Ikelic - Alliance Digital Repository

OIL SANDS
proved environmental mitigation techniques and
significantly
higher oil prices.
However, the authors suggest that certain small
deposits of tar sands which also contain a high
concentration of certain metals may be
developed first; coproduction of metals could
provide sufficient synergy to make these deposits
commercial.
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TECHNOLOGY
COMBINED HSC ROSE PROCESS OFFERS
NEW ROUTE FOR UPGRADING HEAVY
FEEDSTOCKS
The High conversion Soaker Cracking (HSC)
process is one of the latest upgrading tech
nologies for bottom-of-the-barrel, licensed by
Toyo Engineering Corporation (TEC), Japan.
The HSC process is an advanced continuous
thermal cracking technology, featuring a wide
range of conversion levels between visbreaking
and coking while producing pumpable liquid
residue at process temperature.
A broad range of heavy feedstocks such as
heavy crude, oil sand bitumen, long and short
residue and visbroken residue can be charged to
the HSC process.
The cracked distillates from the HSC process are
mostly light and heavy gas oils with fewer un
saturates than coker distillates.
The process uses no hydrogen, no catalyst and
no high pressure equipment. The investment
cost and utilities consumptions are only slightly
higher than those of the conventional visbreaker
with vacuum gas oil recovery.
3-14
Process Description
Feedstock is first charged to a charge heater
achieving temperatures of 440 to 460C, depend
ing
(Figure 1). Cracking
on the desired conversion in the soaker drum
in the heater tube is mini
mized by employing high liquid velocity and
steam injection.
The heater effluent passes into a soaking drum,
where sufficient residence time is provided to
crack to the desired conversion. The soaking
drum is operated under atmospheric pressure
with steam injection for stripping at the bottom of
the drum.
In the soaking drum, liquid flows downward pass
ing
through a number of perforated plates to the
bottom. Steam with cracked gas and distillate
vapors flows upward through the perforated
plates, countercurrent to liquid flow, up to a free
board in the top of the drum where they are
separated from the liquid.
Temperature in the drum decreases from top to
bottom due to adiabatic reaction and stripping of
cracked distillate. The liquid from the bottom is
pumped out and quenched by heat exchange to
temperatures below 350C.
Vapors from the soaking drum are transferred to
a single combination tower, where the distillates
are fractionated into desired product oil streams
including a heavy (vacuum) gas oil fraction.
Coke-Free Operation
Conversion by conventional visbreakers is limited
by the stability of the visbroken residue. High
conversion operation of the conventional
visbreaker tends to produce unstable residue
with excessive precipitation of asphaltene ag
gregates which eventually leads to coking in the
plant.
In the HSC process, however, a homogeneous
stable dispersion of asphaltene in the residue is
THE SYNTHETIC FUELS REPORT, JANUARY 1995