ENERGY SAVING OPPORTUNITIES IN AMMONIA AND UREA PLANT : KRIBHCO

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ENERGY SAVING OPPORTUNITIES IN AMMONIA AND UREA
PLANT KRIBHCOs EXPERIENCE
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OPPORTUNITY FOR ENERGY SAVINGS

• OPPORTUNITIES RELATED WITH TECHNOLOGICAL
  INNOVATIONS / IMPROVEMENTS
• OPPORTUNITIES RELATED WITH IMPROVEMENTS IN
  EQUIPMENT MACHINERY INCLUDING MATERIALS
• OPPORTUNITIES BY BETTER OPERATION ENERGY
  MANAGEMENT

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MODERN LOW ENERGY AMMONIA PLANT PROCESS
TECHNOLOGY

• KELLOGG BROWN ROOT (KBR)
• HALDOR TOPSOE
• UHDE
• AMMONIA CASALE

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ENERGY LOSS AREA IN AMMONIA PLANT

• SURFACE CONDENSERS
• CO2 REMOVAL SECTION
• PRIMARY REFORMER FURNACE STACK
• HEAT LOSS IN CW EXCHANGERS
• OTHER LOSSES
• - PURGE GAS
• - FURNACE STACK OTHER THAN PRIMARY REFORMER
• - STEAM LOSS THROUGH VENTS
• - ENERGY LOSS THROUGH STEAM TRAPS
• - LOSSES THROUGH FLASH GASES

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ADVANCES IN REFORMING AREA

• PROCESS TECHNOLOGY
• OPERATION AT INCREASED PRESSURE
• DECREASE OF STEAM ADDITION
• INCREASING EXIT TEMP FROM P/R AND S/R
• INCREASING PREHEAT TEMP FOR FEED, PROCESS AIR,
  COMBUSTION AIR
• PART LOAD SHIFTING FROM P/R TO S/R
• NEW CONCEPT OF GHR AND KRES
• EQUIPMENT OR METALLURGY
• USE OF MORE SOPHISTICATED ALLOY FOR TUBES

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ADVANCES IN SHIFT CONVERSION AREA

• PROCESS TECHNOLOGY
• DEVELOPMENT OF MORE ACTIVE LT SHIFT CATALYST
• NEW COPPER PROMOTED HT SHIFT CATALYST
• ISOTHERMAL SHIFT (LINDE CONCEPT)
• EQUIPMENT OR METALLURGY
• CHANGE IN FLOW PATTERN WITHIN HT LT SHIFT
  REACTORS

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ADVANCES IN CO2 REMOVAL AREA

• PROCESS TECHNOLOGY
• USE OF IMPROVED SOLVENT BASED SYSTEMS
• USE OF IMPROVED ACTIVATORS, CORROSION INHIBITORS
• USE OF INTERNAL HEAT RECOVERY SCHEMES USING
  EJECTOR, HEAT PUMPS, SECOND REGENERATORS
• USE OF ADSORPTION BASED PROCESS
• USE OF MEMBRANE BASED PROCESS (FUTURISTIC)
• EQUIPMENT OR METALLURGY
• USE OF IMPROVED PACKING/TRAYS
• USE OF IMPROVED TOWER INTERNALS

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COMPARISON OF ENERGY FOR DIFFERENT CO2 REMOVAL
PROCESS
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ADVANCES IN SYNTHESIS GAS PURIFICATION

• PROCESS TECHNOLOGY
• USE OF METHANATION CATALYST
• USE OF MOLECULAR SIEVE
• USE OF INTER-STAGE CHILLERS IN THE SYN GAS
  COMPRESSOR
• USE OF CRYOGENIC SYSTEM FOR REMOVING ALL
  IMPURITIES
• DE HYDRATOR CONCEPT

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ADVANCES IN AMMONIA SYNTHESIS

• PROCESS TECHNOLOGY
• LOWER PR. OPERATION OF SYNTHESIS LOOP
• HIGHER CONVERSION OF AMMONIA
• INDIRECT COOLING
• LOW INERT LEVEL
• NEW TYPE OF CATALYST
• EQUIPMENT OR METALLURGY
• LOWER PR. DROP IN THE LOOP OR CONVERTER, REDUCING
  POWER REQUIREMENT IN RECYCLE GAS COMPRESSOR

