工艺条件对RFT-2催化剂固定床费-托合成性能的影响

在固定床费-托合成装置上研究了反应温度、压力、n(H2)/n(CO)、空速、汽包压力和表观气速对工业生产的RFT-2催化剂反应性能和催化剂床层温度分布的影响。结果表明反应温度对RFT-2性能影响显著,随温度提高活性迅速增加,催化剂床层的热点区域变宽和峰值增加,而且在不同温度范围对敏感程度不同。提高压力可以增加反应活性,改善选择性,催化剂床层温度分布变差。n(H2)/n(CO)主要影响费托合成催化剂的活性和产物选择性,对催化床层温度分布影响较小。空速增加会造成CO和H2的转化率的下降,选择性和催化剂床层温度分布变化不明显。通过调节汽包压力来控制催化剂床层温度非常有效和灵敏,对反应性能和温度分布影响显著。表观气速提高可以改善催化剂床层径向的传热,使反应管的传热得到强化,温度分布更加均匀。     

Mass transfer mechanisms in fixed-bed adsorption of erythromycin

The equilibrium and kinetic characteristics of the adsorption of erythromycin to Sepabeads SP825 were determined. The equilibrium data in a batch system was well described by a Langmuir isotherm. The separation performance was investigated in a fixed-bed system with respect to the adsorption superficial velocity, ionic strength and pH. A mathematical model was used to simulate the mass transfer mechanism, taking film mass transfer, pore diffusion and axial dispersion into account. The model predictions were consistent with the experimental data and were consequently used to determine the mass transfer coefficients.     

现代煤气化技术及其煤种的适应性分析

结合国内外煤气化技术发展现状与趋势,讨论了煤质特性对气化过程的影响及其在不同气化炉型中的适应性。分析表明,煤种的多样性及气化工艺的选择促进了煤气化技术的快速发展,气流床和流化床代替固定床是煤气化技术发展的必然所趋。在充分认识各类煤气化技术优缺点的基础上,应发挥优势,针对煤种选用炉型,开发具有单炉生产能力高、煤种适应性强、气体成分可调等优势的加压气化技术以及可有效利用煤气高温显热的两段或多段式气化技术。     

乙醇脱水固定床反应器数值模拟的研究

应用计算流体力学软件Fluent,选用多孔介质模型,对φ50 mm×500 mm的乙醇脱水固定床反应器建立了单管反应器整体反应数学模型,模拟了反应器内温度和浓度分布,并对模拟结果进行了实验验证。研究结果表明,催化剂床层上部的径向温差较大,最大温差可达50℃,是脱水反应发生的主要区域;在反应器内高温区域有利于产物乙烯的生成,低温区域则有利于乙醚的生成;在400℃、WHSV=1.0 h-1的条件下,温度分布的模拟值和实验值的偏差不超过10℃,反应器出口乙烯选择性的模拟和实验值分别为98.6%和96.9%,乙烯选择性相对误差1.8%。实验证实选用的模型能较准确模拟乙醇脱水反应器内温度和浓度的分布情况。     

Comparative Evaluation of Nanoporous Hydrocracking Catalysts in Fixed-Bed and Swing-Batch Reaction Systems

Abstract

A comparison of the results using Ni-W and Ni-Mo loaded catalysts with desulfurized vacuum gas oil shows that both the fixed-bed reaction and swing-batch reaction systems can be used efficiently for the catalysts evaluation. The results from a fixed-bed reaction showed that Cat-2 catalyst was more active than both Cat-1 and Cat-3, while the hydrodesulfurization (HDS) activity of Cat-3 catalyst was slightly better than that of Cat-1 and Cat-2. In the swing-batch reaction, Cat-1 and Cat-2 showed higher activity as compared to Cat-3 and Cat-4 catalysts. NiW loaded catalysts were found more active than NiMo loaded catalysts. HDS and cracking activities in the swing-batch reactor were found lower as compared to the fixed-bed reactor, probably due to recombination reactions involving sulfur and other cracked molecules.     

Kinetic Modeling of MTO Process Applying ZSM-5 Zeolite Modified With Phosphorus as the Reaction Catalyst

In the present study, a number of phosphorus modified HZSM-5(Si/Al = 250) zeolite as MTO catalyst were prepared and characterized by various methods. A kinetic model for MTO process over PZSM-5 catalyst was developed based on data obtained from a differential fixed bed reactor within the temperature range of 360–425°C and 1 bar pressure applying the Langmuir-Hinshelwood formulation. The kinetic parameters were evaluated from the experimental data using genetic algorithm. It was found that the predicted data from the model were well correlated with the experimental results, indicating that ethylene and propylene are primary olefins.     

固定床渣油加氢技术工程化的问题及对策

介绍国内工程化应用的渣油加氢技术,分析了渣油加氢工程化过程中遇到的问题,包括级配催化剂失活不同步及前置反应器结垢、压力降上升快等。对产生这些问题的原因进行了详细分析,包括:①原料变化;②运转时间变化;③级配催化剂变化;④操作温度变化等。提出了全面应对级配催化剂失活不同步的措施,包括:①合理选择原料;②合理选择催化剂;③适时调整操作;④流程设计为操作留有调整空间。对前置反应器结垢、压力降上升快的问题也提出了具体的解决方案。     

固定床“一步法”连续合成对乙酰氨基酚的研究

:采用钯炭颗粒催化剂 ,研究了固定床“一步法”连续合成对乙酰氨基酚的工艺条件。在催化剂重 0 .50 g,对硝基酚质量分数 5.0 % ,醋酐与对硝基酚的摩尔比为 1 .2～ 1 .4,液时空速 0 .50～ 3.0 0 /h,氢压 1 .0～ 1 .4MPa,反应温度 1 60～ 1 80°C等条件下 ,对硝基酚转化率 1 0 0 % ,成品对乙酰氨基酚选择性达 95.0 %以上。     

催化裂化汽油在LBO-A/LBO-16催化剂上的芳构化

以催化裂化汽油为原料,LBO-A催化剂和LBO-16催化剂混合物(二者质量比为1∶1)为芳构化催化剂,在小型固定流化床反应器和中型提升管反应器上进行了芳构化反应性能研究。结果表明,在2种反应器中,产品液体收率大于89%,改质汽油烯烃体积分数下降20个百分点以上,芳烃体积分数增加10个百分点以上,产品分布和汽油质量得到改善。在小型固定流化床中的芳构化改质汽油中,烯烃体积分数下降幅度及芳烃体积分数增加幅度大于在中型提升管反应器上的。     

煤气发生炉气化过程能量分析计算

目前在我国使用最多的是常压固定床两段式煤气化技术,着重分析了常压固定床两段式煤气化炉内气化过程的能量损失分布的计算方法,并对型号CG3Q3.0-1的煤气发生炉进行具体计算,为今后常压固定床两段式煤气化炉的结构创新和节能降耗提供理论依据。