Nitrogen solutions

These nitrogen solutions are used both for direct field appHcation and as a nitrogen ingredient in fluid mixed fertilizers. 

For the year ended June 30, 1990, about 39% of the total primary nutrient used in the United States was apphed in mixtures, whereas the remaining 61% was apphed by direct apphcation. Breakdown by plant nutrient is shown in Table 11. High usage of anhydrous ammonia and nitrogen solutions (Fig. 

The flexibility of the bulk blending system and the close relationship with the farmer allow the bulk blender to provide a number of valuable supplementary services, such as adding herbicides, insecticides, micronutrients, or seeds to the blends bagging blends liming and sampling soil. Consultation services and custom appHcation can also be provided as can sale of anhydrous ammonia or nitrogen solution. 

Micronutrients in Fluid Fertilizers. In terms of homogeneity and even distribution, fluid fertilizers are probably the best micronuttient carriers. Fluid carriers of micronutrients usually are nitrogen solutions, clear Hquid mixtures, or suspensions. Some micronutrients, however, are appHed as simple water solutions or suspensions. FoHar micronuttient sprays often contain only the micronuttient material in water solution. 

Several zinc and copper micronuttient compounds are soluble in a variety of nitrogen solutions. Ammonia—ammonium nitrate solutions containing 2.5% Zn and 1% Cu can be prepared (100). Micronutrients are not very soluble in urea—ammonium nitrate solution unless the pH is raised to 7 or 8 by adding ammonia, whereupon zinc and copper become much more soluble. 

Markets. Industrial use of ammonia varies according to region. Eor example, industrial usage represents 20% of the ammonia production in the United States and Western Europe, 10% in the USSR, 1—10% in Asia, and 5% in Latin America and North Africa (79). Fertiliser ammonia consumed domestically in most countries is converted to straight or compound fertilisers such as urea, ammonium nitrate, diammonium phosphate, and various grades of mixed fertilisers. However, almost 29% of ammonia nitrogen in the United States is consumed as direct appHcation material. The use of nitrogen solution such as urea and ammonium nitrate (UAN) has also become popular in the United States and the USSR. 

Nitrogen solutions consist of fertilizer product combinations, eg, ammonium nitrate —ammonia, urea—ammonium nitrate—ammonia, urea—ammonium nitrate, and urea—ammonia solutions. Mixed fertilizers cover a broad range and can be loosely defined as fertilizers which contain chemically mixed nitrogen, phosphoms, and potassium (N—P—K). Examples are ammonium phosphate—potash mixtures and ammonium phosphate nitrates. 

Uses. Since 1947, 70 to 85% of the annual USA production of nitric acid has gone into the production of NH4 nitrate fertilizer, initially in the form of solid prills currently, increasing amounts have been supplied mixed with excess ammonia and/or urea as aqueous nitrogen solution for direct application to the soil. Some 15% is used in explsj (nitrates nitro compds), and about 10% is consumed by the chemical industry. As the red fuming acid or as nitrogen tetroxide, nitric acid is used extensively as the oxidizer in proplnts for rocketry. It is estimated that current USA capacity for nitric acid is in excess of 10 million tons (Refs 30, 34, 36 37)... 

The pressure being higher, all features of rotational structure disappear and the difference between spectra of various spin modifications becomes so smooth that any of them practically reproduces the whole contour shape. In Fig. 5.14 the theoretical contours are shown calculated with and without adiabatic correction of the impact operator for an ideal nitrogen solution in Ar. They are compared with the experimental one related to the same value of... 

The matrix polymer morphology of a collection of LDPE foams manufactured from a high-pressure nitrogen solution process was analysed at different length scales. 

EFFECT OF CELL SIZE ON THE PHYSICAL PROPERTIES OF CROSSLINKED CLOSED CELL POLYETHYLENE FOAMS PRODUCED BY A HIGH PRESSURE NITROGEN SOLUTION PROCESS... 

The thermal conductivity, thermal expansion, mechanical properties at low strain rates and dynamic mechanical properties of a collection of crosslinked closed cell PE foams manufactured by a high pressure nitrogen solution process were studied as a function of the cell size. The... 

Properties of peroxide cross-linked polyethylene foams manufactured by a nitrogen solution process, were examined for thermal conductivity, cellular structure and matrix polymer morphology. Theoretical models were used to determine the relative contributions of each heat transfer mechanism to the total thermal conductivity. Thermal radiation was found to contribute some 22-34% of the total and this was related to the foam s mean cell structure and the presence of any carbon black filler. There was no clear trend of thermal conductivity with density, but mainly by cell size. 27 refs. 

