Ikelic - Alliance Digital Repository

COAL
- The
- The
- A
- A
spectrum of coals. Also, spiral flow
produces hot gas circulation through the
slag tap holes, which enhances better
slag release.
pneumatic dry coal feed system
reduces oxygen consumption, therefore
increasing the efficiency. It also
eliminates any limitation of coal
properties imposed on a slurry or wet
system.
multi-burner system with a specially
equipped coal distributor makes it pos
sible to gasify a large amount of coal in a
small but easy to scaleup gasifier.
slag self-coating refractory with water
cooled tubes increases refractory wall
life of the gasification zone and its
reliability.
hot direct char recycle system directly
increases total gasification efficiency
while simplifying the process configura
tion.
Operating Experience
The initial 2 years were a shakedown phase,
during which the objectives were to verify the
equipment and process configurations, and to
make any necessary modifications.
HYCOL's first full-capacity
operation occurred in
July 1993. The highlight of the 3-year operating
term was a continuous 49-day run from Decem
ber 14, 1993 to January 31, 1994. By
January 25, 1994, a 1,000-hour, uninterrupted
and full-capacity operation with total direct
recycle of hot char was completed.
Carbon conversion efficiency reached
80-100 percent and the cold gas efficiency of
Taiheiyo coal with char recycle was in the range
of 65-79 percent at a 0.64-0.92 oxygen/coal
weight ratio. Char recycle increased both carbon
conversion and cold gas efficiency. Cold gas ef-
ficiency
reached a maximum at the
AST
0.78 oxygen/coal ratio targeted in the gasifier
design.
Additional runs were made to demonstrate
operability
of the process with a wide spectrum
of feed coals. Muswellbrook (Australia), Datong
(China) and Blair Athol (Australia) coals were
tested. On-the-fly feed switching from Mus
wellbrook to Datong was carried out successfully
in March 1994.
years'
Through the 3 activity, operational knowhow
was accumulated in such aspects as initial
and continuous coal feeding technique, changing
coal feed rate, control techniques for gasification
temperature, several emergency measures,
safety
Summary
shut down sequence and so on.
of Results
Plant runs and inspections have validated the
original design concept and features of the
HYCOL technology. Substantial progress was
made by the research activity at the pilot plant in
the last 6 months of operation.
- Operations
-
- Targeted
- Four
- Problems
at several oxygen/coal ratios
confirmed favorable temperature profiles
in the gasification section as envisioned
in the design concept.
Reliability was verified.
carbon conversion rates and
cold gas efficiencies were obtained.
on-
coals were gasified including an
the-fly feed coal switching. Addition of a
fluxing
fully.
agent was demonstrated success
due to ash components which
were experienced during the shakedown
phase were successfully overcome.
Overall plant performance closely matched
projections before startup. According to the
project sponsors, the test results confirmed that
the HYCOL process has a great potential to con-
THE SYNTHETIC FUELS REPORT, JANUARY 1995