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Fluid Catalytic Cracking (FCC) is a major secondary conversion process in a
refinery for upgrading low value heavy hydrocarbons into high value light
distillates and LPG. The process works in the presence of fine zeolitic
catalyst particles in a fluid bed reactor/regenerator system.
FCC is a flexible process in terms of loading/unloading and switch over of
catalysts/additives. Contrary to the operation in fixed bed catalytic
reactors, the fluid bed riser (reactor) and regenerator in FCCU makes the
operation easier since at any point of time, the spent catalyst can be
withdrawn from the system and fresh catalyst can be loaded to maintain
the catalytic activity and get the desired yield pattern. The flexibility
for easy switch over to new catalyst and additive is advantageous as better
catalyst with improved yield pattern and product quality can be introduced
to the system at any point of time. The addition rate of catalyst and
additive can also be varied optimally as per the requirement of the unit.
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 FCC Catalyst / Additive Selection |
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Since the performance of the FCC unit significantly
depends on the catalyst and additives, it becomes very important to select
the best suitable catalyst for a particular system. One FCC catalyst may
perform better for particular unit where as its performance may not be
the same for the other unit. Hence, the selection of a suitable catalyst
for the particular unit is very much unit specific.
Many FCC additives are available in the market e.g. ZSM-5 for LPG
boosting, bottom cracking additive (BCA), CO-Promoter, SOX addtive etc.
The performance of these additives sometime is feedstock dependent
and unit specific. Hence, it is very useful to evaluate their
performance on case-to-case basis before taking plant trial.
IndianOil Research and Development Centre (IOC R&D) has developed a
fullfledged facility for evaluation, characterization and selection of
FCC catalyst and additive while working in the area of FCC since
almost two decades. Most of the refiners are fully dependent on the
catalyst vendors for the performance prediction of the catalyst and
additive supplied by them. Each catalyst supplier claims his catalyst
to be the best. Hence, it is very useful to benchmark the catalysts
based on R&D evaluation in a common platform before actually
introducing the catalysts to the system.
IOC R&D has established its credibility in evaluation,
characterization and selection of FCC catalysts. Many catalysts and
additive samples are evaluated using the indigenously developed
methodology and the best catalyst and additive are recommended to the
refinery on regular basis.
IOC R&D Centre has many micro-reactors and FCC pilot plants for
evaluation of FCC catalyst and additives. It has also developed an
in-house kinetics based FCC simulator which can predict the
catalyst/additive performance based on the data generated from the
micro reactors. Using the prediction obtained from this simulator,
at least 15- catalyst/additive change over have been successfully
implemented in the commercial FCC plants.
In addition to fresh catalyst selection, the centre also provides technical
service to refiners on FCC catalyst quality check up, condition monitoring of
equilibrium catalyst and on optimization of the process.It regularly provides
technical solutions to revamping, trouble shooting and hardware constraints to
IndianOil's own FCC units and also to other non-IOC FCC units.
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At IOC R&D, the catalyst/additive is initially
studied in the micro reactor and the data generated from these reactors
are used for predicting the plant performance with the help of FCCMOD
simulator. The accuracy of simulator predicted data and actual plant data
could be compared with some of the catalyst swich over cases recommended
by IOC & R&D. The economic benefits derived from such switch over are also
quite significant as can be seen from the following tables :
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| Plant Performance Vs R&D Prediction
CO Promoter Additive
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| Yield, wt% |
Incremental Shift |
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Plant |
R & D Prediction |
| Gasoline |
+3.0 |
+2.3 |
| CLO |
-3.0 |
-3.41 |
| Coke |
-0.50 |
-0.46 |
| Regen Temp |
+18 |
+22 |
| CRC |
-0.13 |
-0.25 |
| Net Economic benefit : US$ 0.86 million/yr
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| Plant Performance Vs R&D Prediction
Catalyst Switch Over
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| Yield, wt% |
Incremental Shift |
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Plant |
R & D Prediction |
| Dry Gas |
-0.22 |
-0.02 |
| Gasoline |
+3.90 |
+1.94 |
| CLO |
-3.67 |
-2.35 |
| Net Economic benefit : US$ 1.05 million/yr
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| Plant Performance Vs R&D Prediction
Bottom Cracking Additive
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| Yield, wt% |
Incremental Shift |
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Plant |
R & D Prediction |
| LPG |
+0.06 |
+0.16 |
| Gasoline |
-0.15 |
-0.13 |
| TCO |
+1.71 |
+2.15 |
| Net Economic benefit : US$ 0.41 million/yr
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| Plant Performance Vs R&D Prediction
Lotus Catalyst Switch over
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| Yield, wt% |
Incremental Shift |
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Plant |
R & D Prediction |
| DG |
+0.43 |
+0.09 |
| LPG |
+0.67 |
+1.66 |
| TCO |
-3.12 |
-0.64 |
| Bottom |
-0.11 |
-0.76 |
| Net Economic benefit : US$ 2.9 million/yr
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Facilities at IndianOil - R&D Centre |
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Fully automatic FCC pilot plants |
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ASTM and Standard MAT units
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ACE MAT for resid cracking |
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Hydrothemal deactivation unit |
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Cyclic deactivation unit |
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Regenerability test unit |
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FCC cold stand |
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Attrition test unit |
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Catalyst Characterization Facilities |
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The facilities for the measurement of surface area,
pore volume, pore size distribution, particle size distribution, acidity,
apparent bulk density, true density, metal surface area/metal dispersion,
crystallinity, morphology, DTA/TGA, CHNS content and carbon-sulphur
content etc. are available.
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FCC feed and product characterization facilities |
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Analytical facilities to measure pour point, flash
point, density, viscosity, sulfur and nitrogen content, moisture content,
RON etc. are available. R&D Centre has other analytical instruments e.g.
SDA, HTSIMDIST, RGA, GC-MS, HPLC, NMR spectrometer, XRF etc.
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Jointly define the objectives of
the FCC unit e.g. profit/LPG/Gasoline maximization etc. |
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Collection of base case plant
operating data, feed and catalyst samples. |
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Collection of prospective catalyst/additive
from different vendors. |
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Establish the test condition for hydrothermal deactivation/MAT unit so
as to simulate the plant condition adequately. |
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Generate the micro reactor data with base and
new catalyst using the composite plant feedstock. |
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Tune the FCC simulator with base case plant data. |
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Insert the micro reactor data of new catalyst in the
FCC simulator and predict the plant performance. |
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Selection and recommendation of best catalyst for
plant trial. |
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