KINETICS AND REACTION ENGINEERING—PART I. ANNUAL

ANNUAL REVIEW

K. H. LIN J. A. PALERMO

PART 1

Kinetics and Reaction Engineering I n this issue, we present Part I of a new annual review of kinetics and chemical reaction engineering. Although the subject is great in scope and application and is constantly changing in organization, the authors have selected a format which we feel will be of maximum benefit to their colleagues in industry. The first part of the review deals with books and reviews, basic experimental investigations, fundamental theories, and catalysis-theoretical and experimental. Part 11, which will appear in the February issue, will deal with kinetics of polymerization, reactor technology and engineering, pilot plant and commercial scale studies, less common reactions, industrial chemical processes, industrial catalytic practice, and equipment. The effort required to produce the review is evident in the comprehensive documentation. The editors believe that the value of the review is well worth the effort and feel fortunate in having obtained the services of the authors in this initial offering in a new series.

THEEDITORS Books and Reviews

large number of books and review papers have been published on various phases of the subject of chemical reaction kinetics and catalysis and its application to industrial processes. Laidler (43A) has revised the text “Chemical Kinetics” which has been published recently as a second edition. This author and Polanyi (444) have discussed the theories of bimolecular reactions in a recent paper citing over 150 references. In another review (74A),published in a British journal, the developments in organic reaction mechanisms are discussed. This paper has 200 references. I n a series of recent publications, Oae has reviewed the mechanism of organic reactions and the isotope effect (58A) and the reaction mechanisms of various organic sulfur compounds including sulfoxides (54A), sulfonium salts (55A), and sulfones (564, 57A). Otsuji (59A) in a paper on the recent advances in organic photochemistry has discussed the activated state of the olefins, cyclization of conjugated polyenes, intermolecular addition of saturated bonds, isomerization, decarbonylation, addition, and isomerization of cross-conjugated dienones. Dogonadze (79A) has discussed the theory of homogeneous and heterogeneous electronic processes in liquids. A theory of homogeneous reactions and redox reactions is developed and discussed with a general consideration of the events occurring in the liquid state and the electronic mobility in liquids. The kinetics of redox reactions on metallic and semiconductor electrodes are discussed, as are photoelectric effects.

A

During the past year investigators have given considerable attention to studies dealing with reaction rates and rate constants of chemical reactions. I n a recent paper citing nearly 200 references, the authors reviewed the measurements of reaction velocities and equilibrium constants as a function of temperature (664). Another review (67A), which lists 101 references, deals with the techniques for the estimation of the rate constants of the individual steps of radical polymerization and presents numerous tabulations of rate constant values from the literature. A recent paper (88A) has reviewed radiochemical methods for the direct determination of reaction rates with special emphasis on the use of brief pulses of high energy electrons. Japanese investigators (33A) have published a review on the problem of solving rate equations for consecutive competitive reactions. Another investigator at a Japanese university has extensively reviewed energy transfer and chemical reaction rates in several publications dealing in particular with molecular collision and energy exchange (26A), quantum mechanisms of transfer of vibrational energy (27A), the rate of unimolecular reactions (28A), and the rate of recombination reactions (29A). Norrish (504 57A) in two reviews has discussed the kinetics and analysis of fast chemical reactions. A Czech investigator (23A) has discussed the methods of investigation of the kinetics of fast reactions in solutions in a review paper in which several examples are described. A researcher (32A) at the Max-Planck Institute of Physics and Chemistry has critically reviewed VOL 5 9

NO. 1

JANUARY 1967

51

the relaxation methods for studying rapid reactions in solution, discussing in particular the reactions involving H+ and OH- ions and metal complex formation. Ark’ (7A) textbook entitled “Chemical Reaction Analysis” has been published recently. Another excellent book, in which this same author emphasizes reactor design, has recently appeared under the title of “Introduction to the Analysis of Chemical Reactors” (24.

Kunugi (42A) in a recent review has critically discussed some of the more pertinent problems of chemical reaction engineering in the development of new processes. Other authors have, in recent papers, reviewed chemical reactor theory (35A) and model-building techniques for heterogeneous kinetics ( 3 9 A ) . Continuous ion exchange processes in stirred reactors (77A) by the countercurrent method and exchange processes by the semicontinuous and batch methods have been described in a recent review. Another review (49A) discusses the pulse reactor. A final report recently published by a catalyst research task group (78A) summarizes the work on tests for determining the reforming activities of catalysts. Hydrogen and methane-steam mixtures were used in reduction methods in the forms of nickel found in catalysts, catalyst regeneration, and equipment and procedures used in redox tests. A Soviet investigator has reviewed in two papers the bases of selection of catalysts. He has discussed the theoretical bases of the selection, preparation, and use of industrial catalysts ( 9 A ) . Although recent advances in catalysis are based largely on experimental investigations, theory is becoming more important. Theory must take into account the optional value of the intermediate interaction energy of reactants with catalyst, as well as porosity and mechanical strength, I n another paper (8A), Boreskov has discussed some of the problems involved in the prediction of the catalytic activity and in searching for new catalysts from the standpoint of the chemistry of catalytic processes. Another Soviet investigator (27A) has considered the different methods of preparation of catalysts for individual cases from the standpoint of the specific activity of the resulting catalyst and the surface which can be reached by the reacting molecules. In this paper the methods of achieving a given pore structure are reviewed. Fluidization and fluidized beds have been reviewed recently by Corral (76A) and Rowe (68A). The latter author has qualitatively treated fluidized-bed characteristics, development, and processes and has discussed bubble formation, particle motion, tracer technique, heat transfer, and kinetics. I n another interesting publication (65A) on the applications of fluidized beds in chemical engineering, it is emphasized that the main advantages of fluidization are uniformity of particle size distribution and temperatures in the fluidized bed, almost instantaneous heat transfer, conditions close to chemical equilibrium, high capacity, intimate gas-solid contact, high thermal yield, strict control of gas composition, and lower maintenance. Further, typical 52

INDUSTRIAL A N D ENGINEERING CHEMISTRY

industrial applications are also discussed including exothermic and endothermic reactions at low and high temperatures. Additional references on literature reviews and books in kinetics and reaction engineering are tabulated in Tables I and 11. Basic Experimental Investigation

Experimental Techniques. The gas residence time experimentally determined in an agitated gas-liquid contactor could be expressed as a function of (Po/V8)0.45, where P, is the power input gassing condition and V is the superficial gas velocity (82%). The volumetric mass transfer could be represented by dimensionless parameters :

where V/Q8 is the gas holdup, a is the bubble radius, V is the liquid volume, 8 is the average gas residence time, k is the first-order reaction rate constant, and D is the diffusivity. A quartz gas discharge tube, fitted with various accessories and capable of operating under vacuum, has been employed to determine the coefficients of the recombination of the gas atoms (H, N, and 0) on solid surfaces under both jet and diffusion conditions (73B). A rotating drum (787B) may be used in studying gas-liquid reactions. The interfacial area between the two phases could be measured for this type of reactor. Using the plasma jet, a group of Russian investigators (36B, 264B) studied the rate of conversion of hydrocarbons to acetylene. The yield of acetylene was sensitive to the control of the plasma jet temperature and was favored by careful control of the residence time and the temperature at several points of the jet. The similar type of pyrolysis to produce acetylene could also be achieved by an electric arc (3750 volts and 216 amperes d.c.) ( 7 I B ) . The specific electrical energy consumption decreased with increasing C-index. The insufficient cooling and long contact time favored decomposition of acetylene, thus decreasing the yield. The high voltage generated by a 15,000-volt leakage transformer has been used in the thermal cracking of liquid hydrocarbons (774B). Abadzhev and Shevchuk ( I B ) investigated the kinetics of reactions involved in the high-temperature conversion (800-1500° C.) of acetylene. The rate equation for a set of consecutive reactions of the type A + B + C was expressed as :

The integrated form of the rate equation was presented and the numerical data were given. The gamma rayinduced chlorination of benzene is of the first order with respect to chlorine concentration (76B). The rate constant varied with the dose rate and residence time. Studies by Dalrnatskaya (67B) on the carbonation of sodium silicate solutions under various reaction conditions revealed that the rate of reaction was controlled by the resistance of the gaseous film. An optimum

TABLE 1. Substance or General Subject

ADDITIONAL REFERENCES ON LITERATURE REV1EWS

Areas of Study Progress in manufacturing, electronic computer control and optimization Today’s plants:’ designs, operating conditions, and economics Manufacturing and industrial practice; 6 3 references B products from coke-oven gas a p o r - p h a s e and liquid-phase ammonolysis zx, hydrolysis; comparative review, 141

Ammonia

I

1

I Gas phase reactions

I

Industrial processes in production of PhOH, M e G O , acetic anhydride, acetaldehyde and AcOH

1 I

I TABLE 11.

Catalysis by metals, advances in preparation, mechanisms, and applications; 151 references Catalysis and chemisorption by metals; 229 references Catalytic activity of metals, effect of ingredients. 41 references Catalysis b; rare earth elements, effect on organic reactions; 37 references Catalytic activity of transition metals, their alloys and compounds us. that of nonmetals Catalytic activity of tungsten in petroleum processes Cracking catalysts, reactivation by ion exchange Heterogeneous catalysis, mechanisms and measurement of adsorption. 21 references Heterogeneous catalysis, mecdanism and role of physical factors; 33 references Heterogeneous catalysis, physical transport processes, 29 references Principal t;ends in investigations; 47 references Homogeneous hydrogenation catalysis 10-year review Kinetics of processes; 15 references Molecular-sieve catalysts,, properties, ,cause of catalytic activity, reaction mechanism, and uses; 17 references Complex catalysts includin Ziegler catalysts, activity centers, factors asecting activity, and use in copolymerization; 47 references

Materials of construction

Halo en and halogen compound resistance; 1 references High temperature and pressure chemical plant applications

Methods of kinetic data interpretation; 78 references Effect of composition and pressure on rate of reaction Reactions of hydrogen, 162 references Inhibition of free radical chain reactions

Oxidation

Polymers

Catalysis

r f e-. P r_. P._ n r__ rs -V_.