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FACTORS AFFECTING AMMONIA PRODUCTION

• 1. OPERATING PR.- AFFECTS CONVERSION, COMPRESSION
  COST, PRODUCT NH3 REMOVAL, LOOP CAPITAL COST
• 2. OPERATING TEMP.- AFFECTS REACTION RATE,
  CATALYST VOLUME
• 3. DEGREE OF CONVERSION-AFFECTS RECYCLE
  FLOW,PRODUCT NH3 REMOVAL
• 4. INERT LEVEL - AFFECTS PURGE FLOW, DEGREE OF
  CONVERSION
• 5. LEVEL OF REMOVAL OF PRODUCT NH3 - AFFECTS
  REFRIGERATION LOAD, CW LOAD, NH3 YIELD
• 6. CONVERTER FLOW PATTERN - AFFECTS CONVERTER
  PRESSURE DROP
• 7. METHOD USED FOR MID STREAM REMOVAL OF HEAT -
  AFFECTS DEGREE OF CONVERSION, CATALYST VOLUME
• 8. PRESSURE DROP IN CONVERTER LOOP - AFFECTS
  RECYCLE COMPRESSION POWER

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OPTIONS FOR ENERGY SAVING IN STEAM POWER SYSTEM

• REDUCING POWER REQUIREMENT AT PROCESS LEVEL
• REDUCING POWER REQUIREMENT AT MACHINE LEVEL
• INCREASING THE EFFICIENCY OF CONVERSION TO
  PRODUCE POWER
• INTRODUCING FEATURES TO RECOVER LOW LEVEL HEAT
  AVAILABLE IN THE SYSTEM

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ADVANCES IN STEAM POWER SYSTEM

• PROCESS TECHNOLOGY
• RECOVERY OF HEAT BY GENERATION OF HP STEAM IN SYN
  LOOP
• STEAM PRODUCTION SUPERHEATING DOWN STREAM OF
  S/R
• PRODUCTION OF PROCESS STEAM FOR LOW LEVEL HEAT BY
  FEED GAS SATURATOR
• STRIPPING OF PROCESS CONDENSATE WITH LP OR MP
  STEAM FOR RE-USE AS BFW
• CONTD..

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• CONTD.
• USE OF COMBINATION OF BACK PR., CONDENSING
  TURBINES AND MOTOR DRIVES TO OPTIMISE THE SYSTEM
• EQUIPMENT OR METALLURGY
• IMPROVED DESIGN OF COMPRESSOR AND TURBINE WITH
  HIGH EFFICIENCY
• USE OF GT AS DIRECT DRIVE OR PART OF COGENERATION
  UNITS PRODUCING STEAM POWER

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BETTER OPERATION ENERGY MANAGEMENT

• PROCESS CONTROL SYSTEMS
• KEY PARAMETERS TO BE CONTROLLED ARE
• STEAM TO CARBON RATIO
• METHANE LEAKAGE
• H2 TO N2 RATIO OF SYNTHESIS GAS
• CONVERTER TEMP CONTROL
• SYNTHESIS LOOP PURGE
• REFRIGERATION PURGE

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ADD-ON UNITS

• PGR UNIT
• DEMETHANIZATION
• METHANOLATION

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MODERN UREA TECHNOLOGIES

• Stamicarbon CO2 STRIPPING PROCESS
• Snamprogetti NH3 STRIPPING PROCESS
• ACES-21 CO2 STRIPPING PROCESS
• UREA CASALE SPLIT FLOW LOOP

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ADVANCES IN UREA PLANT

• PROCESS TECHNOLOGY
• PRILLING - FORCED DRAFT PRILLING TOWER REPLACED
  BY NATURAL DRAFT
• UREA CONCENTRATION - OLD ROUTE OF CRYSTALIZATION,
  SEPARATION, DRYING AND THEN RE-MELTING REPLACED
  WITH VACUUM CONCENTRATION AND DIRECT PRILLING
• IMPROVEMENTS IN STRIPPING CYCLE TO MINIMUM USE OF
  STEAM
• CONTD.

