Industrial processes Haber process

Nitrogen is a diatomic molecule, which is effectively triple-bonded and has a high dissociation energy (940 kj mol" ). It is therefore inert and it only reacts readily with lithium and other highly electropositive elements. The direct combination of nitrogen and hydrogen occurs at elevated temperatures and pressures (400-600°C, 100 atmospheres) and is the basis of the industrially important Haber process for the manufacture of ammonia. 

Hnman-indnced N-fixation— For about 60 years mankind has used industrial processes (Haber-Bosch) to form ammonia through the combination of hydrogen and atmospheric nitrogen under high pressure and temperature. Globally, industrial N-fixation through fertilizer... 

Although the left to right reaction is exothermic, hence giving a better equilibrium yield of sulphur trioxide at low temperatures, the reaction is carried out industrially at about 670-720 K. Furthermore, a better yield would be obtained at high pressure, but extra cost of plant does not apparently justify this. Thus the conditions are based on economic rather than theoretical grounds (cf Haber process). 

Industrially, production is either from the Haber process at high pressure ... 

F. Haber s catalytic synthesis of NH3 developed in collaboration with C. Bosch into a large-scale industrial process by 1913. (Hater was awarded the 1918 Nobel Prize in Chemistry for the synthesis of ammonia from its elements Bosch shared the 1931 Nobel Prize for contributions to the invention and development of chemical high-pressure methods , the Hater synthesis of NH3 being the first high-pressure industrial process.)... 

It is estimated that each year approximately 150 million tonnes of nitrogen are fixed biologically compared to 120 million tonnes fixed industrially by the Haber process (p. 421). In both cases N2 is converted to NH3, requiring the rupture of the N=N triple bond which has the highest dissociation energy (945.41 kJmol )... 

Ammonia is one of the most important industrial chemicals more than ten million tons of NH3 are produced annually in the United States. You will recall (Chapter 12) that it is made by the Haber process... 

Haber process An industrial process used to make ammonia from the elements, 342-343,559-560... 

In an important industrial process for producing ammonia (the Haber Process) the overall reaction is... 

The Haber process for the synthesis of ammonia is one of the most significant industrial processes for the well-being of humanity. It is used extensively in the production of fertilizers as well as polymers and other products, (a) What volume of hydrogen at 15.00 atm and 350.°C must be supplied to produce 1.0 tonne (1 t = 10 kg) of NH3 (b) What volume of hydrogen is needed in part (a) if it is supplied at 376 atm and 250.°C ... 

Each year, about half the 3 X 108 kg of hydrogen used in industry is converted into ammonia by the Haber process (Section 9.12). Through the reactions of ammonia, hydrogen finds its way into numerous other important nitrogen compounds such as hydrazine and sodium amide (see Section 15.2). 

As an example, consider the industrial synthesis of ammonia (NH3). Ammonia is made by the Haber process, a single chemical reaction between molecules of hydrogen (H2) and nitrogen (N2) Although it is simple, this synthesis has immense industrial importance. The United States produces more than 16 billion kilograms of ammonia annually. 

C04-0069. Most of the ammonia produced by the Haber process is used as fertilizer. A second important use of NH3 is in the production of nitric acid, a top-15 industrial chemical. Nitric acid is produced by... 

C04-0074. Ammonia is produced industrially using the Haber process N2 + 3 H2 2 NH3 Suppose that an industrial reactor is charged with 75.0 kg each of N2 and H2. Use a table of amounts to determine what mass of ammonia could be produced if the reaction went to completion. 

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. 

Bosch also helped develop Haber s process into an industrial process. In 1913, Haber and Bosch opened an ammonia manufacturing plant in Germany. A year later, World War I started. Saltpeter had another use besides making fertilizer. It was also necessary to make nitric acid that was used to make explosives. When the war started, the British Navy quickly cut off Germany s supply of Chilean saltpeter. If not for the Haber process, some historians estimate that Germany would have run out of nitrates to make explosives by 1916. The war lasted another two years, however, because Germany did not need to rely on outside sources of nitrates for fertilizers or explosives. 

What is the best set of temperature and pressure conditions for the Haber process—the industrial process to convert hydrogen and nitrogen to ammonia ... 

The Haber process is the economically important industrial process for making ammonia, NH3, from... 

The conditions used industrially for the Haber process are those that sustain the economic viability of its manufacture. Out of necessity, a high yield in a long time must be balanced against a low yield in a shorter time, whilst minimising energy costs. The conditions employed indicate a compromise between these opposing outcomes, as the graphs illustrate. 

Karl Bosch (1874-1940) and Alwin Mittasch (1869-1953) of Badische Anilin- und Soda-Fabrik eliminated the nitrate shortage that occurred after the British sea blockade effectively cut off the nitrate supply from Chile. By May of 1915, they had successfully developed at their Oppau Plant an industrial-scale process for oxidizing ammonia. Their process converted the large quantities of synthetic ammonia produced by the Haber process to nitric acid and other nitrates that were essential for fertilizers and explosives. (10)... 

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]. 

The discoveries of M. Sabatier with regard to the conversion of olein and other unsaturated fats and their corresponding acids into stearin or stearic acid have created an enormous demand for hydrogen in every industrial country the synthetic production of ammonia by the Haber process has produced another industry with g eat hydrogen requirements, while the Great War has, through the development of the kite balloon and airship, made requirements for hydrogen in excess of the two previously mentioned industries combined. 

In this chapter, you learned about the Haber process for manufacturing ammonia. You used this process to help you understand various concepts related to equilibrium. As you can see in Figure 7.11, ammonia is a valuable industrial chemical. Its annual global production is well over 100 million tonnes. The vast majority of ammonia, roughly 80%, is used to make fertilizers. You will now examine how the equilibrium concepts you have been studying work together to provide society with a reliable, cost-effective supply of ammonia. 

Transition metals and their compounds are used as catalysts. Catalysts you may already know are Iron In the Haber process (Industrial production of ammonia) platinum in the Ostwald process (Industrial production of nitric acid) and platinum, rhodium and palladium In catalytic converters. 

With the technical development achieved in the last 30 years, pressure has become a common variable in several chemical and biochemical laboratories. In addition to temperature, concentration, pH, solvent, ionic strength, etc., it helps provide a better understanding of structures and reactions in chemical, biochemical, catalytic-mechanistic studies and industrial applications. Two of the first industrial examples of the effect of pressure on reactions are the Haber process for the synthesis of ammonia and the conversion of carbon to diamond. The production of NH3 and synthetic diamonds illustrate completely different fields of use of high pressures the first application concerns reactions involving pressurized gases and the second deals with the effect of very high hydrostatic pressure on chemical reactions. High pressure analytical techniques have been developed for the majority of the physicochemical methods (spectroscopies e. g. NMR, IR, UV-visible and electrochemistry, flow methods, etc.). 

Another important application of iron is as an industrial catalyst. It is used in catalyst compositions in the Haber process for synthesis of ammonia, and in Fischer-Tropsch process for producing synthetic gasoline. 

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