摘要 |
A solvent deasphalting of crude oil or petroleum heavy fractions and residues is carried out in the presence of a solid adsorbent, such as clay, silica, alumina and activated carbon, which adsorbs the contaminants and permits the solvent and oil fraction to be removed as a separate stream from which the solvent is recovered for recycling; the adsorbent with contaminants and the asphalt bottoms is mixed with aromatic and/or polar solvents to desorb the contaminants and washed as necessary, e.g.. with benzene, toluene, xylenes and terahydrofuran. to clean adsorbent which is recovered and recycled; the solvent-asphalt mixture is sent to a fractionator for recovery and recycling of the aromatic or polar solvent. The bottoms from the fractionator include the concentrated PNA and contaminants and are further processed as appropriate. |