The Chemical Engineering Journal最新文献_第5页

Solution of hollow fibre bioreactor design equations for zero-order limit of Michaelis-Menten kinetics 中空纤维生物反应器零级极限Michaelis-Menten动力学设计方程的求解

The Chemical Engineering Journal Pub Date : 1993-06-01 DOI: 10.1016/0300-9467(93)80032-J

V.K. Jayaraman

引用次数: 2

Author index of volume 51 第51卷作者索引

The Chemical Engineering Journal Pub Date : 1993-06-01 DOI: 10.1016/0300-9467(93)80033-K

引用次数: 0

Temperature vs. time sequences to palliate deactivation in parallel and in series-parallel with the main reaction: parametric study 与主反应平行或串联平行的温度与时间序列缓和失活:参数化研究

The Chemical Engineering Journal Pub Date : 1993-06-01 DOI: 10.1016/0300-9467(93)80027-L

A.G. Gayubo, J.M. Arandes, A.T. Aguayo, M. Olazar, J. Bilbao

{"title":"Temperature vs. time sequences to palliate deactivation in parallel and in series-parallel with the main reaction: parametric study","authors":"A.G. Gayubo, J.M. Arandes, A.T. Aguayo, M. Olazar, J. Bilbao","doi":"10.1016/0300-9467(93)80027-L","DOIUrl":"10.1016/0300-9467(93)80027-L","url":null,"abstract":"<div><p>The calculation of temperature <em>vs</em>. time sequences to palliate catalyst deactivation in an integral reactor has been studied either by maintaining constant the conversion at the reactor outlet in a simple reaction or by maintaining constant the concentration of a given component at the outlet in a complex reaction system. The experimental systems studied, which are a simple one (dehydration of 2-ethylhexanol) and a complex one (isomerization of <em>cis</em>-butene), have kinetic models of the Langmuir-Hinshelwood-Hougen-Watson type for the main reaction and deactivation, with deactivation by coke dependent on the concentration of the reaction components. In the reaction of dehydration of 2-ethylhexanol deactivation occurs in parallel with the main reaction and in the isomerization of <em>cis</em>-butene deactivation occurs in series-parallel with the main reaction. A parametric study has been carried out for both reaction systems. The sequences calculated have been experimentally proven in an automated reaction apparatus.</p></div>","PeriodicalId":101225,"journal":{"name":"The Chemical Engineering Journal","volume":"51 3","pages":"Pages 167-176"},"PeriodicalIF":0.0,"publicationDate":"1993-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0300-9467(93)80027-L","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"53640630","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Modelling of solid-liquid adsorption: effects of adsorbent heterogeneity 固液吸附模拟:吸附剂非均质性的影响

The Chemical Engineering Journal Pub Date : 1993-06-01 DOI: 10.1016/0300-9467(93)80026-K

Anabela Leitão, Alírio Rodrigues

{"title":"Modelling of solid-liquid adsorption: effects of adsorbent heterogeneity","authors":"Anabela Leitão, Alírio Rodrigues","doi":"10.1016/0300-9467(93)80026-K","DOIUrl":"10.1016/0300-9467(93)80026-K","url":null,"abstract":"<div><p>Effects of adsorbent heterogeneity on the adsorption of cobalt phthalocyanine dye on activated carbon have been studied. Adsorption experiments were carried out by varying the temperature and adsorbent mass in batch adsorbers and, in addition, the adsorbent particle size and fluid flow rate in a continuous stirred tank reactor (CSTR)-type adsorber in order to investigate the equilibrium and the kinetics of adsorption.</p><p>The Brunauer-Emmett-Teller (BET), Langmuir with uniform distribution (LUD) and Langmuir-Freundlich equations are able to represent the equilibrium data with similar accuracy within the range of measurements. Reasonably large values of the heterogeneity parameter (2.69–2.86) show that the carbon surface is energetically heterogeneous.</p><p>A mathematical model that describes the adsorption dynamics, including film-, pore- and concentration-dependent surface diffusion on an energetically and structurally heterogeneous adsorbent, is presented here and fitted to the experimental concentration <em>vs</em>. time curves obtained in the continuously stirred tank adsorber.</p><p>Structural heterogeneity of the carbon, if not accounted for in the kinetic model, can be responsible for the very strong concentration dependence of the surface diffusion coefficient and for the variation in the parameter <em>D</em><sub>o</sub> with particle size and adsorber porosity as shown in this work.</p></div>","PeriodicalId":101225,"journal":{"name":"The Chemical Engineering Journal","volume":"51 3","pages":"Pages 159-166"},"PeriodicalIF":0.0,"publicationDate":"1993-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0300-9467(93)80026-K","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"53640620","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Mixing in unstirred batch fermenters 在未搅拌的分批发酵罐中混合

