N EXPERIMENTAL program has been in progress in these laboratories for some time on the kinetics of the gasification of low temperature char by hydrogen steam mixtures. Relatively large quantities of methane were obtained in these experiments ( 6 , 7 ) , particularly at high pressures and high hydrogen-sfeam ratios. I n order to provide a better insight into the mechanism of methane formation, it was desirable to study the rate of gasification of char in pure hydrogen. This study is also of potential practical importance in connection with the production of high B.t.u. gas by the hydrogenation of coal or char. Some data have already been reported (7) on the hydrogenation of char a t 1600" F. These data have been extended to cover a wider pressure range and also two other temperatures.It has been long known that methane can be synthesized by the direct hydrogenation of carbon. The only extensive work that has been done previously in this field, however, is that of Dent and coworkers (2-4). These workers obtained integral rate data by heating various British coals and cokes in a batch bed to final temperatures of 800" to 900" C. under hydrogen pressures up to 50 atmospheres. When the final temperature was reached, it was maintained constant while the hydrogenation was continued. It is only during this period that a comparison between their data and our data is possible.
EXPERIMENTAL TECHNIQUEProcedure. The equipment and experimental procedure employed in this investigation were substantially the same as described previously for the char-steam kinetics work (6, 6).The inlet gas in the majority of the runs was pure hydrogen which was passed over a nickel catalyst for the removal of oxygen and through silica gel and magnesium perchlorate drying tubes before entering the reaotor.The feed char in all runs was the prepared 65-to 100-mesh Disco which was used in the previous char-steam kinetics studies. The char in each experiment was pretreated for one hour at the reaction temperature by fluidizing in purified nitrogen before the hydrogen was introduced. A fluidizing velocity of 0.44 foot per second was employed.Exit gas rates and gas samples were taken throughout the runs using pure hydrogen as the inlet gas while the temperature, pressure, and fluidizing velocity were held constant. The weight of feed char used in most runs was 0.4 pound. The reactor was the same ll/&ch diameter Uniloy reactor previously described (6).Besides the pure hydrogen runs, a series of experiments was conducted to determine the effect of methane in suppressing the reaction rate by adding methane to the inlet hydrogen. It was
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