Haber process hydrazine from


This reaction is an undesirable side reaction in the manufacture of hydrogen but utilised as a means of removing traces of carbon monoxide left at the end of the second stage reaction. The gases are passed over a nickel catalyst at 450 K when traces of carbon monoxide form methane. (Methane does not poison the catalyst in the Haber process -carbon monoxide Joes.)  [c.181]

Let us consider the formation of sodium chloride from its elements. An energy (enthalpy) diagram (called a Born-Haber cycle) for the reaction of sodium and chlorine is given in Figure 3.7. (As in the energy diagram for the formation of hydrogen chloride, an upward arrow represents an endothermic process and a downward arrow an exothermic process.)  [c.73]

In the original Haber-Bosch process, the hydrogen source was coke derived from coal. In this process, shown in Figure 5, coke is first blasted with air and the heat Hberated by the formation of carbon dioxide raises the coke to incandescence. The products of combustion leave the system by going to the atmosphere. Steam is added next to produce water gas containing carbon dioxide, carbon monoxide, and hydrogen. The nitrogen is usually furnished by adding a sufficient quantity of the combustion products from the blasting step to the gas stream. Dust particles and undecomposed steam are then removed by water scmbbing. A gas holder provides storage. The carbon monoxide in the gas is converted to hydrogen and carbon dioxide by reaction with steam over a catalyst and the converted gas is stored in another gas holder, compressed, and the carbon dioxide removed by water scmbbing. The gas is then compressed and scmbbed using an ammoniacal cuprous solution to remove unconverted carbon monoxide. The resultant, relatively pure gas, consisting of three parts hydrogen to one part nitrogen, is then fed as makeup gas to the synthesis loop.  [c.341]

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.  [c.161]

Cryogenic processes using turboexpanders facilitate high levels of ethylene recovery from refinery gas while producing byproducts of hydrogen- and methane-rich gas. In a cryogenic process, most of the ethylene and almost all of the heavier components are liquified and ethylene is separated from this liquid.  [c.58]

When two light elements collide with sufficient energy they may "fuse" and form a third, heavier, element, A simple mass balance would show that there is a small mass loss in this process, corresponding to a significant energy release. Many light elements can undergo exothermic fusion reactions, but fusion of the isotopes of hydrogen and helium are the easiest reactions to induce. The most probable fusion reactions and their released energies are  [c.389]

Nearly all the fractions produced by the processes mentioned above contain certain objectionable eonstituents or impurities. The third basic category is, therefore, treating. This group of processes includes the removal of the unwanted components, or their conversion to innocuous or less undesirable compoimds. Removal of the impurities is sometimes accomplished by physical treating, as exemplified by the process for manufacturing kerosene, wherein sulfur and certain undesirable hydrocarbons are removed by extraction with liquid sulfur dioxide. Alternatively, the removal may be carried out by converting the unwanted compounds to a form more readily removed as is done in the hydrodesulfurization of diesel fuel. Here the sulfur compounds are cracked and hydrogenated. The sulfur is converted to hydrogen sulfide which can be readily separated from the heavier diesel oil by fractionation. An example of the eonversion of undesirable components to innocuous compounds which remain in the product is found in the gasoline sweetening processes. There the mercaptans present give the produet a foul, objectionable odor. The sweetening proeess  [c.2]

It now seems likely that the 5 stable isotopes Li, Li, Be, B and "B are formed predominantly by spallation reactions (i.e. fragmentation) effected by galactic cosmic-ray bombardment (the x-process). Cosmic rays consist of a wide variety of atomic particles moving through the galaxy at relativistic velocities. Nuclei ranging from hydrogen to uranium have been detected in cosmic rays though ll and " He are by far the most abundant components f H 500 Hc 40 all particles with atomic numbers from 3 to 9 5 all particles with Z > 10 1]. However, there is a striking deviation from stellar abundances since Li, Be and B are vastly over abundant as are Sc, Ti, V and Cr (immediately preceding the abundance peak near iron). The simplest interpretation of these facts is that the (heavier) particles comprising cosmic rays, travelling as they do great distances in the galaxy, occasionally collide with atoms of the interstellar gas (predominantly H and He) and thereby fragment. This fragmentation, or spallation as it  [c.14]

Quantities of middle distillates, such as diesel fuel, can be increased by several processes. Mild thermal cracking, a process known as visbreaking (viscosity breaking), breaks heavier molecules down with heat to reduce their viscosity. The heaviest fractions from the distillation towers can also be transformed using more severe conditions to crack heavy hydrocarbon molecules into lighter ones. Fluid catalytic cracking ( cat cracking ) uses intense heat, low pressure, and a catalytic substance to accelerate these thermal reactions. Hydrocracking employs a different catalyst, slightly lower temperatures, much greater pressure, and a hydrogen atmosphere to convert heavy molecules.  [c.337]