The Chemical Engineering Journal Pub Date : 1993-06-01 DOI: 10.1016/0300-9467(93)80031-I

Ana I. García, Luis A. García, Mario Díaz

引用次数: 14

Large-scale purification of Leuconostoc mesenteriodes NRRL B512F dextransucrase for use in the biosynthesis of dextran by batch and continuous chromatography 间歇式和连续色谱法大规模纯化介肠系膜Leuconostoc mesenteriodes NRRL B512F葡聚糖蔗糖酶用于葡聚糖的生物合成

The Chemical Engineering Journal Pub Date : 1993-06-01 DOI: 10.1016/0300-9467(93)80029-N

J.N. Ajongwen, A. Akitoye, P.E. Barker, G. Ganetsos , M.T. Shieh

{"title":"Large-scale purification of Leuconostoc mesenteriodes NRRL B512F dextransucrase for use in the biosynthesis of dextran by batch and continuous chromatography","authors":"J.N. Ajongwen, A. Akitoye, P.E. Barker, G. Ganetsos , M.T. Shieh","doi":"10.1016/0300-9467(93)80029-N","DOIUrl":"10.1016/0300-9467(93)80029-N","url":null,"abstract":"<div><p>The extracellular enzyme dextransucrase was produced from <em>Leuconostoc mesenteriodes</em> NRRL B512F and purified by ultracentrifugation and cross-flow ultrafiltration for use in the biosynthesis of the macromolecule dextran by ion exchange chromatographic reaction—separation techniques. The two-stage purification process yielded over 90% pure dextransucrase with overall enzyme recovery of over 60%. A second stage of centrifugation was required to achieve complete cell removal. The purified enzyme contained 1–2 g l<sup>−1</sup> of solute ions, which affected the operation of the chromatographic system. Gel filtration removed over 93% of the remaining ions but resulted in high activity losses. Two-phase separation with polyethylene glycol (PEG) and purification by ion exchange chromatography were less successful in desalting the enzyme. PEG precipitation was successful in concentrating the enzyme, but the ions remained predominantly with the enzyme portion of the two phases. The purified enzyme was found to be unstable during storage.</p><p>Use of the enzyme in chromatographic reactor—separators for the production of dextran resulted in over 33% more high molecular weight dextran (the desired product) and a useful pure fructose byproduct being obtained than for a conventional reactor. Sodium and potassium ions in the enzyme hampered continuous operation by displacing calcium ions from the resin and thus reducing the separation efficiency of the system. Partial regeneration of the resin with calcium nitrate rather than complete enzyme desalting, which was very expensive and resulted in high activity losses, helped overcome this effect.</p></div>","PeriodicalId":101225,"journal":{"name":"The Chemical Engineering Journal","volume":"51 3","pages":"Pages B45-B50"},"PeriodicalIF":0.0,"publicationDate":"1993-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0300-9467(93)80029-N","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"53640646","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 6

The estimation of kinematic viscosity of petroleum crude oils and fractions with a neural net 用神经网络估计石油原油及其馏分的运动粘度

The Chemical Engineering Journal Pub Date : 1993-06-01 DOI: 10.1016/0300-9467(93)80025-J

T.J. van der Walt, J.S.J. van Deventer, E. Barnard

引用次数: 9

Subject index of volume 51 第51卷的主题索引

The Chemical Engineering Journal Pub Date : 1993-06-01 DOI: 10.1016/0300-9467(93)80034-L

引用次数: 0

The order of micromixing and segregation effects on the biological growth process in a stirred-tank reactor 搅拌槽反应器中微混合和分离顺序对生物生长过程的影响

