Application: The Shell Deep Thermal Conversion process closes the gap between visbreaking and coking. The process yields a maximum of distillates by applying deep thermal conversion of the vacuum residue feed and by vacuum flashing the cracked residue. High-distillate yields are obtained, while still producing a stable liquid residual product, referred to as liquid coke. The liquid coke, not suitable for blending to commercial fuel, is used for speciality products, gasification and/or combustion, e.g., to generate power and/or hydrogen.
Description: The preheated short residue is charged to the heater (1) and from there to the soaker (2), where the deep conversion takes place. The conversion is maximized by controlling the operating temperature and pressure. The soaker effluent is routed to a cyclone (3). The cyclone overheads are charged to an atmospheric fractionator (4) to produce the desired products like gas, LPG, naphtha, kero and gasoil. The cyclone and fractionator bottoms are subsequently routed to a vacuum flasher 5), which recovers additional gasoil and waxy distillate. The residual liquid coke is routed for further processing depending on the outlet.
Yields: Depend on feed type and product specifications.
Feed, vacuum residue Middle East
Viscosity, cSt @100°C 615
Products in % wt. on feed
Gasoline, ECP 165°C 8.2
Gas oil, ECP 350°C 19
Waxy distillate, ECP 520°C 22.8
Residue ECP 520°C+ 46.2
Economics: The typical investment for a 25,000-bpd unit will be about $1,900 to $2,300/bbl installed, excluding treating facilities. (Basis: Western Europe, 2004.).
Utilities, typical consumption/production for a 25,000-bpd unit,
dependent on configuration and a site’s marginal econmic values for
steam and fuel:
Fuel as fuel oil equivalent, bpd 417
Power, MW 1.2
Net steam production (18 bar), tpd 370
Licensor: Shell Global Solutions International B.V. and ABB Lummus Global B.V.