用固定床和搅拌槽进行吸附（离子交换）柠檬酸的特性研究

用固定床和搅拌槽进行了吸附(离子交换)柠檬酸实验。研究固定床工艺和搅拌槽工艺对吸附剂吸附效率和工作吸附容量的影响,比较了逆流解吸和顺流解吸对回收率的影响。在装填大孔吸附剂的固定床上用逆流解吸获得96％的回收率。在搅拌槽中,吸附剂的吸附效率大于固定床中吸附剂的吸附效率,建立了柠檬酸吸附动力学模型,获得理论计算值与实验值一致的结果。     

稻草与煤固定床共热解特性的研究

选取稻草为生物质原料,将其与两种不同煤阶的煤(内蒙褐煤和神府烟煤)分别以0∶100、20∶80、40∶60、60∶40、80∶20、100∶0的干基质量比均匀混合.借助固定床反应器,研究了稻草与两种煤的共热解特性,探讨了共热解过程中可能存在的协同作用.结果表明,稻草添加有利于共热解气体产物的生成,且对神府煤作用更明显;稻草含量越高,热解气体产量的实验值与加权平均计算值的偏差也越大,说明稻草与煤共热解过程发生了协同作用.而共热解所得焦产量的实验值与加权平均计算值基本一致.热解焦傅里叶红外光谱分析结果表明,稻草添加对热解焦的官能团未造成显著影响.     

油页岩固定床热解反应器中内构件强化作用

在内构件(传热板和中心集气管)外热式固定床反应器中研究了油页岩热解产物生成特性,并与无内构件的相同常规固定床反应器内的油页岩热解行为对比,考察了两反应器中油页岩升温特性、热解产物分布、页岩油品质以及气体产物组成的变化规律.结果表明,内置传热板和中心集气管显著强化了反应器内的传热,相对于无内构件常规固定床反应器,料层升温速率提高了约2倍.对于依兰油页岩,其热解页岩油产率明显提高,最高达11.1 wt%(干燥基),明显高于无构件常规固定床反应器获得的页岩油产率.随着外加热炉温度的升高,内构件固定床反应器的页岩油产率逐渐增加,而无内构件常规固定床反应器的页岩油产率则明显降低.当外加热炉温度为1000℃时,前者页岩油产率是后者的2.3倍,并且内构件固定床反应器的热解水产率较低.两反应器中热解气产物组成相近,其H2与CH4之和占气体总量的70 vol%左右,热值为4406~5400 kcal/Nm3.     

基于废铁渣载氧体煤加压化学链燃烧试验研究

针对废铁渣载氧体,在小型固定床反应器上进行了燃煤加压化学链燃烧试验以及载氧体持续循环能力的研究,结果表明,压力增加抑制了煤的初始热解过程,提高了煤焦的气化过程以及气化产物与载氧体之间的反应.随着压力增加,CO2浓度和燃料的转化率增加,CO和CH4的浓度降低,载氧体的转化率也随压力的增加而增加.由于载氧体载氧能力一定,随...     

强碱性阴离子交换树脂催化菜籽油酯交换反应合成脂肪酸甲酯

以强碱性阴离子交换树脂作为催化剂,催化菜籽油与甲醇酯交换反应制备脂肪酸甲酯(FAME)。结果表明,产品收率随着醇油比增大而提高,当醇油比(V/V)达到7.21后,收率增加逐渐变慢;在树脂最高使用温度以下,反应温度越高,产品收率越高;产品收率随催化时间增长而提高,但提高速度逐渐趋缓;催化剂活性稳定,利用再生树脂连续催化28.7h,未见活性下降。常压下,醇油比4.54,60℃下反应54.7min,FAME产品收率达96.80%。     

Comparative study of kinetic modeling for the oxidative coupling of methane by genetic and marquardt algorithms

