Kinetics and Equilibria R, H. WILHELM and R. K. TONER PRINCETON UNIVERSITY, PRINCETON, N. 1.
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HIS review includes literature for the calendar year 1949, although occasional papers are mentioned for 1948 and early 1950. Selection has been made from the extensive literature in kinetics and thermodynamics primarily to illustrate basic advances in these subjects. Specific applications in t.he various unit processes are not considered here, but are dealt with in the succeeding papers in this Annual Review,
I.
KINETICS
BOOKS
Two volumes have appeared of a series dealing with advances in catalysis and edited by Frankenburg, Komarewsky, and Rideal (I). The first volume (1949) treats catalyst surfaces from the viewpoints of heterogeneity, area measurements, geometrical factors, and x-ray diffraction studies. In addition, specific reactions are studied including alkylation, isomerization, and FischerTropsch and hydrogenation reactions. The second volume (1950) reviews principles and mechanisms of catalytic activity, including the role of adsorption. Chapters are devoted to mechanisms of alkene polymerizations, and to hydrofluoric acid w a catalytic agent. Experimental techniques in catalytic, photochemical, and electrolytic reactions are the subject of a book by Komarewsky, Riesz, Noyes, Boekelheide, and Swann (d). Reviews of theory as well as laboratory techniques are given. A monograph on re action mechanisms of free radical reactions was written by Waters (6),in which the theory of such reactions and a wide survey of reaction types are discussed. A comprehensive book by Nachod (3) on ion exchange, its theory, and application has been published. Attention is drawn to a mathematical analysis of the kinetics of fixed-bed ion exchange in a chapter by H. C. Thomas. The catalytic applications of ion exchange are reviewed in the Nachod book by s. Suasman. The proceedings of a symposium on combustion, flame, and explosion phenomena, which was held at the University of Wisconsin in 1948,were published during 1949 ( 4 ) . One hundred and two papers appear in 11 categories of subject matter. Included are papers on the kinetics and mechanism of combustion reactions and flame propagation in explosivegas mixtures.
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RATE PROCESS THEORY
The fundamentals of rate processes received the attention of a number of authors. Golden (30) and Golden and Peiser (31) present a quantum mechanical formulation for the rate of a chemical reaction. They transcribed the quantum mechanical results into terms of the collision theory and of the activated complex theory. Their theory was applied to a displacement re action of the type AB C -6 A BC. The authors conclude that absolute rate may not be calculated without a great deal of uncertainty. However, relative results, such as effect of ternperature on rate, are very acceptable. The present theory of reaction rates assumes a dynamic equilibrium between reactants and activated complex. The applicability of this theory to irreversible reaction or to the rate of approach to equilibrium has been questioned by a number of authors, and two nonequilibrium theories of reaction rates have been proposed (67,48). Hulburt and Hirschfelder ( 4 6 ) present
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a third theory €or the rate of an irreversible reaction and reach qualitative conclusions also concerning the rate of approach to equilibrium. Brunner (13)proposes an alternative formulation of the absolute reaction-rate constant to that used by Eyring. The effect of pressure on the formation of the activated complex and on the rate of reaction in solution is discussed by Gonikberg and Povkh (38). The conditions for the pulsating progress of sequential homogeneous chemical reactions are the subject of a mathematical paper by Sal'nikov (61). Adirovich ( 6 ) reported upon differential equations of consecutive reactions. Data for chain reactions involving radicals or atoms are presented by Evans and Szwarc (W) in a study of the magnitude of the probability factors in such reactions. The steric factors for several reactions involving free .radicals are calculated from the theory of absolute reaction rate by Hill (48). Skrabal (66) discusses chain reactions from the viewpoint of simultaneous reactions, and Polyakov (68),the influence of the walls of a vessel on chain reactions which may be mistaken for purely homogeneous reactions. Constable (do), and Cremcr (98) in 1925 and 1929,uncovered an effect of interest in catalytic reactions. When a given reaction is brought about on a series of catalysts, a relation frequently is obtained of the form: log A = ( p / a ) constant, where A is the Arrhenius frequency factor and q, the energy of activation. This compensating effect is the subject of several papers. Cremer (91) discusses the kinetics of a variety of heterogeneous reactions in terms of the relationship. An explanation is offered through the assumption of a Boltzmann distribution of active centers and the assumption that the rate-determining step is the leakage of electrons through a potential barrier. Cremer and Baldt (93)present new data on ethyl chloride decomposition on a chloride catalyst. They found that the relation between frequency factor and energy of activation waa valid, but that the temperature of catalyst preparation primarily affected the energy of activation, not the frequency factor as was previously supposed. The literature on the compensating effect is reviewed by Kunze (49)and Patat (67) and mechanisms to explain the effect are discussed. I n an important paper, Schwab and Schwab-Agallidis (6%)present results of experimental studies on simultaneous dehydration and dehydrogenation of ethyl alcohol and formic acid vapors on sixteen different catalysts. Activation energy is found to be a linear function of the logarithm of the frequency factor in accord with the Constable-Cremer relationship. Also, the function is the same for both reactions of a given reactant. Christiansen (18) presents a derivation showing the mathematical conditions necessary for the compensating effect to hold in a homogeneous reaction. The literature on catalysis during 1949 is substantial. Halsey ($6) discusses catalysis on nonuniform surfaces and proposes an explanation for the duality in which the evidence is strong that ratalyst surfaces are nonuniform, yet the assumption of uniformity in the development of heterogeneous rate equations frequently leads to the successful description of experimental results. Balandin (@, who in 1925 proposed a theory which seeks to link catalyst adivity with the fitting of a reactant molecule to lattice spacings, presents a paper which relates his multiplet theory and the transition state theory of chemical reaction by means of statistical thermodynamics. Catalytic processes on homogeneous surfaces are analyzed by Levin and RoghskiI (61) in terms of statistical mechanics. A new and powerful experimental tool for investigating catalyst surface processes is de-
1644
September 1950
INDUSTRIAL AND ENGINEERING CHEMISTRY
