Gaseous pretreatments at high temperatures of high-alloy steels used in the coils of ethylene coils sometimes result in much improved pyrolysis operation. Recently, Nova Chemical Co. has reported pretreatments with hydrogen/steam mixtures that reduce the need to decoke from about 30-40 days to up to 515 days in both the coil and the accompanying transferline exchanger. Many pretreatments cause significant diffusion of Cr and Mn to the surface and of Fe and Ni to layers below the surface. The phenomena occurring during pretreatments and differences in resulting surface changes are still not well understood. The results obtained when Incoloy 800 coupons were pretreated were compared over a wide range of pretreatments. Temperature, time of pretreatment, and gas used all have important effects on surface compositions and suggest even more improved coils can be developed.

A sequential design strategy for selecting experimental runs to obtain model discrimination and precise parameter estimation is tested via a simulation study of propylene oxidation kinetics. The strategy is used to design all runs including the preliminary ones which were arbitrarily chosen by earlier researchers. To design initial runs, crude initial parameter guesses may be used in the rival models until least squares estimates can be calculated. Even under conditions of very bad initial guesses and high error variances, this procedure selects whichever model is the correct one and estimates with precision its parameters, in fewer runs than previously reported.

Dispersions containing 10-85% H2SO4 and the remainder 2,2,4-trimethylpentane (2,2,4-TMP) were investigated in a well-agitated reactor mainly at 10 degrees C. 2,2,4-TMP degrades and isomerizes because of reactions that occur in the vicinity of the interface between the liquid phases. The interfacial areas of these dispersions were calculated by comparing the kinetics of these reactions in the dispersions with those in a cell (whose cross-sectional area equals the interfacial area between the two phases). Some area measurements were also made for nonreacting dispersions in an image analysis system. The interfacial areas were highly dependent on the volume percent acid in the dispersions, acid composition, agitation rate, and temperature. For acid-continuous dispersions, the maximum interfacial area occurred at about 75% acid by volume. To model the area data, the following physical properties were measured: acid viscosity, acid density, and interfacial tension of acid-hydrocarbon interfaces. The model developed may be applicable to dispersions in alkylation reactors. Methods of improving the operation and design of alkylation units are proposed.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAlkylation of isobutane with C4 olefins. 1. First-step reactions using sulfuric acid catalystLyle F. Albright, Mark A. Spalding, James A. Nowinski, Robert M. Ybarra, and Roger E. EckertCite this: Ind. Eng. Chem. Res. 1988, 27, 3, 381–386Publication Date (Print):March 1, 1988Publication History Published online1 May 2002Published inissue 1 March 1988https://doi.org/10.1021/ie00075a003RIGHTS & PERMISSIONSArticle Views587Altmetric-Citations44LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (734 KB) Get e-Alertsclose Get e-Alerts

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAlkylation of isobutane with C4 olefins. 2. Production and characterization of conjunct polymersLyle F. Albright, Mark A. Spalding, Christopher G. Kopser, and Roger E. EckertCite this: Ind. Eng. Chem. Res. 1988, 27, 3, 386–391Publication Date (Print):March 1, 1988Publication History Published online1 May 2002Published inissue 1 March 1988https://pubs.acs.org/doi/10.1021/ie00075a004https://doi.org/10.1021/ie00075a004research-articleACS PublicationsRequest reuse permissionsArticle Views618Altmetric-Citations49LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAlkylation of isobutane with C4 olefins. 3. Two-step process using sulfuric acid as catalystLyle F. Albright, Mark A. Spalding, Janelle Faunce, and Roger E. EckertCite this: Ind. Eng. Chem. Res. 1988, 27, 3, 391–397Publication Date (Print):March 1, 1988Publication History Published online1 May 2002Published inissue 1 March 1988https://pubs.acs.org/doi/10.1021/ie00075a005https://doi.org/10.1021/ie00075a005research-articleACS PublicationsRequest reuse permissionsArticle Views650Altmetric-Citations50LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

