Reaction rate of coke and other carbonaceous materials with CO2

The reaction rates of Bintyo char, Bamboo char, activated carbon, coke, graphite and glassy carbon with pure CO, have been obtained by thermogravimetric method. After the reaction, N2 was introduced to the reaction tube to obtain the amount of adsorbed CO on the active reaction sites. The specific surface area after the reaction was measured by BET method. The results are summarized as follows: The reaction rate per unit mass were in the order of Bintyo char=Bamboo char=activated carbon > graphite=coke > glassy carbon. The difference between the maximum and minimum were two orders of magnitude. The activation energy was 180 to 220 kJ/mol. The reaction rate per unit area of graphite, however, was an order of magnitude higher than those of Bintyo char and Bamboo char. The estimated amount of adsorbed CO was positively correlated to the reaction rate. The reaction rate constant which is independent from surface area was obtained using the reaction rate and the amount of CO adsorption, respectively per unit area. They are ranged in the order of 10-4 to 10-3 l/s. The differences among Bintyo char, Bamboo char and graphite became smaller. The enthalpy of CO adsorption was estimated as about 230 kJ/mol for Bintyo char and Bamboo char, and about 280 kJ/mol for graphite.