Interaction of carbon monoxide and hydrogen under silent discharge: production of formaldehyde

Abstract

Production of formaldehyde by the interaction of carbon monoxide and hydrogen under silent discharge at 500 cycles frequency has been investigated with respect to (1) the gas composition, (2) the rate of circulation, (3) the ozoniser size and (4) the excitation potential. The gas mixture was circulated through the reaction vessel at atmospheric pressure and formaldehyde was removed from the effluent gases by scrubbing through water wash traps. The optimum values for formaldehyde formation in respect of factors 1 to 4 have been determined. An increase above this value of 2 decreases the yield due to (in part) incomplete absorption of the product. A larger ozoniser size increases the net yield but entails a waste of the reacting mixture. Increase of the excitation potential increases the velocity of the change but reduces the yield due to secondary changes in the formaldehyde produced. Equimolecular mixtures of the reacting gases with optimum values under 2, 3 and 4 correspond to 0·046 gm., i.e., 16 gm. per KW-hour.