Ammonia fertilizers

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. 

Carbon dioxide is sometimes added to irrigation water, in the same manner as fertilizer ammonia, in hard water regions. Carbon dioxide is also used with other gases in treating respiratory problems and in anesthesia. 

NH3. Ammonia is a colorless gas. It is a strong base, forms hydrogen bonds, is soluble in water, and is a fairly reactive molecule. Each year 12.4 million metric tons are manufactured by the Haber process (N2 + 3H2 2NH3 at 400°C and 250 atm), principally for nitric acid production, which is then used to make fertilizers and explosives. As a fertilizer, ammonia can be utilized in three ways first by direct injection... 

The production of nitrogen fertilizers is a major activity of the chemical industry. Every year, the top 15 chemicals in industrial production in the United States include several nitrogen-containing compounds whose major use is in fertilizers. Molecular nitrogen serves as the primary source of nitrogen for chemical production. Gaseous ammonia (NH3), which is synthesized from N2 and H2, can be injected directly into the ground, where it dissolves in moisture in the soil and serves as a fertilizer. Ammonia is more widely used in reactions with acids to produce other fertilizers Ammonia and nitric acid produce ammonium nitrate (NIL) NO3), while ammonia and sulfuric acid produce ammonium sulfate. These chemicals and urea,... 

Fertilizers - [AMMONIA] (Vol2) -in bioremediation piOREMEDIATION] (Supplement) -blended [POTASSIUM COMPOUNDS] (Vol 19) -boron in [BORON COMPOUNDS - BORON OXIDES, BORIC ACID AND BORATES] (Vol 4) -cyanamidein [CYANAMIDES] (Vol 7) -lecithin in [LECITHIN] (Vol 15) -molybdenum compounds m [MOLYBDENUM AND COMPOUNDS] (Vol 16) -nitric acid m mfg [NITRIC ACID] (Vol 17) -potassium hydroxide mmfg of [POTASSIUM COMPOUNDS] (Vol 19) -radioactive tracers for [RADIOACTIVE TRACERS] (Vol 20) -role of H2 m production of [HYDROGEN] (Vol 13) -specialty liquid [POTASSIUM COMPOUNDS] (Vol 19) -tanks for [TANKS AND PRESSURE VESSELS] (Vol 23) -use of diatomite m [DIATOMITE] (Vol 8) -use of sulfur for [SULFUR] (Vol 23)... 

Ammonia Ammonia and its synthesis by the Haber process serve as the gateway to nitrogen chemistry because ammonia is the starting material for the industrial synthesis of other important nitrogen compounds, such as nitric acid. Used in agriculture as a fertilizer, ammonia is the most commercially important compound of nitrogen. 

Ammonia and some of its salts and derivatives are used as fertilizers. Ammonia also is a very important building block for many other chemical commodities as shown in Figure 2.2. 

In the Minifos process of Fisons (now Hydro Fertilizers), ammonia and phosphoric acid (45 - 54 % P2O5) react at 0.21 MPa to give an N/P ratio of 1 (see Figure 12.2). The liquid product is flash-sprayed in a natural-draught tower, where the droplets solidify to form a powder with 6% to 8% residual moisture296. 

For years, the liquefied petroleum gas (LPG) industry has used pressurized underground liquefied gas storage. This technique has been applied to ammonia also. DuPont has operated a rock cavern in the United States with a capacity of 20 0001. Norsk Hydro has one in Norway at 50 000 t. Because of the contaminants occurring in liquid ammonia stored this way and the lack of suitable construction sites, no further storage facilities of this kind have been built for a long time. Underground fertilizer ammonia storage was planned in Russia [1310]. 

In 1997 about 85% of ammonia production was consumed for fertilizers. Ammonia is either converted into solid fertilizers (urea ammonium nitrate, phosphate, sulfate) or directly applied to arable soil. 

Ammonia is an important primary inorganic material. 85% of the worldwide production is utilized in the manufacture of synthetic fertilizers. Ammonia production therefore represents an indicator of the size of the fertilizer industry in a particular country. 

Water supply to the plant is either ground water (wells), surface water (lakes, rivers), or city water. Raw water is typically contaminated with salts, oils, various organic substances, calcium, clay, silica, magnesium, manganese, aluminum, sulfate, fertilizers, ammonia, insecticides, carbon dioxide and, of course, bacteria and pyrogens. A city water treatment plant removes most of these impurities, but adds chlorine or chloramines and fluoride. Table 1 summarizes the level of contaminants by type of raw water. 

The largest and most significant use of ammonia and ammonium compounds is the agricultural application of fertilizers. Ammonia and ammonium compounds used as fertilizer represent 89% of the commercially produced ammonia, with plastics, synthetic fibers and resins, explosives, and other uses accounting for most of the remainder (Kramer 2002). Direct uses of ammonia as fertilizer can be broken down into the following categories anhydrous ammonia, 30% urea/ammonium nitrate solutions, 24% urea, 17.5% ammonium nitrate, 5% ammonium sulfate, 2% other forms, 2.5% and multiple nutrient forms, 19% (Kramer 2000). Most ammonium compounds and nitric acid, which are produced from anhydrous ammonia, are used directly in the production of fertilizers. 

Aluminium in soils is closely connected to soil acidity and is also discussed in the chapters on acid soils and ion-water reactions. The acidity of acid soils is due to the reactions of water with exchangeable Al3+ on the surface of soil particles. The strong Al-water reaction repels H+ from the water molecules iuto the soil solution. This can create soil acidities as low as pH 4.5. Stronger acidity means other H+-yielding reactions—organic acids from soil organic matter decay, sulfur and sulfide oxidation, phosphate fertilizers, ammonia oxidation, acid rain, and Fe- and Mn-water reactions—are active. 

Reconstruction of the Japanese chemical industry began with the chemical fertilizer (ammonia sulfate) industry, with the government supporting the basic chemical industries such as ammonia, carbide, and sulfuric acid. During the establishment of these basic industries, chemical engineering unit operations provided the technical basis for this industrialization. 

Inorganic fertilizer is often synthesized using the Haber-Boseh proeess, whieh produees ammonia as the end produet. This ammonia is used as a feedstoek for other nitrogen fertilizers, sueh as anhydrous ammonium nitrate and urea. These eoneentrated produets may be diluted with water to form a eoneentrated liquid fertilizer. Ammonia ean be eombined with roek phosphate and potassium fertilizer in the Odda Process to produee eompound fertilizer. 

In addition to their use as fertilizers, ammonia and urea are used as a source of protein in ruminant livestock feeds. Urea is used in mixed feed supplements to supply the nitrogen needed for the biosynthesis of proteins by the microorganisms in ruminating animals such as cattle, sheep, and goats. 

Ammonia is also produced in ammonia plants as a raw material for the manufacture of urea and other nitrogen-based fertilizers. Ammonia in synthesis gas at temperatures between 450 and 500 °C causes nitridation of steel components. When synthesis gas is compressed to up to 34.5 MPa (5000 psig) prior to conversion, corrosive ammonium carbonate is formed, requiring various stainless steels for critical components. Condensed ammonia is also corrosive and can cause stress corrosion cracking (SCC) of stressed carbon steel and low-alloy steel components. 

---