The nuclear fusion of light elements powers the sun and other stars. The fusion process in stars and supernovas creates from primordial hydrogen heavier elements, including those needed for chemistry and life. Nuclear fusion is analogous to the chemical reaction of burning, such as the joining (fusing) of hydrogen and oxygen to produce water vapor and release energy. Both processes produce something new while releasing energy.  [c.871]

In the Haber process hydrogen /= and nitrogen are compressed to high pressure say, 50 MPa which is 7,250 psig (pounds per sq. inch gage). If a pipe is 6 in. i.d. and must not be stressed above 200 ksi (thousand pounds/ sq. in.), how thick must the wail be Answer From equation 9.1-2, t = p r/s = 7250 3/200E3 = 0.10 in.  [c.334]

Ammonia and Hydrogen Production. The earliest route for manufacture of ammonia from nitrogen was the cyanamide process commercialized in Italy in 1906. In this process calcium carbide manufactured from coal was treated with nitrogen at 1000°C to form calcium cyanamide, CaCN2. The cyanamide was hydrolyzed with water affording ammonia and calcium carbonate. Production reached 140,000 t/yr in Germany in 1915, but this process was energy intensive and soon was displaced by the more efficient Bosch-Haber process. This process was developed by BASE and commercialized in 1913 and involves the high pressure reaction of nitrogen and hydrogen over an iron catalyst. Most of the world s hydrogen production is used in ammonia synthesis by the Bosch-Haber process. The hydrogen for ammonia synthesis generally is obtained from synthesis gas produced by steam  [c.164]

In 1914, while abundant in the atmosphere, natural supplies of nitrogen in manure and in deposits of sodium nitrate were insufficient to meet the demand of war The solution was the Haber process for producing ammonia (NHj) by heating hydrogen and nitrogen gas at high pressure. Hydrogen is obtained by decomposing water (HjO) using heat or electricity. Burning coke and water produces steam, carbon monoxide, and hydrogen (water gas). Water gas reacts with steam and a catalyst to yield more hydrogen, and carbon dioxide which is removed by water dissolution. The mixture of carbon monoxide and hydrogen is the synthesis gas for methanol as shown in Figure 7.2-1. IS ihe source of ammonia and methanol. The hydrogen for ammonia is obtained from the water-gas sliifE reaction. Originally the process used coke from coal or lignite (brown coal), but the.se has been replaced by petroleum products and natural gas.  [c.265]

An even more effective homogeneous hydrogenation catalyst is the complex [RhClfPPhsfs] which permits rapid reduction of alkenes, alkynes and other unsaturated compounds in benzene solution at 25°C and 1 atm pressure (p. 1134). The Haber process, which uses iron metal catalysts for the direct synthesis of ammonia from nitrogen and hydrogen at high temperatures and pressures, is a further example (p. 421).  [c.43]

By placing a high electrical potential on an insulated electrode in the mist issuing from the inlet of the capillary tube, a plasma discharge can be struck. The spray of droplets passes through the plasma and electrons are stripped from neutral molecules such that the final yield of ions is greatly increased. Ionized molecules collide with neutral molecules, leading to hydrogen transfer and the formation of protonated molecular ions (as with chemical ionization). This process has led to the method known as atmospheric-pressure chemical ionization (APCI). Both solvent and solute (sample) ions are generated, but, as before, mostly only the heavier sample ions are extracted into the analyzer of the mass spectrometer. The addition of a plasma device turns thermospray into a much more sensitive inlet/ion source known as plasmaspray. This name is somewhat misleading in that the plasma does not cause the spray, which is still generated thermally.  [c.73]

Essentially all the processes employed for ammonia synthesis are variations of the Haber-Bosch process developed in Germany from 1904—1913. One of the all-time breakthroughs of chemical technology, the synthesis process involves the catalytic reaction of a purified hydrogen—nitrogen mixture under high (14 to 70 MPa (2,030 to 10,150 psi)) pressure and temperature (400 to 600°C). The preferred catalysts consist of specially activated iron. The ammonia that forms is condensed by cooling with Hquefied ammonia the unreacted gases are recycled to the synthesis loop. In over 80% of the ammonia plants of the 1990s, the hydrogen—nitrogen feed mixture is prepared by a series of reactions known as steam reforming, for which the raw materials are steam, natural gas (methane), and air. Commercial plants have also been based on use of naphtha or coal (coke) as feedstock. AH facets of ammonia production are highly sophisticated engineering processes requiring both a high level of technical know-how and a large capital investment.  [c.216]

