KRIBHCO SHYAM FERTILISERS LTDAMMONIA PLANT

INSTALLED CAPACITY - 1520 MTPD

PROCESS LICENSOR - HALDOR TOPSOE, DENMARK

PROCESS TECHNOLOGY - NG STEAM REFORMING

RAW MATERIAL - FEED-NG

FUEL – NG AND/OR NAPHTHA

Natural gas 98% CH4

Recycle Hydrogen

HP Steam

Steam Comb.Air

Natural gas Purge gas

Stack

DesulphurizerR-1201/1202

Primary Reformer

Sec. Reformer

RG Boiler

0.3%CH4991 Deg C

Boiler feed water

HTShift

FT

Make up syn gas

210 Kg/cm2 & 23 Deg C

CO2TO

UREA

FPT

CO2 Removal

Lean and Semi Lean GV Solution

E1311

0.1%CO2

320 Deg C

Methanator

338 Deg C

Final gas cooler

Separator

Syn gas compressor

Make up gas

chiller

26 Kg/Cm2 38 Deg C

BFW Pre heater

T

SEPL

LTShift

BFW Pre heater

Separator

CG boiler

Trim heater

74.2% H2 & 24.77% N2

1.03% CH4/Ar

Process air

From 2d Stage

387 Deg C

32Kg/Cm2

BFW fromE1502

BFW

Surplus syn gas

10.95% CH4

801 Deg C

360 Deg C 12.96% CO

427 Deg C 3.09% CO

221 Deg C 0.25% CO

17.75% CO2

200 Deg C

NG NAPHTHA (MSM3/DAY) (MT/DAY)

FEED TO REFORMER 1.008 NAFUEL TO REFORMER 0.273 NIL

OR*OR*

0.137110FUEL TO SUPER HEATER 0.068 NIL

OR*OR*

0.017 45(* IN CASE OF MIX-FUEL FIRING)

RAW MATERIAL CONSUMPTION

MAJOR PROCESS STEPS

HYDRO-DESULPHURISATION PRIMARY & SECONDARY REFORMING CO SHIFT CONVERSION CO2 REMOVAL-GV GLYCINE SYSTEM METHANATION COMPRESSION AMMONIA SYNTHESIS PROCESS CONDENSATE TREATMENT PURGE GAS RECOVERY

DESULPHURISATION

Natural Gas mainly containing methane (98%) and higher hydrocarbon has 10-50 ppm of sulphur. In desulphurization process sulphur content is reduced to 0.05 ppm. Type of catalyst TK-251 Volume of catalyst 8.9 M3

After hydrogenation the process gas is passed through the absorption vessels where the H2S is absorbed on ZNO Type of catalyst HTZ-3 of HTAS Volume of catalyst 13.8 M3

There are two ZNO absorbers in series and one can be isolated in running for replacement of catalyst.

PRIMARY REFORMER

It is a side fired tubular primary reformer with flue gas heat recovery section. Natural gas is reformed with steam to produce a mixture of hydrogen, carbon monoxide, carbon dioxide and methane. There are two chambers and each chamber contains 144 tubes. There are 576 radiant burners are provided. Catalyst volume in Primary reformer is 44 M3

Primary reformer outlet Methane is approx. 11 %.

PRIMARY REFORMER

ID Fan

Stack

FD Fan

SECONDARY REFORMER

Function of secondary Reformer is to reform the Primary Reformer exit residual methane and to add Nitrogen to the process gas.

This is achieved by mixing a stoichiometric quantity of process air to the primary reformer exit gases in Secondary Reformer.

Secondary Reformer outlet gas mixture contains hydrogen, nitrogen, carbon monoxide, carbon dioxide and methane (0.3%).

WASTE HEAT RECOVERY

High temperature process gas exit secondary Reformer at 950 deg C is cooled down in Waste Heat Boiler to 360 deg C and in turn high pressure steam (115 Kg/cm2g) is produced. Steam produced is super heated to 510 deg C and utilized as driving force for Syn gas turbine which in turn generate Medium Pressure steam.

SHIFT CONVERSION

Carbon monoxide is converted to carbon dioxide in two stage shift conversion bringing down the carbon-monoxide content from 12.95% to 0.3 % in the process gas.High temperature Shift converterCatalyst volume 100 M3 Type of Catalyst SK-201 of HTASCO Content reduced to 3.09% from 12.96%.Low temperature Shift converterCatalyst volume 116 M3 Type of Catalyst C-18 G/7 of Sud-ChemeCO Content reduced to 0.25% from 3.09%.

CARBON DIOXIDE REMOVAL

Giammarco Vetrocoke (GV) solution is used to absorb carbon dioxide from the process gas thus reducing carbon dioxide content from 17.72% to 0.05% in gas mixture in CO2 absorber.

