1
PRE- FEASIBILITY REPORT
OF
ANDHRA PRADESH PETROCHEMICAL COMPLEX
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1.0 INTRODUCTION
GAIL (India) Limited is the largest state-owned Natural Gas transportation and distribution
company in India. It has following business segments: Natural Gas, Liquid Hydrocarbon,
Liquefied Petroleum Gas Transmission, Petrochemical, City Gas Distribution, Exploration
and Production and Electricity Generation. GAIL has been conferred with the Maharatna
status by the Government of India.
GAIL owns and operates Petrochemical complexes at Pata, UP and they have also constructed another Petchem complex at Lepetkata, Assam. GAIL also has a share in the Dual Feed Cracker complex at OPaL, Dahej. GAIL presently has the following product portfolio from their Petchem complexes:
LLDPE
HDPE
PP
Butene-1 ( internally used) HPCL is a Government of India Enterprise with a Navratna Status, and a Forbes 2000 and Global Fortune 500 company. HPCL owns & operates 2 major refineries producing wide variety of petroleum fuels & specialties, one in Mumbai (West Coast) of 6.5 Million Metric Tonnes Per Annum (MMTPA) capacity and the other in Visakhapatnam, (East Coast) with a capacity of 8.3 MMTPA. HPCL also owns and operates the largest Lube Refinery in the country producing Lube Base Oils of international standards, with a capacity of 428 TMT. HPCL in collaboration with M/s Mittal Energy Investments Pvt. Ltd. is operating a 9 MMTPA capacity Refinery at Bathinda in Punjab.
GAIL (India) Limited (‘GAIL’) along with Hindustan Petroleum Corporation Limited (‘HPCL’) is
exploring the opportunity for setting up a Greenfield Petrochemical Complex in Andhra
Pradesh to produce 1 MMTPA of ethylene and ethylene derivatives based on imported
ethane and / or Naphtha available in domestic market.
2.0 PROJECT LOCATION AND DETAILS
The proposed Petrochemical complex will be located at A.V. Nagaram village, Thondangi
Mandal of East Godavari district, Andhra Pradesh. The proposed complex is spread across
2000 acres. Nearest airport is Rajahmundry (87 km) from proposed site.
Sub-soil predominantly comprises of sandy/sandy clay/clayey sand soil with very loose/very
soft to very dense/hard consistency. Sandy soil is predominant up to 10.0m depth below
Natural ground level (NGL) and below which the strata is generally clayey. Most of the
boreholes shows fairly competent stratum at shallow depth except in few where very
loose to loose or very soft to firm soil exists up to 8.0-10.0m depth. Available sandy soil in
the plot area is suitable for backfilling in foundations and grading purpose. However,
available sandy clay/clayey sand shall be tested for its suitability.
Power source
33KV /132 KV Power source from AP Transmission Corporation at Pithapuram substation is
available near the site at a distance of about 25 Km.
Construction and Permanent water source
Site has proximity with the source of water. Polavarum left main Canal (AP irrigation) is
approximately 12 KM from the proposed site, Samalkot is an alternate source of water
which is around 28 KM from the proposed site.
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Environmental requirements
No Ecologically sensitive area like national monument / bird sanctuaries/ major settlement is
located within 25 Km of site.
Defence requirements
No Defence base within 25 Km of the site.
Downstream Industry
No downstream industry related to Petrochemical in the vicinity.
Topography of site & development requirement:
The topography of the proposed area is flat terrain with minor sand dune hillocks which
includes one major Creek running across the proposed site.
Project Description
The process facilities with capacities are described in Table 1.
Table 1: Process Unit Capacities
Sr.no. Process Units Capacity, KTPA
1. Cracker Unit 1000
2. C4/C5 Hydrogenation unit 390
3. Pyrolysis Gasoline Hydrogenation Unit 320
4. Benzene Extraction Unit 70
5. Mono-Ethylene Glycol(MEG) Unit 700
6. LLDPE / HDPE 450
7. Butene-1 25
8. Chloro Alkali 177 (Chlorine Basis)
9. VCM 300
10. PVC 300
11. Poly-Propylene Unit 315
Material Balance
Overall material balance is given in Table 2.
Table 2: Overall Material Balance
S.No. Feed (KTPA)
1 Ethane 625.0
2 Naphtha 1045.0
3 Propane 275.0
4 Oxygen 436.2
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5 Water 104.7
6 Salt 322.2
7 Losses (126.8)
S.No. Product
1 Hydrogen ** 91.9
2 Fuel Gas ** 326.9
3 Benzene 68.9
4 PGO 26.7
5 HPG 104.8
6 CBFS 36.6
7 MEG 700.0
8 DEG 57.8
9 TEG 3.0
10 PVC 300.0
11 Caustic 201.4
12 LLDPE / HDPE 450.0
13 PP 313.3
3.0 Process Description
3.1 Cracker and Associated Units
Cracker unit is the heart of the total complex, which gives feed to all the downstream end
product units.
Furnace section:
Cracking furnace or often know as brain behind the steam cracker unit, is the most
important and complex section of the plant. In this section preheated feed stock is getting
mixed with process steam and then sent to convection coils for further heating against flue
gases generated in radiant zone of the furnace. Feed stock is then sent to radiant section
coil where main reaction takes place. Heat of furnace effluents is recovered in the transfer
line exchangers in which very high pressure steam is getting produced and being utilized for
various purposes.
Oil separation and Cracked gas quenching:
Cracking effluent (Cracked gas) is combined from all the furnaces and sent to Primary/
Gasoline Fractionator. Typically in gas cracker (Ethane), Gasoline Fractionator can be
avoided as the there is very less quantity of heavy material (C9+) present in the cracked gas
stream. In Primary/Gasoline fractionation, Oil which is present in cracked gas is separated
and utilized for providing heat duty to several users. Separated oil is sent to battery limit as
slop oil/ PFO product.