AIChE JournalVolume 31, Issue 10 p. 1755-1757 Article Transport eigenvalue problems—Effect of order of approximation and step size on solution accuracy R. M. Ybarra, Corresponding Author R. M. Ybarra School of Chemical Engineering, Purdue University, West Lafayette, IN 47907Department of Chemical Engineering, University of Missouri-Rolla, Rolla, MO 65401Search for more papers by this authorR. E. Eckert, R. E. Eckert School of Chemical Engineering, Purdue University, West Lafayette, IN 47907Search for more papers by this author R. M. Ybarra, Corresponding Author R. M. Ybarra School of Chemical Engineering, Purdue University, West Lafayette, IN 47907Department of Chemical Engineering, University of Missouri-Rolla, Rolla, MO 65401Search for more papers by this authorR. E. Eckert, R. E. Eckert School of Chemical Engineering, Purdue University, West Lafayette, IN 47907Search for more papers by this author First published: October 1985 https://doi.org/10.1002/aic.690311026Citations: 4AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Literature Cited Brown, G. M., “Heat or Mass Transfer in a Fluid in Laminar Flow in a Circular and Flat Conduit,” AIChE J., 6, 179 (1960). Churchill, R. V., Fourier Series and Boundary Value Problems, 2nd ed., McGraw-Hill, New York, 34 (1974). Dinh, S. M., and R. C., Armstrong, “Nonisothermal Channel Flow of Non-Newtonian Fluids with Viscous Heating,” AIChE J., 28, 294 (1982). Hildebrand, F. B., Introduction to Numerical Analysis, McGraw-Hill, New York, 293 (1974). Ybarra, R. M., and R. E., Eckert, “Viscous Heat Generation in Slit Flow,” AIChE J., 26, 751 (1980). Citing Literature Volume31, Issue10October 1985Pages 1755-1757 ReferencesRelatedInformation

An extensive experimental study on the formation of liquid-liquid interfacial areas was conducted using flat-blade turbine impellers in standard mixing tank geometry. The interfacial areas were measured with a light probe for different combinations of volume fraction, continuous and dispersed phase physical properties, and mechanical mixing conditions.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMaximization of the conversion to m-toluenesulfonic acid in liquid-phase sulfonationVilas S. Patwardhan and Roger E. EckertCite this: Ind. Eng. Chem. Proc. Des. Dev. 1981, 20, 1, 82–85Publication Date (Print):January 1, 1981Publication History Published online1 May 2002Published inissue 1 January 1981https://pubs.acs.org/doi/10.1021/i200012a012https://doi.org/10.1021/i200012a012research-articleACS PublicationsRequest reuse permissionsArticle Views66Altmetric-Citations1LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access options Get e-Alerts

The onset of significant departure from isothermality caused by viscous energy dissipation in flow through a slit is determined for isothermal and adiabatic walls. A series solution of the energy equation enables calculation of dimensionless profiles for any power law fluid. Such solutions provide useful standards for judging performances of numerical schemes for solving complex nonisothermal flows.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTInteractions between Kinetics and Mass Transfer in the Liquid Phase Chlorination of n-DodecaneMichael P. Ramage and Roger E. EckertCite this: Ind. Eng. Chem. Fundamen. 1979, 18, 3, 216–221Publication Date (Print):August 1, 1979Publication History Published online1 May 2002Published inissue 1 August 1979https://pubs.acs.org/doi/10.1021/i160071a003https://doi.org/10.1021/i160071a003research-articleACS PublicationsRequest reuse permissionsArticle Views86Altmetric-Citations7LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access options Get e-Alerts

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTKinetics of the Liquid Phase Chlorination of n-DodecaneMichael P. Ramage and Roger E. EckertCite this: Ind. Eng. Chem. Fundamen. 1975, 14, 3, 214–221Publication Date (Print):August 1, 1975Publication History Published online1 May 2002Published inissue 1 August 1975https://pubs.acs.org/doi/10.1021/i160055a013https://doi.org/10.1021/i160055a013research-articleACS PublicationsRequest reuse permissionsArticle Views124Altmetric-Citations9LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access options Get e-Alerts

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTOn Fitting Combined Integral and Differential Reaction Kinetic Data. Rate Modeling for Catalytic Hydrogenation of ButadienePradeep P. Sane, Roger E. Eckert, and John M. WoodsCite this: Ind. Eng. Chem. Fundamen. 1974, 13, 1, 52–56Publication Date (Print):February 1, 1974Publication History Published online1 May 2002Published inissue 1 February 1974https://pubs.acs.org/doi/10.1021/i160049a010https://doi.org/10.1021/i160049a010research-articleACS PublicationsRequest reuse permissionsArticle Views87Altmetric-Citations1LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access options Get e-Alerts

