textural parameters and surface chemistry of four kinds of AC samples were measured and analyzed. Static and dynamic equilibrium adsorption experiments were carried out to compare the effect of AC on organic impurities adsorption and hydrogen peroxide decomposition. The effects of AC pore structure and surface chemistry on the adsorption of organic impurities were investigated. The fitting operation conditions, i.e., operating temperature and AC dosage, were also examined. The results showed that AC adsorption capacity on organic impurities from industrial aqueous hydrogen peroxide solution was mainly influenced by micropore structure of AC, as well as decomposition of hydrogen peroxide. The pore size of 1–3 nm is most effective for adsorption of organic impurities. It was found that the organic impurities in industrial hydrogen peroxide solution could be reduced effectively to meet the standard of ultra-pure hydrogen peroxide of SEMI-C8 level with the proposed AC and adsorption techniques.     

Influence of Water and Supercooling on Permeability and Compressibility of Acrylic Acid Crystal Beds

The performance of a solid‐liquid separation process is often limited by size distribution and morphology of the crystals. To predict the filtration behavior, a robust and applicable model based only on crystallization process parameters is necessary. Therefore, a model has been successfully developed for the industrial system of aqueous acrylic acid melt to predict compressibility and permeability of a crystal bed. For this purpose, common equations are transferred successfully to nonspherical particles. Chord length distributions (CLDs) obtained from an inline focused beam reflectance measurement (FBRM) probe and crystal aspect ratios have been used in combination to determine the major input parameters for the model. Integration of a complex mathematical restoration of crystal size distribution (CSD) from CLD data by the use of existing models is avoided. Considering acceptable fault tolerances of the model, a simple approach used as a robust industrial application is employed. The adjustment of all required constants used in the permeability model was based on simple filtration tests.     

Extraction of Caprolactam from Aqueous Ammonium Sulfate Solution in Pulsed Packed Column Using 250Y Mellapak Packings

1 INTRODUCTION Caprolactam is a major ingredient in the manufacture of nylon 6 fibers. In the process of caprolactam production, there is about 1% caprolactam in the aqueous ammonium sulfate solution after Beckmann rearrangement and neu-tralization. So far, the 1% caprolactam has been extracted by benzene in an ordinary sieve-plate column with 60% recovery in Zhejiang Juhua Group Company in China, while being extracted in a pulsed packed column with 95% recovery abroad[1—3]. Because …     

Removal of Divalent Metal Cations and Their Mixtures from Aqueous Streams Using Micellar-Enhanced Ultrafiltration

ABSTRACT

Micellar-enhanced ultrafiltration (MEUF) is a novel membrane-based separation technique that can be used to remove multivalent metal cations from aqueous streams. In this technique an anionic surfactant is added to the aqueous stream containing the metal cations to be removed. The surfactant forms highly charged aggregates called micelles onto which the metal cations adsorb or bind. The aqueous stream is then passed through an ultrafiltration membrane with pores small enough to block the passage of the micelles and adsorbed metal cations. In this study, MEUF has been shown to remove divalent cadmium, zinc, copper, and calcium ions and their mixtures with rejections of at least 96%. A previously developed equilibrium binding model describes the results successfully. Under reasonable conditions the flux rates are not substantially below that of pure water, indicating the feasibility of MEUF for industrial application.     

Enhanced decolorization of reactive black 5 dye by active carbon sorbent-immobilized-cationic surfactant (AC-CS)

Activated carbon-immobilized-cationic surfactant (AC-CS) was designed to enhance the decolorization behavior of reactive black 5 (RB5), as an anionic dye, from aqueous and industrial wastewater samples in presence of various controlling experimental conditions. Experimental data indicated that the dye adsorption capacity by (AC-CS) was higher in strongly acidic and basic solutions. An anion exchange and ion–ion interaction mechanisms were proposed in the acidic solution, while only anion exchange mechanism was suggested in the basic aqueous solution. The adsorption behavior and thermodynamic parameters were also evaluated. Treatments of textile industrial wastewater and real water samples were successfully established (95.23–100.00%).     

有机溶剂析盐法生产试剂氯化钾

进行了用丙酮结晶析出工业氯化钾饱和水溶液中的氯化钾的研究。丙酮能有效地从饱和溶液中分离出氯化钾 ,据此开发出一种生产试剂氯化钾的新工艺 ,该工艺与传统工艺相比 ,具有流程简单 ,操作条件宽松 ,能耗低等优点     

Fibre Chemisorbents for Treatment of Industrial Sewage

An industrial method was developed for treatment of electroplating plant sewage to remove heavy metal ions [zinc, chromium (VI)] with chemisorption materials. The high efficiency of removal of toxic contaminants from aqueous medium with fibre sorbents is demonstrated.     