Temperature of Cracked gas coming from Gasoline Fractionator is typically 102-105 deg C.
Cracked gas is further cooled in Quench water column with the quench water. Cracked gas
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leaving the Quench water column is typically at 42-45 deg c. In quench water column,
Process water and gasoline fraction is separated from cracked gas. Process water is again
utilized for generating process steam for steam cracking.
Cracked gas compression and drying:
This is often referred as heart of the steam cracker unit. Cooled cracked is now compressed
in Cracked gas compressor. Cracked gas compressor typically compresses cracked gas to
the level of ~33-36 kg/cm2g in a 5stage machine. New low pressure technologies are also
utilizing cracked gas compressor pressure level of as low as ~ 23 kg/cm2g in 3 stage
machine. Pressure level of compressed cracked gas is solely depending on the
configuration of separation section. Cracked gas compressor section caustic scrubbing of
cracked is also given which removes CO2 and H2S from the cracked gas as low as 100 ppm
CO2 and H2S. Typically Caustic scrubber is placed at the pressure level of 7-18 Kg/cm2g
depending upon the cracked gas compressor stages.
In this section, cracked gas and cracked gas condensate which being generated in liquid
knockouts are sent to cracked gas dryer and cracked gas condensate dryer. Dryer is
removing moisture from the cracked gas and condensate to the level of as low as 1 mol
ppm. Drying of cracked gas is required for avoiding hydrate (ice) formation in the chilling
sections of steam cracker unit.
Front end Separation of cracked gas:
This system derives which frond end separation is to be configured based on the processing
objective and economics of the steam cracker. Front end systems are Depropaniser,
Deethaniser and demethaniser. Every licensor tries to optimize their plant by keeping them
at best suitable place.
Acetylene Convertor:
Acetylene convertor is provided for converting acetylene in to ethylene. CO present in the
feed enhances the selectivity towards ethylene over ethane. In the front end depropaniser
and Deethaniser scheme, Hydrogen and CO are present in the feed but in Front end
demethaniser, hydrogen is supplied externally. Typical spec of Acetylene in polymer grade
ethylene is 1 ppm (vol).
Hydrogen & Methane Separation:
Hydrogen and methane present in the cracked gas are separated in the coldest section of
the steam cracker unit. Hydrogen rich gas is recovered in the series of chilling and knockout
while methane rich fraction is recovered from demethaniser top.
Ethylene fractionation and Propylene fractionation:
C2 fraction from DeEthaniser top goes to Ethylene Fractionator from where, Ethylene is
recovered and ethane is recycled back to furnaces. C3 fraction from Depropanizer top or
DeEthaniser bottoms is sent to propylene Fractionator from where propylene is recovered
and propane is recycled back to furnaces. Propylene fractionator depending upon the
technology licensor can be one or two columns.
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Refrigeration system:
Typically in the Cracker unit, two main refrigeration systems are present, ethylene
refrigeration and propylene refrigeration. The two types ethylene refrigeration cycles are
provided one is open loop (heat pump configuration) other is closed loop (conventional
cycle). Propylene refrigeration is typically closed loop cycle. Licensor now a days also
provide multi component refrigeration system, with the combination of methane, ethylene
and propylene.
Debutanizer and C4 hydrogenation:
From debutanizer, C4 and C5 are separated. C5+ fraction is sent to PGHU unit and mixed
C4 fraction is sent to C4 hydrogenation unit. In configuration-1, as the quantity of C6+
component is very less. C4/C5 can be separated together and sent C4/C5 hydrogenation. In
C4 or C4/C5 hydrogenation, total hydrogenation of feed stream is taking place and
hydrogenated stream is sent to furnace as a recycle feed.
3.2 Pyrolysis Gasoline hydrogenation unit (PGHU):
This section is valid only for configuration-2. Feed to this unit is coming from the cracker unit,
which is C5+ fraction.
In first stage hydrogenation, dienes and styrenes present in the feed are selectively
hydrogenated and converted to olefins and ethyl benzene. Hydrogenated feed is sent to
dehexanizer, which is then separated in to C5/C6 fraction and C7 + fraction. C7/C8 fraction
is further separated from C9+ fraction in deoctanizer. C7/C8 which are coming from top are
cooled and condensed and then sent to Battery limit as Hydrogenated Pyrolysis gasoline.
C9+ fraction which is a bottom product is cooled and sent to battery limit. C9+ fraction is also
used as wash oil in cracker unit. Separated C5/C6 fraction, is further Hydrogenated in 2nd
stage gasoline hydrogenation for removing Dienes and olefins which are still present in the
C5/C6 fraction and desulphurization. Hydrogenated C5/C6 fraction is separated in to C5
fraction and C6 fraction in Depentanizer. C5 Fraction is recycled back to cracker unit and C6
fraction is used as a feed to Benzene extraction unit.
3.3 Benzene Extraction Unit (BzEU)
C6 fraction is used as a feed, from which benzene is extracted. Extraction is done By N-
Methyl-Pyrrolidone solvent.
C6 fraction is fed to Extractive distillation/ raffinate column. Top section is the raffinate
section and the bottom section is the extractive distillation column. Feed and solvent are
washed counter currently by which benzene is completely absorbed in the solvent. Toluene
and other heavy hydrocarbons are vaporized due to reboiling. Vaporized components go to
raffinate column in which, they are further separated from the solvent component. Raffinate
column overhead is then cooled and condensed. Part of the condensed overhead is sent
back to column and other is sent to cracker unit as a raffinate product. Benzene + solvent
stream is then fed to benzene stripper, in which benzene is separated from solvent and sent
to battery limit storage.
3.4 LLDPE / HDPE
Catalyst preparation
Ziegler Catalyst: High activity Ziegler catalyst is used for the production of narrow molecular
weight distribution products. This catalyst is supplied ready-to-use.
