The relative coke-inducing tendencies of pyrolysed, gasified and combusted Devonian oil shales

Abstract

A dual fluidized-bed reactor system was used to examine the isothermal kinetics of carbon deposition when nascent shale oil vapours were passed through beds of pyrolysed, gasified and combusted Devonian shale. Naturally occurring samples of the principal silicate minerals found in Devonian shale (kaolinite, illite and quartz) were also tested. The rate of carbon uptake declined with increasing carbon deposition on the solids. The coke-inducing activities of the processed shales were ranked as: combusted shale gasified shale pyrolysed shale. The effect of coking temperature on carbon deposition was relatively small, which has important implications for solids-recycle oil shale retorts.