Process for removing nitrogen from shale oil

摘要

There is provided a process for reduction of the nitrogen content of shale oil. The process comprises contacting shale oil with a low acid strength solvent in a first extraction zone, followed by contacting the shale oil with a high acid strength solvent in a second extraction zone. A portion of the high acid strength solvent containing extracted nitrogen-containing and non-nitrogen-containing compounds is passed to the first extraction zone and diluted to form low acid strength solvent, and at least a portion of the non-nitrogen-containing compounds redissolve into the shale oil in contact with the low acid strength solvent and are recovered. Thus, oil recovery is maximized at high nitrogen removal.