Low-temp. pyrolysis of oil shale - with indirect heat transfer from fluidised-bed combustion of pyrolysis residue

摘要

Process and appts. are claimed for the low-temp. carbonisation of oil shale. Shale pref. flows downwards in vertical channels, and obtains at least part of the required heat by indirect transfer, using gas or vapour heat carriers, from the combustion of carbonisation residues in a separate zone. Heat carrier may be the combustion gases from this latter zone, or it may be a material which is heated indirectly there and circulates between it and the carbonisation zone. Combustion zone may be a fluidised bed, which coils for the heat carrier material which abstracts sufficient heat to maintain the bed at 700-900 deg.C. Process utilises internally the energy content of the carbonisation residues more simply and reliably than in previous known methods, e.g. the mixing of the hot solids from combustion with fresh shale.