As far as is known, nuclear fusion, which drives the stars, including the Sun, is the primary source of energy in the universe. The process of nuclear fusion releases enormous amounts of energy. It occurs when the nuclei of lighter elements, such as hydrogen, are fused together at extremely high temperatures and pressure to form heavier elements, such as helium. Whereas practical methods for harnessing fusion reactions and realising the potential of this energy source have been sought since the 1950s, achieving the benefits of power from fusion has proved to be a difficult, long-term challenge.  [c.150]

Because of the inherent stabiUty of the N2 molecule, high temperatures are often used to coax its reactivity. Temperature elevation promotes N2 reactions with chromium, siUcon, titanium, aluminum, boron, calcium, strontium, beryUium, magnesium, and lithium to form nitrides at 400°C, nitrogen reacts with oxygen and chlorine to form nitrosyl chloride at 900°C, graphite and sodium carbonate react with nitrogen to form carbon monoxide and sodium cyanide at 1500°C, nitrogen reacts with acetylene to form hydrogen cyanide. Also at high temperatures, N2 and O2 react to give NO. Arguably, the most important industrial process which utilizes N2 as a constituent is ammonia formation at high pressures from nitrogen and hydrogen in the presence of heat and a catalyst, known as the Haber-Bosch process (1,11)-  [c.74]

The value of nitrogen compounds as an ingredient of mineral fertilizers was recognized ia 1840. Nitrogen is an essential element to plant growth and ammonia is the primary nitrogen source used ia fertilizers (qv). Until the early 1900s, the nitrogen source ia farm soils was entirely derived from natural sources from mineral resources such as CtuleaQ nitrates, from manure and the putrefaction of vegetable wastes and from ammonium sulfate from coal coking, seed meals, sewage sludges, and food processiag by-products. The synthesis of ammonia directiy from hydrogen [1333-74-0] (qv) and nitrogen [7727-37-9] (qv) on a commercial scale was pioneered by Haber and Bosch ia 1913, for which they were awarded Nobel prizes. Further developments ia economical, large scale ammonia production for fertilizers have made a significant impact on iacreases ia the world s food supply.  [c.335]

Ammonium compounds were produced ia the 1890s on a large scale as by-product ammonium sulfate [7783-20-2] from coke oven gas. Coke oven gas also provided the feedstock for the Haber-Bosch process, the first technology to synthesize ammonia directiy from elemental hydrogen and nitrogen. The first commercial Haber-Bosch iastaHation went on stream ia 1913 at a Badische Anilin and Soda Fabtik (BASF) faciUty ia Ludwigshafen-Oppau, Germany. It had a design capacity of 30 metric tons per day. The successful commercialization of this process not only produced first-of-a-kiad high temperature and pressure equipment designs but also resulted ia the promoted iron catalyst which is essentially stiU used for ammonia synthesis.  [c.339]

The distillation cut points must be closely controlled to yield a product that meets the requirements of flash point on one hand and freezing point on the other. In practical terms, a jet fuel requires a fraction of about 60°C initial boiling point and a final boiling point not exceeding 300°C. The lighter portion of this fraction contains gasoline components and meets the specification for JP-4. The heavier portion above 160°C must be tailored to either the Jet A or Jet A1 freezing point, but the final boiling point is dependent on cmde composition. With higher aromatic cmdes, undercutting is required to meet compositional limits or a test such as smoke point. Lower boiling components compensate for aromatic or freezing point limitations, but sometimes it is impossible to take advantage of them because a dual-purpose kerosene usually requires a higher flash point than jet fuel. The distilled fractions from the cmde are apt to contain mercaptans or organic acids in excess of specification limits. A caustic wash is normally used to control acidity and to remove traces of hydrogen sulfide. Removal or conversion of odorous mercaptans is carried out in a sweetening process. The most widely used chemical treatment today, Merox sweetening, utilises dissolved air to oxidi2e mercaptans to disulfides over a fixed-bed cobalt chelate catalyst (5). It has the advantage of simplicity and minimum waste disposal problems but does not lower the sulfur content. A modern version of the old doctor process. Bender sweetening, uses lead plumbite deposited on a fixed bed to carry out the mercaptan oxidation and the spent doctor regeneration processes simultaneously, but product quahty is more difficult to control, and waste disposal problems are greater.  [c.410]


See pages that mention the term Haber process hydrazine from : [c.77]   
Chemistry of Petrochemical Processes (2000) -- [ c.148 ]