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Haber ammonia synthesis

A second and greater opportunity came his way in the spring of 1922. Professor Fritz Haber, discoverer of the Haber ammonia synthesis process and head of the Kaiser Wilhelm Institute for Physical Chemistry (now known as the Max Planck Institute), contacted Professor Schlenk. [Pg.14]

If this is done enough times, fairly pure hydrogen can be generated for use in Haber ammonia synthesis. The carbon monoxide and hydrogen can also be converted to methanol, an alcohol that can be burned as a fuel, or, if repeated many times and with a catalyst, converted into the long-chain carbon compounds that make up waxes and oils. [Pg.168]

The exact role of promoters is not very well understood in many cases, but it is now generally accepted that it is related to the formation of specific electronic surface states necessary for the given catalytic reaction. It apparently does not matter how that electronic state is produced that is, whether it is formed in the preparation of the native catalyst surface or by the presence of some other component which induces the necessary state. As an example, the presence of small amounts of aluminum and potassium oxides on iron-iron oxide catalyst in the Haber ammonia synthesis greatly improves its activity. Either promoter alone has no significant effect on the process. Why Such questions remain as fodder for further industrial or graduate research. [Pg.193]

These pioneers understood the interplay between chemical equiUbrium and reaction kinetics indeed, Haber s research, motivated by the development of a commercial process, helped to spur the development of the principles of physical chemistry that account for the effects of temperature and pressure on chemical equiUbrium and kinetics. The ammonia synthesis reaction is strongly equiUbrium limited. The equiUbrium conversion to ammonia is favored by high pressure and low temperature. Haber therefore recognized that the key to a successful process for making ammonia from hydrogen and nitrogen was a catalyst with a high activity to allow operation at low temperatures where the equiUbrium is relatively favorable. [Pg.161]

As an indispensable source of fertilizer, the Haber process is one of the most important reactions in industrial chemistry. Nevertheless, even under optimal conditions the yield of the ammonia synthesis in industrial reactors is only about 13%. This Is because the Haber process does not go to completion the net rate of producing ammonia reaches zero when substantial amounts of N2 and H2 are still present. At balance, the concentrations no longer change even though some of each starting material is still present. This balance point represents dynamic chemical equilibrium. [Pg.1136]

Silvery, shiny, and hard. Unique metal, gives off an odor as it forms volatile 0s04 on the surface (oxidation states 81). Osmium is the densest element (22.6 g cm3 record ). Was replaced in filaments (Osram) by the cheaper tungsten. Used in platinum alloys and as a catalyst. Haber s first catalyst in ammonia synthesis was osmium, which fortunately could be replaced by doped iron. The addition of as little as 1 to 2 % of this expensive metal increases the strength of steel (e.g. fountain-pen tips, early gramophone needles, syringe needles). [Pg.73]

Mont Cenis [Named after a coal mine in the Ruhr] An early ammonia synthesis process, basically similar to the Haber-Bosch process but using coke-oven gas. Operated by The Royal Dutch Group at Ymuiden, The Netherlands, since 1929. [Pg.183]

SCFs will find applications in high cost areas such as fine chemical production. Having said that, marketing can also be an issue. For example, whilst decaffeina-tion of coffee with dichloromethane is possible, the use of scCC>2 can be said to be natural Industrial applications of SCFs have been around for a long time. Decaffeination of coffee is perhaps the use that is best known [16], but of course the Born-Haber process for ammonia synthesis operates under supercritical conditions as does low density polyethylene (LDPE) synthesis which is carried out in supercritical ethene [17]. [Pg.137]

Due to the high hydrogen storage capacity of the ammonia molecule (17.7 wt% equal to an energy density of 4,318 Wh kg 1), its decomposition is intensely investigated for COx-free hydrogen production for mobile fuel cell applications [146]. However, compared with the well-established Haber Bosch process for ammonia synthesis, its decomposition is underdeveloped and requires substantial improvements before it can be considered as a practical contribution to the energy supply toolbox. [Pg.421]

Since 1923, methanol has been made commercially from synthesis gas, the route that provides most of the methanol today. The plants are oEten found adjacent to or integrated with ammonia plants for several reasons. The technologies and hardware are similar, and the methanol plant can use the CO2 made in the Haber ammonia process. In this case, the route to methanol is to react the CO2 with methane and steam over a nickel catalyst to give additional CO and H2 and then proceed to combine these to make methanol ... [Pg.177]

To demonstrate the accurate approximation approach for parameter estimation, we summarize a case study presented in Vasantharajan and Biegler (1990). Ammonia synthesis performed in a Haber-Bosch reactor is operated at high pressures in an autothermal manner, and produces ammonia from the following catalyzed reaction N2 -t- 3H202NH3. [Pg.226]

The reasoning which led the author to make this first shot in the dark regarding the usefulness of combinations of solid compounds as ammonia catalysts was as follows If we assume that a labile iron nitride is an interminate in the catalytic ammonia synthesis, every addition to the iron which favors the formation of the iron nitride ought to be of advantage. In other words, the hypothesis was used that surface catalysis acts via the formation of intermediate compounds between the catalyst and one or more of the reactants. An experimental support for this theory was the fact that a stepwise synthesis via the formation and successive hydrogen reduction of nitrides had been carried out with calcium nitrides (Haber), and cerium nitrides (Lipski). Later, the author found molybdenum nitride as being the best intermediate for such a stepwise synthesis. [Pg.87]

To conclude, it is worth recording the advice given to the author at the very start of his career by the veteran catalytic chemist Alwin Mittasch, who had been Fritz Haber s officer in charge of catalyst research for the ammonia synthesis In all catalytic studies only the very purest is good enough . [Pg.132]

Reactions which may occur on sites consisting of one or two atoms only on the surface of the catalyst are generally known as facile reactions. Reactions involving hydrogenation on metals are an example. Eor such reactions, the state of dispersion or preparation methods do not greatly affect the specific activity of a catalyst. In contrast, reactions in which some crystal faces are much more active than others are called structure sensitive. An example is ammonia synthesis (discovered by Fritz Haber in 1909 (Moeller 1952)) over Fe catalysts where (111) Fe surface is found to be more active than others (Boudart 1981). Structure-sensitive reactions thus require sites with special crystal structure features, which... [Pg.152]

Reduction in price of raw material (nitric acid) by the commercialization of the Haber-Bosch process for ammonia synthesis. [Pg.38]


See other pages where Haber ammonia synthesis is mentioned: [Pg.3]    [Pg.107]    [Pg.20]    [Pg.3]    [Pg.107]    [Pg.20]    [Pg.277]    [Pg.164]    [Pg.216]    [Pg.84]    [Pg.339]    [Pg.183]    [Pg.273]    [Pg.682]    [Pg.510]    [Pg.23]    [Pg.24]    [Pg.10]    [Pg.76]    [Pg.35]    [Pg.326]    [Pg.39]    [Pg.272]    [Pg.275]    [Pg.112]    [Pg.106]    [Pg.408]    [Pg.86]    [Pg.51]    [Pg.28]    [Pg.297]   
See also in sourсe #XX -- [ Pg.168 ]




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