沥滤法制备骨架镍催化剂的过程动力学

详细探讨了镍铝合金在氢氧化钠水溶液中的沥滤机理,用 EDTA 滴定的方法测得其动力学数据,拟合得到动力学方程式:log[x/(1-x)]=α·log(β·t),求得几种条件下的参数α、β值及沥滤过程的活化能 E_(n)=71.17 kJ·mol~(-1),同时研究了合金颗粒尺寸和氢氧化钠浓度对沥滤速率的影响。     

Raney－Ni浸取方法对木糖加氢活性的影响

在木糖加氢反应中，考察了浸取（Ｌｅａｃｈｉｎｇ）方法对Ｒａｎｅｙ－Ｎｉ催化剂活性的影响。合金原料是１６０～２００目及＜３２０目的Ｎｉ－Ａｌ－Ｔｉ。实验表明，温度（５０～９３℃）及ＮａＯＨ浓度（２～６ｍｏｌ／Ｌ）越高，催化剂活性越好。但是，若先在低温和稀碱下浸取，再继以高温和浓碱的后处理，则比单一条件浸取时活性好。浸取起始１０～２０ｍｉｎ的反应剧烈程度，对合金破碎情况和催化剂活性均有显著影响；而后处理使活性提高的主要原因是对催化剂微孔的扩孔作用。     

EVALUATION OF LEACHING CONDITIONS FOR DISSOLUTION OF PYRITE IN CHLORINE-SATURATED WATER

The optimum leaching conditions for the dissolution of pyrite in water saturated with chlorine gas were investigated. Reaction temperature, solid-to-liquid ratio, reaction time, and particle size were selected as the leaching parameters. 2ⁿ factorial experimental design and orthogonal central-composite design methods were used. A mechanical stirring speed of 500 rpm and chlorine gas-flow rate of 1379 mL/minute were chosen as the fixed parameters in all experiments. The degrees of effectiveness from high to low were found to be, in respective order, the particle size, the reaction temperature, the solid-to-liquid ratio, and leaching time. A reaction temperature of 30°C, solid-to-liquid ratio of 0.167 g/mL, particle size of 150–212 μm, and reaction time of 360 minutes were found to be the optimum leaching conditions. The dissolution yield of iron from pyrite was 98.4% under optimal leaching conditions.     

南方稀土矿浸出传质的研究

本文从传质的角度，研究了淋侵速度、浸出剂浓度、矿石粘度、原矿稀土品位对南方某稀土矿浸出效果的影响；用色层塔板理论和vanDeemter方程进行分析，找出了然浸速度与浸出效果之间的规律，为高效、低耗、合理地开采南方稀土矿提供了理论依据．     

COMPARISON OF KINETIC MODELS FOR THE AQUEOUS SOLID-LIQUID EXTRACTION OF TILIA SAPWOOD IN A CONTINUOUS STIRRED TANK REACTOR

The kinetic study of the aqueous extraction of Tilia sapwood was based on temperature, while all the other factors were kept constant. Several models were used and compared to explain the kinetics of the aqueous solid-liquid extraction of Tilia sapwood. For each model, the rate constant, the equilibrium extraction capacity, and the initial extraction rate were evaluated to analyze the suitability of these kinetic models to describe the leaching process for temperatures ranging from 313 to 363 K. The pseudo first-order model could not be applied during the whole of the process. The Elovich model provided a good degree of correlation (from 0.929 to 0.988) and could be applied all along the extraction process. The pseudo second-order model was satisfactorily applied, with coefficients of correlation over 0.998, showing that it perfectly described the process. A physical explanation of these models was finally proposed.     

影响固态发酵速率的因素及其动力学

论述了固态发酵过程中基质的形态特性、基质含水量、通气速率与气体组成、发酵温度诸因素对发酵速率的影响；探讨了固态发酵过程动力学模型及其特征。     

铝矾土种类和用量对锆刚玉莫来石性能影响的灰色关联分析

采用工业氧化铝、锆英石和氧化铈合成锆刚玉莫来石,着重讨论了两种铝矾土部分取代工业氧化铝对锆刚玉莫来石材料性能的影响。通过灰色关联分析,得到结论为:铝矾土中的熔剂数量是影响材料抗折强度的主要因素,当铝矾土中杂质少SiO2含量较高时,试样的吸水率与铝矾土的加入量关联性最大。     

MODIFIED PLANTAIN PEEL AS CELLULOSE-BASED LOW-COST ADSORBENT FOR THE REMOVAL OF 2,6-DICHLOROPHENOL FROM AQUEOUS SOLUTION: ADSORPTION ISOTHERMS,KINETIC MODELING,AND THERMODYNAMIC STUDIES

