Interaction between Carbon-Dioxide and Hydrogen with Promoted Metallic Surfaces

The interaction between carbon dioxide and hydrogen was studied in presence of nickel and nickel thoria catalysts at atmospheric pressure and at elevated pressures of the order of 150 lbs. per sq.inch. In part I, the reaction is studied at atmospheric pressure with nickel thoria catalyst. The preparation of the catalyst is described in detail in Chapter I. The description of apparatus employed, reduction of the catalyst, and experimental procedure are dealt with in the following chapters. In chapter V, the results and discussion of the results are given. Here, the method of calculation for a run is shown. Experiments were carried out by varying the partial pressure of both the components. Equations from kinetics of heterogeneous reactions are applied to interpret the results and it is found that both the gases are adsorbed on the catalyst surface. The trend of results obtained by keeping the partial pressure of one component constant and varying that of the other suggests that reaction takes place by the interaction between adsorbed molecules of carbon dioxide and hydrogen. Results when plotted on log log graph showed that diffusion of neither reactants nor products through a gaseous film seem to exert any great influence on the rate of reaction. In part II, nickel catalyst was employed. The apparatus employed, experimental procedure, and method of calculation are all the same as that in nickel thoria section. The reaction is studied first by keeping the partial pressure of hydrogen constant and varying that of carbon dioxide and then by keeping partial pressure of CO2 constant and varying that of H2. The results suggest the same sort of mechanism as in nickel thoria catalyst. In section B, part II, a method is presented to determine the most plausible mechanism out of a number of postulated mechanisms. The complete derivation of the equation for one of the mechanisms is shown and the method of analysis using experimental results also is illustrated. A final equation is recommended for the hydrogenation of carbon-dioxide at atmospheric pressure in presence of nickel catalyst. In part III, the reaction is studied at elevated pressures using nickel and nickel thoria catalysts. The general layout of the plant and a detailed description of the parts are given in Chapter I. In the next chapter is described the operation of the plant. The results are discussed in chapter III. The calculations for a run are shown. The effect of pressure on yield through its effect on the density etc. is discussed. The trend of results point out to the same conclusion as that arrived at under reaction at atmospheric pressure