scribed by Wright and Taylor (76). The reaction of methane and methane-& on nickel was studied. Evidence of the nature of the surface population was obtained by hydrogenating catalyst surface residues and analyzing the hydrogenated fragments by means of a mass spectrometer. Eley (26) presents a review of mechanisms of hydrogen catalysis, including the subjects of chemisorbed films, mixed monolayers, para-hydrogen conversions, and exvhange reactions. The subject of catalyst activity and the physical structure of the catalyst has been of increasing interest Over the years. Selwood has used magnetic properties as a tool for investigating catalysts. He now reviews the structure of solid catalysts and the phenomenon of valence induction (63). Valence induction is the tendency of oxides of the transition metals to assume the crystal structure of their support. Magnetic susceptibility is+ therms of supported oxides of iron and the computed valence induction based on these measurements are reported by Sdwood, Ellis, and Wethington (64). Hill and Selwood (41) made a study on the structure and activity of supported nickel catalysts. Conclusions are reached regarding the geometric aggregation of metal atoms as a major factor in the catalysis of benzene hydrogenation. In a technique paper, the newer tool of nuclear induction is presented by Spooner and Selwood (68) to complement measurements of magnetic susceptibility as means of obtaining information regarding catalyst structures. Natta (64)stressed the importance of solid state reactions in the formation and aging of catalysts. By using hydrogen overvoltage on metals as a tool of investigation, Leidheiser (60) contributed to the literature which concerns the importance of interatomic spacing in catalysts. Neimark and Sheinfain (66)studied the effect of porosity of silica gel catalyst on a vapor-phase hydrolysis. The sintering of vanadium catalysts and its detection by electron optical methods, and the preparation and aging of Raney nickel catalysts, were the subjects of investigation by Pongratz (69) and by Smith, Bedoit, and Fuzek (67), respectively. The detailed properties of sulfide catalysts were measured by Badger, Griffith, and Newling (7)in connection with the catalytic decomposition of simple heterocyclic compounds. Adsorption as a component mechanism of the catalytic process has received continued attention. Hill (&) presents a theoretical paper on localized unimolecular adsorption on a heterogeneous surface using the techniques of statistical mechanics. The series of studies on adsorption-desorption isotherms for catalysts waa continued by Ries, Johnson, and Melik (60). Nitrogen and stearic acid adsorption on supported catalysts was studied and conclusions are drawn regarding pore structure and the effect of the supporting structure on the structure of the supported catalyst. A review of chemisorption of hydrogen and water on zinc and aluminum oxide and the catalytic decomposition of alcohols on these oxides is the subject of a published address by Wicke (73). Gorter and Frederiske ($3) treat physical adsorption from thermodynamic and kinetic viewpoints. The adsorption of hydrogen by cupric oxide is reported by Hasegawa (38). Tho activation of chemical reactions by means of ultrasonic energy has become an intriguing subject for investigation, although success to date has been limited. Promising results by Weissler (7.9) have been reported in the study of three reactions in the liquid phase. I t was-found that ultrasonic waves causod chemical reactions only in the presence of dissolved gases; this indicates that cavitation is responsible for the reaction. Wagner (7f)describes the means for producing ultrasonic oscillations and mentions a few reactions that are observed in an ultrasonic field. Mastagli and Mahoux (6.9)found the hydrolysis of dimethyl sulfate to be favored and the hydrolysis of ethyl acetate not to bo favored by ultrasonic vibrations. The results between the two systems are rtscribed to differences in mixing rates. A general paper was written by Thompson (69),in which the unsatisfied requirements in the field of ultrasonics from the standpoint of a chemical engineer were stressed.
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Acid-catalyzed reactions continue to be investigated kinetically. The Hammett add-function against which the rate constants of so many electrophilic reactions have been successfully correlated has been extended by a study of the system phosphoric acid-water, by Heilbronner and Weber (40). The kinetics of aromatic sulfonation in sulfuric acid was studied by Brand and Rutherford (11); it is concluded that sulfonation is a further example of superacid catalysis in which a group -X is inserted by the reaction of the aromatic system with cation -X+-i.e., SOIH+. The Friedel-Crafts reaction involving migrations in the benzene nucleus also is described by Pajeau and Fierens (66) as an example of an acid-catalyzed electrophilic transformation. The Br@nsted, Bjerrum, and Lewis acid-base theories are reviewed by Ebert and Konopik ($4). The presence of hydrogen ions in alumina-silica vapor phase cracking catalysts has been of interest. Grenall (36)presents evidence for the presence of such ions in a clay catalyst by a titration method. The influence of the solvents on the kinetics of reactions between ions and polar molecules was the subject of an investigation by Moelwyn-Hughes (63). A change from methanol to acetone as solvent for the reaction of methyl bromide plus an iodide resulted in a thousandfold increase in the velocity constant. Application of the method of least squares to the quantitative study of reactions by chemical kinetics is discussed by Callia (16). Reactions in the solid phase are one of the more difficult domains of kinetics. The field has been advanced during 1949 by a number of contributions. A broad-gaged discussion of the present state of knowledge of reactions in a solid state is given in an address by Hedvall (39). An experimental paper by Gregg and Razouk (34) on the thermal decomposition of magnesium hydroxide gives fairly good agreement with Mampel's theory of reaction in the solid state. Actording to this theory the rate of nuclei formation follows a unimolecular law and the interface, which is the seat of reaction, advances at a constant; linear velocity. Magnetic measurements are used by Forestier, Haasser, and Escard-Longuet ($8) to detect reaction between powdered mixtures of Fez03 and oxides of nickel, lead, and magnesium at temperatures low enough for diffusion to be neglected. Experimental results are explained in terms of the number of contsct points and the effect of adsorbed water vapor on the surface of the crystal lattice. The initiation of reaction between solid phases in contact is the subject of a discussion by Smekal (66). The kinetics of cryatallization by Bransom, Dunning, and Millard (1.9)and the study of crystal growth and surface stmcture by Burton and Cabrera (16) are two rate studies in a major symposium on crystal growth published in the Discussionrr of the Faraday Society. The transport properties-viscosity and thermal and molecular diffusion-are important subjects in rate theory and in fields of application. Fundamental definitions and concepts in diffusion processes are discussed by Hartley and Crank (37). Two papers by Hirschfelder, Bird, and Spotz 46) represent outstanding advances in the field of gas and gas mixture transport properties. The properties are related through intermolecular forces between gaseous molecules. The theoretical tools provide a new and successful method of formulating and predicting the viscosity and other transport properties of gases and gaseous mixtures, which is an improvement over the Sutherland method and therefore is of interest to engineers and scientists. Buddenberg and Wilke (14) propose a mixture law for gas-mixture viscosities, which haa an average deviation from esperimental measurements of 3% for 88 binary m'xtures a t room temperature and 7% for 23 other mixtures a t various temperatures ranging from 99' to 225" C. Gamson (89)proposes a generaliaed thermal conductivity correlation for the gaseous state which employs reduced thermal conductivity, reduced temperature, and reduced pressure. A note by Carman (17) deals with transition from viscous to molecular flow of five gases through a medium having pores comparable in size to the mean free path of the molecules.