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Polymerisation: Reaction Loop
The reactor is designed to ensure good mixing and a uniform temperature within the
fluidised bed. Polymer particles grow within the fluidised bed over a residence time of
several hours. Operating conditions within the reactor are mild. The reactor is made from
carbon steel and has three main sections:
A bottom section with a gas distributor to ensure homogeneous fluidisation. A cylindrical
section containing the fluidised bed and equipped with catalyst injection and polymer
withdrawal facilities. A conical bulb top section where gas velocity reduces, returning
entrained polymer powder particles to the fluidised bed.
The gas leaving the reactor contains unreacted monomer, co monomers, hydrogen and
inerts (primarily nitrogen and ethane). Conversion of monomers per pass is proximately 3%.
Any fine particles leaving the reactor with the exit gas are collected by cyclones and
recycled to the reactor. This greatly reduces fouling in the reactor loop and also prevents
product contamination caused by particles formed in the loop, which may have different
properties to the target grade. This is one of the reasons why the Innovene process makes
such consistently high quality, gel-free products.
The gas then enters the first heat exchanger where the heat of polymerisation is removed
before passing to the Enhanced High Productivity Separator. This specially designed
vessel separates the condensed liquid, typically up to 15% by weight of the stream, from the
loop gas, which is fed to the main fluidisation gas compressor. This provides the volumetric
flow necessary to achieve the required fluidisation velocity in the reactor. The separated
liquid is then pumped into the reactor via proprietary liquid injection nozzles into the heat of
the fluidised bed.
In the reactor, pressure and gas composition are controlled continuously by varying the flow
of feedstock into the reaction loop. The relative proportions of the feedstock are adjusted to
meet the specification of the required polymer product. This is achieved using on-line
analysers for hydrogen, ethylene and co monomers. A purge is provided to prevent
accumulation of inerts.
Polymer Withdrawal and Degassing
The polymer powder is withdrawn from the reactor by simple, robust proprietary lateral
discharge system and passed on to the primary degasser, where a part of the gas is flashed
off, filtered and recycled to the main loop via the recycle compressor.
The polymer powder is transferred to the secondary degasser, where most part of the
residual hydrocarbon is removed and separated in the cryogenic Vent Recovery Unit. The
degassed powder collected in the secondary degasser passes to a purge column, where
trace hydrocarbons are removed and any residual catalyst activity is killed. Powder is then
transferred to the extruder via an intermediate surge bin, mounted directly above the
extruder, which allows for routine extruder maintenance.
Grade Changes
On-line DCS transition control ensures consistently rapid and reliable grade changes.
Changes of grade are made quickly and easily, with the minimum loss of throughput and the
minimum generation of wide-specification product.
Finishing: Product Blending and Extrusion (Pelletising)
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Polyethylene powder is transferred pneumatically to the product powder silo. Powder
master batch incorporating additives is prepared in mixers or may alternatively be supplied in
flexible intermediate bulk containers. The additives are commercially available but the
formulations, which are part of Innovene technology, will be disclosed when a licence
agreement has been signed. Virgin powder and additives are weigh-fed into the extruder.
Pellets are extruded under water and are then dried before being conveyed by air to storage.
The pellets conveyed from the pelletising section are homogenised in static homogenisation
silos. After homogenisation, the pellets are transferred to storage silos.
3.5 Butene-1
The dimerization reaction is activated by the mixing of two specific catalysts. The first one,
named T.E.A, is an alkyl-aluminium compound, the second one, named LC 2253 (AXENS
proprietary catalyst) is made of a titanium compound and a promotor.
Both catalysts are separately stored in diluted T.E.A. day drum and LC 2253 storage drum,
filtered and then pumped by metering pumps to the Reactor.
The diluted alkyl-aluminium catalyst (T.E.A) and the diluted LC 2253 catalyst are fed to the
reactor 32-R-201 through the pumparound loops.
In case hexane is used (during start-up), it can be dried before using via Hexane Dryer,
before being sent to Washing Hexane Drum. The regeneration of the dryer is carried out with
hot nitrogen heated up in Nitrogen Heater. Effluents from regeneration are then sent to flare.
Nitrogen Heater ensures also the drying of Pumparound Loops after maintenance with hot
nitrogen.
Reaction / Catalyst removal sections
The ethylene feedstock coming from Polymer Unit downstream of purification section or
directly from cracker is mixed with the unconverted ethylene which is recycled from the
recycle column reflux drum. The ethylene stream enters the reactor through a distributor,
which improves the dispersion of the ethylene in the liquid.
The reaction is exothermic: the heat of reaction is removed by the pumparound coolers
installed on recirculation lines around the reactor. The recirculation is maintained by
pumparound pumps. The liquid reactor effluent withdrawn from bottom of reactor must be
vaporized to remove all the traces of catalysts. Part of the vaporization occurs in the
vaporizers by steam condensation; the vapor and liquid phases are separated in the flash
drum. The last step of vaporization is achieved through the thin film evaporator which is fed
under flow-control reset by the level of the flash drum.
The residual liquid is collected in the evaporator receiver drum and feeds under level control
the spent catalyst drums which are connected to the flare and steam traced to remove the
remaining light compounds. The remaining liquid is either sent to isocontainers and then to
incinerator or sent to Fuel Oil. The vapors from the thin film evaporator flow through the
evaporator K.O. drum which traps any liquid carry-over. The vapors are then mixed to those
got from the flash drum and to the vapor flow from the reactor top. The product, currently
stripped from the catalysts, is condensed through the recycle column feed condenser and
feeds the recycle column feed surge drum.
To stabilize the product before vaporizing it, pure amine is injected to the reactant effluents
filters. This prevents any detrimental isomerization of butene-1 into isobutene and butene-2,
which could be promoted by temperature downstream, during the vaporization step, without
amine injection.