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CONTD..

• VAPOUR RECYCLE SYSTEM(VRS)
• EQUIPMENT OR METALLURGY
• INCREASED CONVERSION THROUGH SPECIALLY DESIGNED
  TRAYS
• SAFUREX ALLOY

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CONSUMPTION OF DIFFERENT UREA PROCESSES
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BETTER OPERATION ENERGY MANAGEMENT IN UREA PLANT

• PROCESS CONTROL SYSTEMS
• KEY PARAMETERS TO BE CONTROLLED ARE
• HP NH3 FEED TO REACTOR
• N/C MOLAR RATIO
• REACTOR CONVERSION PER PASS
• SPECIFIC STEAM CONSUMPTION
• 1ST DECOMPOSER STEAM CONSUMPTION
• 1ST SEPARATOR TOP TRAY TEMP
• CARBAMATE CONCENTRATION ANALYSER SCALE READING
• INTERNAL WATER BALANCE CONTROL
• HYDROLYSER STRIPPER TOP TRAY TEMP
• HYDROLYSER STRIPPER FEED TRAY TEMP
• UREA RECYCLE

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KRIBHCOs EXPERIENCE
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ENERGY LOSS AREA IN AMMONIA PLANT

• GCAL/MT AMMONIA
• SURFACE CONDENSERS 1.367
• CO2 REMOVAL SECTION 0.577
• PRIMARY REFORMER FURNACE STACK 0.292
• HEAT LOSS IN CW EXCHANGERS 1.054
• (Excluding Surface Condensers)
• OTHER LOSSES 0.180
• -Purge Gas
• -Furnace Stack Other Than Primary Reformer
• -Steam Loss Through Vents
• -Energy Loss Through Steam Traps
• -Losses Through Flash Gases
• TOTAL 3.470

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PRIMARY REFORMER OF KRIBHCO
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PRIMARY REFORMER OF KRIBHCO(After Tube Change)
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RESULTS OF P/R RETROFIT

• PRESSURE DROP ACROSS THE TUBES REDUCED FROM 3.5
  Kg/Cm2 TO 2.2 Kg/Cm2
• S/C COULD BE REDUCED MARGINALLY
• THE REVAMED REFORMER PERFORMANCE RESULTED IN
  LOWER CH4 SLIP FROM THE P/R EFFLEUENT
• EXISTING BOILERS 101-C, 102-C, 103-C, AND THE BFW
  PREHEATER 123-C ABSORBED MORE HEAT
• CAPACITY OF PRIMARY REFORMER INCREASED PROVIDING
  POTENTIAL FOR MORE PRODUCTION

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PROCESS CONDITION OF KRIBHCO AMMONIA CONVERTER
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AMMONIA CONVERTER RETROFIT

• MAIN FEATURES
• GAS FLOW IS CHANGED FROM AXIAL TO AXIAL-RADIAL.
• REDUCING THE PATH FOR GAS TO TRAVEL FROM 9 M TO
  0.6 M.
• REDUCING THE PR. DROP.
• 1.5 MM CATALYST IS USED INSTEAD OF 6-10 MM.
• HIGHER NH3 CONCENTATION ARE ACHIEVED UPON USE OF
  SMALL CATALYST.
• INTRODUCTION OF GAS/GAS EXCHANGER BETN. 2ND AND
  3RD BED ELIMINATES THE QUENCH
• PROVIDES THERMODYNAMIC ADVANTAGES IN IMPROVING
  THE CONVERSION FURTHER.

