Distillation nitrous oxide

Isotope Enrichment by Distillation of Nitrous Oxide or Water... 

Davis and Abrams [8] report the following experimental observations in support of this supposition. On heating a solution of ammonium nitrate in sulphuric acid to 150°C, nitric acid cannot be distilled, but nitrous oxide is evolved, probably from the decomposition of nitramine. If, however, the solution is kept for a long time between 90 and 120°C, nitric acid can be obtained by distillation. The authors ... 

Methylnitramine is very readily soluble in water, alcohol, chloroform and benzene but is less soluble in ether. It is a strong acid which easily forms salts, including explosive ones. It is not decomposed by boiling water, even in the presence of alkalis, but it is liable to destructive distillation yielding dimethylnitramine (CH3)2NN02, m.p. 57°C, methyl alcohol, nitrous oxide and many other products. 

The solution which results when ammonium nitrate is dissolved in a large excess of concentrated sulfuric acid evidently contains nitroamide.1 If the solution is warmed directly, no nitric acid distils from it but at about 150° it gives off nitrous oxide which corresponds to the dehydration of the nitroamide by the action of the strong acid. The nitroamide moreover, by the action of the same acid, may be hydrated to yield nitric acid, slowly if the solution is digested at 90° to 120°, under which conditions the nitric acid distils out, and rapidly at ordinary temperature in the nitrometer where mercury is present which reacts with the nitric acid as fast as it is formed. 

Irradiation Procedure. 30% w/w solutions of poloxamer were prepared in distilled water by the cold process and saturated with nitrous oxide. This agent is a known scavenger of hydrated electrons and is known to enhance crosslinking of poly(oxyethylene) chains (9). Vials containing these solutions were irradiated at ambient temperature in a 2000 Ci ° Co source at a dose rate of 0.5 Mrad h- Physicochemical measurements were performed on solutions prepared by dilution of these irradiated samples. 

Nitrous oxide (laughing gas) [10024-97-2] M 44.0, b -88.5. Wash the gas with concentrated alkaline pyrogallol solution, to remove O2, CO2, and NO2, then dry it by passing it through columns of P2O5 or Drierite, and collecting in a dry trap cooled in liquid N2. It is further purified by freeze-pump-thaw and distillation cycles under vacuum [Ryan Freeman J Phys Chem 81 1455 1977, Schenk in Handbook of Preparative Inorganic Chemistry (Ed. Brauer) Academic Press Vol I pp 484-485 1963]. 

The process has a very high selectivity toward the target phenol. Unreacted benzene is completely recycled. The separation is a simple distillation - there is minimal aqueous waste, no inorganic salts and some of the by-products can be Isolated and sold. The total organic waste is expected to be less than 2% of the phenol manufactm-e. And last, but not least - the process uses waste nitrous oxide, abatement of which currently consumes natural gas and emits much more CO2 than is expected to be emitted by the benzene to phenol process. 

Mendes et al. (37) studied the use of SC-C02 for vitamin E concentration in deodorizer distillate of soybean oil. Lee et al. (38) applied a SFE method to test the feasibility of tocopherol concentration from soybean sludge with SC-C02. Shishikura et al. (39) separated tocopherols from soybean sludge by SC-C02 and nitrous oxide (SC-N20). Lecithin and other compounds can be concentrated in liquid wastes with continuous/semicontinuous SC-C02 operations production costs will be substantially reduced in comparison with batch operations. 

Properties and reactions of nitramines Secondary nitramines are neutral, primary nitramines form salts with bases, but an excess of alkali often causes decomposition to the carbonyl compound, nitrogen, and water. Secondary nitramines and aqueous alkali afford nitrous acid, aldehyde, and primary amine. Acids decompose primary aliphatic nitramines with formation of nitrous oxide in a reaction that has not yet been clarified thus these compounds cannot be hydrolysed by acid to amines in the same way as nitrosamines, although, like the latter, they can be reduced to hydrazines. Primary and secondary aromatic nitramines readily rearrange to C-nitroarylamines in acid solution. Most nitramines decompose explosively when heated, but the lower aliphatic secondary nitramines can be distilled in a vacuum. 

The nitrous oxide was passed through two successive alkaline py-rogallol solutions and finally through triply distilled water. The aromatic compounds were either Baker Analyzed reagents or Baker Grade reagents. 

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