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The amine, unloaded from drums by the amine unloading pump, is stored in the amine
storage drum, and sent to the process by the amine pumps.
Distillation section
The liquid phase from recycle column feed surge drum is pumped to the recycle column.
A partial condensation of its overhead vapors takes place in the recycle column condenser.
Due to the presence of methane and ethane in the feedstock, a slight venting to Naphtha
Cracker is necessary to prevent from any incondensable vapor accumulation. The vapor
(mainly ethylene) is recycled back under pressure control to the reactor feed line.
The reboiling of the column is ensured in the recycle column reboiler under temperature
control resetting the steam flow rate to the reboiler. The bottom product of the column is
routed under flow-control, reset by level, to the butene-1 column.
The butene-1 column duty is to provide the specification in heavy components of butene-1
product. The butene-1 product is withdrawn as liquid distillate from the column overhead by
means of the butene-1 column reflux pumps under level control of the butene-1 column
reflux drum.
The C6+ cut is withdrawn, at the butene-1 column bottom. The C6+ cut is routed, after
cooling through the C6+ product cooler, to the C6+ storage drum.
Product drums storage
The butene-1 leaving the distillation section can be routed to any of the storage drums "on-
spec" drum or an “off-spec” drum after has been cooled down at 40 deg. C in the butene-1
cooler.
The butene-1 on-spec product is routed to OSBL storage tank after analysis, by means of
the pump. The off-spec product is routed to C4 mix storage, but can also be recycled in the
butene-1 column, if it’s content in C6 and heavier is too high. A part of this butene-1 product
is used for flushing pumparound pumps, reactor effluent pumps, passivation pumps and
ethylene distributor by means of flushing pumps. Another part of this butene-1 is used as
carrier or T.E.A. and LC 2253 catalysts to the reactor.
The Membrane Cell process is proposed to be adopted wherein the electrolysis of NaCl
takes place forming Chlorine and Sodium which further forms Sodium Hydroxide and
Chlorine.
Process Chemistry:
In this process, the anode and cathode are separated by a water-impermeable ion-
conducting membrane. Brine solution flows through the anode compartment where
chloride ions are oxidised to chlorine gas. The sodium ions migrate through the membrane
to the cathode compartment which contains flowing caustic soda solution. The
demineralized water added to the catholyte circuit is hydrolysed, releasing hydrogen gas and
hydroxide ions. The sodium and hydroxide ions combine to produce caustic soda which is
typically brought to a concentration of 32-35% by recirculating the solution before it is
discharged from the cell. The membrane prevents the migration of chloride ions from the
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anode compartment to the cathode compartment; therefore, the caustic soda solution
produced does not contain salt as in the diaphragm cell process. Depleted brine is
discharged from the anode compartment and resaturated with salt. If needed, to reach a
concentration of 50% caustic soda, the caustic liquor produced has to be concentrated by
evaporation (using steam).
Auxiliary Facilities required for the Unit is as below:
• Salt unloading and storage
• Brine purification and resaturation
• Chlorine processing
Caustic processing: The Membrane Cell process is proposed to be adopted wherein the
electrolysis of NaCl takes place forming Chlorine and Sodium which further forms Sodium
Hydroxide and Chlorine.
Process Chemistry:
In this process, the anode and cathode are separated by a water-impermeable ion-
conducting membrane. Brine solution flows through the anode compartment where
chloride ions are oxidised to chlorine gas. The sodium ions migrate through the membrane
to the cathode compartment which contains flowing caustic soda solution. The
demineralized water added to the catholyte circuit is hydrolysed, releasing hydrogen gas and
hydroxide ions. The sodium and hydroxide ions combine to produce caustic soda which is
typically brought to a concentration of 32-35% by recirculating the solution before it is
discharged from the cell. The membrane prevents the migration of chloride ions from the
anode compartment to the cathode compartment; therefore, the caustic soda solution
produced does not contain salt as in the diaphragm cell process. Depleted brine is
discharged from the anode compartment and resaturated with salt. If needed, to reach a
concentration of 50% caustic soda, the caustic liquor produced has to be concentrated by
evaporation (using steam).
Auxiliary Facilities required for the Unit is as below:
• Salt unloading and storage
• Brine purification and resaturation
• Chlorine processing
• Caustic processing.
3.6 VCM Unit
Process Chemistry:
EDC is thermally dehydrochlorinated (cracked) to VCM and Hydrogen Chloride (HCl). VCM
is recovered as high purity monomer suitable for storage or shipment in carbon steel vessels
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and suitable for polymerization to all grades of Polyvinyl Chloride (PVC) without further
purification. The coproduct HCl is recovered as gaseous, high purity, anhydrous HCl at a
pressure suitable for direct feed to the Oxychlorination process.
Process Description: Oxyhydrochlorination:
The Oxychlorination (OHCl) process combines HCl with ethylene and oxygen to produce
ethylene dichloride (EDC). Ethylene and hydrogen chloride feeds flow upward through the
Reactor and in the presence of the fluidized catalyst react to produce EDC according to the
following reaction:
C2H4+ 2HCl + 1/2 O2 C2H4Cl2 + H2O Ethylene + HCl + Oxygen EDC + Water + Heat
The HCL received from the VCM recovery and purification section contains a small amount
of acetylene that is reacted with hydrogen to form ethylene and a small amount of ethane in
the HCl hydrogenation reactor. This reaction is highly exothermic and takes place at a
temperature of 220 to 240oC in a fluid bed of catalyst impregnated with cupric chloride. To
ensure maximum conversion and high purity product EDC, the reaction temperature is
closely controlled by the use of the fluid bed reactor. The reaction products are recovered by
condensation in the recovery unit. The gases leaving the reactor pass through a quench
column where un-reacted HCl is scrubbed out with a recycle water stream. The scrubbed
gases emerging from the top of the quench column pass through a crude EDC condenser
where they are cooled and the bulk of the EDC and water is condensed. The EDC and water
phases are stripped with a small amount of nitrogen in the CO2 Stripper to remove dissolved
carbon dioxide, and then separated in the crude EDC decanter.
