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TÜV SÜD South Asia Pvt. Ltd

WATER AUDIT AT HALDIA REFINERY

INDIAN OIL CORPORATION LIMITED, REFINERIES DIVISION, HALDIA REFINERY

Project: Detailed report of water audit at Haldia Refinery Document : Final Report Submission Dates: April 2015 Version Number: 4 Revision Number: 4


REPORT VERSION: 4, April 2015

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1

Contents 1. ACKNOWLEDGEMENT .................................................................................................. 4

2. ABBREVIATION............................................................................................................... 5

3. EXECUTIVE SUMMARY ................................................................................................ 6

4. CHAPTER 1: INTRODUCTION ....................................................................................... 8

1.1. Background ...................................................................................................................... 8

1.2. Objective .......................................................................................................................... 8

1.3. Limitation ......................................................................................................................... 9

5. CHAPTER 2: INVENTORY OF WATER USE ................................................................ 9

2.1. Water Footprint .................................................................................................................. 11

2.2. Fresh water withdrawn ....................................................................................................... 12

2.3. Water Consumption ........................................................................................................... 16

2.4. Effluent generation and reuse ............................................................................................ 18

2.5. Plant Water Balance Diagram ............................................................................................ 22

6. CHAPTER 3: Water utilization ........................................................................................ 25

3.1. Cooling Tower................................................................................................................ 25

3.2. RO Unit .......................................................................................................................... 29

3.3. Process ............................................................................................................................ 31

3.3.1. Fuel oil block .......................................................................................................... 31

3.3.2. Lube oil block ......................................................................................................... 36

3.3.3. DHDS ...................................................................................................................... 40

3.4. DM Plant ........................................................................................................................ 44

7. CHAPTER 4: WATER CONSUMPTION REDUCTION OPPORTUNITIES ............... 47

4.1. Water conservation across process units ............................................................................ 47

4.2. Cooling Tower ................................................................................................................... 49

4.3. DM Plant ............................................................................................................................ 50

4.4 Monitoring ......................................................................................................................... 50

8. CHAPTER 5: CONCLUSION ......................................................................................... 51



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Table 1: Synopsis of water loss from cooling tower ....................................................................... 6

Table 2: Water withdrawal from tube well ................................................................................... 12

Table 3: Water withdrawn/ sourced from PHE ............................................................................. 13

Table 4: Water sourced through HFC tube well ........................................................................... 14

Table 5: Total raw water withdrawn ............................................................................................. 15

Table 6: Segregation of water consumption ................................................................................. 17

Table 7: Raw and total water consumed ....................................................................................... 18

Table 8: ETP capacities ................................................................................................................ 20

Table 9: Effluent Treatment .......................................................................................................... 20

Table 10: Cooling Tower specification......................................................................................... 25

Table 11: Estimation of water saving through increased COC in PCT cooling tower ................. 26

Table 12: Estimation of water saving through increased COC in TPS cooling tower ................. 27

Table 13: Estimation of water saving through increased COC in DHDS cooling tower ............. 27

Table 14: Estimation of water saving through increased COC in OHCU cooling tower ............. 28

Table 15: Estimation of water saving through increased COC in GT cooling tower ................... 28

Table 16:Water use as bearing water in CDU-2 ........................................................................... 33

Table 17: Water use for bearing cooling in CDU-I ..................................................................... 34

Table 18: Water use for bearing cooling in CRU/KHDS ........................................................... 34

Table 19: Estimation of bearing cooling water used in FOB ........................................................ 35

Table 20: Total financial saving ................................................................................................... 35

Table 21: Water use for bearing cooling in loss across unit 39 (MCW) ..................................... 37

Table 22: Water use for bearing cooling in loss across unit 84 (CIDW) .................................... 37

Table 23: Water use for bearing cooling in loss across unit 32 ( PDA) ..................................... 38

Table 24: Water use for bearing cooling in loss across unit 31 ( VDU-1) ................................. 38

Table 25: Water use for bearing cooling in loss across unit 37 (VBU) ...................................... 38

Table 26: Water use for bearing cooling in loss across unit 33 ( FEU) ..................................... 38

Table 27: Water use for bearing cooling in loss across unit 35 ( HFU) .................................... 38

Table 28: Total water used for bearing cooling in LOB ............................................................... 39

Table 29: Water use for bearing cooling in Unit 24,25 (old HGU and DHDS) .............................. 40

Table 30: Water use for bearing cooling in VDU-II unit ............................................................ 41

Table 31: Water use for bearing cooling in MSQ units ............................................................... 41

Table 32: Water use for bearing water cooling in FCCU ......................................................... 42

Table 33: Water use for bearing cooling in ARU and SWS unit ................................................ 42