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lW6
INDUSTRIAL AND ENGINEERING CHEMISTRY
Truly fundamental attacks upon the theory of transport processes in the liquid phase are inordinately difficult because of the
complexity of and limited knowledge about the liquid state. Papers in this field are necessarily highly mathematical. Recent advances are contributed by Kirkwood, Buff, and Green ( 4 7 ) and Yang (76, 7 7 ) . The Eyring application of the absolute rate theory to liquid-phase transport processes, combining theory and empiricism, has presented a useful, immediate, and valuable scientific tool in the study of these processes. Brunner (15) and Balazs (9)have proposed modifications of the Eyring formulation for the viscous flow equation. A significant paper for the estimation of liquid diffusion coefficients is that of Wilke ( 7 4 ) , which used the Eyring theory and the Stokes-Einstein equation as a basis. The effect of concentrations on the diffusion coefficient was considered and a comparison was made between calculated and observed values for 178 experiments. Agreement is within 10%. Trevoy and Drickamer ( 7 0 ) measured diffusion in 12 binary liquid hydrocarbon mixtures. The results were tested by the equations of Arnold, of Stokes and Einstein, and of Stern, Irish, and Eyring. Only the semiempirical equation of Arnold gives satisfactory agreement with experiment. Barrer and Jost (10) analyze the mechanism of activated diffusion in which each unit diffusion process involves a jump from one sorption site to another as in zeolites. MODES OF PERFORMING REACTIONS
A number of papers can conveniently be classified under the method by which chemical reactions are performed-that is, in continuous tubular reactors, in continuous agitated reactors, or in fluidized beds. I n laminar flow in an unpacked cylindrical reactor it is well known that different filaments of the stream travel at different speeds. The different sections of the fluid therefore have different reaction times. Both the distribution of streamlined velocities and the diffusion of molecules from one streamline to the other during the flow are involved. Bosworth (79) addresses himself to the problem of distribution of reaction times in such a reactor. In a comprehensive paper, Yang and Hougen (101) present summarized procedures for establishing rate equations for numerous postulated mechanisms of four simple reaction types in flow system reactors. The effects of pressure, feed composition, and temperature on the extent of convopion are the variables used in distinguishing between mechanism rate equations. Winslow (100) discusses vapor-phase research in flow reactors using the oxidation of tolueue as an example. The catalytic isomerization of butene, studied by Hay, Coull, and Emmett (86), provides an example of the Hurt heightrof-reaction-unit method of organizing kinetic information. Experimental procedures for controlling the temperature of endothermic reactions in flow systems are dewribed by Gadsby arid Sykes (84). Continuous stirred reaction systems have advantages in preparative work, in the study of reaction kinetics, and in some industrial reactions that require long times of residence. Hammett and co-workers in a series of three papers discuss stirred reactors as tools for the study of reaction kinetics. A first paper by Rand and Hammett (96) deals with apparatus and methods for the study of reaction rates and heats by means of the temperature rise in such reactors. Saldick and Hammett (97) study the techoiquea of rate measurement by continuous titration in a stirred flow reactor, and, finally, Young and Hammett (102)illustrato the devised procedures by means of kinetic measurements of UII alkaline bromination of acetone. Johnson and Edwards (88) consider continuous flow reactors for the study of transient strate reactions. They examined the physical displacement charttcteristics of such a system and found that it follows closely the predicted course, Glycine formation by ammonolysis was measured in the reactor and conversion is compared with that obtained in a batch process and in a tubular reactor.
Vol. 42, No. 9
The literature in the field of fluidization and fluidized reactionn in 1949 was extensive. A nomenclature and symbols (83) for fluidization were presented. This compilation was made with the idea of stimulating progress toward a permanent nomenclature. Two papers were published dealing with chemical reactions performed in the fluidized bed. Lewis, Gilliland, and Reed (92) studied the reaction of methane with copper oxide. The data are correlated on the assumption that the limiting factor is the reaction of carbon dioxide and water vapor with methsne. Lewis, Gilliland, and McBride (91) investigated the gasification of carbon by carbon dioxide in a fluidized powder bed. The data from this study are correlated by an equation of the Langmuir type. The quality of fluidization is important because the uniformity of temperature, concentration, and particlefluid contact in chemical reactors depends upon it. Two complementary contributions by Morse (94) and Matheson, Herbst, and Holt (93)provide the most satisfactory theory and criteria for the quality of fluidization presented to date. A balance is postulated between (1) the segregation tendency or rate of separation of fluid from particles to form bubbles or pockets and (2) the remixing tendency or rate of gravity flow of particles into the pockets. Morse stressed the segregation tendency and the latter authors, the viscous properties of gas-solid mixtures which affect the remixing tendency. Reis (96) in a theoretical and experimental study of fluidized catalyst systems measured the nonuniformity of fluidized beds by the use of an optical system wherein a beam of light of controlled intensity passes laterally through a glass reaction tube and is reflected onto a photocell connected with an oscillograph circuit. Zenz (105) studied the horizontal and vertical transport of particles. Schematic “phase diagrams” were developed to illustrate qualitative relationships between partirle-gas flow and fluidization. Measurements, correlations, and qualitative observations are reported by Lewis, Gilliland, and Bauer (90)for fixed and circulating fluidized beds using air and water as the fluidizing medium. Turbulent mixing is important in achieving uniform bed temperatures. It is. :elated also to the mechanisms of heat transfer in fluidked beds. Gilliland and Mason (85) made exploratory measurements with fluidized cracking catalysts in air, of the extent of mixing in the gas phase and among the particles. Brinkman (80) discusses problems of the flow of fluid through swarms of particles and through macromolecules in solution. Ergun and Orning (81)studied the flow of fluid through randomly packed columns and fluidized beds and extend the pressure drop treatment of Carman-Kozeny to include the effect of turbulence by the use of an appropriate term in the square of the velocity. Leva, Weintraub, Grummer, and Pollchik (89) present new data on the fluidization of an anthracite coal. Appropriate consideration of internal particle porosity permits the data to be correlated according to earlier proposed methods. The development and evaluation of stirred-type and baffled fluid reactors are the subject of a paper by Beck (78). Attrition characteristics of fluidized cracking catalysts and erosion to dust particles in a gas stream are subjects investigated by Forsythe and Hertwig (82) and Stoker (99),respectively. Huhndorff (87) discusses statistical procedures for use in pilot plant studies of fluidized bed catalytic cracking units. DIFFUSION EFFECTS
In this section are listed work in which thermal or mass diffusion effects are important in chemical processes. Studies also are included in which the diffusional steps are separately measured and analyzed in a variety of physical circumstances. The thermal design of gas-solid flow system catalytic reactors was the subject of investigation by Hall and Smith (111). The oxidation of sulfur dioxide was measured in small and large bed depths, fractions conversion and temperature gradients were
INDUSTRIAL A N D ENGINEERING CHEMISTRY
September 1950
measured, and finally a design procedure was tested as a bridge between the two scales of operation. Wilhelm (187) reviews elements of chemical rate processes and diffusion rate processes. An andytical treatment for a case in which both chemical and physical diffusion rates are important is illustrated by means of a design outline for a sulfur dioxide converter. New data are presented on the effect of temperature on liquid phase diffusion processes. Adameon and Grossman (104) studied the kinetics Of zeolitic ion exchange of univalent ions in dilute solution and explain their results by the diffusion of ions through a bounding liquid film. A mathematical theory of steady-state onedimensional flames w a investigated by Hirschfelder and Curtiss (118). A set of firsborder ordinary differential equations suitable for solution by differential analyzers or high speed digital computing devices was published. Sedov (128) gives a theoretical treatment of chemical kinetics, taking into account the effects of viscosity, diffusion, stirring of the gas, and variations in temperature or pressure. The diffusion, fluid flow, and reaction velocity in the interior of porous catalyst bodies have been advanced in an important paper by Wicke and Brotz (126). Measurements were performed with a constanbvolume first-order reaction and a variable-volume firstorder reaction. Effective diffusion coefficients were determined on the basis of purely reaction-kinetic measurements. Three papers deal with the problem of diffusion in liquid phase hydrogenations catalyzed by suspended catalysts. Reaction rates are found to depend upon the concentration of catalyst and the degree of agitation. The authors are Erdey-Gruz (108), Erdoy-Grua and Szabo (IO@, and Gol’danskil(110). Drozdov (106) studied the kinetics of the cementation displace Ni++. The reaction rate ment reaction: Cu++ Ni -+ Cu was found to vary between a first-order chemical rate law and a diffusion process depending upon the nature and amount of c o p per deposited about the nickel particles. The reaction of a gas on a solid in which it diffuses is the subject of a theoretical kinetic study by Dunoyer (107). Diffusion-controlled reactions in homogeneous liquid solutionb are discussed by Collins and Kimball (106). Diffusion can become important for very rapid bimolecular reactions such 89 quenching of fluorescence or free radical polymerization because of point concentration gradients and transients. Mess transfer rates across phase interfaoes have been reported by a number of investigators. Resnick and White (180) studied m a transfer between gases and fluidiaed solids. McCune and Wilhelm (118) investigated mass and momentum transfer in solid-liquid systems and included fixed bed, fluidized beds, and individual particles. The diffusion of mass from granular solids to a liquid phase in fixed beds also waa the subject of investige tion by Hobson and Thodos (114). Hixson and Smith (118) studied the rate of transfer between two liquid phaaes in propellersgitated vessels. The rate of solution of sodium chloride crystals and the effect of diffusion in natural convection and under controlled agitation conditions are reported by Wagner (186) and Tovbin and Baram (1.944). Heat and mass transfer t o a gas flowing through commercial tower packings waa investigated by Taecker and Hougen (123). The transmission of heat through fluidiaed beds of fine particles ia reported by two groups of authors, Leva, Weintraub, and Grummer (116) and Mickley and Trilling (119). 8chumacher (181) investigated the transfer of heat to gases flowing in packed tubes. Temperature gradients and turbulent eddy diffusivlties were measured in air ducts by McCarter, Stutzman, and Koch (117) and the resulta are discussed in the light of variables affecting diffusion and miffing. McCann and Wilts (116) present a discussion of the application of electric-analog computers to heat transfer and fluid flow problems.
