Zum reaktionsmechanismus der vergasung von kohlenstoff mit kohlendioxid—I

Kinetics of Catalysed and Uncatalysed Coal Gasification

“…In a later evaluation Lowe [56] points out that the rate data of Mentser and Ergun for isotopic exchange are incompatible with the gasification results and that their high exchange rate is possibly due to a parallel exchange reaction, not involved in the gasification cycle. Brown [69] measured a carbon transfer to the surface of graphite and sugar char from both CO and CO 2 • The sugar char was found more active than the graphite.…”

“…The steady state is maintained, but for the·e( 16 0) species can be written: At t>O the concentration of labeled oxygenated surface species varies as: (55) SO: (56) The rate of decay in the C(180 ) species can be followed by the production rate of C 16 0 180, and leads to k_ 1 • The total amount of C160 180 released equals the steady state concentration of oxygenated surface species, analogously to (51). For instance, under steady state gasification conditions the gas atmosphere is changed from e 16 0 2 to e 18 0 or vice versa.…”

“…Ergun and Mentser [56,76] found that eq. (63) was satisfied for the chars investigated by them, (table 5) and model V can describe their results.…”

“…Examples of kinetic modeling are given by Froment and Bischoff [2], Boudart [1] and reviews related to gasification reactions are given by Lowe [56], Ergun and Mentser [57], Walker et ai. [7,19], Laurendau [58] and Johnson [5,6].…”