Table 34: Water use for bearing cooling in OHCU Block........................................................... 43

Table 35: Total water used for bearing cooling across all the units ............................................. 44

Table 36: Estimation of financial loss .......................................................................................... 44

Table 37: DM Water generation & Condensate recovery from different units ............................ 45

Table 38: DM water supply to units and processes ...................................................................... 45



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Figure 1: Schematic diagram of water inventory areas ............................................................... 10

Figure 2: Specific water consumption .......................................................................................... 11

Figure 3: Specific water consumption and water re-use Figure 4: Specific water consumption 2014-15 .......................................................................... 111

Figure 5: Average water withdrawn from tube well on monthly basis......................................... 12

Figure 6: Average water withdrawn from tube-well on hourly basis ......................................... 122

Figure 7: Average water sourced from PHE on monthly basis .................................................. 133

Figure 8: Average water sourced from PHE on hourly basis .................................................... 133

Figure 9: Total water sourced from HFC tube well on monthly basis ...................................... 144

Figure 10 : Average water sourced from HFC tube well on monthly basis ............................... 144

Figure 11: Total raw water withdrawn per month ( cumulative for three source) .................... 155

Figure 12: Average hourly water withdrawn from three sources .............................................. 155

Figure 13:Source wise water withdrawn .................................................................................... 166

Figure 15: Water supply network across FOB unit .................................................................... 321

Figure 16: pump draining water to drain in FOB

Figure 17: Water is being supplied to Pump No SS-121 under maintenance 35 Figure 18: Steam condensate routed to drain .............................................................................. 38

Figure 19: Condensate drain across unit no 39 ........................................................................... 39

Figure 20: Bearing cooling water drained to surface drain in Unit-82 ..................................... 410



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ACKNOWLEDGEMENT This study has been conducted by TUV SUD under guidance of Shri P. S. Goswami. TUV SUD wishes to thank the following individuals that contributed technical expertise and guidance in providing direction and support in conducting the water audit. Shri S. Chaudhuri Shri R Paul Shri R Tirkey Shri K C Nayek Shri Prabir Mandal Shri Susanta Mandal Shri Mukul Sarkar Shri Biju Antony We trust that the findings of this study will help the management in improving the performance with optimum water consumption in M/s. Indian Oil Corporation Ltd., Haldia Refinery

TÜV SÜD South Asia Pvt. Ltd



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ABBREVIATION Acronym DescriptionIOCL Indian Oil Corporation LimitedFCCU Fluidised Catalytic Cracking UnitVBU Visbreaking UnitDHDS Diesel HydrodesulphurizationVDU Vacuum Distillation UnitCDU Crude Distillation UnitHSD High Speed DieselFO Fuel OilGT Gas TurbineLPG Liquefied Petroleum gasK-HDS Kero- Hydrodesulfurization UnitPDA Propane Deasphalting UnitFOB Fuel Oil BlockOHCU Once Through Hydrocracker UnitCRU Catalytic Reforming UnitSRU Sulphur Recovery UnitARU Amine Recovery UnitSWS Salt Water StripperSDU Solvent Dewaxing UnitLOB Lube Oil BlockPCT Process Cooling TowerTPS Thermal Power StationDM plant Demineralization Plant (Water treatment)



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EXECUTIVE SUMMARY Water is critical, directly or indirectly, in the entire process of evolution, growth and survival of all living beings and it plays a vital role in the industrial development. Water has come to be

its supply can threaten the life, livelihood as well as the functioning of the economy. Conserving water resources in this strategic

maintaining economic growth but also for the human development objectives that aim at alleviation of poverty, unemployment and meeting the Millennium Development Goals (MDGs). IOCL has always been in the forefront of promoting inclusive and sustainable development and reducing water footprint is one of its endeavors towards contributing to environmental cause. This is due to increased reuse of waste water and nearly zeroing discharge. Developing an inventory or water balance is a first step of water audit. The unit has substantially slashed its water usage with current specific water consumption in tune of 0.85 m3/MT in compared to 1.75 m3/MT in 2009-10. The specific water consumption is very much in tune with the national practice of water usage of 1 m3/MT. Some of the critical areas were identified that were resulting to water loss and improvement could further lower the specific water consumption and few are outlined as follows.

1. Measurement is the first step towards resource conservation. It is thus recommended that the monitoring devices which are non functional should be repaired or replaced .

