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02149 A new distributed activation energy model using Weibull distribution for the representation of complex kinetics
16
Fuel science and techndagy (fundamentalscience, analysis, instrumentation)
Methods of moasurlng oxldrtion growth stroswr 99B2142 Evans,H. E. and Hunk, A M. Mareriuls at High Temperatures, 1994.12, (2), 111-117. Stresses developed isothermally at tern nture in both the oxide layer and e oxidation process are known as metal substrate as a consequence of tK” ‘growth stresses’. They seem to k an indigenous feature of all oxidation systems and, conquently, offer a ps’ential threat to the long-term integriby of protection oxide layers. To k m a position to provide a compreknsive prediction of lifehme kkviour, it then becomes necessary to ~hara~erize the growth stresses for any particular metal/oxide system of of this process is the measurement of both the u$erest. An important agn and magnitude op”the stresses produced. The paper surveys current experimental methods of performing such measurements and pays particular attention to the advantages and disadvantages of each. Mod01 accuracy for economic optlmlzlng control95B2144 km: The bias updata case Forks, J. F. and Marlin, T. E. Ind Eng. C/run. Res., Aug. 1994, 33, (8)). 1919-1929. In many advanced control a lications the numkrs of mani ulatcd and controlled variables are not t!pc same. A combination of steadpy-state cconomic o timization and model predictive control has been employed to exploit tRc optimization opportunities presented by such ‘non-square’ systerns. The economic optimization subsystem uses a process model and is usually coupled with a model updating scheme to compensate for plant/model mismatch. The paper presents a rigorous criterion for determining under what conditions the model-based optimization embedded within the model predictive controller, using bias update, is capable of finding the plant optimum despite plant/model mismatch. A demonstration of the methods on a real-time gasoline blending control and optimization problem is included in this paper. Mcdollng plane turbulent Courtto flow 95/9214!5 Andersson, H. I. and Pettersson, B. A. Znt. J. Heat & Fluid Flow, Dec. 1994. 15. 16’1.447-455. The ala& &ette fIow is the shear-driven motion of fluid bounded by two par ap cl planes in relative motion. The Couctte flow is turbulent in the majority of practical cases, e.g., engineering flows associated with lubricstion technolo thin-film coating, and stratified two-phase flow, and in natural fIows PIke the wind-induced motion in shallow lakes. From a turbulence modeler’s point of view, the conceptually simple fully developed turbulent Couette flow between two infinite plates is particuarly attractive due to its homogeneity in planes parallel with the bounding plates. The purpose of the present mvestigation is to address the co&k&g hypotheses relating to Couette flow. thereby attempting to resolve the apparent difficulties associated with the modclling of the seemingly simple flow.
A new dlstrlbutad acthmtion onrrgy modal u8lng 96m2149 Welbull dlstrlbutlon for the npresontatlon of complox klnotlcs Lakshmanan, C. C. and White, N. Enern & Fue4 Nov.-Dec. 1!@4,8, (6), 1158-1167.
in parameter e&i&ion substantially and allow -mpid analysis of the threedimensional error surface of the objective function over a wide range of kinetic parameters while retainin the true nonlinearity of the model. The existence of multiplicity-a num 6 r of sets of kinetic parameters which descrik the observed data, generally within the limits of experimental auscy-is also demonstrated using experimental data on kerogen decomposition. 95lO2169 New size laboratory ball mill for bond work Index detormlnatlon Nematollahi, H. Min Eng. (Littleton, Cola.), 1994, 46, (4), 352-353. Desaibes the use of a small ball mill to determine the Bond work index and the grindability of ores or minerals. The test is carried out just as the standard Bond test, but with a smaller amount of sample. %/02151 NMR studies of p rldlno-Insoluble nrlduo of vltraln and lts hydrocracklng prcJ ucts Yang, B. et al., Bopuxue Zuzhi, 1994, 11, (2). 119-126. (III Chiieae) Discusses the p ridine-insoluble and ‘IX&insoluble residues of hydrocracking procructs of vitrain pyridinc-insoluble residue and of pyridme-insoluble and THF-insoluble residues of vitrain itself by solid state 13CCPA4AS NMR technique. %I021 52 Non-Darcy forced convectlon bounda over a wedge embedded In a saturated porous nJlzr flow Hessian, M. A. et al., Numerical Heat Twufer, Parr A, Get. 1994, 26, (4), 399-414. The paper deals with non-Da&n, forced convection, boundary layer flow over a wcd4e with a variable free stream, taking into account the effects of convective mertia, solid boundary, and porous inertia as well as Darcy flow resistance. Three novel methods, namely, the extended series method together with Shanks’ transformation, the local nonsimilarity method, and the finite difference approximations combined with the KelIer box method, are employed to inte ate local nonsimilarity momentum and energy qustions governing the f ow. The results thus obtained are compared with the local skin friction and the local Nusselt number at the surface.
