Nitrogen ammonia production from

Appl, Dr. M., "A Brief History of Ammonia Production From The Early Days To The Present", Nitrogen, 100, 47-58 (1976). 

So now we have established that chemical reactions are dynamic and reversible, and, as a result, chemical reactions are an equilibrium mixture of reactants and products. We have also seen that sometimes the reaction strongly favors the products (as in reacting gunpowder) and sometimes the reaction strongly favors the reactants (as in Haber s ammonia synthesis from nitrogen and hydrogen). We haven t answered one question. 

Up until 1913, the bulk of the world s artihcial nitrogenous fertilizers was made from sodium nitrate obtained from Chile. Calculations showed that this supply would soon be exhausted if demand continued to expand, and so Fritz Haber (1868-1934) attempted to make ammonia directly from nitrogen and hydrogen gases. After 8 years, Haber produced ammonia efficiently on a small scale. Collaboration with the brilliant chemical engineer Carl Bosch (1874—1940) enabled the production to be scaled up, and ammonia was first manufactured on a large scale in 1913. The world s production of ammonia now exceeds 100 million tonnes. About 80% of all ammonia produced is used to make fertilizers with another 5% being used to make nylon, and a further 5% used to make explosives. 

AppI, Max. 1976. A Brief History of Ammonia Production from the Early Days to the Present, Nitrogen, 100 47-58. 

In 1912 the German chemist Fritz Haber (1868-1934) developed a process for S5nthesizing ammonia directly from nitrogen and hydrogen (Figure 15.4 ). The process is sometimes called the Haber-Bosch process to also honor Karl Bosch, the engineer who developed the equipment for the industrial production of ammonia. The engineering needed to implement the Haber process requires the use of temperatures and pressures (approximately 500°C and 200 atm) that were difficult to achieve at that time. 

The industrial-scale availability of nitrogen and hydrogen at the turn of the 19th to the 20th century enabled a host of new applications. The BASF company, for example, succeeded in developing an ammonia synthesis from nitrogen and hydrogen in 1913. This paved the way for mass production of fertilisers. 

In commercial applications diverse catalyst types can be used. For example, the production of ammonia, NH, from nitrogen and hydrogen through the Haber process, uses a heterogeneous catalyst based on Fe on SiO or AI2O3 support as shown in Equation 6.71. 

Appl, M. 1976. A brief history of ammonia production from the early days to the present. Nitrogen 100 51 Nagel et al. (5), p. 52. 

The reason for the popularity of anhydrous ammonia is its economy. No further processing is needed and it has a very high (82.2%) nitrogen content. Additionally if held under pressure or refrigerated, ammonia is a Hquid. Being a Hquid, pipeline transport is practical and economical. A network of overland pipelines (Fig. 4) is in operation in the United States to move anhydrous ammonia economically from points of production near natural gas sources to points of utilization in farming areas (see Pipelines). 

Coal is expected to be the best domestic feedstock alternative to natural gas. Although coal-based ammonia plants have been built elsewhere, there is no such plant in the United States. Pilot-scale projects have demonstrated effective ammonia-from-coal technology (102). The cost of ammonia production can be anticipated to increase, lea ding to increases in the cost of producing nitrogen fertilizers. 

Ammonia production by partial oxidation of hydrocarbon feeds depends to some degree on the gasification step. The clean raw synthesis gas from a Shell partial oxidation system is first treated for sulfur removal, then passed through shift conversion. A Hquid nitrogen scmbbiag step follows. 

Recovering ammonia as a by-product from other processes accounted for less than 1% of the total U.S. ammonia production in 1987. The principal source of by-product ammonia is from the coking of coal. In the coking operation, about 15—20% of the nitrogen present in the coal is Hberated as ammonia and is recovered from the coke oven gas as ammonium sulfate, ammonia Hquor, and ammonium phosphates. The recovery product depends on the scmbbing medium employed, sulfuric acid, milk of lime, and phosphoric acid, respectively. Ammonium sulfate recovery by the so-called semidirect process, is most widely employed. 

Direct synthesis from nitrogen and finely divided titanium metal can be achieved at temperatures of >ca 1200° C (4). Typically, titanium sponge or powder is heated in an ammonia- or nitrogen-filled furnace and the product is subsequently milled and classified. 

The interest in gaseous losses of nitrogen from soil is now extensive and includes the well established community of soil scientists concerned with losses of fertilizer-applied nitrogen by nitrification and denitrification. More recently, interest in ammonia losses from plants and soil has been stimulated by the very large emissions from intensive cattle production in the Netherlands and their... 

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