Since 1990, Amec Foster Wheeler and UOP have designed and licensed more than 50 visbreaking units.
Visbreaking is a non-catalytic thermal process that converts atmospheric or vacuum residues via thermal cracking to gas, naphtha, distillates, and visbroken residue. Atmospheric and vacuum residues are typically charged to a visbreaking unit to reduce fuel oil viscosity and increase distillate yield in the refinery.
- High sulphur fuel oil reduction
- Reduces distillate cutter stock requirements, hence distillate available for more valuable transportation fuels
- Low cost upgrading.
There are two types of visbreaking technology that are commercially available: the ‘coil’ or ‘furnace’ type and the ‘soaker’ process. Together with UOP, we offer both types. The coil visbreaking unit design achieves the desired conversion and viscosity reduction within a dedicated soaking coil in the furnace. We have engineered a number of soaker type visbreaking units in which the majority of conversion reactions take place over a longer residence time in a soaker drum.
Visbreaking units can be configured with vacuum flashers on the tar stream to produce more heavy gas oil distillate and can also be configured as two-stage visbreaking/thermal cracking unit for maximum yield of lighter distillates. A number of the units we have designed have integrated visbreaking and thermal cracking sections.