Advanced Materials Research Vols. 550-553

Abstract: Three different kinds of MnOx desulfurization sorbent were prepared by different calcination temperature and reduction method. The properties of H₂S removal and COS formation over the prepared MnOx were measured in the fixed bed at 550°C, and the MnOx phases before and after desulfurization were characterized by XRD and XPS. The results show that the sequence of the amount of COS formation over three MnOx samples is Mn₃O₄>Mn₂O₃>MnO, and the sequence of H₂S penetration time is Mn₃O₄2O₃2 are good for COS formation. With the single sulfur and MnS₂ accumulated in MnOx desulfurization sorbent, the more and more the amount of COS formed during desulfurization.

Abstract: Ionic liquid (IL) N-methyl-N-methylimidazoliumdimethyl phosphate ([DMIM][DMP]) and active carbon (AC) binary system were established and demonstrated to be effective for the deep removal of sulfur compounds (Dibenzothiophene, DBT) from model oil at room temperature. Mass ratio of IL to active carbon on the extractive performance, desulfurization temperature, time and desulfurization reagent to model oil were investigated. In the first stage desulfurization efficiency of binary system, IL and active carbon were 65.09%, 51.72% and 47.3%，which was followed the order of binary system > IL > active carbon. It was suitable to carried out desulfurization process with mass ratio of IL to active carbon in 1:1, binary system to model oil in 1:1 for 10 min at 25-45oC. In the optimiazed condition, desulfurization efficiency of binary system was nearly 100% after the fifth stage desulfurization process.

Abstract: The absorption of CO₂ with ethanolamine (MEA) was studied in this paper, and proper additives such as piperazine (PZ) and N- methyldiethanolamine (MDEA) were mixed in different proportion to the main reacting substance. The performance of absorbents with different formula were studied by analyzing and comparing the characteristic indexes of absorbents, including absorption rate, regeneration temperature, absorption capacity of CO₂, and regeneration degree. The results have been shown that aqueous solutions added PZ could increase absorption rate and improve absorption capacity than that of MDEA, and Aqueous solutions added MDEA could decrease regeneration energy and improve regeneration degree than that of PZ. The formular of 16%MEA+4%PZ could be the most suitable absorbent of CO₂ in the study.

Abstract: In this paper, the C-doped TiO₂ was prepared by hydrothermal method with butyl titanate and glucose as the precursors. Then, C-doped TiO₂ was further modified by CTAB during the above hydrothermal method. The synthesized samples were characterized by BET before and after the modification. The results show that the surface area of C-doped TiO₂ became smaller after the modification (from 236 m2/g to 99.7 m2/g), but the adsorption amount for methyl orange was enhanced greatly after the modification. The biggest adsorption amount for methyl orange was up to188.7 mg/g for modified TiO_2-XC_X in the methyl orange solution of 200 mg/L.

Abstract: The fractions of benzyl benzoate and fluorenone were enriched from the benzoic acid residua by flash separation. Then this fraction was separated by vacuum batch distillation. The recovery of benzoic acid residua was implemented. The experiment proves this method is feasible. And purity about 90% of benzyl benzoate and more than 85% of fluorenone products were obtained. Simultaneously the study analyzed the impact of tower top pressure, tower top and bottom temperature, reflux ratio on product purity. The optimal condition in operating was defined in the experiment condition.

Abstract: Chemical-looping combustion (CLC) is a novel technology, which has inherent property of separating the greenhouse gas CO₂, which uses oxygen carriers to transfer oxygen for combustion from air to fuel. The reactivity of Fe₂O₃/Al₂O₃ oxygen carrier was assessed by measuring their ability to oxidize CO. The kinetics and mechanism of oxygen carrier have been studied by TG and DTG techniques. The kinetic mechanism function of the reaction between Fe₂O₃/Al₂O₃ and CO has been built using the Coats-Redfern equation.

Abstract: Gas-liquid flow in a stirred vessel was simulated numerically with computational fluid dynamics(CFD). Gas was treated as discrete phase and described by discrete phase model (DPM), while the liquid was considered as a continuum and solved under Euler reference frame. The liquid velocity, gas holdup and gas residence time distribution in the stirred vessel were predicted. The simulation results show that gas dispersion in the stirred vessel is very non-uniformity and high gas holdup is found in the centre of the stirred vessel and vortexes while relatively low in bottom region and region between two impellers. Liquid velocity has great influence on bubble residence time and size distributions.

Abstract: To study the macroporous resin separation and purification of total flavonoids of Plantago optimum conditions, the static adsorption and desorption experiments by filtering out the best macroporous resin, and plantain extract for the assessment of total flavonoid content indicators in the single-factor test based on the orthogonal design, the amount of resin in the hole, eluent concentration, alcohol consumption and other factors for the study to optimize the AB-8 macroporous resin separation and purification of total flavonoids plantain best process conditions. The results show that: the effect of various factors affecting the size of the order of separation and purification has to: eluent concentration> ethanol consumption> macroporous resin usage, optimization of the optimum conditions: resin dosage is 1 times the amount of crude drug, the use of eluent volume fraction of 40% ethanol, elution agent is 12.5 times the amount of crude drug. Verify the conditions in this test, three repeated experiments were similar, the average flavonoid content 0.2127%, the transfer rate of 90.57%, indicating that the scientific and rational and stable process conditions can be effectively used plantain purified flavonoids.

Abstract: In this study, physical properties of chitosan edible films incorporated with essential oil monomers were tested. Emulsifying nature of chitosan could be combined essential oil monomer forming emulsions, hence homogeneous, thin and pale yellow membranes were achieved. With different of the essential oil monomer content, the nature of the films had undergone a drastic change. Water-solubility and water vapor permeability of chitosan edible films reduced when essential oil monomers concentration increased. All the mechanical properties(tensile strength and elongation) increased when essential oil monomers concentration gradual increased. Compared with single chitosan films, essential oil-chitosan films have been greatly enhanced their mechanical properties and antibacterial activities.

Abstract: The purpose of this study was to enhance the dissolution rate of daidzein (DZ) by solid dispersions. DZ solid dispersion was prepared by solvent method, with PVP K30 and surfactant as carriers. The influences of drug-carrier proportion, the kind of surfactant and the amount of surfactant on the dissolution of DZ were examined. Solid dispersions were characterized by infrared spectroscopy (IR), X-ray diffraction spectroscopy, and dissolution tests. When appropriate amount of poloxamer was added into the solid dispersion, the dissolution of DZ could be improved obviously. The data of IR showed that the absence of well-defined drug-polymer interactions. The data of X-ray diffraction showed that the drug might exist in the form of amorphism or molecule in solid dispersions. Both the binary and ternary solid dispersions enhanced the dissolution of DZ. Moreover, poloxamer played an important positive role in improving the dissolution rate of DZ in the solid dispersion.