11

Energy Conservation In

Fertilizer Industry

Best Practices & Case Studies

P. Chandra MohanDGM (Technical S ervices)

Nagarjuna Fertilizers & Chemicals Ltd.,Kakinada

2

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

3

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

4

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

106

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

25

Indian Ammonia Plants Brief Details

291210

33

1960s1970s1980s1990s

Total

No. of Plants

Vintage

2454

33

GasNaphthaFuel Oil

Total

No. of Plants

Feedstock

4 3

1016

33

< 600600 to < 900900 to 1000 but 1500>1500 but

39

Energy Consumption of Ammonia Plants (2007-08)

7.65

15.06

Weighted Average 8.97

6.00

7.00

8.00

9.00

10.00

11.00

12.00

13.00

14.00

15.00

16.00

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29

Plants

Ener

gy (G

Cal

/MT)

10

Energy Consumption in Urea Plants (2007-08)

12.52

5.16

Weighted Average 6.29

0.00

2.00

4.00

6.00

8.00

10.00

12.00

14.00

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26

Plants

Ener

gy (G

Cal

/MT)

11

8.9712299.933Total11.721386.04Fuel Oil

9.851411.35Naphtha

8.499646.624Gas

Energy Consumption

(GCal/MT)

Effective Capacity(000 MT)

No. of Plants

Feedstock

Feedstock wise Capacity and Energy Consumption in Operating Ammonia Plants (2007-08)

12

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.

413

ENERGY CONSERVATION SCHEMES

14

Macro Level - MethodologyAny process/unit operation

TheoreticalRequirement (B)

Unavoidable losses (C)

Energy input (A)

(D)Avoidable

lossesA = B + C + D

15

Macro Level - Methodology

Focus should be To concentrate on avoidable losses

Quantify the lossesIdentify ways and means for reduction

PROCESS FLOW DIAGRAM AMMONIA PLANTS

Steam

De-sulphurisation

PrimaryRef ormer

SecondaryRef ormer

HT ShiftConv ertor

LT Shif tConv ertor

Ref rigeration Sy stem

CO2Stripper

CO2Absorber

Chilling Ammonia Conv ertor

Sy n. GasCompressor

Methanator

PGR Unit

GV Solution

CO2 toUrea Plants

Tail Gas as Fuel

Prod. H2

Liquid AmmoniaProduct

AirFlue Gas

Process Gas

Carbon Dioxide ( CO2)

Process Gas

Natural Gas

517

PROCESS FLOW DIAGRAM AMMONIA PLANTS

18

REFORMING SECTION

l Additional heat recovery in reformer convection zonee. g.

l New BFW coil in convection sectionl Air pre-heater

19

SHIFT CONVERSION SECTION

l LTS Guard Bed with heat recovery

lHTS & LTS Converter revamp with radial or axial-radial converter catalyst basket

20

CO2 REMOVAL SYSTEM

l Single stage to two stage regenerationl Use of more efficient packingsl Usage Hydraulic turbine

Technologies Available:l Giammarco Vetrocoke Processl Benfield Processl aMDEA

621

SYNTHESIS

l S-50 and S-300 Converters

lGas purification

l Liquid ammonia wash of makeup synthesis gas lMolecular Sieve dryingl Chilling of Makeup synthesis gas

22

ROTARY MACHINERY

lUsing Gas Turbines to drive major compressors.

lChanging from Steam drives to Electric Power drives

l Suction chilling of Compressors/Gas Turbines

23

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

24

ENERGY CONSERVATION SCHEMES AT NAGARJUNA FERTILIZERS

RECENTLY IMPLEMENTED

725Nagarjuna Fertilizers and Chemicals Limited

ISO 9001:2008 ISO 14001:2004

OHSAS 18001:2007

BRITISH SAFETY COUNCIL

PSMS&

RCM

26

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

27

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

829

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

30

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

31

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

32

Energy Conservation Best Practices

Three-pronged approach

Capacity utilisation

Operational Excellence

Technology upgradation

933

Best Practices - Capacity Utilization

lDe-bottlenecking

lRevamping

lReliability Improvement measures

34

Best Practices - Technology Up gradation

l Studying the feasibility and adopting the latest technologies

lConducting Benchmarking Studies and implementing the identified improvements

35

Best Practices Operational Excellence

l Process Parameters Optimizationl Specific Energy Monitoringl Specific Consumptions MonitoringlMachinery MonitoringlCatalyst Performance Monitoring

36

Process Parameters Optimization

PANNELOPERATOR

SHIFTINCHARGE

SECTIONHEAD

HOD

SITEINCHARGE(MEETING

WITH HODS)

IMPLEMENTTHE CAHNGE

OPERATING PARAMETERS

10

37

Energy monitoring Daily Complex Sp.energy calculations Plant wise Specific Energies Identifying & Arresting Energy drains Steam Balance NG Balance CO2 removal section Specific Energy

Specific Energy Monitoring

38

l Monitoring the specific consumptions

Specific consumptions per MT of Urea Specific ammonia 0.570 MT

Specific CO2 381 Nm3

Specific Steam 0.95-1.1 MT

Specific Power 25-28 Kw

Specific Consumptions Monitoring

39

l Equipment monitoring Preventive and Predictive Maintenance

Boiler Efficiency calculation

Gas Turbine Efficiency calculation

Compressor Efficiency, Power calculation

Steam Turbine Efficiency, Power calculation

Machinery Monitoring

40

lCatalyst performance Approach to Equilibrium

Exit Analysis

Remaining life assessment

Normalized pressure drop

Catalyst Performance Monitoring

11

41

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

43

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

44

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

12

45

Installation of fluid coupling

Constant speed driveVariable speed drive

(Fluid Coupling)

SUCTION THROTTLING NO SUCTION THROTTLING

Motor MotorFluid

Coupling

CONCEPT Performance Optimization of Blowers

46

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

47

CONCEPT Decreasing the DP across the plant equipment

48

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

13

49

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

50

APCOptimum

3.50

CONCEPT Installation of Advanced Process Controller

51

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

52

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

14

53

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:

54

COMPLEX SPECIFIC ENERGY CONSUMPTION

5.5885.526

5.6075.6305.662

5.7185.756

6.015

5.846

5.615

5.2

5.3

5.4

5.5

5.6

5.7

5.8

5.9

6

6.1

2001

-0220

02-03

2003

-0420

04-05

2005

-0620

06-07

2007

-0820

08-09

2009

-1020

10-11

YEAR

Ener

gy G

cal/M

T U

rea

Target

55

Industry in Harmony with Nature

Thank You