In this study, the feasibility of using modified plantain peel to remove 2,6-dichlorophenol from iaqueous solutions was investigated under batch mode. The effects of physical factors such as initial 2,6-dichlorophenol concentration, contact time, biosorbent particle size, biosorbent dosage and temperature on the removal process were evaluated. The results showed that biosorption of 2,6-dichlorophenol was dependent on these factors. The equilibrium biosorption data were analyzed by the Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich (D-R) adsorption isotherm models. The four tested isotherm models provided good fits to the experimental data obtained at 30°C; however, the Freundlich isotherm model provided the best correlation (R² = 0.9874) of the experimental data. The maximum monolayer biosorption capacity (Q _max ) was found to be 14.25 mg/g. The biosorption kinetics data of 2,6-dichlorophenol were analyzed by pseudo-first-order, pseudo-second-order, Elovich, intraparticle diffusion, and liquid film diffusion models. The five kinetic models fitted well to the biosorption kinetic data; however, the pseudo-second-order kinetic model gave the best fit when the biosorption mechanism was controlled by film diffusion. Thermodynamic quantities such as standard Gibbs free energy (ΔG°), standard enthalpy (ΔH°), standard entropy change of biosorption (ΔS°), and activation energy (E_a) were evaluated, and it was found that the biosorption process was spontaneous, feasible, endothermic in nature and of dual nature, physisorption and chemisorption; however, the physisorption process was dominant. Therefore, modified plantain peel has potential for application as an effective bioadsorbent for removal of 2,6-dichlorophenol from aqueous solution.     

副产物含量对栲胶脱硫液性质的影响

在栲胶脱硫生产过程中除了主反应外,同时还伴随Na2S2O3,Na2SO4,NaSCN及NaHCO3等盐类生成的副反应.这些副产物的生成会影响栲胶脱硫液的性质,并最终影响整个脱硫循环工艺的稳定.为了避免这些影响,从表面张力、黏度和密度三个方面分析了Na2S2O3,Na2SO4,NaSCN和NaHCO3四种栲胶脱硫工艺的副产物对栲胶脱硫溶液的影响.结果表明,副产物的积累可以引起脱硫溶液表面张力的下降以及溶液黏度和密度的增加,从而引起脱硫工艺中操作条件的改变,最终影响整个系统的脱硫效率.     

不同污泥负荷厌氧-好氧间歇式活性污泥工艺除磷

基于厌氧-好氧-间歇式活性污泥系统,探讨了反应温度分别在15、25℃下COD污泥负荷对生物除磷系统的影响.将进水TP的质量浓度恒定为(10±0.5)mg·L~(-1),以比较厌氧段末和出水TP的含量.结果表明,在2个温度条件下,随着COD污泥负荷的升高,出水TP含量降低,当COD污泥负荷≥0.46 mg·mg~(-1)·d~(-1)时,出水TP的质量浓度低于1 mg·L~(-1);厌氧段释磷量与COD污泥负荷均存在很好的线性关系:y_1=0.72+71.91_x1(25℃),y_2=2.81+73.3_x2(15℃);在COD污泥负荷相同条件下,15℃时TP去除效果比25℃平均高5%左右.     

STACK-WIDE EFFECTS IN THE MODELING OF SOLAR KILNS FOR DRYING TIMBER

This study examines the stack-wide effects due to the humidification and cooling of air as it passes through a 6 m wide stack of Australian ironbark timber for conditions that are representative of those for solar drying (dry and wet-bulb temperatures of 60 and 50°C, respectively). A solar kiln model for a greenhouse-type design has been modified to account for the drying of timber boards and the possibility of stack-wide effects, in terms of moisture-content differences in the streamwise direction of air flow through the stack. The maximum difference between the moisture contents of the leading and trailing boards is predicted to be 0.011 kg kg^-1 for these conditions, compared with timber moisture contents of 0.15-0.35 kg kg^-1. Hence, the stack-wide effect is insignificant for these conditions in this greenhouse kiln design and may be ignored, reducing the simulation time by over 50%. In addition, 14 elements within a finite-difference model for the drying of the timber boards (25 mm thick) gives predictions of the drying time that are acceptably accurate, while minimizing the computational time.     

C207甲醇合成铜基催化剂本征失活动力学

一、前言工业生产中广泛使用的甲醇合成铜基催化剂具有活性高、选择性好、起始活性温度低等优点。但铜基催化剂抗毒性能差,影响了它的使用寿命。铜基催化剂的主要毒物是原料气中所含的 H_2S。铜基催化剂 H_2S 中毒失活研究,国内未见报道,美国的 Wood 等和 Rdvodic 等作过一些研究。本文通过对国产 C207铜基催化剂硫化氢中毒失活动力学的研究,建立描述活性衰退过程的失活动力学方程,得到活性与硫化     