Preparation by dehydrogenation of butane and butylene; equilibrium, catalysts, rates, and modern methods: 117 references

Coal, kinetics and theory of pyrolysis Synthetic r

48 references Synthesis of high polymers by radiation; 352 references Gamma ray-induced Dolymerization of ethyl. . SvSiesis

k

Areas of Sdudy Polyvinyl chloride manufacturing processes from crude oil cracking products

Methods of ammonification of superphosphate; 2,8 references Cat alytic oxidation on platinum

Butadiene

Thermal decomposition

Substance or Generdl Subject

II

cyclic polymerization

REFERENCES TO RECENT BOOKS Tttle

“Advances in Kinetics of Homogeneous Gas Reactions” “Catalysis and Chemical Kinetics” “Catalysis Then and Now” “Chemical Kinetics” “Chemicka Kinetika a Katalyza” (“Chemical Kinetics and Catalysis”) “Fundamentals of Chemical Reaction Engineering” “Gas Phase Reaction Rate Theory” “Heterogen Katalizatorok” (“Heterogeneous Catalysts”) “Oxidation Mechanisms” “Principles of Reaction Kinetics” “Suggested Mathematical Model for Tubular Reactors” (Dechema Monograph) “Kinetic Analysis of Chemical Processes. 111. Complex Reactions” (An installment of a serially published textbook) “Law of Mass Action” “Why Do Chemical Reactions Occur?”

reaction condition was suggested. A resistance vacuum gage was used in measuring the linear pressure variation with the rate of thermal dissociation of K M n 0 4 and PbOz in the pressure range of 20 to 350 mm. of Hg (32%). Stadnik and Stetsovich (238B) have conducted experiments with the oxidation of SO2 at the catalyst temperature of 200-600° C. and the chilling temperature 23-26’ C. The reaction mixture consisted of 9.5y0 SO2 and 70.5% air, and the distance between the catalyst tube and the chilling tube was 7.4 mm. No effect of chilling on the oxidation of SO2 was observed under these conditions. The pulse flow technique combined with a gas chromatograph column was employed by several researchers (5B, 25B, 240B) to analyze for reaction products. The thermal decomposition of benzene on a heated molybdenum wire has been investigated by motion picture photography a t the rate of 1000 frames per second (726B). The results showed that clouds of carbon

black formed by a periodic process a t a definite frequency. Heat transfer was the controlling factor in the process. For the purpose of facilitating the stripper-efficiency studies on fluid catalytic cracking units, vapor- and catalyst-sampling equipment and a radioactive density gage were designed and their uses were described by Inkley and Murran (776B). T h e strong electromagnetic field produced by flowing cracking catalyst was taken into consideration in the design. Romero and Smith (272B) presented the method of flash x-ray radiography to study the internal structure of a fluidized bed of sand. The advantage of this method over the others is the fact that the bed is not disturbed by the measurement. The reactive grinding technique (257B) could be applied to a process where chemical reactions are accompanied by surface grinding. An elementary theory of reactive grinding was derived by Tanaka (257B) and was confirmed experimentally using a jetVOL. 5 9

NO. 1

JANUARY 1967

53

injected fluidized bed. A flow-circulating device based on thermal circulation has been introduced by Nagiev (775B) for the kinetic studies of heterogeneous catalytic reactions of liquid hydrocarbons. The flow-discharge tube is commonly used in the study of both surface and gas-phase recombination rates and chemiluminescent reactions. A specific application of this device has been made to study the temperature dependences of the KO-0 and CO-0 chemiluminescent reactions (95B). Another application was described in the study of the effect of specific energy on the kinetics of nitrogen oxidation (1548). Nuclear magnetic resonance (N.M.R.) spectroscopy has been used extensively in the quantitative study of various kinetic problems (4B, 67B, ?37B, ?53B, 797B, ZOOS). A number of gas-phase reactions have been followed by the mass-spectrometric technique (57B, 84B, 704B). The semiconductor probe generally consists of a ZnO film-coated quartz frame. The rate of change of its electric conductivity varies with the concentration of free radicals. This device was utilized in the investigation of the surface recombination of various materials of free methyl radicals generated by the photolysis of acetone (773B). An additional application was illustrated in the study of the photochemical decomposition of CzH4 (260B). The temperature jump method, a chemical relaxation technique, was another popular method in dealing with the kinetics of ionic reactions in aqueous solutions (27B, 43B, Q6B, 242B, 27OB). When the change in the velocity of sound is related to the concentration of reactants in a solution, the ultrasonic method could be used in obtaining kinetic data (266B, 275B, 276B). Rate Data. The rotating sector technique was used by Howard and Ingold (?09B, 770B) in obtaining absolute rate constants for the autoxidation of hydrocarbons. The rate constants listed were: for the propagation, k,, for the bimolecular termination, k,; and for the first-order termination, k,. The rates of chain initiation and chain propagation could be affected by chemically inert solvents. Rate constants and activation energies for the alkaline hydrolysis of nitriles have been determined based on the study of decontamination of nitrile-containing waste waters in plants (748B). The catalytic dehydrogenation of primary alcohols was studied by Yada and Kudo (272B) who presented the rate data by a mathematical formula. Studies on the kinetics of reaction between tetrafluorohydrazine and fluorine by Levy and Copeland (147B) resulted in an expression of the form: dCF2 - - - kCF2CNZF4 1 / 2 dt

where C is the concentration of the material participating in the reaction. The rate constants for the reaction were given. I n the alkaline hydrolysis of BH4- at 15-35' C., the kinetically measured rate constants were in good agree54

INDUSTRIAL AND ENGINEERING C H E M I S T R Y

ment with the empirical equations (765B). Half lives of various ions were also represented by a set of empirical equations in terms of temperature and pH. Mochalov (764B) proposed a generalized scheme for the hydrolysis of borohydride ion and diborane. Rate constants and activation energies were determined at 15-35 O C. The aging kinetics of silica gel in the neutral alkaline and acid mediums could be represented by the rate of change of surface area as (48B, 49B) :

- dS - = kSn dt

where k = 1020.2 exp (-33,22O/T), n = 2.8 ,- 7, and S is the surface area. A method for determination of rate constants for three-step, parallel-consecutive, secondorder reactions was discussed by Reikhsfel'd (207B) based on the generalization of the Svirbely-Blauer method. Kinetics and Mechanism. The three-step reaction (combustion, cracking, and quenching) in the production of CzHz from gaseous hydrocarbons could be accomplished by a single-step process for the autothermal cracking using liquid hydrocarbons (224B). This was done by injecting liquid hydrocarbons together with 0 2 into an empty, water-cooled reactor and cracking hydrocarbons in a flame reaction. C2Hz and CHI were the major products from cracking of CzH4 at 900-1100° C. with contact times of 0.25 to 5 seconds (63B). The second-order reaction was observed and the formation of C2Hz had a maximum which varied with temperature and time indicating that C2Hz was an intermediate product. I n a study of CH4 conversion by COz on a Ni catalyst a t 700-800' C., Sigov and Abdullaeva (237B) found that the rate of reaction was initially proportional to the concentration of CH4. A decrease in the rate was seen as an increasing amount of CO formed. This inhibiting effect of CO on the reaction rate diminished with increasing temperature. The results were presented, relating the conversion of CHI to the rate constant and space velocity. The initial overall rate of cracking of CzHs, evaluated from the pressure change of the reacting system, follows the reaction order between 1 and 1.5 (141B). This cracking process was conducted under static condition at 610680' C. with the pressure varying from 10 to 700 mm. of Hg-. A complex rate equation was derived by assurning the bimolecular free radical formation : 2 C ~ H G 2 CH3.

+ CZHG

Catalytic dehydrogenation of methylcyclohexane has been studied by Ritchie and Nixon (270B) to investigate the feasibility of using hydrocarbons as fuels for high speed aircraft in the range of up to Mach 10. Partial cooling of the fuel could be provided by the endothermic reaction in the conversion of methylcyclohexane to toluene and hydrogen. The radiochemical oxidation of aqueous solution of butanol has been investigated by Komarov ( 739B). The resulting chain reaction showed a linear dependence of t h e reaction rate on the dose

intensity. The reaction products included peroxides, aldehydes, and acids. A third-order rate equation

to be condensed, the following sequence of reactions has been proposed :

+ Hz+NH, + H NHz + NHz NHa + N H NH2

+

resulted from a study on the addition of HI to cyclohexene in hexane, toluene, and chlorobenzene (72B). The addition of HC1 to olefins in nitromethane (69B) also followed a third-order rate expression, k(Colerin) (CHCJ2. First-order kinetics was observed in the removal of olefins from benzene with H z S 0 4 (277B). The rate controlling step varied depending upon the type of olefin, and it might be either by diffusion across the interface and/or by reaction in the acid phase. Production of perchloroethylene by vapor phase dehydrochlorination of pentachloroethane in fluidized catalyst beds was investigated by Murthy (772B). Two different types of catalyst were used-namely, active carbon and BaCl2 on silica gel. The rate equation for the reaction was different for different catalysts. The rate of catalytic hydrodealkylation of toluene was favored by increasing pressure up to 2 atm. (783B). The experimental results could be represented by : r = reaction rate = kPT0-2PHz-0.96PB-0.5

where PT, P H ~and , PB are the partial pressures of toluene, hydrogen, and benzene in atmospheres, respectively. On the other hand, hydrodealkylation of mesitylene, m-xylene, and toluene was reported by Shull and Hixson (230B)to follow the 1.5th-order kinetics. A combination of concurrent and consecutive reactions has been proposed as the mechanism in the catalytic partial oxidation and oxidative ammonolysis of propylene (86B).The proposed mechanism could explain the parallel formation of acrolein, acrylonitrile, and other by-products. The kinetic equations were derived based on the above mechanism. Satterfield and Loftus (218B) have shown that the homogeneous partial oxidation of o-xylene to phthalic anhydride could be described by the first-order kinetics with respect to o-xylene. This who also inconclusion was supported by Aliev (8B), dicated that the rate of formation of maleic anhydride was proportional to the 0.5th power of o-xylene concentration, and that the rate of COZ generation varied almost linearly. Oxidation of coal in the temperature range of 30-100' C. may be represented (169B)by a hyperbolic equation of the form (dC/dt) = cten. The rate of oxidation varied with the temperature, particle size, and type of coal. Activated diffusion was the important reaction in coal oxidation. I n the carbonization of cellulose, vinyl polymers, and coals, Suga (245B) suggested that the degasification rate was related to the degree of polymerization and amount of carbonized residue. The rate of degasification decreased with the addition of a small amount of salts. According to Avramenko and Krasnen'kov (76B), the elementary reaction of nitrogen atom with molecular Hz Nz -P hydrogen is the trimolecular reaction N NH2 Nz. T o account for NH3 being the only product

+

+

The third-order rate equation is not exactly applicable to the reaction between N O and 0 2 a t 25' C. and 1 to 50 mm. of Hg (236B).A four-step reaction mechanism was in qualitative agreement with the experimental data. The oxidation of carbon of various grades at temperatures above 1000' C. could be expressed by:

V

kPo2

=

provided that the degree of reaction is not too high (204B). I n this equation, Y is the rate of gasification, Po, is the partial pressure of oxygen, and n is the order of reaction which ranged from 0.5 to 0.8. A group of empirical curves was obtained by Baranski (ZOB)in the synthesis, decomposition, and condensation of urea at the temperature range 120-1 80' C. Mathematical examination of the results revealed that the mechanism of reaction was different depending on whether urea or ammonium carbonate was involved. The reaction of urea with acetaldehyde to produce ethylidenediurea is reversible (786B). The forward reaction is catalyzed by both general acid and general base, while the reverse reaction is generally acid-catalyzed in acidic buffered solutions. The rate of reaction, estimated from the remaining acetaldehyde, can be described by :

Based on published experimental data and theories, Prodan and Pavlyuchenko (202B) classified kinetic equations and their applications in the thermal dissociation of solids. The kinetic equations were grouped into the following four types : doc

