refining india 2022
Indigenous technologies pave the way for crude oil-to-chemicals transition
Sarvesh Kumar, Madhusudan Sau and SSV Ramakumar IndianOil Corporation Limited
handle kero, SRGO, and straight-run naph- tha, with high conversions and without any feed pre-treatment. The technology pro- duces propylene in the range of 15-20 wt% on a fresh feed basis with a P/E ratio of ~2, depending on the type of feed. Gasoline with a BTX content of up to 40 wt% is pro- duced, which is a suitable feedstock for the aromatic complex. • indResid H is an indigenous slurry hydro- cracking technology for residue upgrad- ing using a proprietary oil-soluble catalyst system. The process upgrades bottom- of-the-barrel (vacuum residue) to mid- dle and lighter distillates using a slurry reactor system under high temperature and hydrogen partial pressure. The over- all conversion of the process is between 94 and 96 wt%, and the middle distil- late yield is around 55-65 wt%. For COTC purposes, the process parameters can be adjusted to improve naphtha yield, and middle distillate can be routed to a middle distillate hydrocracker to improve petro- chemical intensity. • Delayed Coker technology is indige- nously developed and licensed by IndianOil jointly with EIL. The technology has been licensed to two coker units in the IOCL refinery, one of which is currently under operation and producing anode-grade coke. Also, a non-IOCL refinery has selected the technology to revamp their coker unit for processing one of the heaviest feedstocks (CCR ~30 wt%) among the delayed coker units (DCU) in India. • Ind-Coker AT technology has been devel- oped to improve the distillate yield by reducing the lower value coke by 4-5 wt% over conventional DCUs. This patented technology is a key solution to addressing the issue of petcoke disposal.
The crude oil-to-chemicals (COTC) transi- tion is being brought in due to growth in petrochemicals, estimated at 1.4 times GDP, which could contribute to a 35-40% increase in total oil demand worldwide. Traditional refining generates 20% resid, with the major part as fuels, while 5-6% is converted to chemicals. A multi-prong approach targeting the chemical conver- sion of each fraction of crude oil is required to achieve the highest yields of light olefins and aromatic chemicals from crude oil. The refining and petrochemical industry can benefit immensely by adopting indigenous refining technologies developed by the IndianOil R&D Centre to achieve maximum COTC conversions. IndianOil has developed a series of state- of-the-art technologies, such as INDMAX, INDALIN, indLPet, indResid H , Delayed Coker, and Ind-Coker AT , a combination of which can achieve higher crude to chemi- cal conversions. The technology features are described below: • INDMAX is a flagship technology from IndianOil and globally licensed jointly by IOCL and Lummus. This catalytic cracker technology enables the conversion of resi- due and gasoils to light olefins with selec- tive catalyst and hardware technology. The technology can produce ethylene and pro- pylene in the range of 3-5 wt% and 15-20 wt%, depending on the feedstock. The technology has been licensed to nine refin- eries in India and abroad. Three units are operating at different IOCL refineries. • INDALIN is a catalytic cracking technol- ogy suitable for upgrading mainly cracked naphtha to light olefins and BTX with shape- selective catalyst and hardware employing a circulating fluidised bed reactor-regener- ator configuration. This technology can also
Figure 1 4.17 MMTPA grassroots INDMAX unit at IOCL Paradip refinery
• indLPet is a mild hydrocracking technol- ogy which operates in the pressure range between 40 and 60 barg for highly aro- matic FCC LCO conversion with a propri- etary ring-opening catalyst system to BTX and BTX precursor (C₉-alkyl benzenes). The technology produces LPG (4-6 wt%) light naphtha (20-25 wt%), which can be routed to a naphtha cracker unit, heart-cut naph- tha (55-65 wt%), rich in BTX, and BTX pre-
cursor, which can be directly routed to the aromatic complex, and ultra-low sulphur diesel (ULSD) (8-15 wt%). The sulphur and nitrogen in indLPet heart-cut are below <0.5 ppmw. The RON of total naphtha (light + heart-cut) is around 94-95 units and can be routed to the gasoline pool as an alter- native. The technology is available in once- through and recycle configurations. A synergistic combination of the above IOCL technologies can achieve maximum conversion of crude oil to value-added chemicals in the range of 55 to 65 wt%. One typical configuration developed by IOCL is shown in Figure 2 , wherein crude oil is fed to the atmospheric vacuum unit (AVU) to obtain naphtha, gasoils, VGO, and vac- uum residue. The straight-run naphtha with cracked naphtha from other units is fed to the INDALIN and steam cracker unit in the desired proportion for conversion to light olefins and aromatics. After hydrotreat- ment, VGO and indResid H gasoil are routed to INDMAX for further conversion to lighter products, including light olefins. INDMAX HCN and LCO are routed to indLPet to obtain light naphtha and aromatic-rich heavy naphtha for the aromatic complex and low-sulphur diesel as fuel. Vacuum res- idue is processed in the indResid H unit to obtain gases, light naphtha, gasoils, and pitch. Pitch and CLO are routed to the DCU/ Ind-Coker AT unit for conversion to cracked naphtha and gasoil feed for INDALIN and premium quality anode-grade coke.
C =
C =
C =
LCO to indLPet
INDALIN
Gases to GASCON
Gasoline
NCU
To aromatic complex
CN + LCGO
Gases from DCU, NCU indResid H
SRN
C /C to NCU
LCN + MCN
DG + LPG
Para nic r affinates as n aphtha
Naphtha
Kero + LGO + HGO
Ethylene
DG + LPG
LGO
INDMAX
GASCON (PRU, C /C splitters)
Propylene
Aromatics (BTX)
Crude oil
AVU
Butylenes
Aromatic Complex
FG + LPG
HDT VGO
Naphtha
Diesel to p ool
FG + LPG
LCO, HCN
SR VGO
LN to NCU
HDT
Naphtha to INDALIN
indLPet
FG + LPG to GASCON
Gasoline pool
Heart cut
CN + LCGO
INDMAX CLO
ULSD
VR
HCGO
LGO
indResid H
Diesel pool
HGO
FRAC.
DCU/ Ind-Coker AT
FG + LPG to GASCON
Pitch
Anode - grade coke
PFO from NCU
Figure 2 A typical COTC configuration developed by IOCL
Contact: saum@indianoil.in
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