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LITERATURE CITED IN
164z KINETICS
600KS
(1) Frankenburg, W. G., Komarewsky, V. I., and Rideal; E. K., “Advances in Catalysis,’’ New York, Academic Press, Vol. 1. 1948, Vol. 2, 1950. (2) Komarewsky, V. I., Riesz, C. H., Noyes, W. A,, Jr., Boekelheide, V., and Swann, S., Ji., “Catalytic, Photochemical and Electrolytic Reactions,” NPWYork, Interscience PublisherE, 1948. (3) Nachod, F., “Ion Exchange Theory and Application,“ New York, Academic Press, 1949. (4) “Third Symposium on CombuLction and Flame and Explosion Phenomena,” University of Wisconsin, 1948, Baltimore, Williams and Wilkins Co., 1949., (5) Waters, W. A., “Chemistry of Free Radicals,” 2nd ed.. New York, Academic Press, 1949. RATE PROCESS THEORY
Adirovich, E. I., Dokludy Akiid. Nauk S.S.S.R., 61,467 (19481. Badger, E. H. M., Griffith, R. H., and Newling, W. D. S., Proc. Roy. SOC.(London), A197, 184 (1949). Balandin, A. A., Doklady Aknd. Nauk S.S.S.R.. 63, 5.75 (1948). Balass, F., Nature, 164,191 (1949). Rarrer, R. M., nnd Sost, W., l’ra118. Fartidug Soc., 45, 928 (1949). Brand, J. C. D., and Rutherford, A., Resc,nrc*h (Lordon),2, 195 (1949). Bransom, I. 9. H., Dunning, W. J., and Millard, H . , Wcueaions Faraday Soc., 1949, No. 5,83. Brunner, E., J . Chem. Phys., 17, 346 (1949). Buddenberg, J. W., and Wilke, C. R., INI). EN(:. CBEM.,41. 1345 (1949). Burton, I. W. K., aiid Cabrein, N., Diacusaiotrs Faradau SOC,, 1949, No. 5,33. Callia, V. W.. AWLS asaoc. q u h . Brasil. 7 , 178 (1948). Carmen, P. C., Nature, 163, ti84 (1949). Christiansen, J. A,, Acta Chcm. Scand., 3, 61 (1949). Collins, F. C., and Kimball, G.E., IND.ENQ. CHEM.,41, 2561 (1949). Constable, F. H., Proc. Roy. Soc., A108, 355 (1925). Cremer, E., 2. Elektrochem., 53, 269 (1949). Cremer, E., 2. phyaik. Chem., A144, 231 (1929). Cremer, E., and Baldt, R., Monotuh., 79, 439 (1948). Ebert, L., and Konopik, N., Osterr. Chem.-Ztg., 50, 184 (1949). Eley, D. D., Quart. Revs. (London), 3, 209 (1949). Evans, M. G., and Szwarc, M . , Tram. Faraday SOC.,45, 940 (1949). Eyring, H., and Zwolinski, B. J . , J . Am. Chem. SOC..69, 2702 (1947). Forestier, H., Haasser, C., and Escard-Longuet, J., Rtrll. a m . chim. France, 1949, D14ti. Gamson, B. W., Chem. Eng. Progress, 45, 154 (1949). Golden, S.,J. C h m . Phys., 17, ti20 (1949). Golden, S., and Peiser, A. M., Ibid., 17, 842 (1949). Cxonikberg, M. G., and Povkh, G. S., Zhur. Fiz. Khim., 23, 383 (1949). Gorter, C. J., and Frederiske, H. P. R., Phyaica, 15,891 (1949). Gregg, 6. J., and Raaouk, R. I., J . Chem, Soc., 1949, S36. Grenall, A., IND.ENQ.CHEM.,41, 1485 (1949). Halsey, G. D., Jr., J. Chem. Phya., 17, 758 (1949). Hartley, G. D., and Crank, J., Trans. Faraday SOP.,45, 801 (1949). Hasegawa, S.,Rev. Phys. Chem. Japan, 19, 132 (1945). Hedvall, J. A., 2.anorg. Chew&.,258, 180 (1949). Heilbronner, E., and Weber, Sa, Helv. Chim. Acta, 32, 1613 (1949). Hill, F. N., and Selwood, P. R., J . Am. Chem. SOC.,71, 2522 (1949). Hill, T. L., J . C h m . Phua., 17. 503 (1949). . , Ibid., p. 762. Hirschfelder, J. O., Bird, R. B., and Spotz, E. L., Chem. Rma., 44.205 (1949). Hirschfelder, J. O., Bird, R. B., and Spotz, E. L., Tram. A m . SOC.Mech. E ~ T s 71,921 ., (1949). Hulburt, H. M., and Hirschfelder, J. O., J . C h . Phva., 17, 964 (1949). Kirkwood, J. G., Buff, F. P.,and Green, M. S., Ibid., 17, 888 (1949). Kremers, H. A., Phuaih, 7,284 (1940). Kunze, F., Momtah. 79,267 (1948). Leidheiaer, E . , Jr., J . Am. Chen. Soc., 71, 3834 ( I M Q ~ . , y . Levin, V. I., and RoginskiY, S. Z.,Imest. A M . NaU) g Otdel. Khim. Nauk,1949,134.