Important rheological properties of viscoelastic fluids can be obtained by studying continuous flow through a channel approximating infinite parallel plates. This flat plate rheometer eliminates or reduces some problems of conventional ones and extends the region of useful measurements to high shear rates. Four pressure transducers are flush mounted on the top plate to measure the normal stress T22. From these measurements the shear stress can also be obtained. The normal stress in the direction of flow (T11) is obtained from the measurement of the impact of the exit stream. A Weissenberg rheogoniometer (WRG) is used to measure the shear stress and the primary normal stress difference (N1=T11−T22). Data are presented for polyethylene oxide (M̄w=4×106) solutions of 0.25%, 0.9%, 2.0%, and 3.0% in water. Newtonian fluids were used to test and compare the apparatus. Fluid viscosities from 0.01 to 6000 poise and normal stresses from 100 to 450,000 dynes/cm2 were determined for shear rates from 0.03 to 130,000 sec−1. The rotational geometry of the WRG limits its use to shear rates under 102–103 sec−1. Further, the precision of normal stress measurement with the parallel plates is better than obtained with the WRG. The shear stress values obtained with the plates are of equivalent precision and higher accuracy. Normal stress dependence upon shear rate is fit by the molecular dumbbell model of Bird et al. over a wide range of conditions. In the upper region the model predicts a slope of 2/3 and 0.66±0.03 is obtained by regression analysis of the data. In the lower region a slope of 2 is predicted and 2.08±0.37 obtained. Extrapolation of T11 and T22 data using this model allows N1 to be obtained at shear rates far higher than with the WRG. The magnitude of the ratio T22/T11 decreases as Polyox concentration increases and the fluid becomes more elastic. The complete state of stress is determined for all Polyox solutions, and pressures at the exit surface and exit centerline are found to contribute substantially to the total stress tensor.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTEffect of Interphase Mass Transfer on Product Selectivity in Liquid-Phase Paraffin ChlorinationMichael P. Ramage and Roger E. EckertCite this: Ind. Eng. Chem. Process Des. Dev. 1973, 12, 3, 248–254Publication Date (Print):July 1, 1973Publication History Published online1 May 2002Published inissue 1 July 1973https://doi.org/10.1021/i260047a007RIGHTS & PERMISSIONSArticle Views39Altmetric-Citations1LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (848 KB) Get e-Alerts

For viscoelastic fluids the use of a “pressure tap” to measure the normal stress on a channel wall can lead to large errors. In previous studies the true normal stress on the wall was theoretically predicted or indirectly measured and compared to the erroneous measurements. Here pressure transducers are flush mounted on a rectangular channel approximating infinite parallel plates so that the true stress on the wall can be measured experimentally. A transducer is recessed to create a hole; the reading thus obtained is compared with the true stress to determine the hole error. Solutions of 0.9, 2, and 3% Polyox (polyethylene oxide, MW=4,000,000) in water were studied. Shear rates reached 17,000 sec−1 and hole errors up to 6000 dynes/cm3 were found. In the region of creeping flow, the hole error is equal to −0.16 of the primary normal stress difference. Hole errors have been determined at Reynolds numbers from 10−4 to 103 and at the higher values cross zero and become positive, as they are for Newtonian fluids. A mechanism is presented which explains this behavior of viscoelastic fluids over the seven cycle range of Reynolds number.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMaximization of the Conversion to m-Toluenesulfonic Acid in Sulfuric Acid SulfonationAllen R. Broyles and Roger E. EckertCite this: Ind. Eng. Chem. Process Des. Dev. 1973, 12, 3, 295–300Publication Date (Print):July 1, 1973Publication History Published online1 May 2002Published inissue 1 July 1973https://pubs.acs.org/doi/10.1021/i260047a014https://doi.org/10.1021/i260047a014research-articleACS PublicationsRequest reuse permissionsArticle Views122Altmetric-Citations1LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access options Get e-Alerts