Solvahl™ is an efficient solvent deasphalting process (SDA) that removes the asphaltenes, most metals and other impurities contained in atmospheric or vacuum residues. SDA produces an extracted deasphalted oil cut (DAO) from which most of the C7 asphaltenes have been eliminated. The content of metals and coke precursor compounds are also significantly reduced, making DAO a suitable feed for downstream Hydrocracking or FCC units.
Solvents used in the Solvahl process can vary from C3 to C6 depending on feed properties and downstream process objectives. The relative yields of DAO and asphalt, as well as the characteristics of both products, are linked to the nature of the feed, the operating conditions and the solvent type.
Through its experience in hydroprocessing DAO in commercial units, Axens has an in-depth knowledge of the quality required of the DAO fraction.
Solvahl technology is focused on:
- Relevant and optimized separation of DAO and Asphaltenes with associated design criteria to reach specifications.
- Control of DAO quality, and especially its remaining asphaltenes content, is a main concern as it impacts downstream catalyst performance and cycle length.
- Opportunities to extract value from the produced asphalt
- Efficiency of advanced extractor design and solvent recovery at reduced cost
The association of the Solvahl process with other Axens conversion technology such as hydrocracking (HyK) or ebullated bed (H-OilRC and H-OilDC) gives the opportunity to maximize middle distillates yields out of heavy residues.
Thirteen Solvahl units have been licensed by Axens.