- = k&(l

dt

doc - = k(l dt

-

CY)b

-

doc - = kaa dt CY

= ktn

where CY is the degree of dissociation or transformation, k is the rate constant, t represents time, and a, b, and n are constants. According to Pavlyuchenko (193B, 794B,196B) and Samal (217B),the kinetic equation ~ kt describes experimental of the form 1 - (1 - L Y ) ~ / = data on the dehydration of LiC1.HzO and the thermal decomposition of CuS, LiBr. NH3 and FeSz. T h e progress of isothermal decomposition of CaCO3, calcite, and magnesite in vacuo was reported (777B)to follow the equation

+

VOL. 5 9

NO. 1 J A N U A R Y 1 9 6 7

55

I

TABLE VI. M a j o r Reactants

AcOH

TABLE I l l . ADDITIONAL REFERENCES O N EXPERl MENTAL TECHNIQUES Reference

Technique Used Chemiluminescence Constant-current coulometry Electron spin resonance spectra Fluorescence intensity method Infrared Ionization chamber Magnetic permeability method Potentiometrlc method Pulse sampling Pulse technique Radiotracer Spectrophotometry Stopped-flow technique Stopping peak Thermogravimetric technique Thermometric method X-ray technique

I

Acetic anhydride Acetone

(938) ( 7 198) (688, 159B) (2588) (YB, QZB) (2418) (87B, 7008, 2228) (458, 707B,279B, 2448) (2698) (2278) (378) (878, 928, 798B, 1998, 2678) (798, 1668, 2578)

DI

Aliphatic acylals Alkylbenzene Ammonium nitrate NHaNOz Ammonia Aromatic amines

(7468) (46B, 7678) (75B)

Azide ion

(1208)

Barium azide Benzoic acid

TABLE IV. ADDITIONAL REFERENCES ON EXPERl MENTAL TECHNIQUES Subject of Study

Acetylene

Reference

Equipment Used

Continuously acting chemical reactors Control of a continuous-flow agitated tank reactor Electrode kinetics Fluidized-bed reactor for heterogeneous exothermic reactions Gas phase displacement of CFa by Me Inhibition of H d O z reaction by hydrocarbons Kinetics of ion exchange Isotope effect Oxidative dehydrogenation Sealed-tube reactions with stirring Thermal decomposition of trifluoroacetaldehyde

( 7308)

(268B) (2781 (1768)

(248) ( 788) (508) (238, 978) (2778) (2B) (7 4 8

Benzhydryl chloride Boron trifluoride Butadiene and butenes Calcium carbonate CadPOa) and HzS04 Carbon Carbon Carbon dioxide

I TABLE V.

ADDITIONAL REFERENCES ON RATE DATA __

Reacting System Aldehydes Atomic hydrogen; propyl or butyl alcohol Benzene, toluene, or xylene; steam n-Butane or isobutane Butane FezOs or AIzOa; NazC03 or KzC03 Glycolic acid; Ce(IV) salts Halopentarnminecobalt(1V) complexes, Cr Methanol and trideuteromethanol

Minerals (loparite, pyrochlore, zircon, and euxenite) Monochloro complex of Co(II1) Neopentyl alcohol; acetic acid 4-Nitrofluorobenzene; l'w amines Oxygen atom; acetylene Penicillins KO2 and K O H ; water Sulfur heterocycles

I

Trifluoromethyl radicals ; organic halides v ( I I I ) , Cr(I1); perchloric acid

56

Study and Data Conversion in catalytic hydrogenation ZOOo C . ; 50-300 atm. Rate constant; 570-690' C. Rate constant, activation energy; 376400' C. Chemically activated decom osition; rate constant; 25' C.; 0.83-500 mm. Hg Gas-phase radiolysis ; product distribution; room temperature, 12.5-250 mm. Hg Rraction order activation energy, and frequency f d t o r ; 900-1400° K. Oxidation; activation energy and entropy change Reduction; rate constant

Re/erence

Carbon dioxide COz and C O Carbon dioxide Chlorosilicon hydrides and PhCl Citrate and Iz Coal Coal Coal Coke Copper acetylacetonate Cumene

H & D abstraction; rate constant, activation energy, and frequency factor; 103-250' C. Chlorination; rate constant, activation energy, and frequency factor; 55010800 c. Tormation and dissociation; rate constant; 2 j a C. 'roton exchange; rate constant; 25' C.

Cupric salts

rJucleophilic substitution' product yield and rate constant; 2511000 C. i a t e constant, activation energy, and frequency factor; 393-563' K. 3egradation kinetics; rate constant and activation energy; 15-50' C. Zate constant bfethanolysis; rate constant, activation energy, and entropy; 0-50' C. 'hotolysis; rate constant, activation energy, and frequency factor; 338' K. ieduction; rate constant; 25' C.

Dichromatechlorate Ethane Ethane

INDUSTRIAL A N D ENGINEERING CHEMISTRY

Cuprous chloride Cyclohexanone and formaldehyde Cyclohexane

Ethane Ethane Ethanol amines Ethylene Ethylene

ADDITIONAL REFERENCES

Reaction Studied Liquid-liquid phase chemical reaction and mass transfer Hydrolysis at 25' C. in H z 0 and HzO-dioxane mixture Bromination in aqueous HzSOa Reduction in aqueous EtOH solution of CrClz; 8-30' C. Uncatalyzed hydrolysis; 96-116' C. Ionization ratey; 23.5-80' C. Reactivn with CaCOa and MgCOain melt; 150° C. Decomposition in solution

Order o/ Reaction (with Respect to)

1

4 (Water) 1 (Acetone) 3, 4 (Acetvlene Cr * 9 , H h ) Complex 1 (Alkylbenzene)

3 a"(

Decomposition on nonferrous surfaces Acylation in PhNOzHOAc mixture, catalyzed and uncatalyzed; 250 c . Metal-metal ion exchange reactions; 25' C. Thermal decomposition; 130° C., 10-6-100 mm. H6 Liquid-liquid phase reaction with iso-BuOH and Et*" Reaction with organic bases Hydrolysis with trimethylamine oxide; 0-20° C. Chemical absorption desorption Neutralization of HC1; p H 2.5 and 5.1 Solid-liquid reaction, twostage; 300' K . Interaction with COz and 0 2 ; 600-1400° C. Gasification with HzO-H mixture; 950-11503 C., 50 arm. Dissociation at 6,000ll,OOOo K.behind reflected shock waves Reduction with C ; 11501450' C. Exchange of 0 with Fe as catalyst; 800-1000° C. Absorption with reaction into aqueous NaOH Gas phase reaction; 580680' C. Interaction in rhe dark; p H 3.3-4.25 Hydrogenation under high pressure; two steps Oxidation, two steps; 1500 c. Pyrolysis; 400-500° C . Gasification by COz; 1000° C., 1-bar pressure Thermal decomposition, two steps; 380-420' C. Radical formation; 100140° C. Reduction in aqueous solution by C O ; 120' C.; -68 atm. Oxidation in HOAc

XOz)

...

Complex

... Complex Empirical

1 (H-ion)

...

1 (COP and

0 2 )

...

... 1 Complex Complex 2 1 (Iodine)

1 (Coal) Empirical 1-2 (Coal) >>1 Empirical Complex

3ase-catalyzed reaction 2atalvtic dehydrogenatie;; 258-304' C., 47400 mm. H g kid-base reactions in fused salts, two steps 'yrolysis; 1000-1150' K . 3-D exchange on Alz08; 116-200° C. >racking; 750-950' C. 'yrolysis Synthesis; 20-60' C. ladiation-induced reaction in aqueous solution 3xidation in a fluidized bed; 220°, 240°, and 260' C.

0-0.5

Complex Complex 1 1

...

ON KINETICS AND MECHANISM M a j o r Reuctanfs

Ethylene oxide FeCla FeClz FeClz Ferrous ion Fe-sulfates Fluorine FCIOz, FClOa, ClzO,, NOsCI, and N O 8 FzSnOo and C O Fluorosilicic acid Fructose Furfural Gold(II1) complex chlorides Grignard Hexanes Hydrocarbons Hydrogen Hydrogen HC1 and PhCl

HzOz HzOz HzOz Hydroxyl radicals Hydroquinone Indoaniline dyes Iodine and formates Iron oxide Iron oxides Iron pyrite Iso-PrOH Isopropoxyl radical Lead sulfide Liquid phase Metatungstate ions Methanol

Molybdenum complexes Mono(acety1acetonato) iron (111) complex Nickel oxide Ni [RCOCR'C(R") :NCHz]z Nitric acid Nitrogen, active Nitrogen monoxide NOCl Nitrogen monoxide Oil shales Olefins Olefins

OrdyFof Reactioi (with Respect to

Reucfion Studied Reaction with phenols; 80-105O C. Autocatalytic hydrolysis ir aqueous solution; 30' C. Oxidation by 0 2 in HCI; 20-60° C. Reduction by Hz; 450635O C. Autoxidation in acidic pyrophosphate solution Thermal decomposition; 500-1000° C. Reaction with FezSz08; 230-250° C. Decomposition; 0.2-800 mm. H g Reaction; -10-25" C. Two-ste reaction with Al(O&) a; 22-90' C. Oxidation by Ce(S0a)z; 42' C. Oxidation to maleic anhydride Reduction with oxalates

1 (Ethylene oxide 1

References

Major Reactants Olefins Oxygen, atomic

3 Empirical

3 (Overall) 0

2 (Overall) 2

Oxygen Ozone Peroxybenzoic acid Periodate Phosphite ion

Complex 1 2 (Overall)

... 2

Phosphoric acid Potassium aluminate Propene

(Overall) Formation Thermal decomposition; 530° C., 25-300 mm. He Low temperature oxidation; 300-400° C. Thermal reaction with 0 Oxidation of Pt surface

...

1-1.5

... 2

Exchange of C1 atomic Decomposition; 300-900° C. Decomposition; 24-54' C. Stabilization by NanSiOs; 55-750 c. Reaction with CHa, CO, H C H O , and HzOz; 400-650' C. 3xidation by HzOz 4lkaline decomposition Reaction in homogeneous and two- hase li uid system; f5-40' Reduction with hydrogen; 816-1204O C. Zhlorination with chlorine; 200-900° C. Reaction with air and "3; 300-550" C. Dehydrogenation on Z n O catalysts ?yrolysis of the isopropoxyl radical; 160-200° C., 20-230 mm. H g Low temperature reaction of PbS with 0 Liquid-phase reaction 4lkaline degradation 3xidation rate of MeOH H C H O using a FezOaMoOa catalyst; 21090° C. Substitution reactions

... 5 (Overall) Empirical

Zeactions proceeding both in the gas phase and in solution 3xidation to nitrogen dioxide for autoanalysis 3xidation by atmos heric oxygen; 165-1859 C. lromine addition Spoxidation with peroxy acids

Pyrophosphite Quaternary hos phonium fydroxides Radicals

1 1

(HzOz)

Selenium(IV)

2 1 (HzOz)

...