ROLE OF WATER IN THE KINETIC MODELING OF METHANOL TRANSFORMATION INTO HYDROCARBONS ON HZSM-5 ZEOLITE

The attenuating effect of reaction-medium water (feed and/or reaction product) on the kinetics of the steps of methanol transformation into hydrocarbons on a HZSM-5 zeolite catalyst was studied by means of a kinetic model. In this model, the effect of water was quantified in all the steps of the kinetic scheme by means of a kinetic parameter, which is constant with temperature under the conditions of the MTG process. At low temperature, under conditions in which only methanol dehydration occurs, the kinetics of this reaction is attenuated by the presence of water, and the coefficient that quantifies the attenuation decreases as temperature is increased. In addition to considering the effect of water content in the reaction medium, another innovation of the kinetic model proposed, compared to those proposed in the literature consisting of lumps, is the fact that the higher reactivity of dimethyl ether over methanol is taken into account. A step of cracking of gasoline lump hydrocarbons to produce light olefins (ethene and propene) was also taken into account. The kinetic model proposed was verified by using the results obtained in an integral isothermal fixed bed reactor, in the 573-723 K range, for an ample range of space time values. The results revealed that the effect of water is due to its adsorption on the active sites by competition with the intermediate compounds of the kinetic scheme.     

ROLE OF WATER IN THE KINETIC MODELING OF METHANOL TRANSFORMATION INTO HYDROCARBONS ON HZSM-5 ZEOLITE

The attenuating effect of reaction-medium water (feed and/or reaction product) on the kinetics of the steps of methanol transformation into hydrocarbons on a HZSM-5 zeolite catalyst was studied by means of a kinetic model. In this model, the effect of water was quantified in all the steps of the kinetic scheme by means of a kinetic parameter, which is constant with temperature under the conditions of the MTG process. At low temperature, under conditions in which only methanol dehydration occurs, the kinetics of this reaction is attenuated by the presence of water, and the coefficient that quantifies the attenuation decreases as temperature is increased. In addition to considering the effect of water content in the reaction medium, another innovation of the kinetic model proposed, compared to those proposed in the literature consisting of lumps, is the fact that the higher reactivity of dimethyl ether over methanol is taken into account. A step of cracking of gasoline lump hydrocarbons to produce light olefins (ethene and propene) was also taken into account. The kinetic model proposed was verified by using the results obtained in an integral isothermal fixed bed reactor, in the 573–723 K range, for an ample range of space time values. The results revealed that the effect of water is due to its adsorption on the active sites by competition with the intermediate compounds of the kinetic scheme.     

添加剂种类对活性炭纤维中孔结构的影响

纺制了含不同种类添加剂（金属氧化物、聚合物及炭素颗粒）的PAN原丝，经预氧化、炭化活化，制得了中扎含量不同的活性炭纤维，考察了添加剂种类对活性炭纤维中孔结构的影响，发现金属氧化物TiO2、Mgo，聚合物PVA、PVAc及炭黑均可明显提高最终活性炭纤维的中孔率。     

不同瘦化剂在配煤炼焦中的研究进展

对冶金焦粉、石油焦粉和无烟煤等瘦化剂的来源及性质进行了总结。探讨了不同瘦化剂在配合煤成焦过程中的作用机理。得出冶金焦粉可改善焦炭抗碎强度和提高块焦率;石油焦粉可改善焦炭耐磨强度和反应后强度,降低灰分含量;无烟煤可代替部分瘦煤,降低焦炭反应性和硫含量。     

当代生活陶艺设计中媒介语言运用综述

生活陶艺的设计是通过泥、火、釉三大媒介语言来传达的，陶土与釉料的可自由发挥度与烧制方式带来的不可预期性的奇妙结合，给艺术家的灵感、想象和智慧提供了极为开阔的活动空间，使技艺、激情和思想可以自由驰骋其中。     

铸膜液中水含量对聚砜超滤膜结构和性能的影响

试验在环境温度20℃、相对湿度50%、凝胶浴温度20℃的条件下制膜,在聚砜(PS)铸膜液中添加水为非溶剂添加剂,研究水添加量对铸膜液粘度、膜性能和结构的影响.结果表明,水的添加对铸膜液起到了增粘的作用;30℃ PS的质量分数为14%铸膜液所成膜的纯水通量随铸膜液中水的添加量的增加大体上呈增加的趋势,从59.1增大到126.4 L·m~(-2)·h~(-1);截留率则略有下降;相应的膜表面的孔径增大、孔增多;相同水添加量(质量分数0.05%)PS的质量分数为14%的铸膜液粘度随温度的升高而减小;铸膜液温度的升高,相应的膜的纯水通量随之增加,截留率则略有下降.     

煤转化中的三废污染控制和综合利用实例

本文介绍了煤转化过程中的三度污染控制和综合利用的四个实例:粉煤灰用于含氟废水处理;焦渣、炉渣用作废水处理中的生物载体;烟道气用于中和碱性废水和煤气洗涤废水的循环利用。