EDC Recovery
A small portion of the cooled vent gas stream then passes through a chiller where additional
EDC and water are condensed. The vapor/liquid mixture from the chiller flows to a
separator. The liquid from the separator flows by gravity to the crude EDC decanter. The
gaseous phase is discharged to the vent gas incinerator.
EDC Manufacturing and Purification
The EDC purification unit consists of three distillation columns which separate water, light
ends, and heavy ends from the crude EDC in order to supply purified EDC to the EDC
cracking furnaces. The dry crude EDC from the heads column bottoms and the treated
recycle EDC from the VCM purification unit are fed to the hiboil column. Connected to this
column is a reactor that produces EDC by direct chlorination of ethylene. Chlorine and
ethylene are fed to the high temperature direct chlorination (HTDC) reactor under flow
control. The reaction of chlorine and ethylene proceeds according to the equation:
C2H4 + Cl2 C2H4Cl2
Ethylene + Chlorine EDC + Heat
EDC Cracking
Purified EDC is fed to the EDC pyrolysis (cracking) furnaces where it is thermally cracked to
vinyl chloride and hydrogen chloride by the following equation:
C2H4Cl2 C2H3Cl + HCl
Ethylene Dichloride Vinyl Chloride + Hydrogen Chloride
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The pyrolysis reaction takes place at a temperature of 480 - 510oC and pressure of 0.9 –1.2
MPag in a gas fired cabin-type furnace.
VCM Purification
The VCM Purification unit consists of three distillation columns for fractionation of HCl, VCM,
and EDC. The HCl recovered in the overhead of the HCl column flows to the Oxychlorination
process for conversion to EDC. The bottom from the HCl column flows to the VCM column
where VCM is separated from the un-reacted EDC.
3.7 PVC Unit
Process Chemistry
Vinyl Chloride Monomer (VCM), which boils at -13.4 C at atmospheric pressure, is
polymerised in a batch process by dispersing the monomer in water under its own pressure
in a stirred reactor. The reactor contents are heated to the required temperature (typically
56.5°C): the initiator then starts to decompose to give free radicals and the monomer in the
droplets starts to polymerise. The reaction is exothermic, and the heat passes into the water
and is removed by two methods: circulated cooling water in the jacket and cooling water in a
condenser on the reactor top. PVC is insoluble in its monomer and once formed,
precipitates out in the monomer droplets as submicron particles.
Process Description
Polymerisation:
A specified amount of cooled demineralised water being sealed with nitrogen gas in the tank
is charged into Reactor through a batch meter. The catalysts solution is fed into Reactor.
The specified amount of VCM is also fed into Reactor through a batch meter. The reactor
contents are violently stirred in Reactor, keeping the good suspension condition. After
charging of VCM, a specified amount of hot demineralised water is charged into Reactor so
that temperature of the Reactor contents could reach the set polymerization temperature.
Then, cooling water is supplied into Reactor jacket, baffles and Reflux Condenser at high
rate. The temperature of the reactor contents is so automatically controlled as to be
constant at the set polymerization temperature by adjusting the flow rate of the cooling
water. The PVC slurry in Reactor is blown down through Slurry Discharge Pump into Blow
Down Tank, while recovering the un-reacted VCM gas from Reactor and Blow Down Tank
into VCM Gas Holder. The slurry in Blow down Tank is fed to the Slurry Stripping section
through Stripping Slurry Feed Pump.
Slurry Degassing
The PVC slurry in Reactor is blown down through Slurry Discharge Pump, into Blow Down
Tank, while recovering the un-reacted VCM gas from Reactor and Blow Down Tank into
VCM Gas Holder. The slurry in Blow Down Tank is fed to the Slurry Stripping section
through Stripping Slurry Feed Pump.
Slurry Stripping
After degassing in the Stripper Feed Vessel, the slurry contains 2-3 % of the original VCM
charge. In Stripping Column, the slurry passes over a series of trays where it is stripped with
a counter current flow of steam from a 4-6 barg supply. VCM passes to the LP Recovery
Compressors for recovery. From the base of the column the slurry is pumped through the
Spiral Heat Exchanger to preheat the feed and cool the slurry before it goes to the slurry
tank. The slurry from the stripping column then passes to the slurry storage tank.
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Dryer
Slurry from the Slurry Tank is circulated via a ring main to the centrifuges where it is
dewatered to produce a moist PVC powder. The moist PVC powder then passes to the
Dryer. There are two options for the Drying Technology to be used: either a two stage
Flash/Fluid Bed Dryer, or a Contact Fluid Bed Dryer. The polymer then overflows to the
vibrating screens for removal of any oversize material.
VCM Recovery
In this section, the unreacted VCM is recovered and treated for reuse. The unreacted VCM
recovered from Polymerization section and Slurry Stripping section into VCM Gas Holder is
compressed by VCM Compressors. VCM dissolved in waste water is stripped out by means
of steam-stripping by steam fed to the bottom of Column during falling down from top to
bottom. Water vapour and VCM leaves from the top of column and water vapour is
condensed in Waste Water Condenser and uncondensed VCM is recovered and returned to
Gas Holder. VCM stripped waste water is sent from the bottom of Column to Battery Limit by
Waste Water Discharge Pump after being cooled through Waste Water Heat Exchanger.
Product Handling
Screened material from the screens is conveyed to the bagging hoppers. A medium phase
blowing system is used, and two bagging hoppers. The filled bags are transferred from
Bagging Machine to Palletizer through the conveyor, piled automatically up on the pallet and
stored in existing product warehouse.