Silicon and silica Sodium dithionite

Complex

8.

iinetics of the reactions between Fe +2 and acetylacetone Xeduction of NiO by C ; 1150' C. iates of formation; 50° C. ieaction with organic materials; 20-100° C. Xeactions of N atoms Xeduction

Pyridine, pyridazine, and tetracyanoethylene Pyrite

Sodium sulfate Empirical Empirical

...

SnOz, SnO, and Sn Sulfur dioxide

Empirical 1-2 Empirical

... 1-2

... Complex Complex

... Pseudo first

led-Butoxy radicals Tetralin Tin oxide Tri- and tetrametaphosphoric acids 2,4,7-Trinitro-9fluorenyl p tosylate Tungsten, molybdenum

U monocarbide Urethane

Complex

3

... 1-2

Vanadium(II1) and chromium (11) Vanadium pentoxide Vinyl chloride

... Empirical

Water gas

Reaction Studied Oxidation by palladium (11) Reaction of acetylene witk atomic 0 in a moderately fast flow system 7 steps; room tempe;ature Reaction with the styrene double bond to form radicals; 105-125O C. Reaction with hydrogen sulfide in a flow system; room temperature Decomposition in (CHzCl) in Nz atm.; 5 5 O and 65' C. Reaction with iodide ions Reaction between HzP03and HCrOa- ions in acetate buffer; 25O and 1000 c. Ortho-pyro interconversion; 0-looo C. Thermal decom osition; 1100-1350° C! Oxidative ammonolysis and partial oxidation; 410-500° C. Charge transfer; room temperature

Order of Reaction

(with Respect to)

Complex

2

cs8:Yand 0 (HzS) 1.5 ( 0 s )

2 (Overall) Complex Complex

Empirical 1 ( ro ene)

B (82)

Complex

Thermal decomposition in dynamic Ar atm.; 600-653'C. Hydrolysis over a n extensive p H range Decomposition

Empirical

Radiolytic homogeneous reaction under continuous and intermittent irradiation Reaction with 2,3-diaminonaphthalene as function of concentration,, pH, temperature, and ionic strength Interaction; 1700-1 950° C. Thermal decomposition in aqueous solution. 6080' C., p H 4.8-f.0 Reduction by gases resulting from pyrolysis of petroleum liquids; 725' C. Sulfidizing by gaseous sulfur; 600-1000° C. Oxidation in the presence of a Pt catalyst; 424440° C. Solvent effects in the reactions with styrlperoxy radicals Metal-catalyzed autoxidation Reduction by carbon monoxide; 600-900° C. Dissociation constants hy the rate of inversion of sucrose Specific solvent effects involving charge-transfer compledng Oxidation kinetics a t extremely high temperatures; 1300O m.p., 110 atm. Hydrolysis a t high temeratures' 1055O C.; 5)-60 mm! H g Direct synthesis by reaction of organic cyanates with organic halides Reaction in acid solution; 0.2-35O C.

1 and2

Reduction by hydrogen; 520-630° C. Gas hase reaction with H81; 2 5 O , 215O, 164O, and 299O F. Conversion reaction at different pressures. 320-380' C., 1-4i atm.

References

Complex

Complex 3 (Overdl)

Complex

0.5 ( H + ) 1.5 (Dithionite ion) Empirical

Complex

... Complex Complex Empirical

... 1 Empirical

Empirical 1 (Chloride) [V(III)'and cW)1 Empirical Complex

Complex Empirical

VOL. 5 9

NO. 1

JANUARY 1967

57

where y is the initial spherical equivalent radius of the carbonate particles, is the thickness of the product layer a t time t, v represents the volume of undecomposed carbonates, and X is the shape factor. The reduction of Eu~(S04)3by C O takes place in two stages as shown by the chemical, topokinetic, and x-ray analyses (247B). Erofeev equation, Q: = 1 - ektn, describes both stages of the reduction of Eu~(S04)3. T h e reduction of La, Ce, Sm, and Lu sulfates is represented by the Erofeev- 1 = ktn. Studies Bel'kevichequation: [l/(l on the reaction of CuO with gaseous mixtures of SOZ, 0 2 , and N Zby Chen and Hsia (4723) indicated that the rate was governed by the formation of sulfate ion on the solid surface between the adsorbed SOz and on the 0 ions. A fairly complex kinetic equation was derived from the rate measurements. The mechanism of CaCz formation in the fused phase between the graphite crucible and CaO brick has been studied by Torikai (256B) in the temperature range of 1855-2000' C. The formation of the product layer of CaCz proceeded linearly with time from the boundary surface of graphite and CaO into inside the CaO brick. The rate of formation was slow at 1855' C., but was accelerated considerably at 2000' C. The solid-phase reaction between ZnS and CdO conformed to the third-order kinetic relation when the conversion x was higher than 36y0 (734B): dx - = k(1 dt

%)3

I n the synthesis of ammonia at 400-550' C. and 300600 atm. over molten iron catalyst, Vorotilina and Lachinov (263B) observed the self-inhibition effect with increasing concentration of ammonia. This was attributed to the inhibition by P;H3 of the reaction Nz 3 Hz 3 2NH3, provided that the reverse reaction was greatly suppressed. Additional investigations on the rate determining steps in the ammonia synthesis and decomposition have been conducted by several Japanese investigators (249B, 250B). Using 15N as tracer over a singly promoted iron catalyst at a total pressure of 550 mm. Hg and temperatures of 305-340' C., Tanaka (250B) found that the chemisorbed N was in partial equilibrium with the gaseous N H 3 but not with nitrogen. The rate-determining steps were the N chemisorption and desorption, respectively, for the synthesis and deThis rate determining step in the composition of "3. NH3 decomposition is in agreement with the result a t 424' C. of Takezawa and Toyoshima (249B), who has also suggested that at 479' C. the rate determining step was the dehydrogenation of adsorbed amino radicals as proposed in the theory of Horiuti. Kohout and Lampe (737B) showed the direct evidence for their proposal that NzO and HzO were stable products formed in the atomic hydrogen-NO reaction by :

+

58

I N D U S T R I A L A N D E N G I N E E R I N G CHEMISTRY

I n contrast to a frequent assumption, H K O is not a stable product. The reaction mechanism in the heterogeneous Cannizzaro reaction of CoH&HO and K O H varied depending upon whether the reacting mixture is agitated or not. Thus, Ono and Keii (79OB) concluded in their study that the rate determining step was in the aqueous phase with rigorous agitation, while without agitation the diffusion of CsHsCHO into the aqueous phase was the controlling factor. Fundamental Theories

General.-A theory of homogeneous-heterogeneous reactions has been proposed by Levich and Brodskii (6OC) for a flowing system in a cylindrical tube. In developing the theory for the process, two different reaction regions were considered, one within the bulk of the stream (A + B, with a rate equation w1 = -kklCn), and the other on the surface of the tube (A + V, with a rate equation w2 = yCrnlr&. I n these equations, C represents the reactant concentration and R the radius of the tube. The same concept was applied to the derivation of mass transfer equations, resulting in a combined equation of the form :

where 6, and 6' are the thickness of the reaction and the diffusion layers, respectively; x is the distance along the axis of the tube, and u and C, are the average velocity and concentration in the bulk of the stream. The above theory has been extended by considering radical chain reactions with formation and/or annihilation of radicals a t the tubular reactor wall (61C). The resulting expressions are reported to be applicable to such an industrial-scale process as the liquid-phase oxidation of hydrocarbons. Additional theoretical studies on heterogeneous reactions have been made by Japanese investigators (982). They dealt with (1 n)th-order irreversible reactions in a system consisting of a gas, liquid, or solid phase, and a liquid phase. An application of the result was made using an approximate concentration distribution for a heterogeneous liquid phase reaction in which both the film diffusion and chemical reaction played important roles. Diagrams obtained by numerical calculations showed the overall reaction rate as affected by the reaction conditions. A mathematical treatment of the chlorination of organic liquids was given by Hawkins (37C), who assumed that both diffusion and chemical reactions were controlling. Hawkins discussed the general relations of reactor types and the design and optimization of commercial reactors, The kinetics of reactions become complicated when they are accompanied by autocatalysis. Using the acylation of aromatic amines by acid anhydrides and acid chlorides as an example, Litvinenko (65C) conducted a critical evaluation of various methods for computing the rate constants. Recommendations were made as to the best methods and a parameter for charac-

+

terizing the intensity of the autocatalysis. The method of approximation has been used in the study of autocatalytic branched-chain reactions (76C). The plot of 7/qm us. In t always resulted in an S-shaped curve with an approximately linear section in the region of 50% conversion. This relation is represented by :

where 7 is the product concentration at time 7, vm is the maximum product concentration, w is the rate of reaction at the 50% conversion time 7,and r = ln(1

+

W>/.*

The problems of chemisorption have been analyzed through a set of equations derived from the general thermodynamic and kinetic laws (89C). These equations included the equilibrium equation, the kinetic equation, the equation for rate of adsorption, and the resistance equation. A model consisting of a particle of mass m colliding with an atom of a lattice vibrating with an average frequency w has been proposed (74C) in a mathematical analysis of the elementary process of absorption and recombination on the surface of solids. The resulting expression revealed that the rate of surface process was higher than that of the process within the bulk. A gas mixture flowing over a reactive surface could produce a complicated process. As a result of the gas-solid reaction a t the surface, the gas-phase equilibrium is disturbed; this disturbance, in turn, starts a reaction in the gas phase (54C). The fluid dynamics in the immediate region of the surface are also affected by the gaseous products of the reaction a t the surface. This complex condition has been studied by considering the interactions between the processes in terms of an interaction parameter and a stoichiometric factor. Assuming the Knudsen diffusion in porous structures, the effect of diffusion in the interior of catalysts could be estimated from the conversion of multicomponent gas mixtures in flow tubes (47C). The balance diagrams constructed clearly illustrate the effect of diffusion rate in the grain and simplify calculations of conversion within the catalyst pores. A simplified method was proposed by Weiss (96C) in predicting reaction paths for both consecutive and simultaneous reactions; dealkylation of alkylbenzene and alkylnaphthalene was used as an example. Relative rate constants, instead of absolute ones, were determined by the method, and the order of reaction was estimated. The only data required for the method are the amount of charge and the product composition. The rate constants for consecutive second-order reactions could be computed by one of the three methods described by Boguth (9C),depending upon availability of the data. The first method requires a knowledge of the concentrations of two components participating in the reaction, the second utilizes an analog computer, and the third employs numerical integration. A procedure was given for improving the results statistically. The statistical method of sampling in a chemical process frequently fails to characterize the true nature

