Abstract: A process for isolating dinitrogen monoxide from oxidation off-gases formed by the oxidation of a cycloalkanol or a cycloalkanone using nitric acid which off-gases contain dinitrogen monoxide in admixture with nitrogen oxide, nitrogen dioxide, nitrogen, oxygen, carbon dioxide and/or steam which comprises:A. Drying the oxidation off-gas and if necessary removal of nitrogen monoxide, nitrogen dioxide and carbon dioxide.B. Compressing the resultant off-gas from which water has been removed to a pressure in the range of 15 to 300 bars and cooling the same to a temperature in the range of 0.degree. to -88.degree. C.;C. Removing the liquid phase obtained as a result of said compression and cooling; andD. Cooling the resultant gas phase by expansion and passing the same in indirect heat exchange with off-gas which has been prepurified by removal of water content thereof.

Abstract: This invention relates to an improved process for preparing cyanogen chloride by reacting chlorine and hydrogen cyanide in a manganous chloride-containing aqueous medium to form gaseous cyanogen chloride and dissolved hydrogen chloride and to the subsequent conversion of the hydrogen chloride to chlorine employing manganese dioxide and nitric acid as cyclic reagents.

Abstract: Ammonium nitrate is mixed, in a weight ratio of higher than 1:5, with a melt containing ammonium hydrogen sulfate and ammonium sulfate respectively present in the melt in a ratio of at least 4:1. The resultant mixture is subjected to thermal decomposition at 200-240 degrees C to produce nitrous oxide.

Abstract: This invention relates to a process for the thermal decomposition of metal nitrates which decompose below a temperature of about 400.degree. C. to form the corresponding metal oxide as well as oxides of nitrogen, said process involving distributing said nitrate over previously formed oxide and conducting said decomposition under "muffle" conditions such that said decomposition occurs in an atmosphere predominantly comprised of the vapors evolved during the thermal decomposition.

Abstract: This invention is based on the factors that both oxygen gas and nitrous oxides as gas are paramagnetic; as well as are quite soluble in saturated halogenated hydrocarbon liquids; whereas nitrogen is not paramagnetic; thus providing a means of separation of the oxygen and nitrous oxide from the nitrogen by high intensity magnetic forces created by an electromagnet.The absorber liquid, saturated with dissolved oxygen and nitrous oxides, or ammonia is then ozonated using the solvent or absorber liquid dielectric as the dielectric in an ozone generator.The effluent is stripped of nitric oxide with water to form nitric acid or by reduced pressure to recover nitric oxide.

Abstract: Nitric oxide may be removed from gases with which it is admixed by contacting the gases with aqueous solutions containing nitrate ions in sufficient concentration to oxidize the nitric oxide to nitrous acid and to retain it in the solution under stable conditions. Other oxides of nitrogen can also be absorbed producing nitrous acid which is retained in the aqueous solution in a similar manner. Thereafter, the scrubbing solution is regenerated under controlled conditions, producing a gas stream which contains the recovered nitrogen oxides in relatively high concentration and a scrubbing solution which can be recycled. The recovered nitrogen oxides may be used in the manufacture of nitric acid or other compounds or decomposed into harmless gases.

Abstract: Recovery of the chemical components of a cellulosic organic solvent regenerating solution containing a dialkylacylamide, a lower aliphatic monohydric alcohol, a nitrite of the alcohol and nitric acid. The process comprises distilling the solution to remove the alcohol nitrite and alcohol, leaving the dialkylacylamide and nitric acid, recovering the alcohol, hydrolyzing to convert the alcohol nitrite to the alcohol and nitrous acid, neutralizing the nitric and nitrous acid with an alkali or alkaline earth metal oxide or hydroxide and distilling the solution to remove water and to separate and recover the remaining alcohol, the dialkylacylamide and the nitrate and nitrite salts. The nitrite and nitrate salts are converted by pyrolysis to nitrogen dioxide. The process results in substantially total recovery of the process chemicals.

Abstract: A method for the removal of nitrogen oxides from the off-gases of a nitric acid manufacturing facility. The off-gases containing the nitrogen oxides are first contacted at atmospheric pressure and at a temperature below about 90.degree. F with a countercurrently flowing stream of about 10 to about 35% by weight nitric acid to absorb the nitrogen oxides. The rate of flow of the nitric acid is controlled so that the partial pressure of the nitrogen oxides absorbed in the nitric acid is lower than the partial pressure of the nitrogen oxides in the off-gas feed stream. The nitric acid containing the absorbed nitrogen oxides is then countercurrently contacted with a small amount of air at a temperature between about 60.degree. and about 120.degree. F to liberate the absorbed nitrogen oxides so that they can be returned to the reactor section of a nitric acid plant. The nitric acid being recycled to absorb more nitrogen oxides.

Abstract: An oil dispersible rust inhibitor consisting of a chemical complex of a metal nitrite with a hetero-atomic aprotic polar organic solvent. Preferred metal nitrites are the alkali, alkaline earth metals or nickel, zinc, or cadmium nitrites. Preferred solvents are dimethylsulfoxide, dimethylformamide, dibutylformamide, n-methylpyrrolidone, dioxane, ethylcarbonate, tetrahydrofuran and their derivatives. The complex is prepared by reacting a nitrite ion with a solution of a basically reacting metal salt in the selected solvent. The excess metal salt is removed from the solution after completion of the reaction. The complex is readily solubilized in oil through the use of common dispersants.

