The article contains sections titled: 1. Sodium Nitrate 1.1. Properties 1.2. Occurrence 1.3. Production 1.3.1. Chile Saltpeter 1.3.2. Synthetic Sodium Nitrate 1.4. Product Forms, Storage, and Transportation 1.5. Uses 1.6. Economic Aspects 2. Potassium Nitrate 2.1. Properties 2.2. Occurrence 2.3. Production 2.3.1. Bacterial Production of Saltpeter 2.3.2. Converted Saltpeter 2.3.3. Potassium Nitrate from Calcium Nitrate 2.3.4. Potassium Nitrate from Ammonium Nitrate 2.3.5. Potassium Nitrate from Potassium Chloride and Nitric Acid 2.4. Product Forms, Storage, and Transportation 2.5. Uses 2.6. Economic Aspects 3. Calcium Nitrate 3.1. Properties 3.2. Occurrence 3.3. Production 3.3.1. Calcium Nitrate from Limestoneand Nitric Acid 3.3.2. Calcium Nitrate as a Byproduct of the Odda Process 3.4. Product Forms, Storage, and Transportation 3.5. Uses 3.6. Economic Aspects 4. Sodium Nitrite 4.1. Properties 4.2. Production 4.3. Product Forms, Storage, and Transportation 4.4. Uses 4.5. Economic Aspects 5. Potassium Nitrite 5.1. Properties 5.2. Production 5.3. Uses 6. Ammonium Nitrite 6.1. Properties 6.2. Production 6.3. Uses 7. Calcium Nitrite 7.1. Properties 7.2. Production 7.3. Uses 8. Analysis of Nitrates and Nitrites 9. Environmental Aspects 10. Toxicology and Occupational Health

The article contains sections titled: 1. Nitric Acid 1.1. Introduction 1.2. Properties 1.3. Industrial Production 1.3.1. Oxidation of Ammonia 1.3.2. Oxidation and Absorption of Nitrogen Oxides 1.3.3. Equipment 1.3.3.1. Filters and Mixers 1.3.3.2. Burners and Waste‐Heat Boilers 1.3.3.3. Compressors and Turbines 1.3.3.4. Heat Exchangers and Columns 1.3.3.5. Construction Materials 1.3.4. Processes 1.3.4.1. Weak Acid Processes 1.3.4.2. Concentrated Acid Processes 1.4. Environmental Protection 1.4.1. Wastewater 1.4.2. Stack Gas 1.4.2.1. Emission Limits 1.4.2.2. Analysis 1.4.2.3. Control of NO x Emissions 1.5. Storage and Transportation 1.6. Uses and Economic Aspects 2. Nitrous Acid 3. Nitrogen Oxides 3.1. Dinitrogen Monoxide 3.2. Nitrogen Monoxide 3.3. Nitrogen Dioxide and Dinitrogen Tetroxide 3.4. Dinitrogen Trioxide 3.5. Dinitrogen Pentoxide 4. Toxicology and Occupational Health

A new stage-to-stage method has been developed for the calculation of NO, absorption columns. Each stage of the absorption column is simulated as a combination of a bubble column reactor (absorption) and an adiabatic plug flow reactor (oxidation). The bubble column reactor is modelled as two single stirred tank reactors, one as a gas-phase and one as a liquid-phase reactor, both coupled by mass and heat transfer. In this hydrodynamic model, a dynamic approach is adopted, in which the gas-phase transport of N204 is the limiting step for the absorption. A gas-phase pseudo-enhancement factor for N,04 is therefore introduced. The balance equations for a single phase of the bubble column are solved with a Newton-Raphson algorithm. The entire column calculation is divided into a gas and a liquid side. On both sides, the stage-to-stage method is applied in such a way that the overall calculation is performed as a loop process. The direction of the loop calculation follows that of the flow: gas-side upwards and liquid-side downwards.

Laboratory-scale measurements were performed on the absorption of NO, gas into diluted nitric acid. The concentration of NO, gas, which represents an N02/N204 equilibrium, varied from 1000 to 20000 ppm, the carrier gas being nitrogen. The concentration of nitric acid ranged from 15 to 60 mass-%. The absorption experiments were carried out in a double stirred cell, with a defined gadliquid interface as the mass transfer area. The liquid phase was conducted periodically and the gas phase continuously. Mass flow rates were determined. The well-known film model of absorption was used for analyzing the experimental results. Only the N,O, species was considered to pass the gadliquid interface. The measured data yielded values of HN204 (k D,)"2 as well as their variation with temperature and nitric acid concentration.

A cubic equation of state is modified in such a way that prediction of PVT data from 40 model compounds, typical of coal oil, becomes possible with an absolute mean deviation of less than 2 % for saturated liquid volumes and vapour pressures > 1 bar. Additional correlations for binary interaction parameters are obtained by an optimization procedure using vapour-liquid equilibrium (VLE) data from known heavy hydrocarbon liquidhight gas systems. When the modified equation is applied to coal-derived liquids, only specific gravity and boiling analysis data of the coal liquids are required, primarily in order to determine the equation-of-state parameters. The proposed equation is shown to allow a good prediction of VLE data for systems consisting of wide-boilingrange coal oils and light gases. Experimental values were obtained at elevated temperatures and pressures with a circulation flow apparatus.