GB463804A - Improvements in and apparatus for the manufacture and production of gases rich in nitrogen and free from oxides of nitrogen - Google Patents

Abstract

Mixtures of nitrogen with small amounts of hydrogen or oxygen, or pure nitrogen are <PICT:0463804/III/1> obtained by first producing a mixture of nitrogen and hydrogen rich in hydrogen by the process described in the parent Specification by the catalytic combustion of ammonia with less than 0,75 part by volume of oxygen and subsequently partly or wholly burning the hydrogen present by means of oxygen or air. Oxides of nitrogen or nitrogen-oxygen mixtures poor in oxygen may also be used for the second combustion, thus increasing the nitrogen content of the resulting gases. According to examples: (1) 16 cubic m. of ammonia and 32 cubic m. of air are passed through the catalyst c consisting of nickel nets in the apparatus shown. 18 Cubic m. of air are fed in through pipe h into the space behind the nets where the heat from the catalyst is sufficient to initiate the second combustion. The reaction gases pass over water d to absorb unconverted ammonia, pipes b and e being cooled by water jackets g. 50,8 Cubic m. of a gas mixture containing 6,2 per cent hydrogen and 93,8 per cent nitrogen are obtained; (2) by the partial combustion of 14,75 cubic m. of ammonia and 29,5 cubic m. of air and subsequent addition of 26,7 cubic m. of air in the same apparatus, a gas mixture containing 99 per cent nitrogen and 1 per cent oxygen is obtained.