Abstract: Recovery of the chemical components of a cellulosic organic solvent regenerating solution containing a dialkylacylamide, water, nitrous and nitric acid. The process comprises neutralizing the solution to form the metal salts of nitrous and nitric acid, distilling the neutralized solution to remove and recover the water and dialkylacylamide solvent and pyrolyzing the metal salts in the presence of oxygen to remove and recover nitrogen dioxide gas. The process results in substantially total recovery of the process chemicals.

Abstract: A method of generating electricity and fixing nitrogen oxides is disclosed in which coal is gasified at high pressure to produce a mixture of carbon monoxide and carbon dioxide, with a minimal amount of hydrogen and water, as a gas stream. This high pressure gas stream is mixed with an oxidant to introduce mixtures of nitrogen and oxygen and then completely combusted. The high temperature combustion gas is then further ionized to form a plasma and its velocity is increased, while its high pressure is maintained. The high pressure, high velocity plasma is fed into an MHD generator to produce electricity and where it is adiabatically expanded to fix the nitrogen oxides contained therein. The final gas stream, with the fixed nitrogen oxide compounds therein, is thereafter reacted to form nitric acid.

Abstract: Nitric oxide may be removed from gases which it is admixed by contacting the gases with aqueous solutions containing nitrate ions in sufficient concentration to oxidize the nitric oxide to nitrous acid and to retain it in the solution under stable conditions. Other oxides of nitrogen can also be absorbed producing nitrous acid which is retained in the aqueous solution in a similar manner. Thereafter, the scrubbing solution is regenerated under controlled conditions, producing a gas stream which contains the recovered nitrogen oxides in relatively high concentration and a scrubbing solution which can be recycled. The recovered nitrogen oxides may be used in the manufacture of nitric acid or other compounds or decomposed into harmless gases.

Abstract: Chlorine or bromine are produced from the respective hydrogen halide in a reaction system, wherein a stoichiometric excess of active nitrogen is maintained within the reaction system over the amount of hydrogen halide in the system. Preferably the reaction system is a single tower wherein sulfuric acid is introduced to the top of the tower where it absorbs the active nitrogen while conditions are so set that at the bottom of the tower the gases, introduced there, strip the active nitrogen away from the acid. It is a further characteristic of the process, that the nitrogen compounds stripped at the bottom, are mainly stripped as a mixture of nitrogen monoxide and nitrogen dioxide. A major portion of the nitrogen monoxide stripped, is oxidized with the oxygen, present in the gases fed in the bottom, to form nitrogen dioxide. If hydrogen halide is fed in the bottom, it will also strip nitrogen compounds, but mostly in the form of nitrosyl-halide.

Abstract: A process for removing nitrogen oxide contained in a waste gas is disclosed which includes oxidizing the nitrogen oxide to nitrogen dioxide by mixing the gas with nitric acid vapor in the presence of porous adsorbing agent such as silica gel, colloid earth, alumina, molecular sieves or the like and removing the nitrogen dioxide by absorption with an alkali aqueous solution.

Abstract: The deposition of an aromatic diazonium nitrate on the walls of a pipeline through which is conducted a residual gas produced in the diazotization of a primary aromatic monoamine is prevented by heating the walls of the pipeline, limiting the residence time of the gas in the pipeline, or providing for the absence of nitrogen dioxide in the gas. Nitrogen dioxide can form in the pipeline when nitric oxide and molecular oxygen are present, but the deposition of the diazonium nitrate, formed from the nitrogen dioxide via a reaction with the monoamine, is prevented by the hot pipeline walls and/or short residence time.

Abstract: Sulphur dioxide is reacted with silver nitrite at room temperature to release nitrogen dioxide in a known ratio and the nitrogen dioxide may, then, be measured as an indication of the presence and amount of sulphur dioxide.

Abstract: 1. In the vapor phase reaction of F.sub.2 with a member selected from the group consisting of ClF.sub.3, Cl.sub.2, BrF.sub.3, BR.sub.2 and SF.sub.4, at elevated pressures and temperatures in a chemical reactor, carried out batch-wise so that reactant gases and product gases are permitted to mix; the improvement which comprises increasing the production capacity of the chemical reactor by raising the temperature of the reactor and contents non-uniformly with respect to position in the reactor so that the reactant and product gases are subjected to different temperature zones depending on their position in the reactor, the temperature of at least one of said zones being high enough to initiate and maintain the reaction therein, the temperature differential between at least two zones of different temperature being at least 3% of the maximum temperature attained in the reactor when measured on the Kelvin scale.

Abstract: A process for efficiently removing nitrogen oxides with a very high rate from waste gas is provided wherein nitrogen monoxide contained in the gas is oxidized by chlorine dioxide or ozone, and then the oxidized gas is brought into contact with sodium chlorite in water solution in an absorption column.