3.8 MEG Unit
The plant consists of two water cooled Ethylene oxide (EO) reactors system plus recovery
facilities, ethylene oxide purification and storage facilities, glycol reaction, evaporation and
purification facilities. This Plant will produce 935 KTPA Mono- ethylene Glycol (MEG). There
will be two by products – Di-Ethylene Glycol (DEG) and Tri Ethylene Glycol (TEG). This plant
is designed in single production line based on 8000 operating hours. This plant is divided
into two major sections:
• Ethylene Oxide section.
• Ethylene Glycol Section
3.9 Poly Propylene Unit
Fresh propylene from OSBL is fed through a propylene dryer to the reactor along with the
required catalyst, co-catalyst, hydrogen and stereo-modifier. For production of special
grades with small ethylene content, ethylene vapor is also fed to the reactor.
The polymerization reactors each have a stirrer and drive systems. Polymerization itself is
carried out in a gas phase stirred reaction. Heat removal is managed by evaporative
cooling. Liquid propylene entering the reactor vaporizes and thereby removes the
exothermic reaction energy. Reaction gas is continuously removed from the top of the
reactor and filtered. Reactor overhead vapor (“Recycle Gas”) is condensed and pumped
back to the reactor as coolant. Non-condensable gases (mainly H2 and N2) in the recycle
gas are compressed and also returned to the reactor.
The polypropylene product powder is blown out of the reactor under reactor operation
pressure. The carrier gas and powder pass into the powder discharge vessel where powder
14
and gas are separated. The carrier gas is routed through a cyclone and filter to remove
residual powder, then scrubbed with white oil and sent to compression.
Powder from the discharge vessel is routed via rotary feeders to the purge vessels which are
operating in parallel. Nitrogen is used to purge the powder off residual monomers. The
overhead gas from the purge vessels is sent to a common membrane unit for
monomer/nitrogen recovery. As refrigerant for the membrane unit fresh Propylene is used.
The recovered nitrogen is sent back to the purge vessels for further use. The condensed
monomers from the purge gas are combined with the filtered carrier gas, then sent to
scrubbing and subsequently to carrier gas compression.
The PP powder from the purge vessels is pneumatically conveyed by a closed loop nitrogen
system to the powder silos. The powder product from these silos is fed to the extruder where
polymer powder and additives are mixed, melted, homogenized and extruded through
a die plate, which is heated by hot oil. The extruding section is electrically/steam heated.
Pelletizing of the final product is carried out in an underwater pelletizer where the extruded
polymers - after passing the die plate - are cut by a set of rotating knives. The polymer/
water slurry is transported to a centrifugal dryer where polymer and water are separated.
Water is recycled to a pellet water tank, for which demineralized water is used as make-up.
The cooled pellets (~60°C) are pneumatically conveyed to the pellet blending silos by an air
conveying system. After homogenization in the blending silos the pellets are conveyed to the
bagging and palletizing system.
4.0 Utilities Description
Facilities in utility systems are enlisted below:
Cooling water system
Steam, Power and boiler feed water system
Treated Raw water system
DM Water plant
Condensate polishing system
N2O2 (Nitrogen/Oxygen) Plant
Instrument Air & Plant Air system
Effluent treatment Plant
Flare system
Cooling Water Requirement for the Complex is about 125000 M3/Hr. To carter to the
requirement cooling towers with cell capacity of 4000 M3/Hr each. In order to meet the
steam, power and boiler feed water demands of the facilities installed at the Petrochemical
complex, dedicated steam, power and BFW system will be installed as part of the Captive
Power Plant (CPP). Proposed steam and power requirement is given in Table 3.
15
Table 3: Complex Steam and Power
S.No. CPP configuration with Frame-VI FA machine
1 Process steam requirement VHP steam required from CPP = 0 TPH
HP steam required from CPP = 20 TPH
MP steam required from CPP = 40 TPH
LP steam required from CPP = 70 TPH
Process Power = 150 MW
Utilities = 45.4
2 Grid import 206 MW
3 CPP configuration 1 nos. steam turbine of VHP to HP
extraction cum condensing of 20 MW
design operating at 15.5 MW.
1+1 Boilers of each 220 TPH of VHP steam
generation, operating at 198 TPH.
4 CPP fuel consumption Internally Managed from Fuel gas and Hydrogen
Raw Water Requirement
The treated raw water shall be used for cooling water make up, DM water feed, Service
water, and Drinking water and Fire water requirements through their respective pumps. The
Raw Water shall be sourced through Pumps from Polavarum left main canal (12 Kms).
Raw water shall be made available at complex battery limit from canal via Raw Water
Pumping facility. To meet the complex demand one raw water reservoir of 2100000 m3
capacities is considered. This reservoir is designed to cater the 21 days of raw water
demand. The reservoir is provided to ensure uninterrupted supply of raw water to the
complex. The raw water from the reservoir shall be softened, treated for organic and
biological matter, pH adjusted and filtered in a raw water treatment plant to obtain clarified
water. The treated water would be stored in treated water reservoir which would carter to
about 12 hrs of storage. Treated raw water system is given in Table 4.
Table 4: Treated Raw Water System
System Quantity Capacity
Raw water intake well and pump house in
the river.
Pump House Dimensions 25(L)
x 10(W) x 8(H) M
Raw Water Intake pumps 4 + 2 Nos. 1000 m3/hr @ 7.0 kg/cm2 g
Raw Water Pipeline, CS 3 LPE 1 Nos. 48” 13 Kms (Total Length)
Raw Water Reservoir 1 No. 2100000 M3
Raw Water Treatment Plant 1 No. 3900 M3 / Hr
Treated Raw Water Reservoir 1 No. 48000 M3
16
DM Water/Oxygen/Instrument & Plant Air Requirement
The normal requirement of DM water is about 210 M3/Hr of DM water and 590 M3/Hr of net
raw water generation.
