| Author(s) |
Pant, H. J.; Sharma, V. K.; Nair, A. G. C.; Tomar, B. S.; Nathaniel, T. N.; Reddy, A. V. R.; Singh, G.
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Instrumental neutron activation analysis (INAA)
of fluid catalytic cracking (FCC) catalyst samples was carried out
with an objective to identify activable elements and evaluate its
suitability for use as an intrinsic radio tracer for tracing
catalyst itself in Fluid Catalytic Cracking Units (FCCUs) used
in petroleum refining. Two catalyst samples obtained from
two different refineries were analyzed. Twelve different elements
were identified in each catalyst sample and their respective
concentrations were determined. From there corded gamma-ray
spectra, it was found that lanthanum-140(140La) and
sodium-24(24Na) were the predominantly present and
suitable radio nuclides that could be used as radio tracers for
tracing catalyst in FCCUs. Lanthanum being present in much
higher concentration forms
the major component of the radio tracer after irradiation. Based
on the results of INAA, appropriate quantities of the catalyst
samples were irradiated with neutrons to produce the desired
amount of activity of lanthanum-140 and sodium-24 to be used as
radio tracers for tracing the catalyst itself in a pilot as well
as an industrial-scale FCCU. The residence time distribution (RTD)
of catalyst was measured and analyzed to determine mean residence
time (MRT). The axial dispersion model (ADM) was used to simulate
the measured RTD data and investigate the degree of axial mixing.
The results of the experiments were used to improve the design of
pilot-scale FCCU and optimize the performance of the
industrial-scale FCCU.
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