Optimization of froth flotation procedure for poly(ethylene terephthalate) recycling industry

This article addresses the separation of polyethylene terephthalate (PET) from ternary blends with polyvinyl chloride (PVC) and polystyrene (PS) by froth flotation. The experimental work was carried out with representative samples from post‐consumer waste packages collected at drop‐off‐points. Previous to froth flotation, PET selective wetting was achieved by alkaline treatment followed by surfactant adsorption. For this purpose, an aqueous solution of NaOH and an industrial detergent commonly used for waste plastic washing were tested as alkaline treatment, and calcium lignosulphonate and Hostaphat were tested as surfactants. An enriched product with 98.9% grade in PET and only 0.6% in PVC was recovered in the nonfloated product. The PET recovery in this product was 97% while ～96% of PVC and 91% of PS were recovered in the floated product. An analytical method was developed for the quantification of the waste plastic composition. The method was based on the selective dissolution of the plastics in the mixture. POLYM. ENG. SCI., 2012. © 2011 Society of Plastics Engineers     

Integrated conversion of extra-heavy crude oil and petroleum residue with the recovery of vanadium,nickel, and molybdenum

Based on experimental and calculation studies, it was demonstrated that, after the hydroconversion of tars and other heavy petroleum residues in the presence of a nanosized catalyst based on MoS₂ or MoS₂ and NiS, V, Ni, and Mo were quantitatively transferred to high-boiling fractions (HBFs) with boiling temperatures of >420–520°C and coke. At coke yields of <0.5%, V, Ni, and Mo were almost completely concentrated in the HBF removed from the process. A hydrometallurgical process based on the treatment of ash and slag wastes (ASWs) with an ammonia solution of ammonium carbonate was developed. The resulting aqueous solution contained Mo and Ni compounds (nanosized catalyst precursors) with Mo recovery to 80% and V and Ni recovery of >10% (on a weight basis in a HBF or its mixture with coke). Vanadium was extracted as V₂O₅ from the aqueous solution. The extraction of V and Ni from the solid residue after hydrometallurgical processing into commercial products can be performed by currently available industrial processes.     

Preparation of crosslinked β‐cyclodextrin polymer beads and their application as a sorbent for removal of phenol from wastewater

BACKGROUND: Phenols are commonly encountered in aqueous effluents from various manufacturing processes such as oil refineries, coke plants, and phenolic resin plants, and are toxic substances that should be removed from the aquatic environment. This paper reports on the preparation of beaded crosslinked β‐CyD polymers, and the removal of phenol by the β‐CyD adsorbent from raw industrial wastewater discarded from phenolic resin processing. RESULTS: Crosslinked β‐CyD prepolymer was synthesized by treatment of β‐CyD with hexamethylene diisocyanate (HDI) at a molar ratio of 1:8. The suspension of the resulting powdery prepolymer in aqueous sodium alginate was added dropwise into an aqueous calcium chloride solution to precipitate the spherical β‐CyD prepolymer gels. The spherical prepolymer gel was lyophilized and re‐crosslinked with HDI to provide the β‐CyD polymer beads. The physical properties of the beads were as follows: average diameter: 3.4 mm; average compressive strength: 2.17 MPa; porosity: 47.0%; specific surface area: 3.48 m² g^?1. The removal of phenol from raw industrial phenolic wastewater with the β‐CyD polymer beads was carried out in either a shaker or an upflow column at 25 °C. After seven episodes of accumulated adsorption, the initial phenol concentration of 89000 ppm decreased to as low as 350 ppm in the shaker and 490 ppm in the upflow column. CONCLUSION: Adsorbent [β‐CyD/HDI(1/8)]/HDI polymer beads having a good regular shape and high mechanical stability were newly prepared by a stepwise crosslinking method. The results of sorption experiments show that the beads exhibit high sorption capacities for phenolics in raw industrial wastewater. Copyright © 2008 Society of Chemical Industry     

Photocatalytic degradation of aromatic sulfonates present in industrial percolates

Photocatalytic treatment in the presence of aqueous TiO₂ suspensions was applied to an aqueous percolate containing various hydrophilic aromatic pollutants, in particular naphthalene sulfonates. A preliminary feasibility study was accomplished on standards of pure compounds, for which a degradation rate trend inversely proportional to the sulfonation degree was found, demonstrating the important role played by the substrate adsorption on semiconductor particles. The evolution of primary processes, the abatement of TOC and the release of sulfate were monitored. Further experiments performed on samples of percolates taken from an abandoned industrial site demonstrated the suitability of photocatalysis for the effective destruction and mineralization of the investigated contaminants in these complex matrices after a few hours irradiation.     

Application of an electrochemical pulsed flow reactor to electroorganic synthesis Part II: Oxidation of cyclohexanol and pilot plant operation

A pilot plant electrolyser was built, which, in design, was similar to an industrial reactor used for metal recovery from waste waters. Increased mass transport rates were achieved by applying a pulse to the reactor solution. The first reaction tested on this new cell was the indirect oxidation of cyclohexanol in aqueous solution by means of an iodinated intermediate species. Several electrochemical methods, such as cyclic and linear sweep voltammetry and chronoamperometry, were used for the study of the reacting system. The results from these analyses have allowed optimization of the reactor operating conditions. A mathematical model for the process has been established which predicts the reactor yield and conversion as a function of the main operating parameters.     