The requirement of Oxygen is 1450 TPD (Design) and that of Nitrogen is Normal – 12776 NM3/Hr and Max – 20000 NM3/Hr. Oxygen is required in MEG unit as a raw material. The design requirement of Instrument air and plant air is about 6000 NM3/Hr and 5500
NM3/Hr respectively. Effluent Treatment Plant The Effluent treatment plant is shall take care the following effluent quantity.
Oily Effluent 250 M3/Hr.
Wet air oxidation unit to treat spent Caustic of about 2 M3/Hr
Various Effluents generated from the complex shall be treated in a centralized ETP. The various effluents sent to the ETP broadly consist of the following:
Oily Water Sewerage
Contaminated Rain Water Sewerage
Spent Caustic Stream
Sanitary Effluent Flare System
A centralized demountable flare system is proposed for the facility. A Demountable flare system provides flexible flaring operations to so that you can place multiple risers on a single support structure. They also allow you to perform maintenance to the tip at grade with minimal use of personnel at elevation.
3 Risers are presently envisaged in the flare:
Flare gas from Cracker
Flare gas from polymer units
Flare gas from storage facilities
Table 5: Flare System
Flare for EB / Styrene and Cracker 68”, 120 M
Flare for Polymer Units 34”, 150 M
LP Flare for Storage Tanks 28”, 120 M
17
5.0 OFFSITE DESCRIPTION
Offsite facilities will include storage vessels / tanks / sphere for feed, intermediates feed, Off
spec intermediate feed & products, pumping facilities, loading / unloading facilities and
auxiliary facilities like boil off gas compression system, emergency vaporization / heating
system / vapor recovery system etc. Offsite storage summary is given in Table 6.
Table 6: Offsite Storage Summary
Service Phase Capacity /
Nos.
Type of
storage
Location Basis of capacity
Ethane Liquid 100000 M3
x 2 Nos.
DWST At the
KSPL port
2 Ship Parcel of
87000 M3 each.
Which will carter to
about 28 days of
Cracker Operation
Propane Liquid 35000 M3 x
2 Nos.
DWST At the
KSPL port
2 Ship Parcel of
30000 M3 each.
Which will carter to
about 41 days of
Cracker Operation.
Ethane
Buffer
Liquid 1900 M3 x 2
Nos.
Sphere In
Complex
1 Day
Propane
Buffer
Liquid 900 M3 x 2
Nos.
Bullet In
Complex
1 Day
Naphtha Liquid 16500 M3 x
2 Nos.
Internal
Floating
roof tank
In
Complex
7 days
Hexene-1 Liquid 1700 M3 x
1 No.
Cone roof
Nitrogen
Blanketing
Tank
In
Complex
18
Table 6: Offsite Storage Summary
Service Phase Capacity /
Nos.
Type of
storage
Location Basis of capacity
Pentane Liquid 250 M3 x 1
No.
Bullet In
Complex
30 days
Hexane Liquid 500 M3 x 1
No.
Internal
Floating
roof tank
In
Complex
30 days
Salt Solid 15 KTPA Open
Storage
CA Unit 15 Days
Intermediate
Ethylene Liquid 24000 M3 x
2 Nos.
DWST In Complex
7 days
Propylene Liquid 3250 M3 x
5 Nos.
Bullet In Complex
7 days
Butene-1 Liguid 1517 M3 x
1 No.
Mounded
Bullet
In Complex
7 Days
C4 Mix Liquid 2500 M3 x
2 Nos.
Sphere In Complex
3 days
Offspec
C4 Mix
Liquid 1700 M3 x
1 No.
Sphere In Complex
12 Hrs
C6 Cut
(BzeU
feed)
Liquid 1700 M3 x
2 Nos.
Internal
Floating
roof tank
In Complex
3 days
Off spec
Ethylene
Liquid 1767 M3 x
2 Nos.
Sphere In Complex
12 hrs. with 100% plant capacity
Off spec
Propylene
Liquid 1785 / M3 x
1 No.
Mounded
Bullet
In Complex
12 hrs. with 100%
plant capacity
Hydrogen Gas 50 M3 x 2
Nos.
Above
Ground
Bullet
In Complex
7 Days
19
Table 6: Offsite Storage Summary
Service Phase Capacity /
Nos.
Type of
storage
Location Basis of capacity
RPG Liquid 2174 M3 x
2 Nos.
Dome
roof tank
In Complex
3 Days
EDC Liquid 3780 M3 x
3 Nos.
Internal
Floating
roof tank
In Complex
VCM Liquid 3804 M3 x
2 Nos.
Spheres In
Complex
7 Days
Products
MEG Liquid 17100 M3 x
2 Nos.
Fixed roof tank
In Complex
15 days
DEG Liquid 2500 M3 x
1 No.
Fixed roof
tank
In Complex
15 days
TEG Liquid 150 M3 x 1
No.
Fixed roof
tank
In Complex
15 days
HPG Liquid 3000 M3 x
2 Nos.
Internal Floating roof tank
In Complex
15 Days
PGO Liquid 1000 M3 x 2 Nos.
Cone roof
Nitrogen
Blanketing
Tank
In Complex
15 Days
PFO /
CBFS
Liquid 700 M3 x 2 Nos.
Fixed roof
Tank
In Complex
15 Days
Benzene Liquid 2000 M3 x
2 Nos.
Internal
Floating
roof tank
In Complex
15 Days
20
Table 6: Offsite Storage Summary
Service Phase Capacity /
Nos.
Type of
storage
Location Basis of capacity
C6+
Oligomer
Liquid 300 M3 x 1
Nos.
Internal
Floating
roof tank
In Complex
15 Days
Slop Liquid 1700 M3 x
1 No.
Internal
Floating
roof tank
In Complex
From ETP.
Caustic for
sales
Liquid /
Solid
18 KT Warehouse
and Tanks
In Complex
Part of CA ISBL. 30
Days
PVC Solid 27 KT PWH In Complex
30 days.