The Chemical Engineering Journal Pub Date : 1993-04-01 DOI: 10.1016/0300-9467(93)80020-O

M. Atiqullah, A.K.M.S. Rahman, S.A. Beg, M.M. Hassan

{"title":"The order of micromixing and segregation effects on the biological growth process in a stirred-tank reactor","authors":"M. Atiqullah, A.K.M.S. Rahman, S.A. Beg, M.M. Hassan","doi":"10.1016/0300-9467(93)80020-O","DOIUrl":"10.1016/0300-9467(93)80020-O","url":null,"abstract":"<div><p>Depending on the hydrodynamic conditions, a stirred tank reactor may be divided into two micromixing environments: maximum mixing followed by complete segregation (case 1), or vice versa (case 2). The Ng—Rippin two-environment model simulates case 1, whereas the Fan reversed two-environment model covers case 2. The micromixing concepts of Danckwerts and of Zwietering have been applied to both models in terms of the degree of segregation <em>J</em> to evaluate the influence of the order of micromixing—segregation effects on biological growth processes. The model predictions for both endogeneous and exogeneous cell metabolism show that case 2 gives more substrate conversion and cell production than does case 1, for the same extent of micromixing, particularly at low dilution rates. At high dilution rates, both models predict the same reactor performance, independent of the micromixing phenomenon. The substrate conversion and cell production decrease with increasing dilution rate, following a similar trend. Further, the effects of micromixing are found to be strong functions of dilution rate. At high dilution rates for case 2, the micromixing effects are pronounced only when the reactor approaches complete segregation. However, for case 1, the effects are appreciable when the reactor deviates slightly from perfect mixing. For some intermediate dilution rates, the Fan model, unlike the Ng—Rippin model, shows that the reactor output decreases linearly with increasing degree of segregation. Beyond a critical value of the dilution rate, the reactor output falls linearly with dilution rate for exogeneous cell metabolism (case 2). On the contrary, for case 1, the output decreases exponentially throughout the entire range of dilution rates.</p></div>","PeriodicalId":101225,"journal":{"name":"The Chemical Engineering Journal","volume":"51 2","pages":"Pages B25-B33"},"PeriodicalIF":0.0,"publicationDate":"1993-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0300-9467(93)80020-O","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"53640512","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 7

An expert system applied to the control of an industrial-scale bioreactor 应用于工业规模生物反应器控制的专家系统

The Chemical Engineering Journal Pub Date : 1993-04-01 DOI: 10.1016/0300-9467(93)80021-F

Zdenek Sterbacek, Jaroslav Votruba

{"title":"An expert system applied to the control of an industrial-scale bioreactor","authors":"Zdenek Sterbacek, Jaroslav Votruba","doi":"10.1016/0300-9467(93)80021-F","DOIUrl":"10.1016/0300-9467(93)80021-F","url":null,"abstract":"<div><p>Control of a fed-batch industrial-scale fermenter requires a large amount of “finger-tip feeling” on the part of operators, despite reasonably sophisticated instrumentation. The reason for this is that there are no applicable deterministic models giving aid to the control system in deciding the best operation strategies. This is a typical case of a heuristic experimental process, treating inexact knowledge that is excluded from deterministic and statistic modelling <em>a priori</em>. Essential parts of this problem can be solved by means of an expert system shell, capable of dealing with uncertain information, using the linguistic shell application. Knowledge was extracted from process records on fermentation batches producing baker's yeast on an industrial scale. A strategy for heuristically optimized yield and growth rate can be predicted using knowledge gained in previous runs and stored in the knowledge base of the expert system. The expert system, once built up, can also be used for experimental simulation of the effects of fundamental decision parameters: temperature, production rate, ethanol concentration and specific growth rate. The use of expert system consultations can be generally recommended as an efficient aid in fermentation control.</p></div>","PeriodicalId":101225,"journal":{"name":"The Chemical Engineering Journal","volume":"51 2","pages":"Pages B35-B42"},"PeriodicalIF":0.0,"publicationDate":"1993-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0300-9467(93)80021-F","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"53640528","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 8