of the process. The main reasons for this are attributable to the delays in the data collecting and transmitting system and transition processes, and changes in the reactor characteristics with time (35C). I n the case of carbonation process, the data recording intervals less than 3.5 minutes amplify errors in characterizing the real process. The optimum time interval for sampling was shown to be 14 minutes. Theoretical developments of the transient concentration regime were presented by Lelli and Gatta (5QC) for the case of stepwise variation in the feed composition in continuous isothermal reactors. Complex reactions of linear or nonlinear kinetic types were considered with an assumption that the fluid was totally segregated. I t was shown that the behavior of the system was governed by the fluid dynamic as well as the kinetic parameters. The agreement between the theoretical and experimental results was good in the case of a firstorder irreversible reaction in a batch reactor and a multistage reactor. Using a gaseous decomposition as an example, Robinson (84C) discussed methods of treating experimental data for a reaction vessel with dead space. Optimization. The optimum startup conditions for an autothermic reaction have been determined by Jackson (43C) using the maximum principle of Pontryagin. Heat from an external source was required to start the reaction, but the heat of reaction afterward could be utilized to keep the reaction thermally self-sustaining. The initial composition of reactants in adiabatic gas phase reactions was the variable for optimization by Pings (77C). The compositions required for maximizing the yield and for achieving the maximum equilibrium adiabatic temperature were determined separately. A practical and efficient digital computation algorithm has been derived for optimizing the design of a sequence of adiabatic packed-bed reactors (80C). The technique was applied to the water-gas shift reaction. Utilizing the discrete maximum principle, Fan (20C) developed relations for selecting the residence time and temperature for each of a sequence of continuous-flow stirred tank reactors in order to maximize the total profit. A first-order reversible reaction with product recycle was taken as an example, and a gradient search and interval-halving technique was employed to determine the values of the state variables and decision variables. The optimization of two cases of continuous first-order endothermic irreversible liquid-phase reactions has been considered by a couple of Italian investigators (93C). The first case assumed that no temperature limitation was imposed on the process. Under this condition, the maximum profit would be realized by a complete conversion of the feed material. A temperature limitation was placed on the second case because of excessive by-product formation above this limit. In this case, recycle of the unreacted feed was utilized to keep the conversion per pass below 100%. The optimum operating conditions for reactors of combined type may be determined by two methods suggested by King (50C). The oxidation of SOz was VOL. 5 9

NO. 1

JANUARY 1967

59

considered in detail, and the method of dynamic programming was used in obtaining the operating conditions, An automatic optimization of SO2 oxidation was found possible (63C). This requires that the temperature of the gas entering a contact catalyst layer be automatically selected so that the temperature difference in the layer is a maximum. The kinetics and mechanism of reactions in the high temperature cracking of ethane have been studied by Russian investigators (48C) by means of radioactive atoms in a turbulent reactor. The results have led them to propose kinetic schemes for maximizing the production of ethylene. Additional mathematical programs have been proposed by Zeinalov (99C) for determining cracking conditions producing the maximum amount of gas and desired fractions from kerosine. Zhorov (IOOC) derived a mathematical expression of platforming taking into account the effects of reaction conditions, the state of catalysts, etc. A good agreement was obtained between experimental and calculated values. The product yield may be increased through the chromatographic effects in catalytic reactors (85C). For a given reaction time interval, there is an optimum reactor length at which the yield reaches a maximum. Mathematical expressions have been developed by Hills (38C) for defining the minimum volume-temperature conditions for operation of heterogeneous catalytic gas reactors. According to these equations, the optimum temperature should be 5-10' lower than those determined by the conventional kinetic approach. The method of maximum principle could be applied to the determination of the optimum temperature in obtaining the best yield of an intermediate product in consecutive reactions accompanied by a parallel reaction

(68C). Process Simulation and Computer Applications. Simulation of a complex reacting system frequently results in a set of complicated equations which are impossible to solve analytically. The Monte Carlo technique has been proven quite useful in solving complex problems of such kind (15C, 87C). Cohen (15C) illustrated the application of the method to the solution of complex sets of equations representing the concentration-temperature profiles of a chemical reaction. The solution was based on a stochastic model of a chemical reaction in which the reaction path was permitted to vary from trial to trial. Another Monte Carlo simulation was presented by Spielman and Levenspiel (87C) in the study of the effect of coalescence on reactions taking place in the dispersed phase of two-phase systems in a stirred tank reactor. Zero- and second-order kinetics were considered, and a digital computer was utilized in the simulation. The film-penetration theory has been shown to be a more general concept than the film theory and the surface-renewal theory in dealing with the problem of simultaneous mass transfer and reversible chemical reaction (39C). Based on the three theories mentioned above, mathematical models were developed by Huang and Kuo (39C) for the rates of interphase mass transfer 60

INDUSTRIAL A N D ENGINEERING CHEMISTRY

accompanied by a first-order reversible reaction. The problem of heat transfer with a simultaneous reversible gas-phase reaction in turbulent pipe flow could be simplified when the heat flux a t the wall is maintained constant with axial position since the reaction rate will then become invariant with axial position ( 7 IC). The incorporation of a computer in the process streams for the purpose of controlling the process has been assuming an important role in the chemical industry. Landwehr (57C) described integration of gas-stream analyzers into the computer control system and discussed the wide range of factors to be considered in evaluating and applying analyzers with a control computer. Applications of computer systems to the control of crude oil distillation, ultraforming, and alkylation were illustrated by Rhodes and Ritzenthaler (83C). I t has been suggested (23C) that the porous materials contain two major types of voids, one centrally convergent and the other centrally divergent. This model for the structure of porous materials was applied by Foster and Butt to the calculation of counterdiffusional flux through a porous solid. Simulation of the process in a fluidized bed reactor has been proposed by Russian investigators (73C). The process of combustion of particles was used as an example. When a laminar boundary layer in contact with a solid surface undergoes surface catalysis, the effective order of reaction may vary with position along the surface (62C). This behavior has been taken into consideration in performing a theoretical analysis of the hydrogenation of ethylene on a nickel film. Periodic jumps in temperature of a chemical reaction system induced by a microwave pulse generator may be utilized in analyzing rapid chemical reactions ( 72C). Sugiyama and Hasatani (88C) conducted a digital computer simulation of the multistage thermal decomposition of a solid. A good agreement was obtained between the theoretical and experimental data for the two-stage thermal decomposition of gypsum. The kinetic equations derived for the decompositions of methane to produce ethylene were solved both analytically and numerically by Russian investigators (36C). Stability. The existence of multiple steady states for a catalytic particle depends upon whether intraparticle heat conduction or diffusion is important (2C). Three models of the particle were examined in detail by Amundson and Raymond (ZC), and the condition required for the steady-state stability was presented. Dente (19C) has conducted an analysis on the steadystate sensitivity of nonisotherinal and nonadiabatic tubular reactors. The criterion of sensitivity was based on the curvature characteristics of the temperature profile along the reactor. The rate equation : r = kf(C) exp[-E/RT]

was used, where f ( C ) is a function of reagent concentration of the form C" ( n = l / 2 , 1 and 2). An extensive investigation of the stability of continuously stirred polymerization tank reactors has been

carried out by Goldstein and Amundson (32C, 33C). The basis for analysis of interfacial mass and heat transfer was a kinetic model consisting of a first-order monomer initiation, propagation, and material radical termination. More advanced models and complex conditions were also considered, and results were given for steady and unsteady conditions. The optimum conditions for the continuous stirred tank reactors could sometimes fall within the instability region. To predict whether this kind of situation might arise, Ferraiolo (22C) developed expressions containing the most significant parameters of the process under the optimum conditions. The instability curve as well as the safety curve was also determined. A group of Russian researchers (47C) has made a mathematical study of the relation between the stability of chemical reactors and a coefficient derived from the heat-temperature curves. A method based on a Newton-Raphson iteration technique has been developed for investigating the stability to small disturbances of a plug-flow tubular reactor with recycle (87C). The existence of multiple steady states and instabilities was illustrated through numerical calculations for a first-order exothermic reaction. The results of Krasovskii’s theorem for the generation of Liapunov

functions were utilized by several investigators (7C, 66C) to extend the region of proved asymptotic stability of a well stirred flow reactor. Catalysis-Theoretical

and Experimental

Theory. When reactions proceed in several kinetically distinct steps, each step being catalyzed by different types of catalyst, theoretically there is an optimum composite catalyst by which the overall yields and reaction rates could be increased (340). Molecular models of catalysis show that good contact between the catalyst surface and that portion of the molecule to be reduced is required for effective catalytic hydrogenation of organic compounds (250). A method presented by Kittrell (733B) permits precise estimates of the parameters in nonlinear catalytic rate models. The data points should be selected in such a way that the volume of the joint confidence region of estimated parameters is minimized. Whether a reaction may be accelerated or retarded by activators is governed by the type of catalyst involved. Using this concept, Bonchev and Yatsimirskii (720) classified the activators into the following four groups according to the mechanism of their effects: orientation and polarization ; activation of electron transfer ; activaTABLE I X . ADDITIONAL REFERENCES FOR PROCESS SIMULATION AND COMPUTER APPLICATIONS

TABLE V I I . ADDITIONAL REFERENCES ON FU N DAM ENTAL T H EOR I ES

I

Subject Sublect

Reference

Formation of acetylene from saturated hydrocarbons Kinetic acidity dependence in concentratcd acids Estimation of activation energies and rate parameters A graphic method for complex reactions Concentration and temperature fields in ronsecutive reactions First-order consecutive reactions in a flow reactor Chemical reaction in relation to diffusion phenomena Fundamental dimensionless equations and the criteria of chemical kinetics Extreme values of concentrations in a current of reacting gases Kinetics of heterogeneous processes Significance of agitation and the role of gas-liquid interface Kinetic isotope effects Momentum and energy exchange in chemical apparatus Theory of neutralization in production of ammonium nitrate Measurement of reaction rate by competitive removal of reactant Prediction of residence time distribution Effect of reversible stages on the kinetics of chemical reactions Role of steric factors in the noncatalytic and catalytic reactions Kinetics of the thermal ionization of an aerosol Influence of the velocity profile on the reaction yield in tubular reactors Kinetic interpretation of hyperequilibrium concentration of gaseous reaction Droducts

(72C) (53C) (6C) (92-7

(25C) (3OC) (75C)

(IC)

Reference

Increasing the yield of a n inorganic reaction Stochastic approach to first-order chemical reaction kinetics Set-theoretic approach to reaction kinetics Energy distribution among products of exothermic reactions Convective mass transfer in a heterogeneous chemical reaction Chemical conversions of gas mixtures in the tubular reactor without influence of diffusion Influence of the velocity profile on conversion Kinetics of nonlinear systems of homogeneous chemical reactions Evaluation of residence-time spectra Numerical solutions of the problems of chemical kinetics with computers Programs for computing reaction velocity and reaction equipment Numerical analysis and kinetic interpretation of molecular-weight distribution data Calculation of first-order rate constants in a complex system

TABLE V I I I. ADDITIONAL REFERENCES ON OPTIMIZATION Subject Elementary derivation of the maximum principle Some difficulties in the use of Pontryagin’s maximum principle Optimal reaction systems with recycle Evaluation of the state of controlled chemical production processes Real variable control for optimum processes Rapid determination of optimum conditions Optimal design of chemical process systems Optimization in ammonia synthesis Conversion and temperature distribution in cement shaft kiln Use of linear programming in oil refining Optimizing alkylation processes Optimal production control of formaldehyde from methanol