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• BENEFITS
• INCREASE IN NH3 CONC. AND THEREBY REDUCTION IN
  RECIRCULATION RATE. POWER CONSUMPTION IN SYN GAS
  COMPR.IS REDUCED
• REDUCTION IN CONVERTER AND SYN LOOP PR. DROP
• INCREASE IN SYN GAS TEMP EXIT
• INCREASED NH3 CONC FACILITATES MORE NH3
  CONDENSATION IN WATER COOLED CONDENSER AND
  REDUCING POWER CONSUMPTION IN REFRIG. COMPR.
• HIGHER SYN GAS EXIT TEMP FROM CONVERTER IMPROVES
  HEAT RECOVERY IN BFW PREHEATER
• OVERALL BENEFIT IS ENERGY SAVING OF 0.257 GCAL/MT
  NH3 DURING GTR

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• COSTS
• Cost Of License Fee , Design Basic Engg.,
  Detailed Engg.
• Services For Construction,
  Erection,Engineering, And
• Commissioning Rs. 2.90 Cr
• Cost of off shore Material, procurement,
• inspection Rs. 1.63 Cr.
• Cost of catalyst unloading Rs. 0.36 Cr.
• Cost of catalyst (three charges) Rs. 5.79 Cr.
• Cost of Indian material procurement Rs. 4.25
  Cr.
• Cost of civil work, erection, custom duty
• and other expenses Rs. 10.54 Cr.
• TOTAL Rs. 25.47 Cr.
• Energy savings in money terms Rs. 10.57 Cr.
• Pay back period 2.5 Years

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ENERGY SAVING DURING COLD START UP AND LT
REDUCTION

• AS PER ORIGINAL DESIGN
• NG USED FOR HEATING CATALYSTS OF THE
  DESULPHURISER, LT SHIFT CONVERTERS (BOTH LT GUARD
  AND MAIN) WAS BEING VENTED
• NG USED AS CARRIER GAS FOR LT GUARD CATALYST
  REDUCTION WAS BEING VENTED
• NG USED AS CARRIER GAS FOR LT MAIN CATALYST WAS
  BEING VENTED.

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ENERGY SAVING DURING COLD START UP AND LT
REDUCTION

• NG USEDFOR HEATING SAVING IN EACH
  STARTUP DESULPHURISATION CATALYST
• DURING COLD START UP 90,000 NM3
• NG USED FOR HEATING LT GUARD
• LT MAIN CATALYST 60,000 NM3
• 150,000 NM3
• NG USED AS CARRIER GAS DURING
• LT GUARD CATALYST REDUCTION 240,000 NM3
• ANNUAL SAVINGS WITH 3 COLD
• START UP AND 1 LT GUARD
• REDUCTION Rs. 21 LAKHS
• INVESTMENT ON THE SCHEME Rs. 14 LAKHS
• PAYBACK PERIOD 8 MONTHS

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OTHER IMPROVEMENTS DONE IN PLANT

• IMPROVED NH3 CONVERSION BY ADJUSTING OPERATING
  PARAMETERS OF SYNTHESIS CONVERTER
• ADJUSTMENT OF AIR FLOW TO AUXILIARY BOILER
• INCREASING THE CONCENTRATION OF BENFIELD SOLUTION
• CLOSING OF MP STEAM VENT
• PROVISION OF BAFFLES IN P/R CONVECTION
• USE OF SEAL OIL FLASH GAS AS FUEL
• FEED PREHEAT COIL IN LT COVECTION ZONE OF PR

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• ENERGY SAVING GCAL/MT NH3
• IMPROVED NH3 CONVERSION BY
• ADJUSTING OPERATING PARA-
• METERS OF SYN. CONVERTER 0.011
• ADJUSTMENT OF AIR FLOW TO
• AUXILIARY BOILER 0.006
• INCREASING THE CONCENTRATION OF
• BENFIELD SOLUTION 0.002
• CLOSING OF MP STEAM VENT 0.057
• PROVISION OF BAFFLES IN P/R
• CONVECTION SECTION 0.017
• USE OF SEAL OIL FLASH GAS AS FUEL 0.004
• FEED PREHEAT COIL IN LT CONVECTION ZONE OF
  PR 0.035

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IMPROVEMENT IN UREA PLANT

• SCHEME ENERGY SAVED
• Gcal/MT of UREA
• UREA MODERNISATION SCHEME 0.10
• CO2 COMPRESSOR ROTOR CHANGE 0.02

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THANK YOU