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在分析流化床中硝基苯加氢制苯胺工艺条件的基础上,讨论催化剂流化状态、硝基苯质量、氢气质量、氢油比、硝基苯进床温度、反应温度、反应压力和催化剂等各工艺条件对反应的影响,针对工业生产实际操作条件和数据,排除部分工艺条件对反应的影响,对流化床法苯胺产品中轻组分来源进行解析,对工业生产操作具有指导意义。 相似文献
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介绍了硝基苯加氢制苯胺的技术概况,包括固定床加氢法、液相加氢法和流化床加氢法,对各工艺的优缺点进行了评述,并叙述了硝基苯加氢制苯胺催化剂的发展情况。 相似文献
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硝基苯液相催化加氢制苯胺催化剂研究进展 总被引:2,自引:1,他引:1
介绍了苯胺生产中硝基苯液相催化加氢制苯胺工艺,着重介绍了液相加氢催化剂体系中的镍系催化剂和贵金属催化剂的研究进展。液相催化加氢多采用贵金属催化剂和高活性、制备工艺复杂的催化剂,生产成本较高,开发价廉、高效并能满足绿色化工要求的新型催化剂是今后工作的重点。 相似文献
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以苯胺废水处理站剩余污泥为菌源,经富集、扩大培养获得高含量的硝化菌菌液,并以自行研制的纤维颗粒为载体进行了挂膜试验,考察了pH、溶解氧(DO)和无机碳源等主要工艺条件对苯胺降解硝化过程的影响。结果显示,在15d内微生物开始在载体表面形成生物膜,30d后膜厚稳定在120~150μm。条件试验结果表明,pH为8.5时硝化效果最佳,氨氧化速率达到43.22mg/L·d;DO为3.0mg/L时满足苯胺降解菌及硝化菌代谢需要;添加无机碳源可有效促进硝化反应的进行,当NaHCO3添加量为300mg/L,可使硝化速率提高30.68%。由此证明了在三相生物流化床中通过条件优化可消除苯胺废水降解过程释放的富余氨氮。 相似文献
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引 言湍动流化床反应器因具有良好的气固接触氛围和传热性能、高固含率以及有限的轴向返混等优点 ,在工业生产中被普遍采用 ,但对于湍动流化床的模型化工作和反应器性能的报道较少[1] .Thompson等在 1999年提出的一般性鼓泡 /湍动流化床模型最有特色 ,该模型实现了从鼓泡区域到湍动区域的平滑过渡 ,与其他模型相比模型预测值与Sun于 1991年报道的实验数据能更好地吻合[2 ] .但是对于这些模型都缺少更多的工业数据去检验它们应用于工业模拟时的可靠性[1,3] ,对于具有垂直内构件的工业湍动流化床的模型化文献中未见报道 .秦霁光等人[4 ] 提… 相似文献
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This paper presents results for the rise velocities of air bubbles in liquids and liquid-solid fluidized beds. The bubble sizes ranged from approximately 0.03 to 0.45 cm radius. Tap water and distilled water were used as the fluidizing liquids. The solid phase consisted of low density alginate gel beads of mean radius 0.04 cm. The gel beads were translucent which permitted observation of bubbles inside the bed even at large solids volume fractions. Experiments were conducted for solids volume fractions ranging from 15% to 52% and in clear liquids. The goal of the experiments was to determine rise velocities of bubbles and to develop and evaluate correlations of bubble rise velocity based on bubble size, solids volume fraction and liquid properties. It was determined that, for moderate solids fractions (ranging from 28% to 45% solids), a semi-empirical correlation that treated the fluidized bed as a pure liquid with a higher viscosity than the liquid phase could be used to represent the data. The Thomas effective viscosity model was used to predict the viscosity. Provided that one restricts attention to a water fluidized bed, a second empirical correlation can be used to represent the data over a broader range of solids fractions. 相似文献
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K. S. Lim D. V. Khakhar Z. Chen P. K. Agarwal 《Chemical Engineering Communications》1997,161(1):205-229
This paper deals with the raining of particles from an interface between a dense fluidized phase and a gas phase with the fluidized phase uppermost. Such interfaces occur at the upper surfaces of gas bubbles and slugs in fluidized beds. Particle rain in these cases would enhance contact between gas and particles within the bubbles and slugs.