2. Cooling tower is the major water consuming area in the plant. Almost 47% of the water consumed is towards makeup of cooling tower. It was found that the COC is maintained at a level between 1.5 to 2.5, drift eliminator and mist eliminator condition has been damaged in many locations resulting to increased water loss through evaporation. It is highly recommended that the COC be improved in the range of 5 to7 depending upon the economics of scale. An synoptic estimation of possible water saving by increasing the COC is outlined as follows:

Table 1: Synopsis of water loss from cooling tower Sl. No

Name of the Cooling Tower

Current COC

Annual water saving (m3/annum) Improving COC to 5 Improving COC to 7

1 PCT 2.1 565899 637449 2 TPS 2.51 210488 217006 3 DHDS 2.51 564269 678332 5 OHCU 588023 621264 6 GT 13771 174111 Total (million m3) 1.94 2.32

3. Bearing and jacket cooling water being drained. The water as observed has the slightest

or little contamination. However when drained this water is subjected to hydrocarbon contamination and is thereafter being treated in ETP enhancing the cost of treatment and also the stress on treatment plant.



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Sl. No Name of Unit Water quanity (m3/hr)

1 CDU-2 49.41 2 Unit 21, 22 and 23 8.86 3 Unit 39 ( MCW ) 1.01 4 Unit 84 ( CIDW) 5.63 5 Unit 32 ( PDA) 16.61 6 Unit 31 ( VDU-1) 8.01 7 Unit 37 ( VBU) 0.56 8 Unit 33 ( FEU ) 0.04 9 Unit 35 ( HFU) 3.94 10 Old HGU and DHDS (Unit

24 and 25) 8.32

11 VDU-II unit 21.52 12 FCCU 19.03 13 ARU & SWS 0.07

Total water quantity (m3/hr) 143.1

It is recommended that water that is being drained out after bearing cooling or jacket cooling of the utility be collected in existing or newly constructed pit near the unit. The water from this pit is to be directed to a storage tank (within the unit or across the blocks depending upon the availability of space within the units) . The water stored in this storage tank can be pumped again to bearing cooling water piped network of the particular units or to cooling water return line. This can result in substantial water saving.

4. All the water collected from different units with different level of contamination is being drained to a common effluent plant or treatment. This practice actually increases the level of contamination of the less contaminated water.

5. Reducing leaks and over flows: Leakages from overground and underground fire water lines need to be attended.

6. Dedicated periodic operation and maintenance followed by review and monitoring. 7. In DM Plant area leaky valves, taps, coupling/flanges must be fixed immediately. Water

flowing through pH and conductivity sensors may be routed to the raw water tank. A series of other recommended measures are discussed in the subsequent chapters.



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CHAPTER 1: INTRODUCTION 1.1. Background Freshwater is essential to all forms of life and fundamental for human health, for sustainable socio-economic development, and for food security. Even though our planet consists mainly of water but the availability of fresh water is limited. Out of the enormous supply of about 1.36 billion cubic kilometers of water bodies 97% is too salty for human consumption. Of the remaining 3%, most is frozen in polar ice caps or glaciers, or lies hidden away in deep groundwater aquifers which are inaccessible for humans. This leaves human race with a meager 1 % to be shared among not only amongst more than 7 billion people but also with other freshwater and terrestrial organisms. According to a recent estimate by the International Food Policy Research Institute (IFPRI) and Veolia, around 36% of the world's population is already living in water-scarce regions. Looking forward to 2050, around 52% of the world's population, producing 45% of its GDP, is expected to be living in such regions. The water fresh water resources are currently under stress from direct impacts of rapid global changes: population growth, improved living standard, migration, urbanization, climate change, land-use changes and economic development. Once a water abundant country, with per capita water availability of around 4,100 m3 /capita/year (1960) has now turned 'water stressed' with per capita water availability poised at a meagre 1580 m3 /capita/year (2009). Businesses and investors across the world are fast awakening to the reality of water scarcity and its potential to jeopardize economic growth. There is also a growing realization amongst the industrial facilities to conserve water and minimize the use of freshwater through water harvesting, wastewater treatment and reuse. Water audit is the first step and systematic approach towards water conservation as it identifies the key areas of water wastage and recommends measures towards water conservation. 1.2. Objective As a part of the corporate environmental management program and also to upgrade the ongoing water conservation initiatives, the management of Indian Oil Corporation Ltd, initiated a comprehensive water audit program at Haldia Refinery. The objective of water audit is to identify potential and derive opportunities towards reduction of volume and cost of raw water used in the refinery. Subsequently, IOCL, Haldia has appointed M/s TUV SUD South Asia Pvt. Ltd. To undertake the afore mentioned tasks. The objective of water audit is to assess the following.

To establish water balance, To identify losses both physical and non-physical, To identify and priorities areas which need immediate attention in terms of reduction of

water wastage. To raise awareness on monitoring water consumption



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To identify water conservation opportunities To find out simple low cost or no cost measures to conserve water

1.3. Limitation 1. Due to heavy scaling in the supply water network measurement was not possible using

ultrasonic flow meter in most of cases after repetitive endeavor. Secondary/PLC data is being used for analysis wherever data is available.

