REMOVAL OF NITROGEN-COMPOUNDS FROM SHALE OIL BY ADSORPTION ON TO ACID-TREATED SHALE ASH

Basic nitrogen compounds occurring in shale oil can be selectively adsorbed by spent oil shale ash that has first been treated with either a mineral acid, e. g. HCL, or a Lewis acid, e. g. CuCl//2. For Rundle shale oil a reduction in the basic nitrogen level from 0. 55 wt% to less than 0. 05 wt%, and total nitrogen from 1. 2 wt% to 0. 5 wt%, has been achieved using an ash rich in clay minerals and low in carbonates. It has also been shown that pyridine, quinoline and 2,6-dimethylpyridine are all readily adsorbed by ash treated with several common transition metal chlorides. Selection of an appropriate Lewis acid, or mixture of acids should enable adsorption to be optimized when specific impurities are known to be present. Under appropriate conditions most of the reference basic nitrogen compounds can be adsorbed in less than 1 h.