VOL. 5 9

NO. 1

JANUARY 1967

61

tion of shift in equilibrium; and activation of intermediate compound formation. The selection of the most active catalyst for a desired reaction has been discussed by Vol’kenshtein (7300) based on the electronic theory of catalysis. The improper selection of catalyst may lead to serious errors. N2O decomposition, H-D exchange, and CO oxidation have been employed to illustrate the charge transfer theory of heterogeneous catalysis on semiconductors ( 6 5 0 ) . Although the catalyst was considered as an electron reservoir, the rate controlling steps in the reaction might be adsorption and desorption or the surface migration of the reacting species. A method was described by Iwasaki ( 4 2 0 ) for estimating the conversion of a catalytic first-order reaction in a fluidized-bed reactor. Without using any models, the conversion could be estimated from the contact-time distribution functions C(0) derived from the response curves determined by the tracer technique. The effectiveness factor 7 has been used as a measure of the effect of catalyst particle shape on reactions with LangmuirHinshelwood type of kinetics (7070). The effectiveness factor for a spherical particle was shown to be always lower than a slab of the same characteristic dimension ( L = R/3 where R is the radius of the spherical particle and L represents the half-thickness of the slab). In analyzing the problem of chemical reactions in a catalyst pore, the assumption of unidirectional diffusion effect is good for most practical cases. However, in dealing with large, short pores, the transverse concentration gradients must also be considered. A problem of this type has been solved by Bischoff ( 7 0 0 ) . Kinetics equations that are different from those for stationary catalysts were derived by Lavrovskii and Rozental ( 6 2 0 ) for irreversible gaseous reactions in a fluidized catalytic bed reactor. The equations included rate constants for the sorption processes. Hutchings and Carberry ( 3 9 0 ) computed catalytic effectiveness factors for both the isothermal and nonisothermal cases for the Langmuir-Hinshelwood, Hougen-Watson type kinetic laws involving surface coverage by reactants and products. The significant effect of interphase heat and mass gradients around the catalyst was also discussed. Experimental Techniques. The effectiveness factor is generally used as a measure of the effect of catalyst pore diffusion on the reaction rate. Using large (”4 inch) NiO on A1203spherical catalyst pellets, Otani and Smith ( 8 6 0 ) determined the effectiveness factors by measuring oxidation rates of CO. Rates of reaction decreased with increasing density of the pellets caused by increased diffusion resistance. The effectiveness factors have also been measured by Cunningham ( 7 6 0 ) for fine Cu-Mg oxide catalyst particles and l/2-inch spherical pellets of the same material. The experimental values obtained by the measurement of hydrogenation rates of CH4 ranged from 0.2 to 25 depending upon the temperature and density of the catalyst. Additional data obtained in the study were the activation energy, effective thermal conductivity, and effective diffusivity. 62

I N D U S T R I A L A N D E N G I N E E R I N G CHEMISTRY

The methods of determining the fraction of activated surface and the concentration of active centers for the catalyst through poisoning were described by a group of Russian investigators (320, 970). One method ( 3 2 0 ) used P b ( 0 . cEI&o)2 as a poison and determined the activity of poisoned Pt-black catalyst in the decomposition of HzO2 and oxidation of CzH50H. An empirical equation was derived to relate the activity of poisoned area A to that of nonpoisoned area A,

A/Ao = 1 -

cuc

where a is specific poisoning per unit concentration of poison C. An alternative mathematical equation was also given :

A / A o = 1 - P.g,/Zn where Zn represents the number of active centers, is the probability of poisoning, and g, is the amount of Pb per gram of Pt-black. Another method (970) used quinoline as a poison to determine the concentration of active centers on a decationized zeolite of type U in the catalytic cracking of cumene. The acidity of surface acid centers on heterogeneous catalysts can be determined by the thermometric titration which is a relatively quick and simple method. The method has been presented by Valcha (7250) using basic reagents in CsHs in the thermal titration of acid catalysts. During the titration, the temperature rise was recorded and the measured values were plotted. The acidity of acid centers was estimated from the curves. The acid strength distribution on solid acid catalysts was also determined by gas chromatography (720). The distribution was expressed quantitatively on a scale of heat of absorption of C&. The selectivity and activity of a catalyst were also measured, and there was a discussion on the relation between acid strength and selectivity. An application of gas chromatography has been reported in the determination of effective diffusivities of catalysts (66D). The method involves measurements of the pulse broadenings of a nonchemical interacting gas at various flow rates. Additional applications were reported ( 8 0 , 7050) in which the chromatograph was coupled with the catalytic reaction chamber. The electron spin resonance (ESR) method finds extensive applications in the study of catalysts. Thus, the nature and structure of adsorbed species on catalyst surfaces have been investigated by the ESR method by a number of investigators (360, 450, 7290). The ESR method was also utilized in a study of coke deposits on a silica-alumina catalyst produced from the cracking of hexane, cyclohexane, n-hexene-1, C,&, thiophene, and pyridine 97D. Nagy and Horanyi (790) noted the importance of the electrode potential in the catalytic hydrogenation and dehydrogenation in the liquid phase. The selectivity of the catalyst for similar types of reactions was controlled by the electrode potential of the catalyst as well as the “hydrogenation normal potential.” Studies on a number of new types of catalysts have been reported (220, 4 7 0 ) . The supported barium

chromate functioned as a vapor-phase oxidation catalyst a t temperatures over 200' C. ( 2 2 0 ) . Its catalytic activity was dependent on the formation of lattice defects which tended to equilibrate with oxygen. Other new types of catalysts included a group of enzymelike polymeric chelates of Cu, Ni, Fe, Mn, Co, Zn, and Cd ( 4 7 0 ) . They were evaluated a t 0.1 weight yo level by measuring the oxidation rates of cumene in air. A new method has been suggested in deciding the rate controlling step of NH3 synthesis or decomposition ( 7 730). The method is applicable to the case where the overall reaction is somewhat removed from the equilibrium. Rustamov and Aliev (99D) described a new technique for heterogeneous contact catalysis. The technique used an upward continuous flow and a semicontinuous flow, and performances were compared with that of a fluidized-bed method. A function, $, which is dependent on the relative rate, concentration, and degree of conversion, was defined and used together with the gas flow rate v as a means of comparison. For the fluidized method, v = 10-60 cm./second and $ = 130-600, while u = 150-300 cm./sec. and $ = 500-2900, and u = 300-1000 cm./sec. and $ = 2000-2500, respectively, for the semicontinuous and the continuous upward flow method. Experimental Studies of Fundamentals. The relation between the semiconductivity and catalytic activity of Cr203 catalysts has been studied by Spanish researchers ( 2 9 0 , 7200). Thus, Garcia de la Banda ( 2 9 0 ) conducted the investigation in the dehydrogenation of isopropanol. His experimental results included: electric resistance of catalyst pellets as a function of temperature and also as a function of the hydrogen pressure; electric resistance and activity of the catalysts

during the reaction a t various temperatures with different ratios of isopropanol to hydrogen. Dehydrogenation and dehydration of formic acid were studied by Trillo (7200) to establish the relation between the catalytic activity and semiconductivity for C r z 0 3catalysts. T h e selectivity, specific surface, catalytic activity, and electric conductivity were taken into consideration in the results. The conductivity decreased in the presence of formic acid and the reaction products, but it increased with the addition of a small amount of Li or Cd oxides to the C r z 0 3catalysts. There is a close resemblance between the energies of the bonds of H, C, and 0 with the active centers and the magnetic moments of the metal ions for the rare earths. This observation is based on determination of the bond energies in dehydrogenation and dehydration for 25 oxides by the kinetic method in an attempt to clarify the causes for the selectivity of catalysts ( 5 0 ) . T h e results are discussed in terms of the multiplet theory. Studies on the electronic structure of Fe-Co catalysts by Lavrentovich (670) have lead to a conclusion that the maximum catalytic activity in the NH3 decomposition was obtained when the catalyst contained 2.37-2.40 unpaired electrons per atom of alloy. T h e catalytic decomposition of ammonia on tungsten in the presence of hydrogen is favored by high temperature and high N H 3 pressure ( 7 4 0 ) . An increase in the intensity of an external negative electric field up to 50 volts favors the yields in the catalytic oxidation of methanol, ethanol, isopropanol, and butanol (250). The positive field, on the other hand, decreases the yields. This phenomenon was explained on the basis of the theory of heterogeneous catalysis on semiconductors. Dmitrenko (180) discussed the effect of polarization on the activity of

TABLE Xi. ADDITIONAL REFERENCES O N CATALYTIC EXPERIMENTAL TECHNIQUES Technique Used

Carbonium ion theory

TABLE X.

ADDITIONAL REFERENCES O N THEORIES O F CATALYSIS

Subject Catalytic activity Chemistry of solid state Convective diffusion Effectiveness factor Electrode potential and selectivity Elertrical-thermal analogy method Fouled catalyst Gas diffusion Nonlinear estimation Overheat of catalysts

Investigations Derivation oCequationr for calculation for nurnher of nc.ive atinosplieric ccnters Efferrs of lartice defects and addi.iveF in Cooxide carilly,r on hcrerogeneo:ts caralyric re.irrions Cffcrts on nppirenr kinetics of zcro-order suriace-catnl, zcd chemical r e v t i o n s De\clopment of n gcncralized method of prcdicting catdlvat effectiveness factor Relntion betwcen electrode potential and rate of hbdrogrn3.ion in aqueous heterogenro~is medium Calculations of distrib:irions of ternperittire and erhylenr ronccntrdtion over length of a rubular rcactor for oxidation of crh>lene Derivation of equarioni for bulk rate of a rc.4crion o n ?. porous ( . ~ f . ~ l \ s t Mathematical treatment for describing effect of normal gas diffusion on rates of gaseous reactions catalyzed by porous catalysts Study of integral conversion catalytic data by nonlinear estimation Process for theoretical analysis of porous catalysts

Reference

Circulation method

Study Application to developing a process for selective hydrocracking of paraffinic stocks Cracking of cumene on aluminosilicate catalysts

Conductometric method

Catalysts in liquid phase hydrogenation

Differential thermal analysis

Application to evaluation and testing of catalysts Application in study of catalytic processes

Gravimetric method Indirect method for studying mechanism of liquid phase, catalytic reactions Macrokinetics

Microstatic method Ultrasonic field

Homogeneous catalytic hydrogenation of the C-C n-bond in presence of metal ions New macrokinetic equations with time parameter and appli. cations to cracking 0. petroleum distillates Catalytic cracking of hexane Influence on catalytic activity of M n O ? prepared by electrolysis

VOL. 5 9

Conversion and product distribution

(1330)

Reaction rate, composition and structural characteristics of catalysts Relation between conductivity of catalyst and concentration of adsorbed H DTA data, transformation of catalyst

( 7 78D)

Weight-temperature reactions curve, mechanism of

(1260)

Kinetic equations

(7270)

(1770)

( 4 6 0)

Product yield, optimum conditions

Hi her activity of Ruorine-treated alumina Increase in catalytic activity; no change in of catalyst crysral structure