INDUSTRIAL AND ENGINEERING CHEMISTRY blastagli, Y.,and Mahoux, .L P., Contpt. rend., 228, 684 (1949). Moelwyn-Hughes, E. A,, Trans. Faraday SOC.,45, 167 (1949). Natta, G., Bull. SOC. chim. France, 1949, D161. Neimark, I. E., and Sheinfain, R. Y., Zhur. Fiz. Klrim., 23, 595 (1949). ,----,
Pa;&, R., and Fierens, P., Bull. soc. chim. France, 1949, 587. Patat, F., 2. Elektrochem., 53, 216 (1949). Polyakov, M. V., Doklady Akad. Nauk S.S.S.R., 69, 217 (iw9).
Pongratz, il., Mitt. chein. Forsch.-Inst. Ind. oesterr., 3, 41 (1949). Ries, H. E., Jr., Johnson, M. F. L., and Melik, J. S., J . Phys. and Colloid Chem., 53,638 (1949).
Sal'nikov,.I. E., Zhur. Fit. Khim., 23, 258 (1949). Schwab, G. M., and Schwab-Agallidis,E., J . A m . Chem. Soc., 71,1806 (1949).
Selwood, P. W., Bull. SOC. chim. France, 1949, D16i. Selwood, P. W., Ellis, M., and Wethington, K . , J . A w . ('heiti. SOC.,71,2181 (1949).
Skrabal, A,, Monatsh., 80, 21 (1949). Smekal, A., Powder Met. Bull., 4, 120 (1949). Smith, H. A., Bedoit, W. C., Jr., and Fuzek, J. F., J . A?!!. C h m . SOC.,71,3769 (1949).
Spooner, R. B., and Selwood, P. W., Ibid., 71, 2184 (1949). Thompson, D., Chem. Eng. Progress, 46, 3 (1950). Trevoy, D. J., and Drickamer, H. G., J. Chem. Phys., 17, 1117 (1949).
Wagner, G., Mitt. chem. Borscldnst. Ind. oesterr., 3, 63 (1949). Weissler, A., Naval Research Lab. Rept. S-3483 (June 15, 1949).
Wicke, E., Z . Elektrochem., 53, 279 (1949). Wilke, C. R., C h m . Eng. Progress, 45, 218 (1949). Wright, M. M., and Taylor, H. S., Can. J. Research, 27B, 303 (1949). Yang, L. M., Proc. Roy. SOC.(Lortdmb),A198, 94 (1949). Ibid., p. 471. M O D E S OF PERFORMING REACTIONS
(78) (79) (80) (81) (82)
Beck, R. A., IND.ENG.CHEM.,41, 1342 (1949). Boaworth, R. C. L., Phil. Mag., 39, 847 (1948). Brinkman, H. C., Research (London), 2, 190 (1949). Ergun, El., and Orning, A. A,, IND. ENQ.CHEM.,41,1179 (1949). Forsythe, W. L., Jr., and Hertwig, W. R., Ibid., 41, 1200
(1949). (83) Friend, L., etal., Ibid., 41, 1249 (1949). 1841 Gadsbs. J.. and Sykes, K. W,, Proc. Roy. SOC.(London), A193, 40011948). (85) Gilliland, E. R., and Mason, A. E., IND.ENG.CEEM.,41, 1191 (1949). (86) Hay, R. G., Coull, J., and Emmett, P. H., I b X , 41, 2808 (1949). (87) Huhndorff, R. F., Ibid., 41, 1300 (1949). (88) Johnson, J. D., and Edwards, L. J., Trans. Faraday Soc., 45, 286 (1949). (89) Leva, M., Weintraub, M., Grumrner. M., and Pollchik, M., IND. ENG.CHEM., 41,1206 (1949). (90) Lewis, L. K., Gilliland, E. R., and Bauer, W. C., Ibid., 41, 1104 (1949). (91) Lewis, L. K., Gilliland, E. R., and McBride, G. T., Jr., Ibid., 41, 1213 (1949). 492) . . Lewis, L. K., Gilliland, E. R., and Reed, W.A., Ibid., 41, 1227 (1949). ,(93) Matheson, G. L., Herbst, W. A., and Holt, P. H., Ibid., 41, 1099 (1949). (94) Moree, €2. D.,Ibid., 41,1117 (1949). (95) Rand, M. J., and Hammett, L. P., J . A m . Chem. Sot., 72, 283 (1950). (96) Reis, T., Bull. assoc. franc. techniciens pitrole, 76, 3 (1949). (97) Saldiok, J., and Hammett, L. P., J . A m . Chem. SOC.,72, 283 (1950). (98) Sedov, L. I., DokZady Akud. Nauk. S.S.S.R., 60, 73 (1948). (99) Stoker, R. L., IND. ENQ.CHEM.,41, 1196 (1949). (100) Window, E. C., J . C h m . Education, 26, 497 (1949). (101) Yang, K. H., and Hougen, 0. A., Chem. Eng. Progress, 46, 3, 146 (1950). (102) Young, H. H., and Harnrnett, L. P., J . A m . Chen. SOC..72, 280 (1950). (103) Zenz, F. A., IND.ENG.CHEM.,41, 2081 (1949).
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(104) Adamson, A. W.,and Grossman, J. J., J . Chem. Phgs., 17, 1002 (1949). (105) Collins, F. C., and Kimball, G. E., IND. ENG.CEEM.,41, 2551 (1949). (106) Drozdov, B. V . , Zhur. Priklad. Khim., 22, 483 (1949).