95/92149 The mcdrlllng of fluid-flow dlstrlbutlons In annular packed beds Heggs, P. J. et al., Gas Separation & Purijkation, 1994, 8, (4), 257-264. Subject to the basic assumption of unirsdial flow, a model has been establish& which allows the prediction of was flow distribution in annular packed beds. Whilst of general aoolicatlon. the model has been used to simulate the flow distribztion cha;a’cteris& of a specific type of air filter incorporating an ammlar kd of activated carbon. All four possible flow srraniemcnts have been investigated and it has ken shoti that U-type flow gives bettor flow distribution than Z-type flow.
%I02153 Novel optlmlxatlon approach of stochadlc planning models Icrapetritou, M. G. and Pistikopoulos, E. N. Ind Eng. Chem. Res., Aug. 1994, 33, (B), 1930-1942. In this ps ‘ithe problem of planning under uncertainty is addressed. Short term orX uction olanninn with a time horizon of a few weeks or months and long-range piarming&luding capacity expansion options are considered. Based on the postulation of general probability distribution functions describing process uncertainty, a two-stage stochastic programming formulation is devcloued where the obiectivc is to determine an ootimal plan and/or an optinial capacity expiuision policy that maximize 1;1 exp&tcd profit. Three example problems are presented to illustrate the steps of the novel planning under uncertainty optimization algorithm, including a reFmcry with two crude oil inputs and four product outputs.
%I021 47 Mowrbaurr analysis on the mlcrowanmagnetlc de8ulfurlxatlon of raw coal Weng, S. Nucl. Sci. Tech, 1994, 5, (l), 39-45. The selective dielectric heating of microwave energy to convert a portion of each pyrite particle to moderately magnetic pyrrhotite has been sugested to enhance the magnetic separation of inorganic sul hur from coal. !b c results for Mossbauer analyses shows that considera 1 lc amounts of pyrrhotite produced during microwave irradiation, carrying with it some of non-magnetic pyrite, ferrous sulphatc, and troilitc, is completely removed from coal after magnetic separation.
95102154 Numerical rolutlon of drformlng evvrporatlngdrop lets at lntsrmedlats Reynolds numbers Haywood, R. J. et al., Numerical Heat Transfer, Part A, Sep. 1994, 26, (3), 253-272. Describes a fiite volume numerical model, using a nonorthogonal adaptive grid, which has ken developed to examine both steady deformed and transient deforming droplet bchaviour. The model has been tested by comparison with existing numerical solutions and experimental data.
95m2148 Natural-convectlon heat transfer In a nonunlform flnlte rnnulus wlth concentrlc heat source Lei, M. and Kleinstreuer, C. Int. J. Hear % Fluid Flow, Dec. 1994, 15, (a), 456-461. In this aper, the mechanisms of natural-convection heat transfer inside a nomm iporm fiiite annulus have been numerically investigated. The system is actually a streamlines, water-fikd latex ballon with a coaxial cylindrical heating element. The balloon can be aDolied as a local hvwrthcrmia treatment &vice for the removal of undes&blc tissue if sdiiently hi&h temperatures and preferably uniform surface heat fluxes can be maintamed. A validated control-volume-based method has been employed to solve the coupled transient three-dimensional transport equations for laminsr free convection. The effects of heat-source temperature distributions and device orientations on the heat transfer have been studied. Possible design improvements of this device are discussed.
