Processing of eastern US oil shale in a multistaged fluidized bed system

Abstract

A multistaged processing concept for eastern US oil shale, KENTORT II, integrates dense-phase fluidized bed pyrolysis with fluidized bed gasification and combustion steps. The fluidized bed retort produces enhanced yields for eastern US oil shale by minimizing cracking and coking reactions. Residual carbon and sulphur are converted in the gasification zone to medium-Btu, H 2- and H 2S-rich gas, leaving a low sulphur char for combustion. Heat is provided for gasification via recirculating solids from the combustion zone, and for pyrolysis from hot gases and recirculating solids from the gasification zone. Both experimental systems used in this study indicate that carbon and sulphur conversion are sufficiently rapid to proceed under moderate gasification conditions. Coking induced from solids recirculation was small, and particle agglomeration was not observed during combustion.