Vol. 42, No. 9
(107) Dunoyer, J. M., C o m p t . 7e7rd.. 228, 1729 (1949). (108) Erdey-Gruz, T., N U ~ I L 163, I X , 256 (1949). (109) Eidey-Gruz, T., atid Szabo, J., Magyar Kern. Lapju, 4, 101 (1949). (110) Gol'danskiI, V. I., Z h i ~ r Fie. . Khim., 22, 1374 (1948). (111) Hall, R. E;., and Smith, J. M., Chem. Eriu. Piogress, 45, 459 (1949). (112) Hirschfelder, J. O., and Curtiss, C. F., J . Chem. Phys., 17, 1076 (1949). (113) Hixson, A. W., and Smith, M. I., IND.ENG.CHEM.,41, 973 (1949). (114) Hobson, M., and Thodos, G., Chem. Eng. Progress, 45, 517 (1949). (115) Leva, M., Weintraub, M., and Grurnmer. M., Ibid., 45, 563 (1949). (116) IMcCann, G. D., Jr., and Wilts, C. H., J . Applied Mechanics, 16, 247 (1949). ( 1 1 7 ) McCarter, R. J., Stutzman, L. F., and Koch, H. A,, Jr., IND. ENG.CHEM.,41,1290 (1949). (118) McCune, L. K., and Wilhelm, R. H., Ibid., 41, 1124 (1949). (119) .Mickley, H. S., and Trilling, C. A., Ihid., 41, 1135 (1949). (120) Resnick, R., and White, R. R.,Chem. Eng. Progress, 45, 377 (1949). (121) Schumacher, R., Erdoel u. Kohle, 2, 189 (1949). (122) Bedov, L. I., Doklady Akad. Nauk S.S.S.R., 60,73 (1948). (123) Taecker, R. G., and Hougen, 0. A,, Chem. Eng. Progress, 45, 188 (1949). (124) Tovbin, M., and Bararn, O., Zhur. Fiz. Khim., 23, 406 (1949). (125) Wagner, C., J. Phys. & Colloid Chem., 53, 1030 (1949). (126) Wicke, E., and Brota, W., Chemie Ing. Tech.., 21, 219 (1949). (127) Wilhelm, R. H., Chem. Eng. Progress, 45, 208 (1949).
II. THERMODYNAMICS AND EQUILIBRIA The literature on thermodynamics is extensive; this iu also true of published material on unit processes. It is the purpose of this section of the review to cite only those papers which affect both fields. All published research which simply presents equilibrium data for a single condition has been omitted. Likewise emphasis has been placed on the chemical characteristics of the application rather than on data primarily of value in unit c~perations, Chemical engineers are indebted to laboratories, such as the National Bureau of Standards, which are publishing selected values of chemical thermodynamics properties but, in general, it is not the purpose of this paper to include such data. It may be assumed that with the availability of such computing devices as the elertronic numerical integrator and calculator (ENIAC), tables and charts hitherto not available will be forthcoming. For example, Brinkley (e) describes a table whereby the equilibrium composition and thermodynamic properties at equilibrium of a system containing four componenb, carbon, hydrogen, oxygen, and nitrogen, can be determined over an extended range of temperature and pressure. He states that this table will be the result of about a half million individual computations. It is anticipated that such information will be very valuable not only in the solution of combustion problems in such fields as jet propulsion and gas turbine engines but also in predicting the operating conditions for vaiious gas synthesis processes. Hydrocarbon synthesis and hydrocarbon processing have rereived more attention from the thermodynamicist than any other field. Bashkirov and co-workers ( 1 ) have determined the mechanism of the synthesis of hydrocarbons from carbon monoxide and hydrogen. It is their belief, corroborated by analysis of the gaseous product obtained on precipitated iron catalyst, a t atmospheric pressure, with a ratio of CO:H2 = 1:l in the presence of added water vapor, a t 220 O to 250' C. and a t a space velocity of approximately 100 per hour, that the reaction on iron catalysts is 2CO Hz + :CH2 COSin contrast to the reaction CO 2H2 -+ :CHI HzO which occurs on nickel and cobalt. It is postulated that the f i s t reaction is a combination of the second and the subsequent secondary reaction, CO Ha0 -+ COS Ha. The synthesis of hydrocarbons from carbon dioxide and hydrogen is reviewed by Sachsse and Kienitz (18), who summarize fifteen years of research in this field.
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INDUSTRIAL A N D ENGINEERING CHEMISTRY
General thermodynamic equations for synthesis gas production are presented and discussed by Mayland and Hays (IS). With these equations they prepared a chart for determining equilibrium mixtures outside the carbon-deposition boundary at low pressures up to 21 atmospheres and at temperatures from 1200" to 2500 O F. with hydrogen to carbon monoxide ratios of 1.75 to 2.25. Equilibrium calculations for the adiabatic reaction of methane and oxygen and methane and air to give synthesis gas are also given. Mora, Blasco, and Doblas (17)review the literature on aromatization of individual para& and olefinic hydrocarbons, mixtures, and gasolines, and discuss the theory of aromatization and thermodynamic considerations by which the approximate temperature for the desired reaction can be calculated. The most extensive review of the application of thermodynamics to petroleum processing which hm appeared in periodical literature is that of Edmister, who has continued a series which started in July 1947. These articles are not confined to chemical reactions alone but involve all phases of hydrocarbon processing. Generalized correlations of the isothermal effects of pressure on entropy and enthalpy are presented in the form of graphs and tables (6) and compared with the calculated and observed values for pure components and mixtures. Rapid methods of constructing Mollier diagrams for pure hydrocarbons and mixtures are likewise described (6,7). Generalized thermodynamic properties are also used to determine vapor liquid equilibria in ideal mixtures (8) and in nonideal systems (9). This material is extended to the discussion of the experimental vapor-liquid equilibria methods and empirical correlation of data (10). Because a t