Interaction of carbon monoxide and hydrogen under silent electric discharge: Production of formaldehyde - Part II. Influence of temperature

Abstract

The study of the interaction of CO and H2 under silent electric discharge yielding fairly good amounts of formaldehyde has been extended to the investigation of the influence of temperature. About 3 litres of gas mixture in the ratio CO:H2 as 1:1 were circulated at the rate of 5 and 8 litres per minute through a Siemens' all glass ozoniser subjected to an A.C. discharge of 7·2 and 9·6 kV respectively, and 500 cycles frequency. The ozoniser was maintained at a given temperature by heating a surrounding water jacket. After six hours' exposure to discharge the washings from the absorbers were estimated for formaldehyde and acidity and the residual gas analysed with an Orsat's apparatus. Experiments were conducted at 25, 45, 60 and 80° C. Although an overall increase in the total reaction is indicated with increasing temperature, the net yield of formaldehyde, but for a slight increase at 80° C. which is perhaps due to the depolymerising effect at high temperature, is almost a constant quantity. Since very small quantities of CO2 and unsaturated hydrocrbons are indicated in the residual gas and the proportion of CO:H2 in it remains almost the same as the original one, it is concluded that formaldehyde is formed according to the reaction CO+H2→HCHO. © 1950 Indian Academy of Sciences.