USE OF BASIC ALUMINA IN FRACTIONATION OF FOSSIL-FUELS

The use and efficiency of extrographic fractionation are reported for a number of fossil fuels and their processing products. The influence of basic alumina, which is a constituent of the column packing, on the fractionation selectivity is discussed. This fractionation is capable of an efficient separation of non-polar hydrocarbons, pyrrolic-type nitrogen compounds, and phenolic compounds. The hydrocarbon fraction also includes highly condensed polyaromatics. In the chromatographic fractionation these polyaromatics are eluted along with heteroatom-rich compounds. The extrographic fractionation has been found to be independent of column loading on going from a sample-to-sorbent ratio of 1:15 to 1:8 (w/w). However, it is not possible to separate aromatic hydrocarbons according to the ring number, and therefore the extrography is a suitable method for the fractionation of coal-derived liquids containing large amounts of heteroatom compounds of different polarity.