1 1 Energy Conservation In Fertilizer Industry Best Practices & Case Studies P. Chandra Mohan DGM (Technical Services) Nagarjuna Fertilizers & Chemicals Ltd., Kakinada 2 2.9 78 7.5 SSP 19 11 32 No. of Plants 8.1 4.2 21.1 Producti on (million tonnes) 7.1 NP/NPK 7.0 DAP 22.2 Urea Capacity (million tonnes) Fertiliser Capacity and Production of Major Fertiliser Products (2009-10) in India India is the third largest producer of fertilisers in the world SSP NP/NPK Urea DAP 3 Consumption of Different Feedstocks in Fertilizer Sector (2009-10) Gas 14.0 billion NM 3 Naphtha 1.0 million tons Fuel Oil & LSHS 1.7 million tons 4 Relative Energy Intensity Of Fertiliser Industry (Indicative Figures) 16 24.5 11.4 2.15 DAP/NP/ NPK 84 126.6 20.1 6.30 Urea % of Total Energy of Fertilizers Total Energy GCal X 10 6 Total Production Million MT Avg. Energy GCal/MT Product In the ammonia-urea segment, production of ammonia accounts for 80% of the total energy required for production of urea
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Energy Conservation In
Fertilizer Industry
Best Practices & Case Studies
P. Chandra MohanDGM (Technical S ervices)
Nagarjuna Fertilizers & Chemicals Ltd.,Kakinada
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2.9787.5SSP
19
1132
No. of Plants
8.1
4.221.1
Production
(million tonnes)
7.1NP/NPK
7.0DAP22.2Urea
Capacity (million tonnes)
Fertiliser
Capacity and Production of Major Fertiliser Products (2009-10) in India
India is the third largest producer of fertilisers in the world
SSPNP/NPK Urea
DAP
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Consumption of Different Feedstocks in Fertilizer Sector (2009-10)
Gas 14.0 billion NM3
Naphtha 1.0 million tons
Fuel Oil & LSHS
1.7 million tons
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Relative Energy Intensity Of Fertiliser Industry (Indicative Figures)
1624.511.42.15DAP/NP/NPK
84126.620.16.30Urea
% of Total
Energy of Fertilizers
Total EnergyGCal X
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Total ProductionMillion MT
Avg. Energy
GCal/MT
Product
In the ammonia-urea segment, production of ammonia accounts for 80% of the total energy required for production of urea
Feedstock wise Capacity and Energy Consumption in Operating Ammonia Plants (2007-08)
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BENCHMARKING WITH WORLD PLANTS (Energy consumption of Ammonia)
9.06
8.65
9.30
7.5
8.5
9.5
Gc
al/
MT
Plants in IFASurvey
Gas BasedIndian Plants
All Indian Plants
For the year 2002-03
Most ammonia plants (>90%) in the IFA surv ey are based on NG as feedstock. Almost 40% of Indian capacity was based on less efficient naphtha and fuel oil. Still average energy consumption of Indian plants is comparable to the world av erage. Indian gas based plants are more efficient than the world plants.
l Liquid ammonia wash of makeup synthesis gas lMolecular Sieve dryingl Chilling of Makeup synthesis gas
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ROTARY MACHINERY
lUsing Gas Turbines to drive major compressors.
lChanging from Steam drives to Electric Power drives
l Suction chilling of Compressors/Gas Turbines
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UREA MANUFACTURING INDUSTRY –Energy Outlook
l Average energy consumption for ammonia has been reduced from 12.48 in 1987-88 to 8.97 Gcal/MT in 2007-08.
l Average energy consumption for urea has been reduced from 8.87 to 6.29 Gcal/MT over the same period.
