Method for reducing the nitrogen content of shale oil with spent oil shale and sulfuric acid

摘要

A method is disclosed for reducing the nitrogen content of oil shale by removing therefrom nitrogen-containing compounds. The nitrogen content of shale oil is reduced by agitating the shale oil with designated amounts of acidified spent oil shale. Acidification is obtained by contacting spent oil shale with sulfuric acid produced by oxidizing hydrogen sulfide emanating from the oil shale retorting process. Agitation of the acidified oil shale with nitrogen-containing oil shale can be either a batch or continuous process. The method also provides for recycling acidified spent shale back into the process for further reduction of the oil shale nitrogen content.