Computer‐Aided Molecular Design of Environmentally Friendly Solvents for Separation Processes

This review paper presents an optimization technology for the computer‐aided molecular design of environmentally friendly solvents. The approach combines a stochastic optimization method and group contribution methods (GC‐methods) to design solvents with desirable physicochemical and environmental properties. A simulated annealing algorithm is used to investigate feasible molecular structures. The main objective method is adopted to balance the multi‐objective functions. One property is chosen as the main objective function, while the other properties are considered as constraints, and thus, the multi‐objective problem is transformed into a single objective one. The optimal solution is a set of molecules satisfying the formulated target. The properties of each molecule are evaluated through GC‐methods, including pure component properties, mixture properties and environmentally properties. Finally, the proposed methodology is illustrated with several examples of industrial separations.     

Environmentally Friendly Solvent‐ and Water‐Based Coatings for Mitigation of Crystallization Fouling

The surface properties of solvent‐based (SB) and water‐based (WB) coatings and their impact on fouling during convective heat transfer of CaSO₄ solutions were investigated. Experiments demonstrated that the SB coatings had generally better non‐adhesive characteristics, especially at higher values of the electron donor component since the deposits could easily be washed away. For the SB coatings, a longer induction period compared to those of untreated surfaces was observed and a significant reduction of the fouling rate could be achieved. Further analysis of surfaces revealed that SB coatings enhanced the acid‐base repulsive force and thus reduced the deposit/solid adhesion energy. For the WB coatings, the Liftshitz‐van der Waals attractive force plays a decisive role in the adhesion process due to the higher apolar component of the surface energy.     

环保型水下及潮湿界面用防腐涂料的研制

介绍一种以环氧树脂为基料、可用于水下及潮湿界面的环保型防腐涂料;讨论了涂料各组分对涂料性能的影响及选用原则,并简单介绍了水下固化涂料的施工工艺。     

Effect of a Ni‐Based Catalyst on Bio‐Oil Upgrading under CO Atmosphere

A novel method of bio‐oil upgrading over Ni‐based catalysts under CO atmosphere and optimum conditions for a Ni/Cu/Zn/Al catalyst were determined. The oxygen content as well as the water content decreased significantly and the pH value of upgraded bio‐oil was higher than that of crude bio‐oil. The physical properties indicate that upgraded bio‐oil was more stable than crude bio‐oil.     

Preparation of Environmentally Friendly Amino Acid‐Based Anionic Surfactants and Characterization of Their Interfacial Properties for Detergent Products Formulation

In this study, 2 types of amino acid‐based biosurfactants such as potassium cocoyl glycinate (CGK) and sodium cocoyl glycinate (CGN) were synthesized from coconut oil. Their chemical structures were identified using FT‐IR, ¹H NMR, and ¹³C NMR spectroscopies. Characterization of their interfacial properties has shown that both CGK and CGN surfactants are surface‐active and effective in reducing interfacial free energy. Washing test results indicated relatively good detergency compared with surfactants commonly employed in detergent applications. From environmental compatibility tests, both CGK and CGN are found to be readily biodegradable, nontoxic, nonirritating, and very mild. In particular, the CGK surfactant was found to be more efficient in reducing interfacial free energy since a larger number of CGK molecules are preferentially adsorbed at the air–water interface due to higher hydrophobicity and larger mobility of CGK than CGN, indicating possible uses in detergent applications.     

Deoxygenation of Bio‐oil from Calcium‐Rich Paper‐Mill Waste

De‐inking sludge, an ash‐rich recycling paper solid waste, is generated in huge amounts. The catalytic deoxygenation potential of calcium‐based de‐inking sludge in co‐pyrolysis mode with wood and its neat thermal conversion to sustainable biofuels are investigated. Wood, de‐inking sludge, and their blends are processed in a thermocatalytic reforming (TCR) system. In the presence of de‐inking sludge, the oxygen content in the organic phase decreases and the bio‐oil calorific value improves as compared to the neat wood‐derived bio‐oil. The TCR processing of neat de‐inking sludge produces a bio‐oil with low oxygen content and higher calorific value.     