NO. 1

JANUARY

1967

63

promoted Fe catalysts in the ammonia synthesis. A sharp increase in the activity was observed for the first 4-10 minutes of polarization, but then the cathodic polarization caused a gradual deactivation and anodic polarization produced slow activation of the catalyst. The effect of increased activity by cathodic polarization (and, therefore, an increased number of adsorbed negative ions) explains why the rate of electron transfer from the catalyst to the chemisorbed particles is the controlling step in the ammonia synthesis. The activity of Fe catalysts in the ammonia synthesis is also a function of the degree of reduction (7090). The results of an extensive study on the relation between the catalytic activity in the NH3 synthesis and the distribution of the promoter were presented by Krabetz and Peters (540). I n an investigation (1760) of the adsorption of hydrogen, cyclohexane, benzene, isopropanol, and acetone on the Ni surface, the catalytically active part of the surface was characterized by mean adsorption of hydrogen and weak adsorption of the other substrates. This was supported by experimental results from hydrogenation of ethylene in the presence of preadsorbed hydrogen. The following mechanisms have been proposed by Habeshaw and Hill (350) based on an experimental study of the chemisorption of ethylene on supported Cr oxide catalysts: initiation by H transfer from catalyst to monomer and from growing polymer to catalyst at termination ; formation of active sites possessing a strongly acidic hydroxyl group capable of affecting the H transfer combined with ability to coordinate monomer and to resist complete reduction. According to Carter (130), the chemisorbed species in the adsorption of ethylene on A l z 0 3 catalysts can be removed from the surface by treatment with hydrogen. This removal of surface species is facilitated considerably by addition of a small amount of Pt to AlzO,, indicating a cooperative action of Pt and A1203. When basic dyes were adsorbed on aluminosilicates partly as cations and partly as molecules, the adsorption of the ionic part was small compared with the molecular part (7040). Also, the adsorption of a Lewis acid (BF3) from a gas phase at elevated temperatures was much stronger than that of a Lewis base (NHB), suggesting the presence of numerous basic points in the surface. The activity of catalysts is influenced by their particle size and geometry as d l as the surface structure (ID, 170, 280, 550, 680). A 30-fold increase in reaction rate per external catalyst surface area for a three-fold increase in the particle diameter was reported in the hydrogenation of CzH4 with Ni on alumina catalysts (280). A number of different shapes and sizes of vanadium catalysts have been used by Malkiman (68D) in the study of the conversion of SOz to SO3. The effectiveness of the catalyst shape was evaluated from measurements of the activity and pressure drop. The tablet shape was found most effective. The effect of various catalyst geometries on the diffusive flux of reactants to catalytic walls was investigated by Ablow (7D). Applications of the results were made to some published experimental data for oxygen-atom recombination on 64

INDUSTRIAL AND ENGINEERING CHEMISTRY

TABLE X I I . Reacting Syrtern Acetaldehyde

Acetylene Alkyl cyano alk) pyridinium halides Amide

Ammonia

Ammonia

Ammonia

Ammonia

Ammonia

Benzene

Benzene Benzene, toluene, and naphthalene

Benzene, toluene, and polymethylbenzenes Carbon dioxide

Carbon monoxide

Carbon monoxide

Carbon monoxide

Carbon monoxide

ADDITIONAL REFERENCES ON

Study and Rerult

Condensation reaction with aromatic hydrocarbons; rate equation, reaction rate, apparent acrivarion energy, rate constants Catalytic hydration in ar electrochemical field; reaction order and ratt Selective conversion of pyridine ring; conve sion Superimposed general base catalysis in cleavage of anilides; rate equation Chemisorption of nirroFen and hydrogen on iron catalysts for synthesis; chemisorption mechanism Influence of ga3eous oxygen atoms on catalytic oxidation; rate of reaction, activation energy Kinetics of decomposition on iron catalvsts; rate equation, acilvation energy Catalyric activity of mechanical mixtures of a-and y-iron in synthesis reaction; produc tivi ty, activation energy, rate constant Nitrogen fixation on complex catalysts as studied with 15N; conversion Kinetics of catalytic oxidation; order of reaction, energy of activation Vapor phase catalytic reaction with propylene; kinetic equation Surface catalysii by metallic salts in Menschutkin reaction and in aromatic brominarion by Br; order of reacrion, activation energy Zompetitive catalytic hydrogeneration; rate constant, activation energy, frequency facfnr Uechanism of hydrogenation; contact potential differences, proposed mechanism rhermal effects in catalytic hydrogenation; overall heat transfer coefficient, activation energies, rate equation Magnetic properties and catalytic activity; activation energy, rate constant, magnetic moment 3xidation by hlnOnbased catalysts at low pressures; rate equation ' Khim. Tekhnol., Gidradinarn., i'eplo- i'Masso$eredacha, Akad. ~ v a u kSkSR, 0;b. Obshch. i Tekhn. Khim., Sb. Slatei 1965, pp, 416-17 (Russ.). (48C) Kalinenko, R. A., Brodskii, A. M., Kinetika i Katalir 6 (5), 916-21 (1965) (Russ.). (49C) Kil'man, Y . I., Uzbeksk. Khim. Z h . 9 ( I ) , 23-30 (1965)(Russ.). (50C)King, R. P., Chem. Eng. Sci. 20 (6), 537-44 (1965)(Eng.). (51C) Kjaer, J., Chern. Tech. (Berlin) 1 8 (3), 138-42 (1966). (52C) Kono: H., Kogyo Kagnku Zasshi 68 ( l ) ,135-8 (1965)(Japan.). (53C) Kresge A J. O'Ferrall, R. A. M., Hakka, L. E., Vitullo, V. P., Chem. Commun. (&din) i 9 6 5 (3), 46-8 (Eng.). (54C) Kulgein, N.G., Phys.Fluids 6 (E), 1063-9 (1963)(Eng.). (55C) Kuntz, P. J., Nemeth, E. M., Polanyi, J. C., Rosner, S . D., Young, C. E., J . Chem. Phys. 4 4 (3), 1168-84 (1966)(Eng.). (56C) Kuzin, V. P., Trofimenko, S. A , , Khim. P r o m . 4 1 (12), 904-10 (1965)(Russ.). (57C) Landwehr, J. C., Boesch, L. J.: Wolverton, E. hl.,Proc. 'Tall. Anal. Instr. S p p . IOth, Son Francisco 1964, pp. 307-25 (Eng.). (58C) Lelli, U.: IND,ENG.CHEM.FCSDAMENTALS 4 (3), 360-1 (1965)(Eng.). (59C) Lelli, U., Gatta, A , ?Zng. Chim.Ztal. 1 (6), 168-73 (1965)(Ital.). (60C) Levich, V. G., Brodskii, A. M., Dokl. Akad. Nauk S S S R 165 (3), 607-10 (1965) (Rum.). (61C) Ibid., (5), pp. 1115-18. (62C) Libby, P. A,, Tsong, Ivf. L., Phis. Fluids 9 (3), 436-45 (1965) (Eng.). (63C) Liberson, L. M.,Shinderova, T. A , , T I . Nauchn.-Issled. Inst. ,bo Udobr. Insekoiojun;jitsidam h'o. 205, 104-10 (1964)(Russ.). (G4C) Litvinenko L. hl., Oleinik, N. M.,Reaktionnaya Sposobnost. Organ. Soadin., Tartusk. Gor. L T ~ i u2. (Z), 57-76 (1965)(Russ.).

70

INDUSTRIAL A N D ENGINEERING CHEMISTRY

(65C) Litvinenko, L. M., Popov, A. F., Tokarev, V. I., Kinetika i Kataiir 6 (3), 510-21 (1965)(Russ.). (66'2) Luecke, R . H., EiIcGuire, h.1. L., A.I.Ch.E. J . 11 (41, 62-3, 749-50 (1965) (Eng.1. (67C) Luk'yanov, A . T., Pusryl'nikov, L. M.,Shavrov, A . A., Dokl. Akad. h'auk S S S R 166 ( 3 ) , 651-3 (1966)(Russ.). (68C) Matsuyama, H., Kishimura, H., Yagi, S., Kogyo Kagnku Zasshi 6 8 ( l ) , 152-5 (1965)(Japan.). (69C) Meilikhov, E. Z., K o h i d . Zh. 27 (4), 552-5 (1965)(Russ.). ( 7 0 C ) Miyake, R., Yajima, H., Yakugaku Zasshi 85 ( 7 ) , 618-23 (1965)(Japan.). (71C) Nagy, F., Horanyi, G., Kallo, D., M a g y . Tud. Akod. Kozp. Kem. Kut. Int. Korlemen. JYO.7, 1-13 (1961)(Publ. 1962)(Hunp.). (72C) Okuma, K;, Fujiv.:ara, T., Kogyo Kagaku Zasshi 68 (l),159-60 (1965) (Japan.) (73C) Olevskaya, I. V., Itkin, G. E., Mashevskii, G. N., Obogashch. Rud 10 (3), 34-41 (1965)(Russ.). . . (74'2) Osherov V. I., Teor. z Eksperim. Khim., Akod. N a u k U k r . SSR 1 ( l ) , 66-70 (1965)(Russ.$. (75C) Othmer, D. F., Utsumi, T., CHZSA, Main Leclures Intern. C o n y . Chem. Eng., Equipment Design Autam. 1962, 97-1 11 (Publ. 1964)(Eng.). (76C) Peizulaev, S. I., Z h . Fir. Khim. 39 (6): 1435-41 (1965)(Russ.). ( 7 7 c ) Pings, C . J., I N D . EKG. CHEM.FUNDAMENTALS 4 (3), 260-4 (1965)(Eng.). (78C) Pippel, W., Chem. Tech. (Berlin)17 (12), 729-38 (l965)(Ger.). ( 7 9 C ) Polio, I . ? Zeszyty N a u k . Politech. S/ask., Chem. N o . 23, 101-12 (1964)(Pol.). (SOC) Rafal, M. D., Dranoff, J. S., IND.ENO. CHEM.PROCESS DESIGNDEVELOP. 5 (2), 129-35 (1966)(Eng.). (81C) Reilly, M. J., Schmitz, R . A , , ii.I.Ch.E. J . 12 ( l ) , 153-61 (1966)(Eng.). (82C) Repges, R., Bcguth, T.V., Ber. Bunren,ges. Physik. Chem. 6 9 (71, 638-41 (1965) (Grr.).