The rise velocities of single square-nosed slugs injected in incipiently fluidized beds of different diameters were measured. Relatively small columns of internal diameters of 0.0125, 0.019 and 0.0254 m were employed in the experiments; In such beds, square-nosed slugs are formed which span the entire cross-section of the beds and rise entirely due to raining of particles from their top surfaces. Since the upper surface of such slugs is flat, their motion can be analyzed using the one-dimensional hydrodynamic theory. Glass ballotini and sand of different sizes were used as bed particles. Comparison of theory and experiment has enabled the determination of the dimensionless gradient diffusivity characterizing the motion of particles induced by a gradient in the void fraction. The results confirm the scaling proposed by Batchelor (1988). The use of the calculated gradient diffusivity in the criterion for stability of a gas fluidized bed predicts the systems under consideration to be always unstable. 相似文献
The rise velocities of single square-nosed slugs injected in incipiently fluidized beds of different diameters were measured. Relatively small columns of internal diameters of 0.0125, 0.019 and 0.0254 m were employed in the experiments; In such beds, square-nosed slugs are formed which span the entire cross-section of the beds and rise entirely due to raining of particles from their top surfaces. Since the upper surface of such slugs is flat, their motion can be analyzed using the one-dimensional hydrodynamic theory. Glass ballotini and sand of different sizes were used as bed particles. Comparison of theory and experiment has enabled the determination of the dimensionless gradient diffusivity characterizing the motion of particles induced by a gradient in the void fraction. The results confirm the scaling proposed by Batchelor (1988). The use of the calculated gradient diffusivity in the criterion for stability of a gas fluidized bed predicts the systems under consideration to be always unstable. 相似文献
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薛惠芳 《化学反应工程与工艺》1992,8(3):302-307
颗粒速度是快速流化床内重要的流体力学参数,直接测定是困难的,一般都是通过测定其他参数,来计算颗粒的速度。本研究在内径6.6cm 和9.7cm,高3m 的快速流化床内测定颗粒的轴向滞留量分布及压头损失,分析床层内颗粒速度及其影响因素,对三种不同颗粒进行测定,将实验数据进行关联,得出颗粒速度的关联式:适用范围:气体流速:1.4~6.0m/s颗粒循环速度:30~130kg/m~2·s颗粒终端速度:0.133~0.880m/s将实验值与计算的结果比较,基本一致。故可认为该式在实验范围内,可用于推算快速流化床内的颗粒速度。 相似文献
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ABSTRACT An empirical equation as a function of drying time and temperature was developed to calculate the moisture ratio required Tor balch fluidized bed dryers design for amaranth grain drying The relative deviations of the moisture ratio values calculated with the proposed equation with regard to the experimental ones ranged between 0.014 and 0.095 for a drying air temperature between 60 and 100 ° C, and a grain initial moisture content between 23.5 and 16.6 % wb. 相似文献
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研究一种加料不独立的垂直气力输送装置,并以流化床作为料仓和混合区,两者构成固体循环系统。由于系统特性,加料喷嘴的插入高度与加料结构将会直接影响操作的稳定性,从力的平衡出发导出临界结构为he/De<fHL/R,其中f是颗粒特性的函数。 相似文献
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阎铁林 《化学反应工程与工艺》1990,6(4):86-93
本文主要介绍流化床反应器设计中的工程放大技术。其特点是抓住工程放大的核心——克服放大效应,即如何控制气泡直径和防止气体返混这两个基本要点。流化床反应器放大时在以下三方面作了改正:1.气、固分离散术;2.反应热回收技术;3.密相床气泡控制技术。这项设计的技术水平属国内领先、并达到国外同类流化床反应器的生产水平。 相似文献