Nitrogen, cost

Cost of carbide Cost of nitrogen Cost of steam Cost of sulphuric acid Less value of graphite... 

Urea-Ammonium Nitrate Solutions. An important fertilizer is the urea-ammonium nitrate solution which makes up 20% of the nitrogen fertilizer market. This fertilizer utilizes the unusually high solubility between urea and ammonium nitrate (Table 3.15), which allows for a high nitrogen content, low nitrogen cost, and ease of handling. The solution also can contain herbicides since they can be easily added to the solution. However, these solutions are corrosive, so corrosion inhibitors are added such as ammonium thiocyanate, sodium arsenite, sulfonate OA5, or trace ammonia. 

There is good reason to be enthusiastic about these materials. Because liquid nitrogen is quite cheap (a liter of liquid nitrogen costs less than a liter of milk), we can envision electrical power being transmitted over hundreds of miles with no loss of energy. The levitation effect can be used to construct fast, quiet trains that glide over (but are not in contact with) the tracks. Superconductors can also be used to build superfast computers, called supercomputers, whose speeds are limited by how fast electric current flows. Furthermore, the enormous magnetic fields that can be created in superconductors will result in more powerful particle accelerators, efficient devices for nuclear fusion, and... 

In the end, a cost-benefit tradeoff analysis must be made for a particular product that considers the advantage of enhanced wettabihty, thus better yield and rehability, and reduced dross formation compared to the additional nitrogen cost. 

Bleken, M. A., and L. R. Bakken. 1997. The nitrogen cost of food production Norwegian... 

For trace quantities of less than 100 ppm, the most successful method — and the most costly— is neutron activation. The sample is subjected to neutron bombardment in an accelerator where oxygen 16 is converted to unstable nitrogen 16 having a half-life of seven seconds. This is accompanied by emission of (J and 7 rays which are detected and measured. Oxygen concentrations as low as 10 ppm can be detected. At such levels, the problem is to find an acceptable blank sample. 

The density of heavy fuels is greater than 0.920 kg/1 at 15°C. The marine diesel consumers focus close attention on the fuel density because of having to centrifuge water out of the fuel. Beyond 0.991 kg/1, the density difference between the two phases —aqueous and hydrocarbon— becomes too small for correct operation of conventional centrifuges technical improvements are possible but costly. In extreme cases of fuels being too heavy, it is possible to rely on water-fuel emulsions, which can have some advantages of better atomization in the injection nozzle and a reduction of pollutant emissions such as smoke and nitrogen oxides. 

This justifies all the work undertaken to arrive at fuel denitrification which, as is well known, is difficult and costly. Moreover, technological improvements can bring considerable progress to this field. That is the case with low NO burners developed at IFF. These consist of producing separated flame jets that enable lower combustion temperatures, local oxygen concentrations to be less high and a lowered fuel s nitrogen contribution to NOj. formation. In a well defined industrial installation, the burner said to be of the low NO type can attain a level of 350 mg/Nm, instead of the 600 mg/Nm with a conventional burner. 

Potassium nitrate is being used increasingly on intensive crops such as tomatoes, potatoes, tobacco, leafy vegetables, citms, and peaches. The properties that make it particularly desirable for these crops are low salt index, nitrate nitrogen, favorable N K20 ratio, negligible CU content, and alkaline residual reaction in the soil. The low hygroscopicity of KNO (Table 9) leads to its use in direct appHcation and in mixtures. It is an excellent fertilizer but the high cost of production limits its use to specialty fertilizers. 

Coal is expected to be the best domestic feedstock alternative to natural gas. Although coal-based ammonia plants have been built elsewhere, there is no such plant in the United States. Pilot-scale projects have demonstrated effective ammonia-from-coal technology (102). The cost of ammonia production can be anticipated to increase, lea ding to increases in the cost of producing nitrogen fertilizers. 

The tabulation of plant nutrient costs, by product, ia Table 16 shows the principal reasoa for the popularity of anhydrous ammonia as a fertilizer ia the United States. The fob price per ton of nitrogen in the form of ammonia is less than half that for any other nitrogen product. Also, ammonia s relatively high nitrogen content of 82.2% favors low transportation costs, in spite of the need for specialized handling equipment and procedures. 

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