Ammonium sulfate fertilizer

Essentially all the ammonium sulfate fertilizer used in the United States is by-product material. By-product from the acid scmbbing of coke oven gas is one source. A larger source is as by-product ammonium sulfate solution from the production of caprolactam (qv) and acrylonitrile, (qv) which are synthetic fiber intermediates. A third but lesser source is from the ammoniation of spent sulfuric acid from other processes. In the recovery of by-product crystals from each of these sources, the crystallization usually is carried out in steam-heated sa turator—crystallizers. Characteristically, crystallizer product is of a particle size about 90% finer than 16 mesh (ca 1 mm dia), which is too small for satisfactory dry blending with granular fertilizer materials. Crystals of this size are suitable, however, as a feed material to mixed fertilizer granulation plants, and this is the main fertilizer outlet for by-product ammonium sulfate. 

Sulfur (qv) is among the most widely used chemicals and often considered to be one of the four basic raw materials of the chemical iadustry. In 1993, worldwide production of sulfur reached 55 million metric tons (1). Production of sulfuric acid consumes the vast majority (- 90%) of sulfur (2) (see Sulfuric acid and sulfur trioxide). This acid is a steppiag stone ia the production of other sulfur-containing compounds, most notably ammonium sulfate fertilizer which accounts for 60% of the total worldwide sulfur consumption (2) (see Ammonium compounds Fertilizers). 

Ammonium sulfate fertilizer is made by reacting ammonia with sulfuric acid. In many parts of the world, calcium sulfate is in mineral form convertible to ammonium sulfate by combining it with ammonia and water - a virtually limitless source of sulfur. 

Sulfuric acid is the most heavily produced inorganic chemical worldwide, the annual production in the United States alone being more than 4 X 1(J10 kg. The low cost of sulfuric acid leads to its widespread use in industry, particularly for the production of fertilizers, petrochemicals, dyestuffs, and detergents. About two-thirds is used in the manufacture of phosphate and ammonium sulfate fertilizers (see Section 15.4). 

The catalyst was reformulated by Alwin Mittasch, who synthesized some 2500 different catalysts and performed more than 6500 tests. They arrived at a triply promoted catalyst consisting of a fused iron catalyst, with AI2O3 and CaO as structural promoters and potassium as an electronic promoter. The process was first commercialized by BASF, with the first plant located in Oppau in Germany producing 30 tons per day in 1913. The plant initially produced ammonium sulfate fertilizer, but when the First World War broke out it was redesigned to produce nitrates for ammunition. The plant was expanded and in 1915 it produced the equivalent of 230 tons ammonium per day. 

Merseburg A process for making ammonium sulfate fertilizer from gypsum. The gypsum is slurried with water and ammonium carbonate solution added. Calcium carbonate precipitates and is removed, any excess of ammonium carbonate is neutralized with sulfuric acid, and the solution is concentrated until it crystallizes ... 

Uhde-Hibemia A process for making a mixed ammonium nitrate - ammonium sulfate fertilizer (ASN) - which is less liable to explode than ammonium nitrate. Sulfuric acid is added to aqueous ammonium nitrate and ammonia gas passed in. The double salt crystallizes out. Additives are used to improve the handling characteristics of the product. Developed by Hibernia and licensed to Friedrich Uhde. See also Victor. 

U.S. production of sulfuric acid in 2001 was 40.1 million tons, far exceeding that of any other chemical (Table 19.1). It is used mostly to manufacture soluble phosphate and ammonium sulfate fertilizers, but it is essential to many other industries (Figure 19.12). So widespread is the use of sulfuric acid in industrial countries that the amount produced is sometimes regarded as an indicator of economic activity. 

Caprolactam is used principally in the production of nylon 6 fibers. In the production of caprolactam, ammonia is used to maintain a reaction pH of 7 in one step, and in another step ammonia is used to neutralize sulfuric acid. Both of these steps result in the production of a low-grade ammonium sulfate fertilizer. In the classical process 5 kg of (NHO2SO4 are produced per kilogram of caprolactam, hi 1992 about 33% of the worldwide caprolactam capacity was based on DSM s caprolactam process that only produces 1.8 kg of (NH SC per kilogram of caprolactam46. 

The other author (WGD) has been interested in sulfuric acid plants since his 1957 student internship at Cominco s lead/zinc smelter in Trail, British Columbia. Cominco was making sulfuric acid from lead and zinc roaster offgases at that time. It was also making ammonium sulfate fertilizer. 

Ammonium sulfate, fertilizer becomes a solution of food shortage. 

The third and most common method is to use a byproduct from other processes and is presently the only process used in the United States. The low demand for ammonium sulfate fertilizer has made it uneconomical to produce by any other means. 

One of the major restrictions to the sulfuric acid method of hydration has been the cost of reconcentrating the sulfuric acid. The necessity for this reconcentration is brought about by the fact that the strong acid used for absorption of the olefin must be diluted prior to the distillation of the alcohol from the solution. In locations where the dilute acid may be used in conjunction with the production of synthetic ammonia for the formation of ammonium sulfate fertilizers, the hydration operation may be made more profitable by this outlet for the spent acid. 

Sulf-N 45. [Allied-Signal] Ammonium sulfate fertilizer. 

This process was field-tested on 2470 L of coumaphos cattle-dip waste at the APHIS vats In Laredo, Texas. To overcome the need to deliver an extremely large number of Flavobacterlum cells to the site, the organisms were added as a 1% Inoculum (22.8 L of culture grown In nutrient broth plus xylose) along with 9.5 kg of xylose as a carbon source and 4.5 kg of ammonium sulfate fertilizer as a nitrogen source. In order to allow growth of the organisms In the waste. The pH of the material In the tank was adjusted to between 6.8 and 7.0 by the addition of 1.4 kg of monobasic potassium phosphate and 1.8 kg of... 

The Walther process is an aqueous ammonia FGD process that produces ammonium sulfate fertilizer granulate. Ammonia loss due to vaporization into the clean flue gas is controlled by the use of a second absorber vessel with a special mist elimination system specifically designed to remove the ammonia aerosol from the flue gas (Reijnen, 1990). 

Waste treatment - Clinoptilolite, ehabazite, mordenite, and phillipsite remove radioaetive Cs and Sr ° from nuelear waste streams and serve as eneapsulants for these isotopes to faeilitate solid waste disposal. Zeolites, partieularly elinoptilolite, are used in treating sewage and industrial waste streams to remove ammonia and heavy metals. Extracted ammonia is subsequently vented, reeovered for ehemieal use, or eonverted with sulfurie acid to ammonium sulfate fertilizer. 

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