Abstract: In the indirect method of retorting oil shale highly heated gases produced out of contact with flames in a heat exchanger are introduced into the retort and release oil vapor and high-value, high BTU gas and oil vapor from the shale which mix with the hot gas so introduced into the retort. Instead of burning the heat value gas of pipeline quality in the heat exchanger which is the present procedure, this invention fires the heat exchanger with abundant, cheap, low-value gas which for example is produced underground in-situ at or near the retort, thereby preserving the high value gas, after condensation of the oil vapor, partially for recirculation through the heat exchanger and retort and for in-plant operations, such a hydrogenation of the extract shale oil to produce refinable crude or for pipeline use.

Abstract: In a process for the removal of fines from a bed of oil bearing shale in a travelling grate retort, a fluid such as air, inert gas or process gas is drafted through the bed in order to entrain in the fluid substantially all of the fines in the bed. The fines are then evacuated from the bed thus increasing the permeability of the bed and substantially decreasing the fines in the retorted shale oil.