Table 21.2 lists all important direct application materials and their percentage of direct application fertilizers. Direct application use is increasing mainly because of anhydrous ammonia gas becoming popular. It can be pumped in 3-6 in. beneath the soil during plowing and is absorbed by the soil rapidly. Nitrogen solutions can also be applied in this manner (mixture of free ammonia, ammonium nitrate, urea, and water). 

NITRATE-UREA SOLUTION Nitrex Nitrogen Solutions ... 

The prills are drawn off continuously from the hopper bottom of the tower by means of a conveyer and fed to the pre-drier, then to the drier and cooler. From the cooler the prills are elevated to a double deck screen. Oversize and undersize are dissolved in water and returned to the neutralizer or used for producing nitrogen solutions . 

The demand for nitrogen in a chemically fixed form (as opposed to elemental nitrogen gas) drives a huge international industry that encompasses the production of seven key chemical nitrogen products ammonia, urea, nitric acid, ammonium nitrate, nitrogen solutions, ammonium sulfate and ammonium phosphates. Such nitrogen products had a total worldwide annual commercial value of about US 50 billion in 1996. The cornerstone of this industry is ammonia. Virtually all ammonia is produced in anhydrous form via the Haber process (as described in Chapter 2). Anhydrous ammonia is the basic raw material in a host of applications and in the manufacture of fertilizers, livestock feeds, commercial and military explosives, polymer intermediates, and miscellaneous chemicals35. 

Ammonium Nitrate Calcium Ammonium Nitrate Ammonia - Direct Application Nitrogen Solutions Mono- Ammonium Phosphate/ Di-Ammonium Phosphate Other NP compounds NK / NPK compounds Others3 Total nitrogen... 

Absorption Abatement or extended absorption refers to modifications that involve the addition of increased absorption capacity or optimization of the existing absorption system to oxidize and react the nitrogen oxides with water to form acid.. Tail gases are passed through an absorber containing either water or an aqueous solution of ammonia, urea or sodium hydroxide. When water is used as the absorbent, the resultant weak acid is recycled. This increases nitric acid yields by 1% to 3%. When other absorbents are used, the recovered NOx is typically consumed in the production of nitrogen solutions for fertilizer use. If sodium hydroxide is the absorbent, pure sodium nitrite and sodium nitrate may be recovered91,104. 

Commercial grades of AN include solutions that contain about 83% AN and solid products. Both grades are used for direct fertilizer applications, or they are blended with other materials to form mixed solid and liquid fertilizers. High density, prilled AN is usually used for direct applications while other solid AN is mixed with phosphate and potash for multi-nutrient fertilizers. Solid AN has lost market share to urea because it has a lower nitrogen content (33-35% for AN vs. 45-46% for urea), plus it costs more per ton. In addition to direct application, AN solutions are mixed with urea to make nitrogen solution fertilizers240. 

The GaN substrates grown from nitrogen solution in pure gallium possess a high free-electron concentration of about 5 x 1019 cm 3 (if doped with magnesium, crystals are insulating [4]). This... 

Pentacarbonyl(diphenyl telluroketone)tungsten(II)3 Under dry nitrogen solutions of 980 mg (2 mmol) of pentacarbonyl(diphenylmethylene)tungsten in 20 ml of dichloromethane and of 1.38 g (2 mmol) of bis[triphenylphosphine]iminium tellurocyanate in 10 ml of dichloromethane, both at — 90°, are combined and stirred for 10 min at that temperature- The mixture is then chromatographed on silica gel at — 50° with pentane/dichloromethane (10 1 v/v) as the mobile phase. The blue fractions are collected, the solvent is distilled under high vacuum, and the residue is recrystallized from pentane, yield 220 mg (18%) m.p. 35° (dec.). 

TABLE 24.1 Physical and Chemical Characteristics of Urea-Ammonium Nitrate Nonpressure Nitrogen Solutions... 

The high-volume use of these solutions is a result of their economy of production and the safety and convenience of their handling and application. The use of nonpressure equipment and surface application (in contrast to knifing) is normal. Nitrogen solutions of other compositions also are prepared commercially, but are used primarily as intermediates in the preparation of solid fertilizers. Such solutions usually consist of various combinations of water, ammonia, ammonium nitrate, and/or urea. Because of the content of free ammonia, most of these solutions require pressurized handling. 

The rotary drum granulator in this process is essentially the same as was pictured for the diammonium phosphate granulation process. In early versions of the process, feed to the drum of SSP consisted of (1) crushed oversize product and fines, (2) nongranular SSP, (3) nongranular potassium chloride, (4) ammonium sulfate crystals, (5) sulfuric acid, and (6) anhydrous ammonia or an ammonia-containing nitrogen solution. 

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