Solvent Deasphalting (SDA)
Solvent deasphalting (SDA) is a separation process in which residues are selectively separated by molecular type by mixing with paraffinic solvents and precipitating out of solution asphaltenes and other residue heavy components. SDA produces a low-contaminant, relatively high hydrogen deasphalted oil product (DAO) and a pitch product that contains the majority of the residue’s contaminants (metals, asphaltenes, CCR).
Depending on the DAO quality, it can be used for lubes base oil feedstock, for vacuum gas oil (VGO) conversion feedstock (RFCC and ISOCRACKING® technologies) or for residue hydrocracking (LC-FINING™ technology) feedstock. The pitch product is typically used for delayed coking feedstock, as a fuel oil blending component, gasifier feed (E-Gas™ gasification technology), or in some cases can be blended into asphalts. Solvents range from propane for lubes applications through pentane for residue hydrocracking applications.