Thermodynamics of Technical Gas Reactions

Regnault and Wiedemann, cf. Haber s Thermodynamics of Technical Gas Reactions, Eng. trans., lect. 6. 

Further particulars of these methods will be found in W. Nernst, Applications of Thermodynamics to Chemistry, 1906 F. Haber, Thermodynamics of Technical Gas Reactions, 2nd edit., trans. Lamb, 1909. 

The chemical constants may therefore be determined directly by the measurement of vapour pressures, especially at low temperatures. Equation (9), which is more general, shows that the chemical constant is determined for a. homogeneous gas as soon as we know A, and C, as functions of temperature, and the vapour pressure at one temperature. These data, especially vapour pressures at very low temperatures, are not very well known at present, and some other method must therefore be used in the determination of the chemical constant. Several such methods have been proposed by Nernst (loc. cit. cf. also Haber, Thermodynamics of Technical Gas Reactions, pp. 88—96 Weinstein, Thermodynamik and Kinetik III., 2, pp. 1064—1074). 

At first, Clara tried to continue her work in chemistry. She attended chemistry seminars and events, translated two articles from English to German, and helped her husband with his 1906 book, Thermodynamics of Technical Gas Reactions. In an unusual move by a German scientist at the time, Haber dedicated the book to her To my loving wife Clara Haber, Ph.D., thanks for the quiet helping work. ... 

Nemst puts (ao + R) = 3 5 (calones) as an approximation (which is probably only a rough one, f Haber, Thermodynamics of Technical Gas Reactions, appendix to Lecture 3, also Nemst, Applications of Thermo dynamics to Chemistry, p 77) Hence—... 

M F, Haber, The Thermodynamics of Technical Gas Reactions,M English translation by A. B. Lamb, Longmans, Green and Go., London, 1908. 

Haber s work embraced the physical chemistry of gas reactions, following on from the equilibria studies of Le Chatelier and other chemists. Furthermore, Haber, in common with many leading German academic chemists, was well aware of the rewards that might accrue from successful industrial application of laboratory results. Haber s acute awareness of the industrial potential came over in his 1905 book Thermodynamik technischer Gasreaktionen (published in English as Thermodynamics of Technical Gas Reactions) His credentials and background were well suited to the needs of BASF. 

Fritz Haber, Thermodynamik technischer Gasreaktionen. Sieben Vortrdge (Munich R. Oldenbourg, 1905), and, translated by Arthur H. Lamb, Thermodynamics of Technical Gas Reactions (London MacMillan, 1908). Haber s reputation in technical electrochemistry derived from his Grundriss der Technischen Elektrochemie auf theoretischer Grundlage (Munich R. Oldenbourg, 1898). 

Grundriss der technischen Elektrochemicy Munich, 1898 Thermodynamik technischer Gas-reaktioneny Munich, 1905 tr. A. B. Lamb, Thermodynamics of Technical Gas Reactions (with additions by Haber), 1908. 

The first five years of the new century were Haber s most productive period, both in terms of the total number of publications (almost fifty) or the variety of topics he researched. He pursued different kinds of electrochemical studies (ranging from electrolysis of solid salts to the invention of the glass electrode for determining the acidity of liquids), researched the loss of energy by various prime movers (steam engines, turbines, internal combustion engines), and probed the luminous inner core of the Bunsen flame. In 1905 he published a book on the thermodynamics of technical gas reactions, which was soon translated into English. ... 

The product composition is controlled mainly by thermodynamics, which favor the formation of methane at lower temperatures of about 623 K, and of hydrogen at higher temperatures of about 1223 K [113]. The required heat for endothermic SR can be provided by the total oxidation of hydrocarbons. An increase in the molar ratio of water vapor to carbon content also causes a decrease in carbon monoxide content following Eq. (15.9), a decrease in methane content, and an increase in carbon monoxide content according to Eq. (15.10). More details about thermodynamic considerations [116] and more information about the elementary steps of the reaction of aliphatic hydrocarbons [113] are available in the literature. The SR process has been well examined, since the SR of natural gas is the dominant process for industrial hydrogen production with technical availability for large-scale application and cost-effectiveness [118]. 

Bom into a Jewish family in Prussian Breslau, Haber studied chemistry in Berlin, graduating in 1891. After a string of minor industrial and university posts, he settled in 1894 at the Karlsruhe Technical University, where he received his habiUtation and in 1898 became extraordinarius and in 1906 ordinarius (full) Professor of Physical Chemistry and Electrochemistry. Later he would refer to his time in Karlsruhe as the best working years of my life. During the seventeen years in Karslruhe he not only laid the scientific foimdations for the Haber-Bosch process, for which he would receive the 1918 Nobel Prize in Chemistry, but also became a well-known protagonist of physical chemistry through his contributions to the thermodynamics of gas-phase reactions the scope and depth of this work led him to conclusions resembling the Third Law of Thermodynamics. 

Properties for processes can be calculated from thermodynamic quantities for individual species. A sample (Table II) from the NBS Interim Report (4), A Report on Some Thermodynamic Data For Desulfurization Processes, shows typical values for selected quantities of some chemical species extracted from the NBS Technical Note 270-series (5). A sample (Table III) from the NBS Interim Report illustrates a set of processes for a few reactions related to the flue gas washing process. This reaction table can be constructed from the data on individual species. 

Much of our information about the nature of the adsorbed gas layer comes from studies of the amount of gas adsorbed on a surface a (the surface coverage) as a function of gas pressure P at a given temperature. The o-P curves derived from these experiments are called adsorption isotherms. Adsorption isotherms are used primarily to determine thermodynamic parameters that characterize the adsorbed layer (heats of adsorption, and the entropy and heat capacity changes associated with the adsorption process) and to determine the surface area of the adsorbing solid. The latter measurement is of great technical importance because of the widespread use of porous solids of high surface area in various industrial processes. The effectiveness of participation by a porous solid in a surface reaction is often proportional to the surface area of the solid. The simplest adsorption isotherm at a constant temperature is obtained from Eq. 3.85, which we can rewrite as... 

Reactions between a gas and a liquid catalyzed by a solid are frequently encountered in chemical processes of great economical significance. Very often, it is technically impossible to operate with just one fluid phase, gas or liquid, in the reactor. The occurence of two fluid phases mainly depends on the temperature range in which the reaction can occur. It is well known that the low temperature limit depends on kinetics and catalysis whereas the highest possible temperature is fixed either by thermodynamics either by the product and the catalyst heat sensitivity. Nevertheless, some reactants, even at rather low temperature, will never been condensed or soluble enough to eliminate the gas phase. On the other hand, other reactants will never been completely vaporized whatever the temperature. Therefore, three phase catalytic processes will always occur when the volatility of two reactants is very different. This broad class of reactions is very important in chemical industry and, as we shall see, will be more frequent in the future. 

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