l Improvement has been possible due to better feedstock, advanced technologies, modernisation of old plants, improved operating and maintenance practices
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ENERGY CONSERVATION SCHEMES AT NAGARJUNA FERTILIZERS
– RECENTLY IMPLEMENTED
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25Nagarjuna Fertilizers and Chemicals Limited
ISO 9001:2008 ISO 14001:2004
OHSAS 18001:2007
BRITISH SAFETY COUNCIL
PSMS&
RCM
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COMPANY PROFILELocation : Agricultural town close to marketRaw Water : Godavari RiverNatural Gas : ONGC, Cairn & RIL through GAIL Railway : Siding connected to South Central RailwayFacilities :
l Ammonia plants, 2 X 1050 MTPD (Revamped to 1325 MTPD)
l Urea plants, 2 X 1810 MTPD ((Revamped to 2325 MTPD)
l Carbon Dioxide Recovery plantl Water Treatmentl Cooling Towerl Inert Gas Plantl Boilersl Gas Turbinesl Ammonia Storage
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v AMMONIA : Haldor Topsoe of Denmark
v UREA : Snamprogetti of Italy
v CO2 REMOVAL : Giammarco Vetrocoke of Italy
v CO2 Recovery : Mitsubishi Heavy Industries of
Japan
TECHNOLOGY
Plant - I Plant- IIv Commissioning Aug 1992 Mar 1998
PLANTSNagarjuna Fertilizers and Chemicals Limited
Kakinada 533 003
ENERGY POLICY
We strive to achieve 1% specific energy reduction ever y year in next 5 years with the following efforts:
1. By applying innovative/creative ideas in operational techniques as per the suggestions/discussions/brainstorming among Associates (Employees).
2. By i mproving specific energy norm based on process evaluation, machinery performance and condition monitoring with the help of in-house study groups and reputed external agencies and adopting efficient measures.
3. By de-bottlenecking the limiting areas to improve plant reliability and availability with the help of process licensors and engineering consultants.
4. By benchmarking with the most energy efficient plants and comparing the provisions/facilities through survey group study, plant visits, wor kshop/conference participation and implementing the beneficial outcome.
5. By firming up full NG availability for Unit-II operations through various NG suppliers and eliminating Naphtha usage.
Date: March 25, 2005 Director & COO
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8.4858.1506.45313.9108.748Specific Energy (Gcal/MT)
NFCL Ammonia
-II
NFCL Ammonia
-I
Min (Best)MaxAverage
93 Ammonia Plants (Including Two H2 based plants) based on 2006 & 2007 Operating Data
NFCL Energy Performance
NFCL Complex Ammonia Energy for the Year 2009-10 is 8.093 Gcal/MT
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FEED5.80Gcal/MT
FUEL GAS2.00 Gcal/MT
POWER0.23 Gcal/MT
TOTAL 8.09 Gcal/MT100%
71.7 %
2.8 %
24.7 %
0.7 %
Ammonia Plant Energy Input
STEAM0.06Gcal/MT
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Product NH35.0 61.8 %
EG Export0.0
0 %
0. 5 %
DM +LS Export0.04
Stack Losses0.16
CW Loss2.77
34.2 %2.0
%
Hot SurfacesBlow-down etc
0.12
TOTAL 8.09 Gcal/MT
LOSSES
1.5 %
Ammonia Plant Energy Output
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Energy Conservation – Best Practices
Three-pronged approach
Capacity utilisation
Operational Excellence
Technology upgradation
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Best Practices - Capacity Utilization
lDe-bottlenecking
lRevamping
lReliability Improvement measures
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Best Practices - Technology Up gradation
l Studying the feasibility and adopting the latest technologies
lConducting Benchmarking Studies and implementing the identified improvements
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Best Practices – Operational Excellence
l Process Parameters Optimizationl Specific Energy Monitoringl Specific Consumptions MonitoringlMachinery MonitoringlCatalyst Performance Monitoring
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Process Parameters Optimization
PANNELOPERATOR
SHIFTINCHARGE
SECTIONHEAD
HOD
SITEINCHARGE(MEETING
WITH HOD’S)
IMPLEMENTTHE CAHNGE
OPERATING PARAMETERS
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§ Energy monitoringØ Daily Complex Sp.energy calculationsØ Plant wise Specific EnergiesØ Identifying & Arresting Energy drainsØ Steam BalanceØ NG BalanceØ CO2 removal section Specific Energy
Specific Energy Monitoring
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l Monitoring the specific consumptions
Ø Specific consumptions per MT of UreaØ Specific ammonia 0.570 MT
Ø Specific CO2 381 Nm3
Ø Specific Steam 0.95-1.1 MT
Ø Specific Power 25-28 Kw
Specific Consumptions Monitoring
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l Equipment monitoringØ Preventive and Predictive Maintenance
Ø Boiler Efficiency calculation
Ø Gas Turbine Efficiency calculation
Ø Compressor Efficiency, Power calculation
Ø Steam Turbine Efficiency, Power calculation
Machinery Monitoring
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lCatalyst performanceØ Approach to Equilibrium
Ø Exit Analysis
Ø Remaining life assessment
Ø Normalized pressure drop
Catalyst Performance Monitoring
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Replacement of back pressure turbines with motors
CONCEPT – Switching over to Electric Power Intensive mode
1 MW Machine
Driven By
Motor Steam Turbine
1.70 Gcal/Hr 3.90 Gcal/Hr
• = 2.2 Gcal/Hr42
Replacement of back pressure turbines with motors (Cont.)
