Graphite reaction with carbon dioxide

Gadsby and co-workers (63) report that for a coal charcoal, the rate of the carbon-steam reaction is greater by a factor of about three than the carbon-carbon dioxide reaction at 800° and a pressure range of 50 to 500 mm. Hg. The results of Pilcher et al. (68) and Walker et al. (85), using the same graphitized carbon rods and apparatus, essentially agree with this finding. At 1100°, the former workers report a reaction rate of 1.6 g./hr. at a steam partial pressure of 142 mm. Hg, which can be extrapolated to 4.8... 

Carbon dioxide reacts with hot carbon in the form of graphite. The equilibrium constant, K, for the reaction is... 

The effect of oxidation pretreatment and oxidative reaction on the graphitic structure of all CNF or CNF based catalysts has been studied by XRD and HRTEM. From the diffraction patterns as shown in Fig. 2(a), it can be observed the subsequent treatment do not affect the integrity of graphite-like structure. TEM examination on the tested K(0.5)-Fe(5)/CNF catalysts as presented in Fig.2(b), also indicates that the graphitic structure of CNF is still intact. The XRD and TEM results are in agreement with TGA profiles of fi-esh and tested catalyst there is no obviously different stability in the carbon dioxide atmosphere (profiles are not shown). Moreover, TEM image as shown in Fig. 2(b) indicates that the iron oxide particle deposited on the surface of carbon nanofibcr are mostly less than less than 10 nm. 

With carbon dioxide in the solid state the mixture detonates on impact. Therefore, with graphite, carbon dioxide cannot be used as an extinguishing agent for potassium fires. The slow reaction of potassium with gaseous carbon dioxide at ambient temperature gave rise to an accident. Potassium was stored in an aluminium container in a laboratory in contact with carbon dioxide the formation of potassium carbonate caused the corrosion of the container, which caused potassium to combust on contact with air. 

Reaction of carbon with sulfur dioxide was observed by Fischer and Prauschke (131). In my laboratory it was recently found that sulfur is bound by heat-treated carbon blacks and by graphitized carbon black on treatment with hydrogen sulfide, carbon disulfide, or sulfur dioxide at low temperatures, even at room temperature. The sulfur content cannot be eliminated by outgassing at 100° or by prolonged extraction with various solvents. 

Fig. 26. Arrhenius plots for reaction of raw and heat-treated rods of Ceylon graphite with carbon dioxide at 1 atm. pressure. [After F. Rusinko, Jr., Ph.D. Thesis, The Pennsylvania State University, 1968.1...

Fig. 28. Effect of heat treatment on the reactivity of carbon derived from petroleum pitch. Reaction of 2 g. of 6 X 8-mesh carbon with carbon dioxide at 1100°. [After P. L. Walker, Jr., and J. R. Nichols, Industrial Carbon and Graphite, Society of Chemical Industry, p. 334. London, 1957.]...

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