DORAISWAMY

The thermal properties of an ideal gas, enthalpy, entropy and specific heat, can be estimated using the method published by Rihani and Doraiswamy in 1965 ... 

Coefficients of Rihani s and Doraiswamy s method (1965) for calculating enthalpy, entropy, and the for an ideal gas. 

Two lists of gas/liquid reactions of industrial importance have been compiled recently. The literature survey by Danckwerts (Gas-Liquid Reactions, McGraw-Hill, 1970) cites 40 different systems. A supplementary list by Doraiswamy and Sharma (Heterogeneous Reactions Fluid-Lluid-Solid Reactions, Wiley, 1984) cites another 50 items, and indicates the most suitable land of reactor to be used for each. Estimates of values of parameters that may be expec ted of some types of gas/liquid reac tors are in Tables 23-9 and 23-10. 

Two complementai y reviews of this subject are by Shah et al. AIChE Journal, 28, 353-379 [1982]) and Deckwer (in de Lasa, ed.. Chemical Reactor Design andTechnology, Martinus Nijhoff, 1985, pp. 411-461). Useful comments are made by Doraiswamy and Sharma (Heterogeneous Reactions, Wiley, 1984). Charpentier (in Gianetto and Silveston, eds.. Multiphase Chemical Reactors, Hemisphere, 1986, pp. 104—151) emphasizes parameters of trickle bed and stirred tank reactors. Recommendations based on the literature are made for several design parameters namely, bubble diameter and velocity of rise, gas holdup, interfacial area, mass-transfer coefficients k a and /cl but not /cg, axial liquid-phase dispersion coefficient, and heat-transfer coefficient to the wall. The effect of vessel diameter on these parameters is insignificant when D > 0.15 m (0.49 ft), except for the dispersion coefficient. Application of these correlations is to (1) chlorination of toluene in the presence of FeCl,3 catalyst, (2) absorption of SO9 in aqueous potassium carbonate with arsenite catalyst, and (3) reaction of butene with sulfuric acid to butanol. 

Liquid/hquid reactions of industrial importance are fairly numerous. A hst of 26 classes of reactions with 61 references has been compiled by Doraiswamy and Sharma Heterogeneou.s Reactions, Wiley, 1984). They also indicate the kind of reactor normally used in each case. The reactions range from such prosaic examples as making soap with alkali, nitration of aromatics to make explosives, and alkylation of C4S with sulfuric acid to make improved gasoline, to some much less familiar operations. 

The coefficients a, b, and c for hydrogenation were obtained from the literature [13] and those for nitrile and hydrogenated nitrile were calculated from a group contribution method reported by Rihani and Doraiswami [14]. All the necessary data are listed in Table 1. The integration constant / and AHq have been calculated by incorporating the values of AG° and AH° at 298 K in Eqs. (3) and (4). The equilibrium constant at atmospheric pressure and various temperature has been calculated according to the relationship ... 

Szarfman A, Tonning JM, Doraiswamy PM. Pharmacovigilance in the 21st century new systematic tools for an old problem. Pharmacotherapy. 2004 24 1099-104. 

When a number of competing reactions are involved in a process, and/or when the desired product is obtained at an intermediate stage of a reaction, it is important to keep the residence-time distribution in a reactor as narrow as possible. Usually, a broadening of the residence-time distribution results in a decrease in selectivity for the desired product. Hence, in addition to the pressure drop, the width of the residence-time distribution is an important figure characterizing the performance of a reactor. In order to estimate the axial dispersion in the fixed-bed reactor, the model of Doraiswamy and Sharma was used [117]. This model proposes a relationship between the dispersive Peclet number ... 

Doraiswamy, L. K., Sharma, M. M., Heterogeneous reactions - analysis, examples and reactor design, Wiley -Interscience Publications, New York (1984). 

The strategy of introducing water as second phase has been used by Greenfield for obtaining higher yields of dibenzylamine (>97%) by hydrogenation of benzonitrile. In this case, water seems to prevent poisoning of the catalyst (Doraiswamy and Sharma, 1984). 

Doraiswamy and Sharma (1984) have discussed many practical aspects of conducting multiphase reactions to derive some benefits. 

Doraiswamy, L.K. and Sharma, M.M., 1984, Heterogeneous Reactions Analysis, Examples and Reactor Design , Vol. 2, Wiley-interscience, New York. 

A variety of models of chemical reactors is discussed in more detail in Section 5.4. Readers who are interested in modelling of chemical reactors are also referred to books of Carberry and Varma (1987), Fogler (1986), Froment and Bischoff (1990), Levenspiel (1999), Smith (1981), Trambouze et al. (1988), Walas (1959), and Westerterp et al. (1990). With respect to heterogeneous reactions athe book of Doraiswamy and Sharma (1984) is also recommended. 

Requirements regarding laboratory liquid-liquid reactors are very similar to those for gas-liquid reactors. To interpret laboratory data properly, knowledge of the interfacial area, mass-transfer coefficients, effect of contaminants on mass-transport processes, ionic characteristics of the system, etc. is needed. Commonly used liquid-liquid reactors have been discussed by Doraiswamy and Sharma (1984). 

Several group contribution methods have been developed for the estimation of the constants, such as that by Rihani and Doraiswamy (1965) for organic compounds. Their values for each molecular group are given in Table 8.4, and the method illustrated in Example 8.9. The values should not be used for acetylenic compounds. 

Table 8.4. Group contributions to ideal gas heat capacities, kJ/kmol°C (Rihani and Doraiswamy, 1965)...

Rihani, D. N. and Doraiswamy, L. K. (1965) Ind. Eng. Chem. Fundamentals 4, 17. Estimation of heat capacity of organic compounds from group contributions. 

Scates, A. C. Doraiswamy, P. M. (2000). Reboxetine a selective norepinephrine reuptake inhibitor for the treatment of depression. Ann. Pharmacother., 34, 1302-12. 

Babyak, Michael A., James A. Blumenthal, Steve Herman, Parinda Khatri, P. Murali Doraiswamy, Kathleen A. Moore, W. Edward Craighead, Teri T. Baldewicz and K. Ranga Krishnan, Exercise Treatment for Major Depression Maintenance of Therapeutic Benefit at 10 Months , Psychosomatic Medicine 62 (2000) 633-38 Barbui, Corrado, Andrea Cipriani and Irving Kirsch, Is the Paroxetine-Placebo Efficacy Separation Mediated by Adverse Events A Systematic Re-Examination of Randomised Double-Blind Studies , submitted for publication (2009)... 

During, A., S. Doraiswamy et al. (2008). Xanthophylls are preferentially taken up compared to beta-carotene by retinal cells via a scavenger receptor Bi-dependent mechanism. J. Lipid Res. 49 1715-1724. 

Vaidyanathan and Doraiswamy [Chem. Eng. Sci., 23 (537), 1966] have studied the catalytic partial oxidation of benzene in a composition range where the reactions of interest all follow pseudo first-order kinetics. The pertinent stoichiometric equations are... 

Vaidyanathan and Doraiswamy (1968) studied the kinetics of the gas-phase partial oxidation of benzene (CgHg, B) to maleic anhydride (C4H2O3, M) with m in an integral PFR containing... 

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