A New Approach for Process Development of Plant‐Based Extraction Processes

Over the last few years the impact of products from natural sources in food, nutraceuticals, cosmetics, flavors/fragrances, and also the pharmaceutical industry has increased due to the consumer demand for nature‐derived products. Meeting this demand requires that existing manufacturing processes have to be optimized and process development for a variety of new products, sometimes with short life cycles, has to be accelerated. A scientific literature review covering equipment and modeling for plant‐based extractions shows an enormous demand for new approaches in process design for solvent extraction, isolation, and purification of ingredients from botanical sources and its transfer from academic research into manageable solutions for industrial use. An approach combining the design of experiments and rigorous process modeling on the one hand and an intensified collaboration between different disciplines including process engineering, botany, and analytical chemistry on the other hand seems to be the only way forward to address the current issues and shortcomings systematically and efficiently. Hence, a standard apparatus for the assessment of the governing process parameters for plant‐based extraction processes is proposed.     

Economic production of Bacillus subtilis SPB1 biosurfactant using local agro‐industrial wastes and its application in enhancing solubility of diesel

BACKGROUND: The present work aimed to optimize a new economic medium for lipopeptide biosurfactant production by Bacillus subtilis SPB1 for application in the environmental field as an enhancer of diesel solubility. Statistical experimental designs and response surface methodology were employed to optimize the medium components. RESULTS: A central composite design was applied to increase the production yield and predict the optimal values of the selected factors. An optimal medium, for biosurfactant production of about 4.5 g L^?1, was found to be composed of sesame peel flour (33 g L^?1) and diluted tuna fish cooking residue (40%) with an inoculum size of 0.22. Increased inoculum size (final OD₆₀₀) significantly improved the production yield. The emulsifier produced was demonstrated to be an alternative to chemically synthesized surfactants since it shows high solubilization efficiency towards diesel oil in comparison with SDS and Tween 80. CONCLUSION: Optimization studies led to a strong improvement in production yield. The emulsifier produced, owing its high solubilization capacity and its large tolerance to acidic and alkaline pH values and salinity, shows great potential for use in bioremediation processes to enhance the solubility of hydrophobic compounds. © 2012 Society of Chemical Industry     

Elimination of Separation Processes for Post‐Consumer Polyolefin Waste: Reactive Blending Using 1,3‐Phenylene Dimaleimide in Presence of Filler

A novel approach using reactive processing is explored that eliminates the labour‐intensive separation of post‐consumer polyolefin waste from the mixed plastics waste stream. The reactive compatibiliser BMI has been used to form a modified blend of PCPW with 40% improved tensile strength relative to the uncompatibilised control. Addition of 60 wt.‐% magnesium hydroxide [Mg(OH)₂] during reactive compatibilisation with BMI gave rise to an even more significant enhancement (up to 100%) of the tensile strength. BMI was also able to usefully enhance the properties of a composite based on calcium carbonate and the polyolefin waste.

     

Contribution of agro‐waste material main components (hemicelluloses,cellulose, and lignin) to the removal of chromium (III) from aqueous solution

BACKGROUND: Agro‐waste materials can be used as biosorbents of heavy metals in aqueous solution. However, it is necessary to further study the contribution of agro‐waste materials components (i.e. hemicelluloses, cellulose, and lignin) to the heavy metal ions removal from aqueous solution to better understand the biosorption mechanism, and also based on the biosorbents main components, to predict their potential to remove heavy metals. RESULTS: Cellulose is contained in major proportion (greater than 46%) in the agro‐waste materials reported herein compared with hemicelluloses (from 12% to 26%), lignin (varying from 3% to 10%), and other compounds (22% to 30%) that were removed after the neutral detergent fiber procedure. The identified functional groups in agro‐waste materials and their fractions included hydroxyl, carboxyl, and nitrogen‐containing compounds. Lignin contributed in higher proportion than hemicelluloses to Cr (III) adsorption capacity in both sorghum straw and oats straw. On the other hand lignin was the main fraction responsible for Cr (III) adsorption in agave bagasse. CONCLUSION: Hemicelluloses and lignin were the main contributors to Cr (III) removal from aqueous solution, and cellulose contained in the agro‐waste adsorbents studied did not seem to participate. Copyright © 2009 Society of Chemical Industry     

