Application: The Akzo Nobel/Quadrise emulsion residue enhancement process converts highly viscous, low-value, uncut residues from vacuum unit operations to an emulsion fuel for onward sale to third parties. Refiners benefit from term contract offtake of residue and release of HFO cutter-stock back to the refinery, for higher value realization. Quadrise typically purchases the residue at a price higher than its intrinsic value, and assume responsibility for the emulsion fuel sales.
Enhancements include moving to deeper vacuum unit cuts and increasing visbreaker severity or visbreaker vacuum flasher recovery to increase yields of lighter products. Enhancements are achieved without the normal penalty of increased cutter-stock addition to the resulting heavier residues. A combination of modifying process conditions and processing heavier, cheaper, crude oils leads to significantly lower quality residues in terms of density, CCR and viscosity. The technology handles these low-quality residues and produces a transportable emulsion fuel with a viscosity of 200 –1,000cSt at 50°C.
Description: Residues from a vacuum unit, visbreaker, visbreaker vacuum flasher or solvent de-asphalter (1) are taken from the refiners run-down system after process heat has been extracted, but prior to cutter stock addition. The residue stream is processed to a 70:30 oil-in-water emulsion in a proprietary skid-mounted package (2) supplied by Quadrise under license from Akzo Nobel. Various commercial options are available including licence; BOO/BOOT by Quadrise or JV with refiner.
Operating conditions: The residue temperature is adjusted to give a viscosity of around 300cSt for supply to the emulsification process. The maximum supply temperatures are 190°C (standard unit) and 260°C (high-temperature unit). The emulsion fuel run-down temperature to conventional HFO storage tanks is less than 65°C.
Residue viscosities of up to 100,000cSt (standard unit) and 60,000,000cSt (high-temperature unit) measured at 100°C can be handled, without impacting the quality of the emulsion fuel. The standard unit operates at less than 10 bars.
Licensor: Akzo Nobel through Quadrise Fuels International.