A Model for the Combustion Retorting of Shale-Oil

263 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1984.In the combustion retorting of oil shale, a combustion wave is caused to move down through a bed of raw shale particles. Hot inert gases flow ahead of the wave and decompose the kerogen in the raw shale. Oil produced by this pyrolysis reaction is carried from the hot zone as a vapor, which condenses on cold shale particles and falls out the bottom of the bed as a liquid product. The pyrolysis leaves behind a bed of particles containing a carbonaceous residue, a variety of carbonates, some silicates and a large amount of inert rock. The carbonaceous residue in the processed shale provides the fuel for the combustion. The size of the oil yield from the process depends on keeping the combustion zone separated from the retorting zone and on minimizing the combustion of oil by oxygen which has bypassed the hot carbon residue.A model has been developed to describe the characteristics of the thermal wave after it moves a sufficient distance into the bed that the reaction zones have reached fully developed conditions. The flow is assumed to be uniform and adiabatic so that the wave is one-dimensional. The heat and mass dispersion in the flow direction are neglected and the rock fragments are assumed small enough to be isothermal.This model provides a physical understanding of the relation between the structure of the thermal wave and the kinetics of the chemical reactions, defines the parameters governing the process and suggests how to select effective operating conditions.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD