Ammonia synthesis process development

Claude (1) Also called Claude-Casale. A high-pressure ammonia synthesis process, developed by G. Claude in the 1920s. 

LEAD An integrated ammonia synthesis process, developed by Humphreys Glasgow. 

Purifier An ammonia synthesis process, developed C.F. Braun and now licensed by Kellog Brown and Root. An important feature is the cryogenic removal of inert gases from the system. Seventeen plants were operating in 2005. 

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. 

The BYAS (Bypass Ammonia Synthesis) process can be used for economical expansion of existing ammonia synthesis plants. This process introduces additional natural gas at an intermediate stage in the process. The additional nitrogen in the air, which also has to be introduced, is removed by PSA (pressure swing absorption). The process was developed and offered by Humphreys and Glasgow in the UK1. 

The development of a practical ammonia synthesis process in the early years of the twentieth century was a profound scientific achievement of great social significance in view of the subsequent dependence of the world on fertilizer for support of its growing population. 

The thermodynamic equilibrium is most favourable at high pressure and low temperature. The methanol synthesis process was developed at the same time as NH3 synthesis. In the development of a commercial process for NH3 synthesis it was observed that, depending on the catalyst and reaction conditions, oxygenated products were formed as well. Compared with ammonia synthesis, catalyst development for methanol synthesis was more difficult because selectivity is crucial besides activity. In the CO hydrogenation other products can be formed, such as higher alcohols and hydrocarbons that are thermodynamically favoured. Figure 2.19 illustrates this. 

Dual Pressure An ammonia synthesis process, based on the AMV process but providing more capacity by removing some of the product at an intermediate stage. Developed by Krupp Uhde in 2001-2002. 

LCA [Leading Concept for Ammonia, formerly Low-Cost Ammonia] A process for making ammonia from air and natural gas. Essentially a simplified form of the standard ammonia synthesis process, more suitable for smaller plants. Thermal economies are achieved in the steam reforming section. Developed by ICI from 1985 to 1988. Two units began operating at the ICI plant in Severnside, UK, in 1988. The first non-ICI installation was designed by KTI for Mississippi Chemicals, Yazoo City, MS. The name appears to be no longer used. 

Process technology and chemical engineering as we understand it today began with the successful realization of the technical ammonia synthesis. Continuous production with high space velocities and space yields combined with the ammonia oxidation process developed immediately thereafter enabled chemical industry for the first time to compete successfully with a cheap natural bulk product, namely, sodium nitrate from Chile. The synthesis of ammonia thus became exemplary for all subsequent chemical mass production processes. 

Reaction engineers are expected to transform laboratory discoveries of new synthesis routes or design concepts into economic, safe, and environmentally compatible processes. The highly competitive industrial environment has added the need to shorten the time interval in which this task has to be completed and to decrease the production price. This motivated several innovations. The first was development of novel catalysts, which increased the yield in existing processes, such as the novel Kellogg ammonia-synthesis process, which uses the much more active BP catalyst. Other catalysts were designed to provide either new synthesis routes, such as the production of synthesis gas by direct oxidation, or new products, such as production of novel polymers by metallocene catalysts. 

In 1986, Zhejiang University of Technology made an important breakthrough on iron catalyst, invented a novel Fei j 0 based catalyst system.In 1992, the first Fei a 0 based catalyst (A301) at low temperatures and pressures was successfully developed, which was superior to the best magnetite-based catalysts in the world. In 1998, they further developed ZA-5 catalyst, and the running temperature was further decreased, which established the technical foundation for low pressure ammonia synthesis process. 

Layered vessels were developed in the United States and Germany at about the same time during World War II. In Germany they were used in ammonia plants as well as for producing gasoline from coal. In the United States they were used for ammonia-synthesis processes for the ultimate production of nitrates. Since... 

In the United States, a subsidiary of the DuPont Company, Lazote, Inc., made synthetic methanol at Belle, West Virginia. The Belle operation was part of the ammonia plant at the site. The methanol production was actually a step in the ammonia process for removing carbon monoxide, which was an impurity in the ammonia synthesis gas. Commercial Solvents was the first to employ the high-pressure synthesis process, developed by BASF, in the United States. The plant, located in Peoria, lUinois, began operation a few months after the Lazote plant at Belle. The Commercial Solvents plant used an off-gas from a fermentation operation. The off-gas contained carbon dioxide and hydrogen from the production of butanol from corn. This first of a kind plant in the United States was rated at about 4000 t per year. 

Over 95 percent of the 11 million tons of nitrogen supplied to U.S. farmers yearly in commercial fertilizers originates as synthetic ammonia made from air, water, and either a petroleum-based hydrocarbon or coal. The development of a practical ammonia synthesis process in the early years of the twentieth century was a profound scientific achievement of great social significance, in view of the subsequent dependence of the world on fertilizer for support of its growing population. 

The Haber-Bosch ammonia synthesis process led to similar developments in other European countries and the US. As a result, many other commercial processes were being operated during the 1920s. Production rates were very small compared with modem plants but an extremely wide range of operating conditions was introduced together with a number of different catalysts. Despite these initial differences, most plants built in recent years still operate with more or less the same conditions as those chosen for the first BASF process. Some of the early ammonia processes are listed in Table 10.3. 

The ammonium chloride process, developed by Asahi Glass, is a variation of the basic Solvay process (9—11). It requires the use of soHd sodium chloride but obtains higher sodium conversions (+90%) than does the Solvay process. This is especially important ia Japan, where salt is imported as a soHd. The major difference from the Solvay process is that here the ammonium chloride produced is crystallized by cooling and through the addition of soHd sodium chloride. The resulting mother Hquor is then recycled to dissolve additional sodium chloride. The ammonium chloride is removed for use as rice paddy fertilizer. Ammonia makeup is generally suppHed by an associated synthesis plant. 

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