Overall kinetic studies on the oxidative coupling of methane, OCM, have been conducted in a tubular fixed bed reactor, using perovskite titanate as the reaction catalyst. The appropriate operating conditions were found to be: temperature 750-775 ℃, total feed flow rate of 160 ml/min, CH4/O2 ratio of 2 and GHSV of 100 min-1. Under these conditions, C2 yield of 28% was achieved. Correlations of the kinetic data have been performed with lumped rate equations for C2 and COx formation as functions of temperature, O2 and CH4 partial pressures. Six models have been selected among the common lumped kinetic models. The selected models have been regressed with the experimental data which were obtained from the Catatest system by genetic algorithm in order to obtain optimized parameters. The kinetic coefficients in the overall reactions were optimized by different numerical optimization methods such as: the Levenberg-Marquardt and genetic algorithms and the results were compared with one another. It has been found that the Santamaria model is in good agreement with the experimental data. The Arrhenius parameters of this model have been obtained by linear regression. It should be noted that the Marquardt algorithm is sensitive to the first guesses and there is possibility to trap in the relative minimum.     

Fischer-Tropsch synthesis by nano-structured iron catalyst

Effects of nanoscale iron oxide particles on textural structure, reduction, carburization and catalytic behavior of precipitated iron catalyst in Fischer-Tropsch synthesis (FTS) are investigated. Nanostructured iron catalysts were prepared by microemulsion method in two series. Firstly, Fe2O3, CuO and La2O3 nanoparticles were prepared separately and were mixed to attain Fe/Cu/La nanostructured catalyst (sep-nano catalyst); Secondly nanostructured catalyst was prepared by co-precipitation in a water-in-oil microemulsion method (mix-nano catalyst). Also, conventional iron catalyst was prepared with common co-precipitation method. Structural characterizations of the catalysts were performed by TEM, XRD, H2 and CO-TPR tests. Particle size of iron oxides for sep-nano and mix-nano catalysts, which were determined by XRD pattern (Scherrer equation) and TEM images was about 20 and 21.6 nm, respectively. Catalyst evaluation was conducted in a fixed-bed stainless steel reactor and compared with conventional iron catalyst. The results revealed that FTS reaction increased while WGS reaction and olefin/paraffin ratio decreased in nanostructured iron catalysts.     

MgO/Al_2O_3吸附剂对CO_2动态吸附性能的研究

以γ-Al2O3为载体,采用等体积浸渍法制取MgO/Al2O3吸附剂,利用BET、XRD等表征手段对吸附剂进行表征;并通过固定床测量穿透曲线的方法研究其对CO2动态吸附性能的影响,考察了MgO负载量、吸附温度、气体流量等因素对吸附剂吸附CO2性能的影响,同时还通过多次吸脱附实验考察MgO/Al2O3吸附剂的稳定性和再生能力。结果表明,MgO负载量为10%的吸附剂,吸附温度在50℃左右,流量为45 mL/min动态吸附量最大;经数次循环后材料的结构性质和吸附性能未见明显变化,可再生性能比较优异,是一种潜在的可工业化应用的CO2吸附剂。     

书讯

《催化反应工程基础》陈诵英编著ISBN 978-7-122-10297-3定价68.00元化学工业出版社2011年5月出版《催化反应工程基础》(Fundamentals of Catalytic Reaction Engineering)详细了介绍催化反应工程的基础知识,介绍了催化反应工程发展的新趋势以及催化反应器设     

固定床反应器内流动的研究

固定床反应器是化学工业中常用的反应设备。详细研究反应器内的流动,对提高反应器的性能很有意义。本文分别对轴向及径向固定床反应器内的流动作了分析。对轴向床反应器,它的主要问题是流经催化剂床层的流速分布不均匀。作者分析了其原因,提出了用组合式均布装置来解决流速均布的问题,並用冷模实验进行验证。实验结果表明,本装置可使催化剂床层上方截面上的流速分布,相对标准偏差<9％,均布装置的阻力系数ζ≈1.35。对径向床反应器,作者导得了反应器内流体流动的基本方程,並进行实验研究。研究结果表明,反应器结构型式、催化剂床层阻力系数、中心通道与环形通道的面积比以及反应器高径比是影响流经床层流速分布的主要因素。