Oil Shale, Vol.36, No.3, 353-369, 2019
Reactivities of American, Chinese and Estonian oil shale semi-cokes and Argonne premium coal chars under oxy-fuel combustion conditions
Oil shales of various rank and origin from China, Estonia and the United States are investigated and their oxidation reactivities under simulated oxy-fuel combustion conditions, in air, and in 100% CO2 atmospheres explored. Independent of rank and origin, as the oil shale pyrolysis temperature increases, the oil shale semi-coke oxidation reactivity decreases. The oxidation reactivities in air and in simulated oxy-fuel oxidation atmospheres for all of the oil shale semi-cokes tested are more or less the same. Oil shale semi-coke oxidation reaction activation energies in an air atmosphere are similar to the activation energies obtained under the simulated oxy-fuel conditions. These findings are useful for optimizing retrofit of current oil shale-fired systems to oxy-fuel combustion conditions, particularly if they are to be fired with oil shale semi-coke from retorting processes.
Keywords:oil shale semi-coke;coal chars;pyrolysis;oxidation reactivity;oxy-fuel combustion;activation energy