This is the bottom product from the vacuum distillation unit. Just as in the case of the atmospheric residue it has several options for its use in meeting the refinery’s product slate. In the case of the energy refineries it can be upgraded to prime distillate products by a recycling thermal cracking process, coking, deep oil fluid catalytic cracking or hydro-cracking or indeed a combination of these processes.
In the case of the production of lube oils it can be processed to remove the heavy asphaltene portion of the stream. This deasphalted product is excellent lube oil blending stock, commonly called ‘Bright Stock’, which, when de waxed and subject to other lube oil processes becomes the precursor for a variety of lube oil products . The asphalt portion of the de asphalting process has a wide spectrum as precursor to the many grades of bitumen used in building, and road making . The vacuum residue itself also figures in the production of bitumen. Where non-energy products are significant in the refinery’s product slate, the vacuum residue as produced is the key component in bitumen production.