• 3 nos of turbine condensate pumps were replaced.
• Energy saving 58.51 Gcal/day
• Cost of energy Rs.450/Gcal
• Total investment Rs.11.68 Lakhs
• Annual savings Rs. 86.89 Lakhs
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STEAM INTENSIVE TO POWER INTENSIVE MODE
CONCEPT
Back pressureTurbine EfficiencyAppx.40 to 48%
Motor EfficiencyAppx.82 to 92%
EFFICIENCY
Efficiency Gain is Appx.42 to 44%
+Gain in GT efficiency at higher load
If exhaust steam is not used efficiently
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STEAM INTENSIVE TO POWER MODE
The following stand by motor drives taken on line and turbines kept as standby.
1.Induced draft fan of Primary Reformer Unit-I & II2.Forced draft fan of Primary Reformer Unit-I & II3.Boiler feed water pump of Unit-I, II & OSPP4.GV Semi-lean & Lean solution pump of Unit-I
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Installation of fluid coupling
Constant speed driveVariable speed drive
(Fluid Coupling)
SUCTION THROTTLING NO SUCTION THROTTLING
Motor MotorFluid
Coupling
CONCEPT – Performance Optimization of Blowers
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Installation of fluid coupling (Cont.)
Power saving after fluid coupling = 200 KW= 4.13 Gcal/day
Cost of energy = Rs.450/Gcal
Savings per annum = Rs.6.13 Lakhs
Investment = Rs.16 Lakhs
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CONCEPT – Decreasing the DP across the plant equipment
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Months4.0Pay Back PeriodLakhs14Cost of the Valve & ImplementationLakhs / Yr50.2Savings per annumSm3/Hr160Equivalent NG SavingsKcals / hr1408960Energy SavingsTPH2.38SavingsTPH0.1Increase in Steam in Process air compressorTPH2.48Steam saving in Synthesis gas compressor
Savings Calculations
CONCEPT – Decreasing the DP across the plant equipment
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l The significant process variables in Ammonia Plant are interlinked in a complex manner which involve frequent human interference.
l Under constantly changing parameters, Manual control of all the Critical parameters simultaneously is very difficult which leads the operation to go away from optimum economical plant operation.
l To achieve an optimum process control for reducing energy in Ammonia plants, Advanced Process Control (APC) software has beeninstalled.
l With APC process optimization is achieved by means of an algorithm, which determines the optimum steady-state values for the controlled variables in accordance with economic criteria.
CONCEPT – Installation of Advanced Process Controller
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APCOptimum
3.50
CONCEPT – Installation of Advanced Process Controller
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l The APC computes on the basis of a dynamic process model and takes the necessary control steps. The aim of this control is to cause the controlled variables to follow predicted routes for optimum steady state final values.
l The process of implementing APC involves testing the existing controllers configured in DCS system using step test method and developed the controller model that is integrated with the existing DCS systemfor online control.
l With APC in place, operation has become smoother due to a reduced impact from process disturbances and the constraint in handling capability of the controller.
l This resulted in an ability to run the plant as per the actual instead of running it with safer offset in an anticipation of large disturbances. The installation of APC has led to a close monitoring and control ofkey process parameters and less operational intervention.
CONCEPT – Installation of Advanced Process Controller
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l The following Cr itical parameters are directly affected by APC and in turn impact the energy consumption.
1. Steam to Car bon r atio2. Pr imar y r efor mer outlet temper atur e Stabilization3. CH4 slip at secondar y r efor mer outlet4. H2 / N2 r atio in Synthesis Loop5. CH4 in Synthesis Loop
l Savings Calculation:l With the installation of Advanced Process Controller, the Specific
Consumption of Ammonia plants has been reduced by 0.53%.l Equivalent Energy saving per annum was 33604 Gcal / Annum which is
equivalent to Rs. 176 lakhs.l Investment cost for the project is Rs. 150 Lakhsl Payback for the project is 10.2 months
CONCEPT – Installation of Advanced Process Controller
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CONCEPT – Installation of Advanced Process Controller
Before APC Installation: After APC Installation:
For Example, The Variations in the Parameter of Steam to Carbon Ratiois brought down Significantly With APC as Shown in the Graph Below:
