亜硫安液, 亜硝酸ガスおよび亜硫酸ガスからヒドロキシルアミンを製造する試験について

抄録

Based on the new research result obtained in the laboratory process of manufacturing hydroxylamine by three stages, oxidation of ammonia, absorption of nitrous anhydride gas by ammonium sulfite aqueous solution and reduction of the solution by sulfur dioxide, a pilot plant test was done and the following results were obtained.
(1) The yield of hydroxylamine from ammonia in this process is 5-10% higher than that of the process in which ammonium carbonate solution is used as a solvent, and the amount of byproducts, ammonium nitrate and ammonium salt of sulfamic acid, is 2/3-1/2 of that in the latter process.
(2) In the oxidation of ammonia, Pt-Rh catalyst showed the average yield of 86.4% and this yield affects the yield of the following absorption tower.
(3) In the absorption of nitrous anhydride gas, the composition of the gas p is the important factor which affects the yield, and the analysis was done by using the constant of trimolecular reaction velocity observed by Bodenstein.
As the results, it is observed that the oxidation of NO in the absorption tower can not be ignored and that the optimum p is less than 0.40.
(4) In manufacturing hydroxylamine, the most effective factor is the Iodine value ratio of the absorved solvent, the optimum ratio of which is 21%.
(5) The apparent heat of reaction between nitrous anhydride gas and ammonium sulfite solution in this process was measured and the average value of 34.7kcal/(NH₄)₂SO₃mole was obtained.