离子膜碱浓缩装置的比较

从工艺流程、设备材质、操作、汽耗等方面对双效逆流降膜浓缩装置和双效逆流板式蒸发器浓缩装置进行了比较,结果表明两种浓缩装置各有特点。     

离子膜片碱装置的国产化改造

介绍了对离子膜片碱装置部分设备如F-1A片碱机转鼓、降膜浓缩器、碱液预热器等国产化改造的过程及运行效果。     

离子膜烧碱DCS控制系统的改造

介绍了横河公司的分布式控制系统CS3000在离子膜烧碱生产过程中的应用。阐述了系统的工艺流程、硬件配置、软件配置和控制系统的主要功能。     

HZSM-5固载苯并噻唑离子液体催化合成烷基糖苷及其动力学

以自制苯并噻唑离子液体([HBth]HSO4)为活性组分，HZSM-5分子筛为载体，通过过量溶剂浸渍法制备了固载型苯并噻唑离子液体催化剂([HBth]HSO4/HZSM-5)并用于催化合成烷基糖苷，通过傅立叶变换红外光谱、N2物理脱附、场发射电子显微镜和X射线衍射对催化剂结构进行表征，结果表明，[HBth]HSO4被成功地引入到HZSM-5载体的表面及孔道内。当催化剂用量为1.5 wt%，反应温度为105℃，醇糖摩尔比n(葡萄糖):n(辛醇)=6:1时，辛基糖苷得率达148.8%（产物质量/葡萄糖的质量?100%）。底物拓展及催化剂稳定性研究结果表明，[HBth]HSO4/HZSM-5对烷基糖苷及其衍生物都具有良好的催化效果，且催化剂能稳定循环使用四次，活性组分流失是催化剂失活的主要原因。通过对烷基糖苷催化合成机理和动力学的研究，确定了动力学方程。     

Low-pressure CO2 sorption in ammonium-based poly(ionic liquid)s

Ammonium-based ionic liquid monomers and their corresponding polymers [poly(ionic liquid)s] are synthesized and characterized for CO₂ sorption. The polymers have much higher CO₂ sorption capacities than the room-temperature ionic liquids and imidazolium-based poly(ionic liquid)s. For example, P[VBTMA][PF₆] with polystyrene backbone has a CO₂ sorption capacity of 10.67 mol%. The CO₂ sorption is selective over N₂ and O₂. The effects of cation, backbone, substituent, anion and crosslinking on CO₂ sorption are discussed. The sorption mechanism study indicates that CO₂ sorption by the poly(ionic liquid)s is a bulk and surface phenomenon.     

Mechanosynthesis of complex oxides and preparation of mixed conducting nanocomposites for catalytic membrane reactors

Nanopowders of LaGaO₃- and LaMnO₃-based complex perovskites (P) and ceria-based fluorites (F) were prepared by mechanosynthesis. Compatible nanocomposites F + P and P + P with mixed ion and electron conducting (MIEC) properties were prepared and sintered at moderate temperatures up to dense ceramics. The obtained materials were studied by means of XRD, SEM, TEM, electrical conductivity measurements, temperature programmed (TP) reduction/oxidation and preliminary estimations of permeability were obtained. A new strategy based on the advantages of the mechanochemical ceramic approach is proposed to design multilayer ceramic membranes for CMR. Casting technology and one-step sintering were used for the production of thin film membranes with MIEC properties on porous substrates. The coarse fraction of as-milled powders from agglomerates with density 70% was used for the porous substrate, and fine fractions of aggregates with sizes <1 μm were used in preparation of composites for thin dense films. Ceria-based composites prepared by the Pechini route and/or mechanochemical method are proposed as materials for protecting thin films.     

Electrical conductivity and redox stability of La2Mo2−xWxO9 materials

A series of compounds La₂Mo_2−xW_xO₉ (x = 0-2) were synthesized using a freeze-dried precursor method at relatively low temperatures (673-823 K). These materials were characterised by thermogravimetric and differential thermal analysis (TG/DTA), differential scanning calorimetric (DSC), X-ray diffraction (XRD), and transmission electron microscopy (TEM) and dilatometric measurements. Oxygen stoichiometry was evaluated by coulometric titration and thermogravimetric analysis at 873-1273 K. The ionic and electronic conductivities of these materials were analysed by impedance spectroscopy and a Hebb-Wagner ion-blocking method under moderately reducing conditions. The presence of W⁶⁺ leads to an increase of the stability range (about 10⁻¹⁶ Pa for La₂Mo_0.5W_1.5O₉ at 1073 K) and prevents oxygen loss and amorphisation. Within the stability range, the electronic conductivity increases gradually as the temperature increases and as the oxygen partial pressure reduces. This indicates that the electronic transport is mainly n-type as a result of the oxygen-content decreasing in the molybdate lattice. Further reduction of the oxygen partial pressure gave rise to the decomposition of La₂Mo_2−xW_xO₉, leading to the formation of new phases with molybdenum in lower oxidation states, which further enhances the electronic conductivity. The results of the coulometric titration and the thermogravimetric studies under a dry 5% H₂/Ar flow suggest that tungsten doped lanthanum molybdate materials can be used as electrolyte only at low temperature and under moderate reducing conditions.     

Molecular weight distributions and size fractionations of H-coal liquids

This Paper deals with a comparative study on the use of gel permeation chromatography (g.p.c.) and vapour pressure osmometry (v.p.o.) to obtain molecular weight data for the hexane-soluble fractions of three H-coal liquids. The use of two types of column packing materials, polyvinylacetate and styrene-divinylbenzene copolymer gels, is described. A successful, preparative use of the polyvinylacetate gel to fractionate the hexane-soluble fraction of H-coal liquid, atmospheric still overhead (ASO), has been established. Molecular weight data obtained by v.p.o. for the benzene-soluble fraction and the pyridine-soluble fraction of the three H-coal liquids are reported. Solvent extraction has been utilized also to find the amount of oil, asphaltenes and asphaltols in the three H-coal liquids.     

室温离子液体1-烷基-3-甲基咪唑硫酸甲酯的合成及电导率研究

利用硫酸二甲酯分别与N-甲基及N-丁基咪唑在室温下反应,一步合成了离子液体1-甲基-3-甲基咪唑硫酸甲酯和1-丁基-3-甲基咪唑硫酸甲酯,测定了在不同温度下离子液体的电导率.结果表明:随着温度的升高,离子液体的电导率迅速增加;同时电导率与温度的变化关系符合多项式方程和Vogel-Tammann-Fulcher(VTF)方程.     

Compatibilization of PP/elastomer/microsilica composites with functionalized polyolefins: Effect on microstructure and mechanical properties

The morphology and mechanical properties of polypropylene/elastomer/silica composites were investigated with the aim of improving stiffness and impact resistance. Two different types of silica were tested: Precipitated silica and polymer grade microsilica (silica fume). The composites were compatibilized with commercial polypropylene and polyethylene containing maleic anhydride functionality as a means of controlling their microstructure and ultimately their mechanical properties. Comparisons were made with surface coated silica and hydroxyl-functionalized copolymers prepared with metallocene catalysts. The effect of adding the polymeric compatibilizers was assessed by morphology studies, thermal analysis and mechanical testing. Significant improvements in impact strength were obtained by tailoring the microstructure of polypropylene/elastomer/microsilica composites. With introduction of PP-g-MAH as compatibilizer, stiffness was enhanced simultaneously with impact strength. DSC curves of crystallization provided evidence to support the formation of different microstructures.