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91.
R. Sánchez-Sánchez E. Manzanares-Papayanopoulos J. R. Herrera-Velarde A. M. Arriola-Medellín M. V. Peralta-Martínez 《Petroleum Science and Technology》2013,31(13):1480-1493
Abstract The aim of the present study is the investigation of the scaling-up procedures to emulsify heavy oil liquid residuals in water from a continuous emulsion production system at laboratory scale to a semi-pilot plant emulsion production system. The results obtained for the particle size distribution are compared in each case. The experiments were performed using the same liquid residual flow, temperature process, and volume fraction of the dispersed phase at atmospheric pressure. The particle size distribution was measured by a Mastersizer Micro Optical Bench Model MAF5000 from Malvern Instruments. Satisfactory results of the scaled system are presented, and some considerations—mainly in the operational parameters for future studies—are also described. 相似文献
92.
非均相光催化水处理管式反应器的放大设计 总被引:3,自引:0,他引:3
研究了非均相光催化反应器在放大过程中光辐射能衰减和流体返混对其放大过程设计的影响。结果表明,光辐射能随着光源和反应管的中心距的增加急剧衰减,两者呈1 56次方反比关系;管式反应器中流体的返混程度远小于相同反应体积的环型反应器,这有利于提高水中有机污染物的降解率。建立了一套由3组管式反应器串联且光接触面与光源的距离小于10cm的连续光催化水处理中试装置,并对印染废水进行处理。化学需氧量可从150~180mg/L降至50mg/L以下,处理量为50L/h时的出水优于国家一级排放标准。 相似文献
93.
This article presents results of an ongoing effort toward improving the modeling and scale-up procedures for the dense-phase pneumatic conveying of fine powders through pipes. Two new approaches are employed in this study. One approach, derived by modifying an existing reliable dilute-phase model to make it suitable for the dense-phase, has resulted in relatively stable predictions for diameter and length scale-up for two types of fly ash, ESP dust, pulverized brown coal and fly ash/cement mixture. Although some over-predictions still remain for the cases of diameter scale-up, there seems to be a substantial relative improvement in the overall accuracy of predictions (compared to the existing design methods). Another method has been derived using the concept of “two-layer” slurry flow modeling (suspension flow occurring on top of a non-suspension moving layer), and this has also resulted in similar improvements. Although the “two-layer” technique is believed to be more representative of the actual flow conditions under dense-phase conveying, the simpler “modified” method appears to be adequate for practical design purposes. 相似文献
94.
95.
该文研究了青霉烯和碳青霉烯关键中间体4-AA的生产工艺。在-5℃,L-苏氨酸与亚硝酸钠、盐酸、氢氧化钠发生重氮化、分子内亲核取代反应生成(2R,3R)-2,3-环氧丁酸(中间体A),收率74.5%。A再与对甲氧苯氨基乙酸乙酯(中间体B)反应5~6 h制得(2R,3R)-N-乙氧羰甲基-N-(4-甲氧基苯基)-2,3-环氧丁酰胺(中间体C),收率94.3%。中间体C在六甲基二硅氮烷、氨基锂作用下环合成(3S,4S)-3-[(1R)-1-羟乙基]-4-乙氧羰基-1-对甲氧苯基-2-氮杂环丁酮(中间体D),收率72.1%。最后中间体D经羟基保护、水解、氧化脱羧、臭氧化脱保护基制得4-AA{(3R,4R)-3-[(1R)-叔丁基二甲基硅氧乙基]-4-乙酰氧基-2-氮杂环丁酮}。总收率达到34.5%,4-AA液相色谱纯度达到99.34%。 相似文献
96.
条形加氢处理催化剂的工业放大问题 总被引:2,自引:1,他引:1
本文论述了条形石油馏分加氢处理催化剂工业放大的某些问题,包括:(1) 目前存在的问题;(2)工业放大基本概念;(3)工业放大效应分析;(4)工业放大基本条件;(5)产品的物化性质指标的制定。 相似文献
97.
Williams Olughu Gurjot Deepika Chris Hewitt Chris Rielly 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2019,94(3):647-657
Scaled-down models are small-scale bioreactors, used to mimic the chemical (pH, nutrient and dissolved oxygen) and physical (pressure, viscosity and temperature) gradients known to occur in the large-scale fermenter. Conventionally, before scaling up any bioprocess, small-scale bioreactors are used for strain selection, characterisation and optimisation. The typical small-scale environment is homogenous, hence all the cells held within the small-scale bioreactor can be assumed to experience the same condition at any point in time. However, for the large-scale bioreactor, this is not the case, due to its inhomogeneous environment. Three different scaled-down models are reviewed here, and the results suggest that a bacterium responds to changes in its environment rapidly and the magnitude of response to environmental oscillations is organism-specific. The reaction and adaption of a bacterium to an inhomogeneous environment in most cases result in productivity and quality losses. This review concludes that consideration of fermentation gradients should be paramount when researchers screen for high yielding mutants in bioprocess development and doing this would help mitigate performance loss on scale-up. © 2018 Society of Chemical Industry 相似文献
98.
99.
目的:构建完善的生物反应器放大模型,为反应器生产提供指导.方法:通过1.5,5,20,200L规模反应器的试验,对体积溶氧系数kLa、混合时间tm的关联式及参数进行了优化探究,建立了生物反应器模拟放大模型,通过MATLAB搭建了Scaleuper放大系统.结果:对比试验结果最终kLa的模拟偏差在±15%以内,通过在tm的关联式中引入临界转速的定义,对tm的整体模拟偏差较原公式减少了17.4%,在±10%内,通过嵌入BP神经网络减小kLa的模拟偏差,BP模型模拟kLa偏差对训练数据范围最小可达0.1%.结论:基于经验关联式的反应器放大模型,在试验测得相关参数后模拟结果较优;利用神经网络对反应器模拟、放大是可行的. 相似文献
100.
Caixia Chen Takahiro Miyoshi Hidehiro Kamiya Masayuki Horio Toshinori Kojima 《加拿大化工杂志》1999,77(4):745-750
A two-stage air blown entrained flow gasifier is being developed in Japan for the IGCC process. However, its scale-up up faces significant difficulties because of ash/slag deposition problems. The ash/slag deposition in the gasifier depends on both the ash properties and entrainment produced by the swirling gas flow. Therefore, the flow hydrodynamics are critical issues for the control of the ash behavior. In this paper, a comprehensive simulation model is used to examine the effects of the gasifier geometry and jet configuration on the flow hydrodynamics in order to control the ash deposition on the gasifier walls. A swirl number for the multi-stage injection swirling gas flow is defined and proved to be the most important hydrodynamic scaling law for the entrained flow gasifier. 相似文献