高效有机硫脱除溶剂CT8-24的工业应用

针对常规甲基二乙醇胺（MDEA）脱硫溶剂对有机硫脱除率不高、含有机硫的天然气脱硫后不能满足GB17820—2018对管输气要求的问题,中国石油西南油气田公司天然气研究院开发了高效有机硫脱除溶剂CT8-24,在室内研究以及中间放大试验的基础上,在重庆天然气净化总厂引进分厂400×10⁴m³/d装置上进行了工业应用。考察了溶剂在不同循环量、处理量、吸收塔板数以及再生温度等条件下的吸收性能,确定了较适宜的工艺操作参数。结果表明,将引进分厂400×10⁴m³/d装置原用的MDEA水溶液改换为CT8-24后,装置运行平稳。在35层吸收塔板下,产品中H₂S含量＜6mg/m³,总硫＜20mg/m³,达到GB17820—2018的要求。同时分析研究了CT8-24类物理-化学溶剂对MDEA脱硫装置的适应性,为其他净化厂气质达标改造工作奠定了坚实基础。     

Use of a liquid chemical waste to produce a clay–carbon adsorbent

The feasibility of producing an adsorbent from an alkaline aqueous tarry industrial waste has been investigated in this study. The inherent disadvantages of producing a solid carbonaceous material from a waste with its organic content in a dissolved state were overcome by neutralising the waste liquor to pH<2 in the presence of fuller's earth, filtering and producing a solid cake more suitable for thermal treatment. Optimisation of this procedure, followed by ZnCl₂ activation, produced clay–carbon adsorbents with surface areas of up to 225 m² g⁻¹ capable of adsorbing 28% of phenol and 35% of 4-nitrophenol from 10 mM aqueous solution. The potential of this procedure in a beneficial waste reduction and re-use context are highlighted. © 1998 SCI     

Copper and cadmium extraction from highly concentrated phosphoric acid solutions using calcium alginate gels enclosing bis(2,4,4‐trimethylpentyl)thiophosphinic acid

The availability of alginate gels enclosing Cyanex 302 [bis(2,4,4‐trimethylpentyl)thiophosphinic acid] for the uptake of cadmium and copper from highly concentrated solutions of industrial phosphoric acid wet process phosphoric acid (WPA)] was studied. For this purpose, beads of alginate gels enclosing microdrops of kerosene solutions of the industrial extractant Cyanex 302 at different concentrations were prepared. The experimental procedure gives rise to a composite bead in which alginate is the continuous phase and the organic extractant forms the discrete homogeneously distributed phase within the bead. The equilibrium in this three‐phase system (phosphoric acid–extractant solution–alginate gel) was modelled in terms of the corresponding distribution factors, the main chemical reactions and their equilibrium constants. Retention isotherms of both metal ions were obtained experimentally at four concentrations (1.0, 2.5, 5.0 and 7.5 mol L^?1) of pure phosphoric acid. High metal removal efficiency, due to liquid–liquid extraction processes, was observed even in the most acidic conditions. High values of the extraction constants were estimated, with the distribution coefficients between aqueous and alginate phase being near unity. Finally, the results obtained with industrial WPA are in close agreement with those predicted by the physicochemical model developed in synthetic media. Copyright © 2006 Society of Chemical Industry     

氯仿萃取回收己内酰胺的研究

以萃取回收甲苯法生产己内酰胺废液中的己内酰胺为目的,选择氯仿作萃取剂,进行了萃取回收己内酰胺的研究。考察了原料液的pH、萃取温度、萃取时间等因素对氯仿萃取己内酰胺过程的影响。结果表明,在酸性条件下该萃取过程分配比随pH的升高而增大,当pH=7时分配比最大;萃取过程为快速过程,20 min即可达到萃取平衡;水相中硫酸铵和1-磺酸基环己烷羧酸对萃取过程有盐析效应,使分配比增大;萃取过程受温度影响不大,焓变值ΔH=2.86 kJ/mol。实验确定了pH=7时己内酰胺在有机相与水相中的分配平衡关系,当有机相和水相体积比为1时,三级错流萃取的萃取率可达到98%以上。同时,进行了工业废水的萃取验证实验,结果表明,氯仿对废水中己内酰胺的萃取效果良好。     

Effect of aqueous phase pH on liquid–liquid extraction with impinging-jets contacting technique

The influence of aqueous phase pH on the rate of liquid–liquid extraction was investigated using a two impinging-jets contacting device with a high velocity of jet flows. The recommended chemical system of toluene–acetone–water was employed. Applying pH values from its natural value of 5.6–8, a range in which most industrial waters are lain, for the jets colliding force within 70.3–214.6 mN, leads a reduction in extraction efficiency and overall volumetric mass transfer coefficient up to about 18.9% and 35.2% respectively. A significant high variation is observed when the aqueous phase pH exceeds the water neutral value toward alkali conditions. These variations can be attributed to the adsorption of hydroxyl ions and lowering interfacial tension. A comparison between the results in this work and those for drop dispersion extraction indicates a high sensitivity in the impinging technique. As expected, increasing jets force improves the performance of the contacting device; however, simultaneously, the retarding effect of pH would be intensified. The variation of interfacial tension with pH was obtained and with the aid of dimensionless numbers, an empirical correlation was developed for the prediction of overall volumetric mass transfer coefficient.