Poly
Propylene
Solid 28.4 KT PWH In Complex
30 days.
HDPE/
LLDPE
solid 40.5 KT PWH In Complex
30 days.
6.0 LOGISTICS
Mode of transport for various feed, products and various streams to and from the
Petrochemical complex are as listed below in Table 7.
Table 7: Mode of transport for various feed, products and various streams
S.No.
Item
Source
Destination
Phase Mode of
Transport
Product
1. MEG Truck Loading Gantry Buyer Liquid Road
2. DEG Truck Loading Gantry Buyer Liquid Road
3. TEG Truck Loading Gantry Buyer Liquid Road
4. LLDPE Product Warehouse Buyer Solid Road
5. HDPE Product Warehouse Buyer Solid Road
6. Poly
Propylene
Product Warehouse
Buyer
Solid
Road
7. PVC Product Warehouse Buyer Solid Road
8. Caustic Product Warehouse Buyer Solid Road
9. HPG Truck Loading Gantry Buyer Liquid Road
21
10. PGO Truck Loading Gantry Buyer Liquid Road
11. PFO /
CBFS
Truck Loading Gantry
Buyer
Liquid
Road
12. Benzene Truck Loading Gantry Buyer Liquid Road
13. C6+
Oligomer
Truck Loading Gantry
Buyer
Liquid
Road
Feed
1. Ethane Jetty Complex B/L Liquid Note-1
2. Propane Jetty Complex B/L Liquid Note-2
3. Naphtha HPCL Vizakh Refinery Complex B/L Liquid Pipeline
4. Hexene-1 Supplier Truck Loading Gantry Liquid Road
5. Pentane Supplier Truck Loading Gantry Liquid Road
6. Hexane Supplier Truck Loading Gantry Liquid Road
7. Salt Supplier Salt Storage Solid Road
Other Streams
Table 7: Mode of transport for various feed, products and various streams
S.No.
Item
Source
Destination
Phase Mode of
Transport
1. Raw
Water
Polavarum left main
canal
Complex B/L
Liquid
Pipeline.
2. Treated
Effluent
ETP Sea
Liquid
Pipeline
3. Slop Various Sources Buyer Liquid Road
4.
RLNG RLNG if required is considered to be available at complex B/L. Only
metering facility and offsite piping is considered.
Note-1: Liquid ethane shall be imported in Very Large Ethane Carrier’s (VLEC) of 87,000 m3
(approx. 48,000 Tons) capacity. Liquid ethane is proposed to be supplied from port to the
complex through pipeline from Jetty.
Note-2: Liquid Propane shall be imported in Vessels of 30,000 m3 capacity. Liquid Propane
is proposed to be supplied from port to the complex through pipeline from Jetty.
22
Supply of Ethane
Based on the requirement of the parcel size of Ethane import through VLEC (Each having ~
87000 M3 capacity) has been considered as basis for the storage and the capacity has been
fixed to 100000 M3.
The option selected for the proposed complex is tabulated below:
Unloading and storage at port.
Heating and transportation through non-cryogenic pipeline up to Petrochemical
Complex.
VLEC carrier would can be berthed at a jetty near the breakwater of KSPL port. Length of
trestle required is 1.75 km for laying the cryogenic lines from DWST to Jetty. The jetty
location is proposed adjacent to proposed LNG Jetty at KSPL port.
Supply of Propane
Based on the requirement of the parcel size of Propane import through vessel of capacity of
about 30000 M3 has been considered. Based on vessel capacity the storage and the
capacity has been fixed to 35000 M3.
Supply of Naphtha
The Major Facilities are envisaged for transportation of Naphtha:
1+1 Nos pf Booster Pump and 1+1 Nos of Mainline Pump of 200 M3/Hr each will be
installed in the premises of HPCL refinery.
12” Naphtha Pipeline with length of 150 Kms.
Pig Launcher and Receiver
Flow Meters (Both at Dispatch and Receipt facility for custody transfer)
Surge Relief Valve (At Receipt facility)
Corrosion Inhibitor dosing facility (At Dispatch facility)
Marine Discharge of Treated Effluent
The treated effluent is proposed to be disposed in sea via pipeline of total Length 7 Kms
which includes 6 Kms Onshore with 500 M Buried Portion and 1 Km Inside the sea.
Receipt of Salt
Salt would be received by Road.
Dispatch of Products and Unloading of Feeds via Truck Gantry Three out of 4 Nos. gantries are proposed to be kept for Receipt of Raw Material. The number of bays has been considered with a uniform basis of 6 Hrs. per day
effective work and volume of tanker as 15 M3. With the aforesaid considerations the number of bays per product has been worked out as below:
23
MEG: 15 Nos. of Bays
DEG & TEG: 1 Nos of Bay
HPG : 4 Nos. of Bays.
PGO : 4 No. of Bay.
PFO / CBFS : 2 Nos. of Bays.
Benzene: 2 Nos. of Bays.
C6+ Oligomer: 1 Bay
Slop: 1 Bay
Hexene-1: 1 Bay
Pentane: 1 Bay
Hexane:1 Bay Dispatch of Solid Products
The Solid Products are stored in Product Warehouse in bags and stacked on Pallets inside Product Warehouse. Polymer pellets / powder or Caustic Flakes are usually stored in 25 Kg Bags and each Pallet can hold 1 Ton of polymer. The pallets are arranged in warehouse in 3 high configuration. The pallets are moved around inside the product warehouse on fork lifts and dispatched from complex on trucks.
Number of Bagging Lines required for each units are:
• LLDPE/HDPE: 4 + 1 • PPU: 3+1 • PVC: 3 + 1
• Caustic: 2 + 1 7.0 PROJECT COST AND SCHEDULE The petrochemical complex cost is Rs. 30,500 crores and schedule is 60 months including commissioning of the project.
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