Abstract: The invention relates to a continuous process to produce shale oil from oil shales. It comprises an improvement, the purpose of which is to remove relatively small and up to substantial amounts of the water present as steam; and to prevent pitch formation, and "stickiness" in a second or retorting stage of the process, carried out at a much higher temperature.The first step may consist of a fixed vertical vessel in one aspect of the process or alternately a much smaller rotating horizontal vessel than that used in the second step of the process. The first step is conducted at a temperature from ambient, preferably 212.degree. F. up to 550.degree. F. The second or retorting step is conducted at 800.degree. F. to 1000.degree. F. Indirect heating of the oil shales is employed in all cases.

Abstract: A continuous process for removing a substantial amount of the water present in oil shale prior to retorting the same to facillitate the rate of recovery of the oil therefrom in the retorting step of the process and to substantially increase the capacity of the latter step in the process and improve the overall efficiency thereof; which comprises subjecting the said oil shale in subdivided form to indirect heat treatment with hot combustion gases in a partial dehydration step under relatively milder temperature conditions than that of the retort, collecting the vapors and gases from the partial dehydration step, in the temperature range from the prevailing temperature up to about 550.degree. F. to about 650.degree. F.

Abstract: Oil Shale is partially dehydrated prior to retorting. Both the dehydrating and retorting steps carried out by heat treatment in rotating horizontal cylindrical vessels heated by indirect heat exchange with hot gas. The vapors withdrawn from the retorting step are fractionated to yield products including a heavy conversion oil.

Abstract: The invention relates to a unitary and continuous process to produce the desired products, divided for clarity of description, into two sections: (A) Retorting section and (B) cracking section-the first comprising a retorting section which in one principal aspect may be an essentially tubular vertical retort, one type of which is shown in FIG. 1; or in another aspect a horizontal rotating retort sloping downwardly, in which in any event the oil shale is heated indirectly by the hot gases of combustion, and are kept separate from the oil vapors and gases from the oil shale. The hot combustion products of the fuel in general move upwardly and out of direct contact with the shale and products therefrom.