(83C) Rhodes, J. C., Ritzenthaler, B. A., PTGC.N a t l . A n a l . Instr. Synp., 70th, Sari Francisco 1964, pp. 299-305 (Eng.). (84C) Robinson, P. J., Trans. Faraday Soc. 61 (512), 1655-63 (1965) (Eng.). (85C) Roginskii, S. Z., Rozental, A. L., Dokl. Akod. iVouk SSSR 162 (3), 621-4 (1 965) (Russ.). (86C) Smith, G. R., Downing, G. V., Jr., J . P h y . Chem. 7 0 (4), 977-81 (1966) (Eng.). (87C)Spielman, L. A,: Levenspiel, O., Chem. Eng. Sci. 20, 247-54 (1965). ( 8 8 C ) Sugiyama, S., Hasatani, hi., Kagnku Kognku 18 (5), 355-61 (1964) (Japan.). (89C) Szarawara, J., Zesryty ~ V o u k . Politech. Slnsk., Chem. NO. 24, 151-4 (1964) (Pol.). (9OC) Tarabaev, S. I., Vestn. Akad. .Vmk Kaz. S S R 21 ( l l ) , 40-5 (1965)(Russ.). (91C) Tavast, I. R., Jaaksoo, U., Eesti "V'SV Teadusie Akad. Toimetired, Fuusikn,M~at.-]a Tehniknteoduste Seer. 14 (3), 444-54 (1965)(Russ.). (92C) Temkin, M. I., D o d . Aknd. 4 a u k SSSR 165 ( 3 ) , 615-18 (1965)(Rurs.). (93C) Trevissoi, C., Franccsconi, R., Ing. Chim. Ital. 1 (51, 125-36 (1965)(Ital.). (94C) Trombetta, Ivf. L., Chem. Eng. Progr. Symp. Ser. 61 (53); 42-9 (1965)(Eng.). (95C) Weisman. J.: TVood, C. F.:Rivlin, L., Ibid., pp. 50-63. (96C) \Veiss: A. H., Chem. Eng. 7 0 ( 7 ) ,89-92, 94 (1963)(Eng.). (97C)FVirrh, H., Chem. Tech. (Berlin) 17 (12), 743-6 (1965)(Ger.). ( 9 8 ' 2 ) Yamaguchi, I., Oishi, T.: Hashimoto, K.,Nagata, S., ,Mem. Fac. Eng. Kyoto L'nia. 27 (1): 118-42 (1965)(Eng.). (99C) Zeinalov, F. I., Adibekov, P. G., Avetisov, A. K., Akhmedova, A. K., Sorokina. T. S.. Shul'gina, E. hf., Kopysitskii, T. I., Leitman, Y. S., Khim. i Teichnal. Topliv i M a s e i 11 (3), 23-30 (1966)(Russ.). (1OOC) ,Zhorov I. Y. M. Panchenkov G. M Zel'tser, S. P., Tirak'yan, Y. A., Kinetika i K a 6 l i r 6 (6), iO92-7 (1965)\Russ.)."

Catalysis-Theoretical

a n d Experimental

(1D) Ablow, C. M.,Motz, H., Wise, H., J . Chem. Phys. 4 3 ( l ) , 10-14 (1965) (E%.). (2D) Aerov, M. E., Nikitina, N. I., Khim.Prom. 4 1 ( 8 ) , 611-14 (1965)(Russ.). (3D) Andreu. P. Letterer R Low W., Noller, H., Schmitz E. Proc. Intern. Congr. Cntaiysis, 3rd, h s l e r d a m , ' l 9 $ 4 2, 8i7-69, disc, 869-70 (Publ: 19kj)(Eng.). (4D) Ayen, R. J., Ng,Y. S.! Air W'aterPollution 10 (l), 1-13 (1966)(Eng.). (5D) Balandin, A. A . , Tolstopyatova, A. A,: P ~ G Intern. c. Congr. Cataiysis, 3 r d , Arnrlerdam, 1964 1, 533-42, disc. 542-6 (Publ. 1965)(Eng.). (6D) Basov, V. A . , Glagoleva, 0. F., Livshits, R. S., Melik-Akhnazarov, T. K., Orochko, D. I., Arerb. Khim. Zh. 1964 (5), pp. 55-64 (Russ.). (7D) Baum, S. J., Plane, R. A , , J . A m . Chem. SOC.88 (5), 910-13 (1966)(Eng.). (8D) Belousov, V. M.,Rubanik, 51. Y., Gershingorina, A. V., Ukr. Khim. Zh. 31 (5), 444-9 (1965)(Russ.). (9D) Benashvili, E. hl., Soobshch. Akad. N a u k Grur. S S R 38 (Z), 309-14 (1165). (Russ.). (IOD) Bischoff: K. B., IND.ESG. CHEM.FUNDAMENTALS 5 (l), 135-6 (1966)(Eng.), (1lD) Bochner, 41. B., Gerber, S. M., Rodger, A. J., Ibid., 4 (3), 314-17 (1965) (Eng.1. (12D) Bonchev, P. R., I'atsimirikii, K. B., Teor. i Eksperim. Khim., A k a d . N o u k U k r S S R 1 ( Z ) , 179-89 (1965)(Russ.). (13D) Carter, J. L., Lucchesi, P. J., Sinfelt, J. H., Yates, D . J. C., Proc. Intern. Congr. C a t a l p i s , 3rd, B n i s ~ e r d a n ~7964 , 1, 644-53, disc. 653-6 (Publ. 1965) (Eng.). (14D) Chernov, V. A,, Anripina, T. V., SeJtekhirniyo 5 (5), 688-92 (1965)(Russ.). (15D) Chesnokova I. R. V., Gorbunov, A. I , , Lachinov, S. S., Muravskaya, G . K., Erdedi, G. A., Ki)netika i Katalir 6 (Z), 338-42 (1965)(Russ.). (16D) Cunningham, R. A , , Carberry, J. J., Smirh, J. M., A.Z.Ch.E. J . 11 (4), 636-43 (1965)(Eng.). (17D) Deren, J., Haber, J Siechowski, J., Prof. Intrm. Congr. Catalysis, 3rd, Arnrferdam, 7964 2, 993-1002, disc. 1002-9 (Publ. 1965)(Eng.). (18D) Dmitrenko, L. M., Lachinov, S. S., Sivyakova, R. F., Kinetika i Katnliz 6 ( l ) , 121-7 (1965)(Russ.). (19D) Dorfman, Y . A,, Sokol'skii, D. V,, Dokl. Akad. ATuuk SSSR 167 (l), 102-5 (1 966) (Russ.). (20D) Dran, J. C., Cornrn. Energie A t . (France), Roppt. CEA-R 2604, 72 pp. (1964) (Fr.). (21D) Duyverman C. J. Vlugter, J. C., van de Weerdt W J. Proc. Intern. Congr. Catalysis, 3rd, Am;terdad, 7964 2, 1416-27, disc. 1427-30'(P;b1.'1965)(Eng.). (22D) Econom J., hleloon, D. T., Jr., Ostrozynski, R. L., J . Catalysis 4 (4) 446-53 (1965Y)Eng.). (23D) Ertl, G., Z. Physik. Chem. (Frankfurt) 46 (1/2), 49-62 (1965)(Ger.).

(24D) Fel’dblyum, V. S., Komissarova, G. P., Tsailingol’d, T. A., Kinetika i Katalir 7 (l), 175-9 (1966)(Russ.). (25D) Fentsik V. P Stadnik P. M. Poverkkni Kuntaktn. Yavleniya v Polufirov. Sibirsk. Fir.-Tekhn. .bauchnl-Issled. Inh. pri ‘iomskom Gos. Uniu. 1964, pp. 190-8 (Russ.). (26D) Freifelder, M., Platinum Metolo Rev. 9 ( Z ) , 38-42 (1965)(Eng.). (27D) Fukui, Y., Tanaka, H., Ishii, J., Takahashi, T., Kogyu Kagaku Zasrhi 67 (12), 2058-62 (1964) (Japan.). (28D) Fulton, J. W., Crosser, 0. K., A.1.Ch.E. J. 11 (3), 513-20 (1965)(Eng.). (29D) Garcia de la Banda, J. F., Utrilla, R. M., Somoano, J. A. P., Anales Real Suc. Espan. Fis, Quim. (Madrid),Ser. B 61 (4), 603-30 (1965)(Span.). (30D) Germain, J. E., Gaschka, F., Mayeux, A., Bull. Suc. Chim. France 1965 (5), 1445-53 (Fr.). (31D) Germain, J. E., Spender, P., Beaufils, J. P., Ibid., (ll), pp. 3158-62. (32D) Gorokhova, T. I., Mal’tsev, A. N., Kobozev, N. I., Zh. Fir. Khim. 39 (5), 1206-10 (1965)(Russ.). (33D) Gorokhovatskii, Y B Kataliz i Katalizatury, Akad. Nauk Ukr. SSSR, Resp. Mezhved. Sb. 1965, pp. il-gl (Russ.). (34D) Gunn, D. J., Thomas, W. J., Chem. Eng. Sci. 20,89-100 (1965). (35D) Habeshaw, J., Hill, T., Pruc. Intern. Cungr. Catalysis, 3rd, Amsterdam 7964 2, 975-90, disc. 990-2 (Publ. 1965)(Eng.). (36D) Hauffe K., Anales Real Soc. Espan. Fir. Quim. (Madrid), Ser. B 61 ( Z ) , 277-302 (1965)(Eng.). (37D) Hoekstra J., U. S. Patent 3,197,284 (Cl. 23-212) (July 27, 1965, Appl. Aug. 4, 1961).’ (38D) Hugo, P., Chem. Eng.Sci. 20 (ll), 975-83 (1965)(Ger.). (39D) Hutchings, J., Carberry, J. J., A.I.Ch.E. J. 12 (l), 20-3 (1966)(Eng.). (40D) Ioffe, I. I., Kameneva, L. S., Slavinskaya, V. A,, Kinetika i Katnlir 6 (2) 333-5 (1965)(Russ.). (41D) Ishii, T., Osberg, G. L., A.I.Ch.E.J. 11 ( Z ) , 279-87 (1965)(Eng.). (42D) Iwasaki M Furuoya I Sueyoshi, H., Shirasaki, T., Echigoya, E., Kagoku Kogaku 29 (li),292-8 (19ij)TJapan.). (43D) Jiru, P., Witchterlova, B., Tichy, J., Pruc. Intern. Cungr. Catalysis, 3rd, Amrterdam, 1964 1, 199-211, disc. 211-13 (Publ. 1965)(Eng.). (44D) Karn F S Shultz J F Anderson, R. B., IND.ENG.CHEM.PROCESS DESION ’4 (3);’266-70’(lb6?) (Eng.). DEVELOP. (44Da) Johnson, M. F. L., Stewart, W. E., J. Catalysis, 4 (2), 248-52 (1965) (Eng.). (45D) Kazanskii, V. B., Pariiskii, G. B., Pruc. Intern. Cungr. Catalysis, 3rd, Amsterdam, 1964 1, 367-76, disc. 377-8 (Puhl. 1965)(Eng.). (46D) Keely, W. M., Proc. Toronto Symp. I‘hermal Anal., lsl, Toronto 1965, pp. 13140 (Eng.). (47D) Keier N P Nauckn Osnuuy Pudbura i Pruizu. Katalizaturuu, Akad. Nauk SSSR, Sibirsk. 018. 1666: pp. 218-24 (Russ.). (48D) Keier N P Pruc. Intern. Cungr. Catalysis, 3rd, Amsterdam, 1964 2, 1021-31, disc. 103113 (Pu