Development of brannerite glass‐ceramics for the immobilization of actinide‐rich radioactive wastes

Brannerite‐based glass‐ceramics have been developed as potential waste forms for the immobilization of actinide‐rich radioactive wastes. For the first time, the formation of brannerite phases in glass has been demonstrated using uranium (U) and plutonium (Pu) with additions of gadolinium and hafnium as neutron absorbers. Both XRD and SEM‐EDS confirm that brannerite is the dominating phase with compositions close to Y_0.5U_0.5Ti₂O₆, Gd_0.2Pu_0.3U_0.5Ti₂O₆, and Gd_0.1Hf_0.1Pu_0.2U_0.6Ti₂O₆ internally crystallized in the glass. TEM SAED and Raman spectroscopy reveal the typical structure and vibration modes for brannerite. In addition, the presence of U⁵⁺ species as designed in the formulations has been confirmed by diffuse reflectance spectroscopy. More importantly, the U and Pu were partitioned exclusively in the ceramic phases with no detectable actinide in the glass.     

Development of quasi‐solid‐state dye‐sensitized solar cell based on an electrospun polyvinylidene fluoride–polyacrylonitrile membrane electrolyte

Dye sensitized solar cell (DSSC) has been magnetizing more awareness in current research due to more efficiency. The foremost drawback of the solar cell is the evaporation of organic electrolyte. In order to address this problem, the polyvinylidene fluoride–polyacrylonitrile–Electrospinning Fibrous Membranes were prepared by electrospinning method and the photovoltaic performances were evaluated. The polyvinylidene fluoride and polyacrylonitrile were mixed in N,N′‐dimethylformamide and acetone at an applied potential of 15 kV. The surface morphology of membrane is interconnected with network structure and a large number of voids were observed from Field Emission Scanning Electron Microscopy images. The electrolyte uptakes up to 310% were observed and it shows an increase in the ionic conductivity up to 6.12 × 10^?2 S cm^?1 at 25°C. The fabricated DSSCs show open circuit voltage (V_oc) of 0.74 V, fill factor (FF) of 0.65 and short circuit current (J_sc) of 6.20 mA cm^?2 at an incident light intensity of 100 mW cm^?2. The photovoltaic efficiency also reached up to 3.09%. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2014 , 131, 40022.     

Bio‐Based Rubbers by Concurrent Cationic and Ring‐Opening Metathesis Polymerization of a Modified Linseed Oil

Bio‐based rubbers prepared by tandem cationic polymerization and ROMP using a norbornenyl‐modified linseed oil, Dilulin?, and a norbornene diester, NBDC, have been prepared and characterized. Increasing the concentration of the NBDC in the mixture results in a decrease in the glass transition temperature. The new bio‐based rubbers exhibit tensile test behavior ranging from relatively brittle (18% elongation) to moderately flexible (52% elongation) and with decreasing values of tensile stress with increasing NBDC content. Thermogravimetric analysis reveals that the bio‐based rubbers have maximum decomposition temperatures of over 450 °C with their thermal stability decreasing with increasing loadings of NBDC.

     

Antiplasticizing Behaviors of Glucarate and Lignin Bio‐Based Derivatives on the Properties of Gel‐Spun Poly(Vinyl Alcohol) Fibers

Petrol and biochemical plasticizers are added to poly(vinyl alcohol) (PVA) to improve its processability while tuning its moisture sensitivity. But those additives often reduce the mechanical performance of PVA products. In this study, the antiplasticization and properties of PVA containing additives from biorenewable sources are studied. PVA fibers are gel‐spun having up to 3 wt% glucarate salts and 30% lignin. Glucarate lowers the gel melting temperature of PVA and increases fiber draw ratio. Further, glucarate enhances the mechanical performance of PVA beyond that of neat fibers. Interestingly, the combination of lignin and glucarate causes phase separation among fiber—a PVA/glucarate phase as the fiber core and lignin/PVA phase as the fiber shell. Neat PVA partially dissolves in 85 °C water; whereas, fibers containing glucarate and/or lignin resist dissolution. Thus, the combination of glucarate and lignin can induce high strength and moisture resistance, which are desirable industrial fiber properties.     