%I021 55 On the drtrrmlnatlon of donor-acceptor ablllty of coal tar pitches Pragr, P. Acta Mont., Ser. B, 1994, 3, 81-89. Describes the temperature dependence of reaction of 9,10_dihydroanthracene and two Czech pitches. 951021% Organic petrology of doe sea sediments: A compllatlon of results from the ocean drill Png program and the deep sea drllllna prolect Littke, R. a;d’Sadhsenhofer, R. F. Energy & Fuels, Nov.-Dec. 1994, 8, 161. . 1498-1512. Presents a comprehensive overview of the organic petrology of Triassic to Recent deep sea sediments. The data, which are derived from studies in the framework of the Ocean Drilling Program and the former Deep Sea Drilling Project, sre discussed with respect to the plate tectonic setting and the oceanographic environment. ,I
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Fuel and Energy Abstracts March 1995
145
Fuel science and techndagy (fundamentalscience, analysis, instrumentation)
Methods of moasurlng oxldrtion growth stroswr 99B2142 Evans,H. E. and Hunk, A M. Mareriuls at High Temperatures, 1994.12, (2), 111-117. Stresses developed isothermally at tern nture in both the oxide layer and e oxidation process are known as metal substrate as a consequence of tK” ‘growth stresses’. They seem to k an indigenous feature of all oxidation systems and, conquently, offer a ps’ential threat to the long-term integriby of protection oxide layers. To k m a position to provide a compreknsive prediction of lifehme kkviour, it then becomes necessary to ~hara~erize the growth stresses for any particular metal/oxide system of of this process is the measurement of both the u$erest. An important agn and magnitude op”the stresses produced. The paper surveys current experimental methods of performing such measurements and pays particular attention to the advantages and disadvantages of each. Mod01 accuracy for economic optlmlzlng control95B2144 km: The bias updata case Forks, J. F. and Marlin, T. E. Ind Eng. C/run. Res., Aug. 1994, 33, (8)). 1919-1929. In many advanced control a lications the numkrs of mani ulatcd and controlled variables are not t!pc same. A combination of steadpy-state cconomic o timization and model predictive control has been employed to exploit tRc optimization opportunities presented by such ‘non-square’ systerns. The economic optimization subsystem uses a process model and is usually coupled with a model updating scheme to compensate for plant/model mismatch. The paper presents a rigorous criterion for determining under what conditions the model-based optimization embedded within the model predictive controller, using bias update, is capable of finding the plant optimum despite plant/model mismatch. A demonstration of the methods on a real-time gasoline blending control and optimization problem is included in this paper. Mcdollng plane turbulent Courtto flow 95/9214!5 Andersson, H. I. and Pettersson, B. A. Znt. J. Heat & Fluid Flow, Dec. 1994. 15. 16’1.447-455. The ala& &ette fIow is the shear-driven motion of fluid bounded by two par ap cl planes in relative motion. The Couctte flow is turbulent in the majority of practical cases, e.g., engineering flows associated with lubricstion technolo thin-film coating, and stratified two-phase flow, and in natural fIows PIke the wind-induced motion in shallow lakes. From a turbulence modeler’s point of view, the conceptually simple fully developed turbulent Couette flow between two infinite plates is particuarly attractive due to its homogeneity in planes parallel with the bounding plates. The purpose of the present mvestigation is to address the co&k&g hypotheses relating to Couette flow. thereby attempting to resolve the apparent difficulties associated with the modclling of the seemingly simple flow.
A new dlstrlbutad acthmtion onrrgy modal u8lng 96m2149 Welbull dlstrlbutlon for the npresontatlon of complox klnotlcs Lakshmanan, C. C. and White, N. Enern & Fue4 Nov.-Dec. 1!@4,8, (6), 1158-1167.
in parameter e&i&ion substantially and allow -mpid analysis of the threedimensional error surface of the objective function over a wide range of kinetic parameters while retainin the true nonlinearity of the model. The existence of multiplicity-a num 6 r of sets of kinetic parameters which descrik the observed data, generally within the limits of experimental auscy-is also demonstrated using experimental data on kerogen decomposition. 95lO2169 New size laboratory ball mill for bond work Index detormlnatlon Nematollahi, H. Min Eng. (Littleton, Cola.), 1994, 46, (4), 352-353. Desaibes the use of a small ball mill to determine the Bond work index and the grindability of ores or minerals. The test is carried out just as the standard Bond test, but with a smaller amount of sample. %/02151 NMR studies of p rldlno-Insoluble nrlduo of vltraln and lts hydrocracklng prcJ ucts Yang, B. et al., Bopuxue Zuzhi, 1994, 11, (2). 119-126. (III Chiieae) Discusses the p ridine-insoluble and ‘IX&insoluble residues of hydrocracking procructs of vitrain pyridinc-insoluble residue and of pyridme-insoluble and THF-insoluble residues of vitrain itself by solid state 13CCPA4AS NMR technique. %I021 52 Non-Darcy forced convectlon bounda over a wedge embedded In a saturated porous nJlzr flow Hessian, M. A. et al., Numerical Heat Twufer, Parr A, Get. 1994, 26, (4), 399-414. The paper deals with non-Da&n, forced convection, boundary layer flow over a wcd4e with a variable free stream, taking into account the effects of convective mertia, solid boundary, and porous inertia as well as Darcy flow resistance. Three novel methods, namely, the extended series method together with Shanks’ transformation, the local nonsimilarity method, and the finite difference approximations combined with the KelIer box method, are employed to inte ate local nonsimilarity momentum and energy qustions governing the f ow. The results thus obtained are compared with the local skin friction and the local Nusselt number at the surface.