GV solution contains Potassium Carbonate Glycine Di Ethanol Amine & Vanadium penta oxide

GV solution rich in Carbon dioxide is regenerated in HP & LP regenerators by giving heat & Carbon dioxide is sent to Urea Plant.

METHANATION

Oxides are harmful for synthesis converter catalyst, 0.25 % Carbon monoxide from LTS outlet and 0.05% Carbon dioxide from CO2 Absorber are converted into methane in this step.

Catalyst Volume 30 M3 Catalyst type PK-5 of HTAS. The exit process gas (Synthesis Gas) contains

mainly a mixture of hydrogen and nitrogen in the ratio of 3:1.

SYNTHESIS GAS COMPRESSION

Synthesis gas is compressed to 220 Kg/cm2g in synthesis gas compressor. This compressor has four stages and one recycle stage. This compressor was supplied by BHEL.

AMMONIA SYNTHESIS

AMMONIA SYNTHESIS

Conversion of this gas mixture into ammonia takes place in TOPSOE-S200 radial flow converter. Gas inlet temperature is 244 deg C. Converter has two beds with inter-bed heat exchanger.

Catalyst volume is 100 M3. Type of catalyst KM1R/KM1 of HTAS. Converter outlet gas at 455 deg C is cooled in

various heat exchangers and finally separated at 12 deg C in Ammonia Separator.

REFRIGERATION SYSTEM

Gas mixture containing ammonia is cooled down to separate liquid ammonia from the gases by providing ammonia refrigeration. Separated liquid ammonia is sent to Urea Plant at 12 deg C temperature. In case Urea Plant is not in operation, product Ammonia can be sent to Ammonia Storage.

The operating pressure of chillers 0.05 Kg/cm2g 3.5 Kg/cm2g 6.5 Kg/cm2g

STEAM SYSTEM

Steam Type SH SM SL

Superheated Superheated Superheated

Pressure 110 Kg/cm2g 38 Kg/cm2g 3.5 Kg/cm2g Temperature 510 C 381 C 260 C

There are two service boilers and two HRSG boilers in offsite which can generate 100te/hr each at 112Kg/cm2 and 510 DegC. Normally one service boiler and one HRSG boiler are in service. High pressure steam from boiler is distributed to Ammonia plant and Urea plant. In KSFL SH steam pressure is maintained by Offsite.

The HP steam is used in running Syn gas turbine and CO2 turbines.

MEDIUM PRESSURE STEAM

Extraction from Syn gas turbine and Let down from SH steam to SM steam joins SM steam header.

This steam is used in Primary Reformer, all backpressure and condensing turbines.

This SM steam header is connected to Offsite SM Steam header.

Normally SM steam header pressure is maintained by Ammonia Plant.

LOW PRESSURE STEAM

Low pressure steam generated from backpressure turbines is used in Process Condensate stripper, GV system, Deaerator and ejectors of Compressors.

The balance SL steam can be fed in Process Air Compressor to avoid venting of SL steam.

Here also Offsite, Urea and Ammonia Plant headers are interconnected.

SL header pressure is also maintained by Ammonia Plant.

SH STEAM NET WORK

NG FEED STOCK SPECIFICATION

Ammonia plant can be fed with one of the feed/fuel gas having the following characteristics at battery limits:

CASE A CASE B CASE C Rich Gas After LPG extraction Lean gas

Methane 78.84 83.29 98.39 Ethane 7.23 7.60 1.40 Propane 4.59 2.10 0.10 I-Butane 0.88 - - N-Butane 1.10 - - I-Pentane 0.26 - - N-Pentane 0.24 - - Hexane 0.26 - - Carbon Dioxide 6.49 6.9 - Oxygen 0.10 0.10 0.10 Nitrogen 0.01 0.01 0.01

Total Sulfur content as H2S Normal 10ppm Design 50ppm Pressure 43 Kg/cm2g Temperature 30 C

DM WATER NETWORK

Quality of DM water Conductivity 0.30 s/cm Silica (reactive) 0.1 ppm Fe NT TDS 0.10 ppm As (CaCO3)

Total Hardness 0.10 ppm Oil - Ph 7 + 0.5 Total Cation 0.1 ppm Total Anion 0.1 ppm

DM WATER NETWORK

DM water supplied from DM plant at a rate of 500 M3/hr and 5-6 kg/cm2 is preheated in different pre heaters of CO2 removal section ie.E-1303, E-1308, E1313, E-1306, and E-1325.

The heated DM water is distributed to Offsite/Ammonia Deaerator.

Around 150 M3/hr is returned back to Offsite and 350 M3/hr fed to ammonia Deaerator.