Behavior of immobilized glucose oxidase on membranes from polyacrylonitrile and copolymer of methylmethacrylate‐dichlorophenylmaleimide

Two new ultrafiltration membranes were obtained from a polymer mixture, containing 60% polyacrylonitrile (PAN) and 40% copolymer of methylmethacrylate‐dichlorophenylmaleimide (MMA‐DCPMI). Membrane 1 (MB1) contains 40% DCPMI of the copolymer, and membrane 2 (MB2) contains 15% of the copolymer. The pore size, the specific surface, the water content, the water flux, and the selectivity were determined for the two membranes. The presence of dichlorophenylmaleimide in the copolymer ensures the preparation of membranes suitable for direct covalent enzyme immobilization without further modifications. These membranes were used for immobilization of glucose oxidase (GOD). High amount of bound protein was found on each of the membranes. High relative activities of the immobilized GOD were achieved, 72% for MB1 and 68% for MB2. The properties of the immobilized enzyme (GOD) were determined: optimum pH and temperature and pH, thermal, and storage stability, and then compared with the properties of the native enzyme. The kinetic parameters of the enzyme reaction, Michaelis constant (K_m) and maximum reaction rate (V_max), were also investigated. The results obtained showed that the ultrafiltration membranes prepared from the mixture of PAN and the copolymer MMA‐DCPMI were suitable for use as carriers for the immobilization of GOD. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4334–4340, 2006     

Hydrolysis of citrus peel naringin by recombinant α‐L‐rhamnosidase from Clostridium stercorarium

The citrus fruit processing industry generates substantial quantities of waste rich in glycosylated phenolic substances such as naringin, which are a valuable natural source of polyphenols as well as L‐rhamnopyranose. Naringin is the major polyphenol in bitter orange peel and its hydrolysis by α‐L ‐rhamnosidase (EC 3.2.1.40) catalyzes the cleavage of the terminal rhamnosyl groups to form prunin and rhamnose. In this work, a recombinant α‐L ‐rhamnosidase from C. stercorarium was shown to be suitable for narigin hydrolysis. The recombinant rhamnosidase was found to be relatively stable at 60 °C, and a residual activity close to 50% after 180 min of incubation was demonstrated. The purified enzyme established hydrolysis of naringin extracted from citrus peel waste (CPW). The result indicated that recombinant α‐L ‐rhamnosidase has industrial applicability and is an interesting candidate for producing rhamnose from citrus peel. Copyright © 2010 Society of Chemical Industry     

Fabrication of durable hydrophobic cellulose surface from silane‐functionalized silica hydrosol via electrochemically assisted deposition

Durable excellent hydrophobic surface on cellulose substrate was fabricated from the silica hydrosol functionalized with silane chemicals by a facile electrochemically assisted deposition technique. The silica hydrosol was synthesized using tetraethoxysilane (TEOS) as the precursor and sodium dodecylbenzene (SDBS) as the emulsifier under acidic conditions. The hydrophobic silane modifiers including octyltriethoxysiliane (OTES), dodecyltriethoxysiliane (DTES) and isooctyltriethoxysiliane (iso‐OTES) and the silane‐coupling agent γ‐mercaptopropyltriethoxysilane (MPTES) were used to dope the silica hydrosol for preparing durable hydrophobic cellulose surface. The cellulose surface modified with silane modifier iso‐OTES exhibited the best hydrophobicity with water contact angle of 162.3 ± 0.5° due to its non‐polar and hydrolytically stable of ? Si(C₈H₁₇) groups. The addition of silane‐coupling agent MPTES containing the ? SH group led to good durability of hydrophobicity with water contact angle of 130.0 ± 1.2° after 20 washing times. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42733.