Ammonia production economics

Ammonia production. Economic data (Fiance conditions, mid-1986)... 

The importance of size on the economics of ammonia production can be seen from Figure 3-1 and Table 3-4, which was developed in 1967 by G. Russell James, general manager of Chemical Engineering Associates (Armonk, N.Y.)4 Before 1969, a 400-tons-per-day plant was large. Now it can barely compete even if it is updated technologically. 

Researchers returned to the oxidation of ammonia in air, (recorded as early as 1798) in an effort to improve production economics. In 1901 Wilhelm Ostwald had first achieved the catalytic oxidation of ammonia over a platinum catalyst. The gaseous nitrogen oxides produced could be easily cooled and dissolved in water to produce a solution of nitric acid. This achievement began the search for an economic process route. By 1908 the first commercial facility for production of nitric acid, using this new catalytic oxidation process, was commissioned near Bochum in Germany. The Haber-Bosch ammonia synthesis process came into operation in 1913, leading to the continued development and assured future of the ammonia oxidation process for the production of nitric acid. 

Galvez M. E. Halmann M. Steinfeld A. Ammonia production via a two-step A1203/A1N thermochemical cycle. 1. Thermodynamic, environmental, and economic analyses. Ind. 

Since no economical nitrogen fixation process that starts with nitrogen oxides has been discovered, ammonia has developed into the most important building block for synthetic nitrogen products worldwide. Prior to World War II, ammonia production capacity remained relatively stable. But during the war the need for explosives caused an increase in the production of ammonia for nitric acid manufacture. Then, after the war, the ammonia plants were used to manufacture fertilizers. As a result, there was a rapid increase in fertilizer consumption. The advantages of fertilizers were emphasized, and production capacity increased by leaps and bounds. 

The Selectoxo unit can also help in a grass root plant by maintaining carbon dioxide/ammonia production ratios which is favorable for full conversion of ammonia to urea. The economics of this option are to be considered against the extra cost of carbon dioxide production by other means (either from the flue gas of the primary reformer or through back burning of extra synthesis gas)202. 

The removal of ammonia product is accomplished via mechanical refrigeration or absorption / distillation. The choice is made by examining the fixed and operating costs. Typically, refrigeration is more economical at synthesis pressures of 100 atmospheres (1470 psia) or greater. At lower pressures, absorption/distillation is usually favored. The two methods are compared in Table 6.5212. 

In the mid-1990 s the ammonia industry accounted for about 5% of the worldwide natural gas consumption. For economic and environmental reasons, natural gas is the feedstock of choice. However, processes for ammonia production can use a wide range of energy sources. For example, in 2001 60% of China s nitrogen fertilizer production was based on coal. In 2002 natural gas is the most economic feedstock for the production of ammonia as shown in Table 6.736. 

Corneil, H.G., Heinzelmann, F.J. and Nicholson, W.S., "Production Economics for Hydrogen Ammonia and Methanol During the 1980-2000 Period," Exxon Research Engineering Company Report No. BNL-50663, Linden, New Jersey, April 1977. 

Hydrogen for Ammonia Production and the Economics of Alternate Feedstocks... 

This paper analyzes the sources of hydrogen for ammonia production, presents the feed and fuel requirements of the natural gas steam reforming process, estimates the relative economics of alternate feedstocks and briefly discusses the outlook for the ammonia industry. 

Therefore, it is not surprising that currently about 70% of the world ammonia capacity is based on obtaining hydrogen from natural gas reforming. Of course, the economic analysis of various raw materials used for ammonia production is not complete without considering their relative price and availability which could ultimately dictate the choice for a particular feed. 

Production Economics For Hydrogen, Ammonia And Methanol During The 1980-2000 Period, Exxon Research and Engineering Company, Government Research Contract No. 368150-S April 1977, Appendix A by Chem Systems Inc.", Cost of Production Estimates For Hydrogen, Ammonia And Methanol, October 21, 1976, P. 127-166. 

Waitzman, D. A., "A Technical And Economic Review Of Coal-Based Ammonia Production", Proceedings of The 27th Annual Meeting Fertilizer Industry Round Table, 1977,... 

Thus, although hydrogen is used in methanol production, it can be taken straight from the steam-hydrocarbon reformer and does not require further purification and treatment as in the case of pure hydrogen production or ammonia production. The economics of methanol production are significantly affected by the thermal integration of the reformer (or other gas generation unit) with the rest of the plant. 

TABLE 22.4 Feedstock Economics for Ammonia Production Relative Consumptions and Economics for Different Feedstocks... 

Natural gas is by far the most economical feedstock for ammonia production, achieving the lowest energy consumption and requiring the lowest investment [404], This can also be seen from Table 45, which gives an estimate of ammonia production costs in Northwest Europe for different feedstocks using state-of-the-art technological standards. The lump turn key price for the ammonia plant were assumed as 180 x 106 for steam reforming of natural gas, 270 x 106 for partial oxidation of vacuum residue and 400 x 106 for coal-based plants (Capacity 1800 mt/d). 

Due to the large capacities of modem ammonia production lines (>1200 MTPD), small improvements in the performance of the production line result in large economic benefits (e.g. it was estimated recently that 1% increase in the ammonia concentration in the effluent of the ammonia converter with a capacity of 1200 MTPD will have a dollar value of 1.2x10 US /year (Elnashaie et al., 1988b). Mathematical models are very powerful tools for the accurate design. 

Goodman, D. R, Catalysis in ammonia production. The economics of catalyst operation. The Chem. 

Hydrogen conversion is again of prime importance in nitrogen fixation to ammonia by N-ases,47,48 and can be at least partially understood in terms of inorganometallic chemistry. Massive research efforts6,7, 0 49 52 have attempted to model the structure and function of N-ase for ammonia production. Billions of tons of NH3 are produced annually worldwide by the Haber process, which actually is efficient and cheap (any major improvement is now recognized to be unlikely, at least from an economic standpoint). 

As part of the Manhattan District Project during World War II, a small plant to produce heavy water 6 Mg/a) was built by Standard Oil Development Co. at Trail, B.C. and was operated by Cominco from 1944 to 1956 (14). It was based on steam-hydrogen catalytic exchange plus steam-water equilibration coupled to water electrolysis. However, byproduct heavy water from this process is economic only if the electrolysis cost is borne by the hydrogen product, which at Trail was used for ammonia production. In any case, the small scale of operation imposed by electrolytic capacity and the large exchange tower volume have made this production method economically unattractive. 

---