DM WATER NETWORK

BFW DISTRIBUTION

BFW pumps P-1601A/B/C takes suction from Deaerator.

BFW from pump discharge goes to BFW pre heater E-1211 and BFW heated to 176 DegC.

From BFW pre heater E-1211,BFW goes to E-1210 and E-1502 pre heaters in parallel and heated up to 273 DegC.

From E-1210 and E-1502 BFW is fed to RG boiler and Syn Loop boiler for steam generation.

BFW DISTRIBUTION

SERVICE AIR AND INSTRUMENT AIR

Service Air Moisture Saturated Pressure 6-7 Kg/cm2g abs Temperature 40 C

Instrument Air Pressure Max. 9 Kg/cm2g

Min. 6 Kg/cm2gNor. 8 Kg/cm2g

Temperature 40 C Type dry and oil free Dew point -20 C at 7 Kg/cm2g

SERVICE AIR AND INSTRUMENT AIR

Air required for Service air, Instrument air and PSA unit is supplied from 3rd stage of Process air compressor at a rate of 5500 NM3/hr.

Air from HP air receiver also joins this header after pressure reduction.

This hold up volume maintains header pressure in case of tripping of Process air compressor

PROCESS AIR COMPRESSOR AND INSTRUMENT AIR SYSTEM

ELECTRIC POWER

Alternating Current 11000 V 3 phase 50 Hz 3300 V 3 phase 50 Hz 415 V 3 phase 50 Hz 240 V 1 phase 50 Hz

Instrumentation and Control 115 V 1 phase 50 Hz

COOLING WATER

Inlet temperature to the unit 34C Outlet temperature from the unit 44C Fouling factor for shell side 0.0006

m2hC/Kcal

Fouling factor for tube side 0.0006 m2hC/Kcal

COOLING WATER

Ammonia cooling tower was designed by Paharpur. There are six cells and each cell is provided with an

induced draft fan. There are three cooling water pumps out of which

one is motor driven and two are condensing turbine driven.

The normal cooling water flow is 20,000 M3/hr and CW header pressure is 3 Kg/cm2g.

PURE NITROGEN

In KSFL Nitrogen generation plant is not available. So Pure Nitrogen is purchased as per requirement from outside agencies

Quality of Nitrogen Nitrogen plus noble gases 99.99 % vol (min.) Carbon dioxide NT Carbon monoxide NT Water NT Oxygen 10 ppm (max.) Pressure 6 Kg/cm2g Temperature 40 C

PRODUCT SPECIFICATION

Ammonia Quality Ammonia 99.5 wt % max. Moisture 0.5 wt % max. Oil 10 ppm max. Temperature 12/-33 C Pressure 25/5 Kg/cm2g

PRODUCT SPECIFICATION

Carbon Dioxide:

Composition, dry: CO2 98.7 % vol H2 0.8 % vol N2 0.5 % vol Temperature 40 C Pressure 0.8Kg/cm2g Water saturated

DESULPHURISATION SECTION

The desulphurization section consists of three vessels, one containing the hydrogenation (Ni-Mo) catalyst and two vessels containing ZnO catalyst for absorbing H2S.

Over the hydrogenation catalyst the sulphur containing compounds are converted into Hydrogen sulphide at a temperature of about 390 deg C. This Hydrogen sulphide is absorbed in the ZnO absorption vessels. Sulphur outlet of ZnO absorbers will be below 0.05 ppm sulphur.

HYDROGENATION

The Natural gas with recycle gas is preheated to 390-400 deg C in the waste heat section of the primary reformer before entering the hydrogenation vessel R-1201. The Hydrogenation catalyst is TOPSOE TK-251 (Ni Mo). The catalyst volume is 8.9 M3

Normally hydrogen for the hydrogenation is obtained by recycling of synthesis gas after the 1st stage of Syn gas compressor but following alternative sources of hydrogen are also available:

In case of methanator trip the recycle gas can be taken at the outlet of the CO2 removal.

If the CO2 removal is not in operation either, the recycle gas can be taken upstream of theCO2 removal or if the synthesis unit is under pressure recycle gas may be taken from the synthesis loop.

NG DESULPHURISATION

GV FILTARATION AND AERATION

REFORMER NAPTHA FIRING

PRIMARY AND SECONDARY REFORMER

HT AND LT SHIFT CONVERTER

CO2 REMOVAL SYSTEM

CO2 REMOVAL OH SYSTEM

METHANATION SECTION

SYN GAS COMPRESSOR

AMMONIA SYNTHESIS

AMMONIA REFREGERATION

PURGE GAS RECOVERY UNIT

PROCESS CONDENSATE STRIPPER

AMMONIA BOOSTER COMPRESSOR