95/92149 The mcdrlllng of fluid-flow dlstrlbutlons In annular packed beds Heggs, P. J. et al., Gas Separation & Purijkation, 1994, 8, (4), 257-264. Subject to the basic assumption of unirsdial flow, a model has been establish& which allows the prediction of was flow distribution in annular packed beds. Whilst of general aoolicatlon. the model has been used to simulate the flow distribztion cha;a’cteris& of a specific type of air filter incorporating an ammlar kd of activated carbon. All four possible flow srraniemcnts have been investigated and it has ken shoti that U-type flow gives bettor flow distribution than Z-type flow.
%I02153 Novel optlmlxatlon approach of stochadlc planning models Icrapetritou, M. G. and Pistikopoulos, E. N. Ind Eng. Chem. Res., Aug. 1994, 33, (B), 1930-1942. In this ps ‘ithe problem of planning under uncertainty is addressed. Short term orX uction olanninn with a time horizon of a few weeks or months and long-range piarming&luding capacity expansion options are considered. Based on the postulation of general probability distribution functions describing process uncertainty, a two-stage stochastic programming formulation is devcloued where the obiectivc is to determine an ootimal plan and/or an optinial capacity expiuision policy that maximize 1;1 exp&tcd profit. Three example problems are presented to illustrate the steps of the novel planning under uncertainty optimization algorithm, including a reFmcry with two crude oil inputs and four product outputs.
%I021 47 Mowrbaurr analysis on the mlcrowanmagnetlc de8ulfurlxatlon of raw coal Weng, S. Nucl. Sci. Tech, 1994, 5, (l), 39-45. The selective dielectric heating of microwave energy to convert a portion of each pyrite particle to moderately magnetic pyrrhotite has been sugested to enhance the magnetic separation of inorganic sul hur from coal. !b c results for Mossbauer analyses shows that considera 1 lc amounts of pyrrhotite produced during microwave irradiation, carrying with it some of non-magnetic pyrite, ferrous sulphatc, and troilitc, is completely removed from coal after magnetic separation.
95102154 Numerical rolutlon of drformlng evvrporatlngdrop lets at lntsrmedlats Reynolds numbers Haywood, R. J. et al., Numerical Heat Transfer, Part A, Sep. 1994, 26, (3), 253-272. Describes a fiite volume numerical model, using a nonorthogonal adaptive grid, which has ken developed to examine both steady deformed and transient deforming droplet bchaviour. The model has been tested by comparison with existing numerical solutions and experimental data.
95m2148 Natural-convectlon heat transfer In a nonunlform flnlte rnnulus wlth concentrlc heat source Lei, M. and Kleinstreuer, C. Int. J. Hear % Fluid Flow, Dec. 1994, 15, (a), 456-461. In this aper, the mechanisms of natural-convection heat transfer inside a nomm iporm fiiite annulus have been numerically investigated. The system is actually a streamlines, water-fikd latex ballon with a coaxial cylindrical heating element. The balloon can be aDolied as a local hvwrthcrmia treatment &vice for the removal of undes&blc tissue if sdiiently hi&h temperatures and preferably uniform surface heat fluxes can be maintamed. A validated control-volume-based method has been employed to solve the coupled transient three-dimensional transport equations for laminsr free convection. The effects of heat-source temperature distributions and device orientations on the heat transfer have been studied. Possible design improvements of this device are discussed.
%I021 55 On the drtrrmlnatlon of donor-acceptor ablllty of coal tar pitches Pragr, P. Acta Mont., Ser. B, 1994, 3, 81-89. Describes the temperature dependence of reaction of 9,10_dihydroanthracene and two Czech pitches. 951021% Organic petrology of doe sea sediments: A compllatlon of results from the ocean drill Png program and the deep sea drllllna prolect Littke, R. a;d’Sadhsenhofer, R. F. Energy & Fuels, Nov.-Dec. 1994, 8, 161. . 1498-1512. Presents a comprehensive overview of the organic petrology of Triassic to Recent deep sea sediments. The data, which are derived from studies in the framework of the Ocean Drilling Program and the former Deep Sea Drilling Project, sre discussed with respect to the plate tectonic setting and the oceanographic environment. ,I
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Fuel and Energy Abstracts March 1995
145