| INDALIN+:A Novel process for the conversion of Naphtha to LPG
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INDALIN+ is a novel process developed by Indian Oil R&D Center for the first time
in the world for converting various naphtha streams to LPG and gasoline.
In this process, the reaction occurs in a dense fluidized bed reactor and
no hydrogen is supplied. The operating pressure is low and the coke is burnt
in a separate fluidized bed regenerator. The LPG has good olefin content and
the gasoline has good octane number with significant toluene and xylene
content. Both the LPG and gasoline have high petrochemicals value.
The INDALIN process, earlier developed by IOC R&D Centre in 2001 is suitable
for converting olefinic rich naphtha streams (VBN, CN etc.) only. However,
the modified technology INDALIN+ can upgrade the straight run naphtha also,
since the catalyst is modified to attain the desired acid strength for
cracking the paraffin molecules of straight run naphtha.
Patent right for the INDALIN process has been granted for USA and application filed
in several countries.
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INDALIN+ is based on the principle of circulating fluidized bed as employed in
the FCC process. The converter section consists of a small riser, a relatively
larger fluidized dense bed reactor and a small fluidized bed regenerator. The
feed (full range naphtha) is preheated upto 4250C in a pre-heat furnace before
being injected to the bottom of the riser as gas.
The riser is short which allows efficient mixing of the atomized feed and
regenerated catalyst. The extent of reaction inside the riser is insignificant.
The hydrocarbon-catalyst mixture is carried to the dense bed reactor where a
proportionately larger bed of catalyst is maintained to achieve a WHSV of
about 1-2 hr-1. The coke deposition rate on the catalyst is relatively small
which requires a small regenerator capacity.
The spent
catalyst is stripped in a stripper. The relatively higher reactor pressure
(4-5 kg/cm2 abs) as compared to conventional FCC unit allows to minimize the
wet gas compressor load and also the size of the gas concentration section.
In addition, it also helps in increasing the LPG yield and the octane number
of gasoline.
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| Typical operating conditions
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| Reactor top temp, 0C |
480-510 |
| Stripper temp, 0C |
500 |
| Regen. temp, 0C |
630-650 |
| WHSV, hr-1 |
1.0-2.0 |
| CFR |
1-1.4 |
| Cat/oil rato |
4-6 |
| Reactor Pressure, kg/cm2 (abs) |
4-5 |
IOC R&D Center has earlier developed the i-MAX additive based on ZSM-5
zeolite for LPG boosting in FCC process, which has been successfully
demonstrated in IndianOil's Gujarat FCC unit in 2001. The INDALIN+ catalyst
is a modified formulation based on the increased concentration of ZSM-5 zeolite
in the i-MAX. Furthermore, the acid strength of the catalyst has been improved
by suitable steam treatment. The physico-chemical properties and mechanical
strength of INDALIN+ catalyst are similar to commercially available ZSM-5
additives for FCC unit.
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| Yield Pattern & Product Quality
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| Component |
Wt% |
| Dry Gas |
6-10 |
| LPG |
45-55 |
| Benzene rich cut |
4-6 |
| Gasoline |
20-35 |
| Coke |
1.5-2.5 |
| LPG Componenet |
(Wt%) |
| Propylene in LPG |
5-10 |
| Butylene in LPG |
5-10 |
| Gasoline Componenet (wt%) (900C+cut)
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| Total Aromatics |
55-65 |
| Naphthenes |
25 |
| Paraffins |
10 |
| Benzene in gasoline, vol% |
0.7 |
| Toluene in gasoline, wt% |
20 |
| Xylene in gasoline, wt% |
16 |
| Sulfur reduction |
~98% |
| RON of gasoline |
94 |
| Olefins in gasoline, vol% |
<2% |
The full range gasoline has benzene content of about 6 vol%.
Hence, a gasoline splitter is necessary to split into two cuts namely
IBP-900C and 900C+. The properties of the latter cut are shown above in
the table. The benzene rich cut is about 5 wt% of the feed and routed to
naphtha pool.
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 Suitability of INDALIN+ in refineries
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The INDALIN+ process provides significant value addition to a refinery.
It can be used for converting surplus naphtha streams to LPG and gasoline.
Since the gasoline is rich in aromatics (BTX), the same can be used to
replace the role of catalytic reforming unit. Alternately, the INDALIN+
liquid can be sent to aromatic extraction. In the INDALIN+ process, the
olefinic undesirable streams e.g. coker/ visbreaker naphtha are the
preferred feedstock. FCC gasoline can also be sent to INDALIN+ for
conversion of olefins to LPG and also for significant amount of
de-sulfurization of the FCC gasoline without sacrificing the octane
number. Hence this process can play a pivotal role in managing the refinery naphtha pool.
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Considering the simplicity of the process design, a 1.0 MMTPA INDALIN+ unit
is expected to cost about US$ 77 million (ISBL cost). The catalyst
consumption is about 0.8 MT/day for a 1 MMTPA unit with ex-factory
catalyst cost about US$ 7.7 thousand/ton. The catalyst can be supplied
within India.
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