pressures approaching the critical of the mixture the y/x ratios of the components of the mixture approach unity, thereby making separations by fractional distillation impossible, it is of importance to know a t what pressure this phenomenon occurs. Methods are presented ( 1 1 ) whereby this convergence pressure may be estimated, Equilibrium flash vaporization correlation iare also discussed (IB), as well as the effect of pressure on the phase relations in petroleum fractionation (13). The present series of articles concludes (14)with the presentation of the properties of vapor and liquid obtained from equilibrium flash vaporization of petroleum fractions. Not only does this series of articles present many useful charts, diagrams, and tables, but numerous references appear a t the end of each section. The unit process of calcination has been studied from a thermodynamic point of view by Cremer (S), Cremer and Gatt (J), and Gibbs (16). Cremer and Gatt were concerned with the conditions for the equilibrium of the reaction MgCOs -c MgO and C02. Cremer (3)observed that the theoretical pressure of carbon dioxide was higher than previously measured. He was able to determine the dissociation pressure experimentally under special conditions and the results agree within experimental accuracy with the calculated pressure. Cremer and Gatt (4) measured or calculated the molar heats of carbon dioxide, magnesium oxide, and magnesium carbonate in the range of 0" to 1300" K. Gibbs (16),taking into consideration the preheating required for calcining and superheating calcium carbonate, estimated heat losses and heat in the discharged product, kiln-shell heat losses, and kiln-gas heat losses. Spryskov (19) continued his studies on sulfonation by determining the equilibrium constant for the manufacture of Znaphthalenesulfonic acid from naphthalene and sulfuric acid. The equilibrium constant, determined from both sulfonation and hydrolysis sides a t 122" C., is 90; a t 140" and 163" C. K drops to 60 and 40, respectively. The average discrepancy between sulfonation and hydrolysis data was about 4%. Hydrogenation and dehydrogenation were studied by Vvedenski1 and co-workers (23,$4). They found (3.9)that for the dehydrogenation of ethyl alcohol to ethyl acetate and hydrogen, Kp could be represented by the equation log Kp = -(9620/4.57T) 4.66. They observed (94) that in the hydrogenation of im-
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propyl benzene or m-xylene on a nickel catalyst no side reactions occurred below 250" C. Both articles contain specific heat and heat of reaction date and other thermodynamic information COW cerning these reactions. Uchida (32) made a series of phase-rule studies on t'ie ammonia-soda process under high pressures of carbon dioxide, sodium sulfate being used as the raw material. From the phase diagram of the reciprocal system of sodium sulfate-ammonium bicarbonate-water, empirical formulas important in the calculation of the ammonia-soda process of the form y = a f bz and 2 = a bx cz* are derived, where x and y stand for the concen? trations of sulfate ion and sodium ion, respectively, and z variously for the concentration of ammonium ion, carbon dioxide,. alkalinity, or water. The constants a, b, and c were obtained for temperatures and pressures of carbon dioxide of 40" and 4 0 atmospheres, 50" and 40 and 50 atmospheres, 60"and 40 and 6 0 atmospheres, 65" and 60 atmospheres. The entire ammni+ soda process is anaIyied from the standpoint of the phase nude. Stull (BO) investigated the thermodynamics of carbon disulfide, production. The later work of Trotter ($I), in which calculated equilibrium constants for the reaction C (graphite) S&) + CS,(g) combined with vapor pressure data, were shown to be in good agreement with those of Stull, makes it seem likely that the true reactant is S2 (gas). A final summary paper of general interest is that of Wenner (96),in which sources of data and methods of their utilization to predict reaction equilibria are given. Methods of estimating thermodynamic data are reviewed. Industrially important s p terns involving mixed phases are chosen for numerical examples.
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LITERATURE CITED IN THERMODYNAMICS AND EQUILIBRIA (1) Bashkirov, A. N., Kryukov, Y.B., and Kagttn, Y . R.,Doklady Akad. Nauk S.S.S.R.,67, 1029-31 (1949). (2) Brinkley, 8.R., Jr., and Lewis, B., Chem. Eng. News,27, 2540-1 (1949). (3) (4) (5) (6) (7) (8) (9) (10) (11) (12) (13) (14) (16) (16)
Cremer, E., 2. amrg. Chem., 258, 123-31 (1949). Cremer, E., and Gatt, F., Radex Rundechau, 4, 144-9 (1949). Edmister, W . C., Petroleum Refiner, 28, No. 2, 137-48 (1949). Zbid., No. 3, 139-60 (1949).
Zbid., No. 4, 167-66
(1949).
Zbid., No. 6, 149-60 (1949). Zbid., No. 6, 143-8 (1949). Zbid., NO.8, 128-33 (1949). Zbid., No. 9, 95-102 (1949). Ibid., NO. 10, 143-50 (1949). Zbid., NO.11, 149-66 (1949). Ibid., No. 12, 140-6 (1949). Gibbs, R., Paper Znd. and Paper World,31, 1070-3 (1949p. Mayland, B. J., and Hays, 0.E., Chem. Eng. Progress, 45,462-8
(1949). (17) Mora, A,, Blasco Santiago, E., and Doblas, J., I.N.T.A. (Zmtnacl. tk.amm4ut.) Comun. 8 (1946). (18) Sachem, Hans, and Kienita, H., 2. EEektrochem., 53, 264-7 (1949). (19) Spryskov, A. A,, Zhur. ObshcheI Khim. ( J . Gen. Chem.), 17, 691600 (1947). (20) Stull, D. R., IND.ENG.CXEM.,41, 1968-73 (1949). (21) Trotter, I. F., Zbid., 42,670 (1950). (22) Uchida, S.. J. SOC.Chm.'lnd. Japan, 45,682-7,687-91, 816-19987-90,1060-3,1143-6 (1942). (23) Vvedenskil, A. A., Ivannikov, P. Y.,and Nekrasova, V. A... Zhur. Obshchel: Khim. (J.Gen. Chem.), 19, 1094-100 (1949). (24) Vvedenskil, A. A., and Takhtareva, N. K., Zbid., 19, 1083-8 (1949). (25) Wenner, R. R., Chem. ETLQ. Progress, 45, 194-207 (1949).
R M C E I VJune ~ D 24, 1960.
