Abstract: Nitric oxide, NO, and nitrogen peroxide, NO.sub.2, are facilely removed from gaseous admixtures comprising the same, together with gaseous oxygen, advantageously in a plate tower for the commercial production of nitric acid, by countercurrently oxidizing/absorbing said gaseous feedstream in aqueous solution, in a gas/liquid phase contactor, and wherein that section of said phase contactor the NO.sub.x content in the gaseous feedstream is less than 6000 vpm, the improvement which comprises that the residence time in said less than 6000 vpm section of said phase contactor, is increased to a value such that the ratio K, of the liquid retention volume in cubic meters in said phase contactor to the rate of flow therein of said gaseous feedstream in Nm.sup.3 /hour, in excess of 5.10.sup.-4 hour.

Abstract: Intimate and efficient contacting of plural, physically disparate phases, e.g., a gas and a liquid, is achieved by contacting the phases cocurrently in a column. The gas phase is introduced at a velocity between its phase transition inversion point (T) and multiple critical point (M.sub.c) velocities, which velocity is sufficient to create a dispersion of the second phase, i.e., the liquid phase, in the gas and thereby establish at most the following zones, from bottom to top, in the column: a bottom zone of constant liquid concentration designated the emulsion zone, a zone of decreasing liquid concentration, and a zone of constant liquid concentration wherein the liquid exists in the form of droplets. The feed velocity of the liquid is adjusted accordingly to provide a mass liquid concentration value in the emulsion that is between the mass liquid concentration value transition inversion point and multiple critical point values.

Abstract: A reaction mass for use in the preparation of chlorine and ammonia by contact with ammonium chloride, in which the reaction mass contains iron oxide which is capable of chemically combining with chlorine in the reaction with ammonium chloride and an alkali metal chloride, with the ratio of iron oxide and alkali metal chloride being such that the ratio of the chlorine chemically combined with the iron to the chlorine chemically combined with the alkali metal is less than 1.