Characterization of Thai limestone for desulphurization in a fluidized bed combustor

The objective of this study is to determine the chemical kinetics of desulphurization of Thai limestone in an atmospheric fluidized bed combustor (AFBC). The experiments, which employed the batch technique using the limestone samples from six major sources in Thailand, were performed in a laboratory‐scale AFBC. The results obtained were analysed and correlated in the form of apparent reaction rate and deactivation rate constants as a function of operating conditions of the furnace and their properties, respectively. The formulae derived from these correlations were kept as general as possible in order that they could be used as input parameters for the selected mathematical model of desulphurization in an AFBC that is suitable for practical use. The predicted results were in good agreement with the experimental data reported in the literature. Copyright © 2003 John Wiley & Sons, Ltd.     

水质稳定剂LSH-406的研制及应用

针对中国石油格尔木炼油厂10万t／a甲醇装置循环冷却水系统水质差，换热器出现结垢、腐蚀等问题研制开发了水质稳定剂(水稳剂)LSH-406，并进行了工业应用。经过2个月的运行监测，结果表明，系统浓缩倍数大于4，20^#碳钢腐蚀速率小于0．075mm／a，不锈钢腐蚀速率为0．0005mm／a，每月污垢沉积速率小于15mg／cm^2。     

钛铁矿选择氯化法制取人造金红石的热力学与动力学

研究了钛铁矿选择氯化制取人造金红石反应的Fe-Ti-C-O2-Cl2系平衡图，计算了氧与某些氯化物相互作用的自由能变化，采用“通氧一步选择氯化法”，解决了选择氯化“自热”反应持续进行的技术关键，对反应参数进行了实验室，半工业和工业化生产试验研究，研究证明，选择氯化过程的动力学模型是“固体颗粒粒度保持不变的缩核反应模型”，动力学区的活性能为34．33kJ/mol；扩散区的活化能为0．80kJ/mol，研究开发的无筛板沸腾氯化炉可以长期稳定地连续运转，生产出的人造金红石品位为92．10％，经摇床和磁选，品位达到95％，床层单位炉产能达12．4t/(m2.d)，该工艺和设备已成功地应用于工业生产。     

冰覆盖下河道水流特性及床面高程的研究

本文对冰覆盖下的河道水流进行了区域划分,给出了区域分界面上的水流条件。应用水力学中的一些基本概念和基本原理,对冰覆盖下河道水流阻力、水流流速、切力、能坡及床面高程等问题进行了研究,给出了它们的物理概念和计算公式,并用实验观测资料进行了验证,结果令人满意。     

气相聚合流化床内静电与结片现象的研究进展

综述了气相聚合流化床内静电及结片现象的研究进展,对流化床内结片现象进行了描述,将静电与流化床的壁面结片现象关联,并从流化床流体力学行为与静电生成速率的关系出发对静电的生成机理进行了论述。通过对流化床内静电分布分析,确定了流化床内静电积累和消散的位置。提出了流化床内静电检测、静电产生机理、静电信号与工业流化床中结片现象关联等有待继续研究的方向和领域。     

Thermal characteristics of packed bed storage system

The thermal behaviour of a packed bed storage system charged with hot air is modelled using two partial differential equations representing the energy conservation in the air and solid phases constituting the bed. These two equations are coupled through the heat exchange process between the two phases. A fully implicit numerical scheme based on forward, upwind and central differencing for the time, first and second space derivatives, respectively, is used to solve the modelling equations. Marching technique is used for the air equation and a tri-diagonal matrix solver is employed to solve the solid equation. The solution yields the thermal structure of the bed, namely the air and solid temperature distribution inside the bed at any particular time, and the variation of total energy stored in the bed with time. The effect of bed length, solid diameter and void fraction on the thermal characteristics of the packed bed is studied. Further, the performance of the bed under variable inlet air temperature and mass flow rate is investigated.     

Characteristics of the reactive distillation column with a novel internal

A new catalyst loading method, in which catalyst particles are packed in a reactor with a novel internal, has been studied by measuring pressure drop, RTD, liquid holdup and mass transfer. It can be inferred from experimental results that the internal changes the conventional gas and liquid counter-current flow into a new cross-current flow, so the problems of excessive pressure drop and “flooding” are avoided. When pressure drop, liquid holdup, RTD and mass transfer coefficient are similar, the catalyst loading fraction of the new method is much higher than that of conventional methods. Furthermore, the reactive distillation reactor with the novel internal has advantages such as simple structure, low operating cost, and convenience for installation and removal of the catalyst.     

Investigation of the stability of tablets prepared from sucrose and citric acid anhydride utilizing response surface methodology

Inversion of sucrose is a stability problem particularly of candies with acidic taste that contain sucrose and small amounts of organic acids such as citric acid, since the free d-fructose produced by hydrolysis is hygroscopic. The following possibilities were investigated for preventing the hydrolysis of sucrose in tablets containing sucrose and citric acid: Adding various amounts of tri-sodium citrate to the formulation to neutralize the citric acid, (Hot) melt coating of citric acid and tri-sodium citrate with a vegetable fat at different coating ratios, variation of the ratio of coated citric acid and tri-sodium citrate in formulations, and compressing the formulations with different compression forces. After tablet processing and storage of tablets, the concentration of d-fructose was determined on the basis of enzymatic reactions. A response surface central composite design was used. The above-mentioned variations were chosen as independent variables and the amount of d-fructose was chosen as response variable. The lowest rates of inversion could be achieved by increasing the content of tri-sodium citrate and the ratio of coating material and decreasing the ratio of coated citric acid and tri-sodium citrate in the tablet formulations. The compression force had no significant effect on the inversion of sucrose.     

灰熔聚粉煤气化炉存在的问题及改进

对灰熔聚粉煤气化炉运行中存在的问题进行了分析、讨论，并提出了解决方案和建议。     

Kinetics of phenol oxidation in a trickle bed reactor over active carbon catalyst

The wet air oxidation of phenol over a commercial active carbon catalyst was studied in a trickle bed reactor (TBR) in the temperature and oxygen partial pressure ranges of 120–160 °C and 0.1–0.2 MPa, respectively. The performance of the active carbon was compared in terms of phenol and COD destruction. The weight change of active carbon due to reaction was also measured. Finally, oxic phenol adsorption isotherms were assessed in batch conditions at 25, 125 and 160 °C. In order to use the conversion data obtained from the TBR for a kinetic study, special care was taken to check the kinetic control in the TBR experiments. Several kinetic models including power law or Langmuir–Hinshelwood expressions were considered to describe the catalytic oxidation of phenol over active carbon. The simple power law model with first order dependence on both phenol and oxygen concentration predicted satisfactorily the experimental data not only over the entire range of operating conditions studied, but also outside its validity range. Copyright © 2005 Society of Chemical Industry