2. Due to heavy scaling, colour coating undertaking onsite measurement at unit level pertaining to the input and output water flow water balance was not possible.

CHAPTER 2: INVENTORY OF WATER USE The objective of developing a water inventory is to establish a balance between the water withdrawn and water consumed across the process boundary. Water consumption is a subset of total water withdrawn and is the more appropriate measure for resource utilization as this represents water that is removed from the ecosystem and thus made unavailable for future use. Consumption apart from process requirement happens when water evaporates or is contaminated to the point of being unusable. Wastewater discharges of fresh water to aquifers also represent losses of water from an ecosystem because the freshwater is no longer available for use. IOCL, Haldia and its refining process comprises of complex systems of multiple operations where water is being used. The process in a petroleum refinery requires water, however, not each process needs raw or treated water, and water can be cascaded or reused in many places. A large portion of the water used in a petroleum refinery is continually recycled. There are losses to the atmosphere, including steam losses and cooling tower evaporation and drift losses. A smaller amount of water at some point of time also leaves with the products. Understanding water balance for a refinery is a key step towards optimizing water usage, recycle and reuse as well as optimizing performance of water and wastewater treatment systems.



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Typical schematic water flow in and out of the refinery unit is presented as follows:

Figure 1: Schematic diagram of water inventory areas

Rain/Storm Water Steam Loss Cooling Tower Evaporation and Drfit

HFC

PHE Water in Product

Water in Crude

Recycle

Ground Water Waste Water

Refinery ProcessUnits

Loss oling ater

und WWaste Water

Recycle RR

de

WP



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2.1. Water Footprint Statistical assessment of water inventory represented a reduction in specific water consumption across last five years. The specific water consumption has further lowered across the 1st half of2014-2015.

Figure 2: Specific water consumption

Figure 3: Specific water consumption and water re-use

The decrease in specific water consumption can also be attributed to increased water re-use. The quantum of average water re-use has increased from 257m3/hr in 2008-09 to 697 m3/hr across2014-15 (half yearly).

Figure 4: Specific water consumption 2014-15

0.968 0.917 0.851 0.844 0.697 0.702

0

0.5

1

1.5

Apr-14 May-14 Jun-14 Jul-14 Aug-14 Sep-14

(m3/

tonn

e)

Specific Water Consumption

Specific Water Cosnumption (m3/tonne)

1.45 1.75 1.37

1.04 1.13 0.95 0.85

0

0.5

1

1.5

2

2008-09 2009-10 2010-11 2011-12 2012-13 2013-14 2014-15 (Sp-14)

Spec

ific

wat

er

cons

umpt

ion

(m3/

MT)

Specific Water Consumption (m3/tonne)

1.45 1.75

1.37

1.04 1.13 0.95 0.85

26% 27%

45%

62% 49%

75%

93%

0%

20%

40%

60%

80%

100%

0

0.5

1

1.5

2

2008-09 2009-10 2010-11 2011-12 2012-13 2013-14 2014-15 (Sp-14)

m3/

tonn

e

Water reuse and Specific Water water consumption

Specific Water Cosnumption (m3/tonne)

Percentage of water re-used to fresh water consumption



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2.2. Fresh water withdrawn Water intake in the plant utility is from three major heads

1. From PHE (public health engineering department) supply 2. From HFC tube well and 3. Pumped from in plant tube well

Tube Well Sixteen numbers of tube-wells are located within the plant boundary and used to draw underground water based on requirement. The cumulative water drawn across 1st six month of 2014-15 is presented in the table below. Table 2: Water withdrawal from tube well Amount of Water in m3

April 2014 May 2014 June 2014

July 2014

Aug 2014 Sep 2014 Average

Cumulative 119651 96101 80856 88714 104276 109892 99915 Hourly 166 133 108 119 140 152 136 Figure 5: Average water withdrawn from tube well on monthly basis

Figure 6: Average water withdrawn from tube-well on hourly basis

119651

96101 80856

88714 104276 109892

99915

0

20000

40000

60000

80000

100000

120000

140000

Apr-14 May-14 Jun-14 Jul-14 Aug-14 Sep-04 Average

wat

er w

ithd

raw

in

m3/

mon

th

Average water withdrawn from tubewell

166

133 108

119 140

152 136

0

50

100

150

200


Wat

er w

ithd

raw

n in

m

3/hr

Water withdrawn from tubewell



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Measurement and Verification The water withdrawn through tube well is monitored using ultrasonic flow meter. The flow rate data measured is cross verified with the PLC data recorded in house using online flow meter depicting a close resemblance with the data recorded by online flow meter.

From PHE Raw water is procured from public health engineering department/JUSCO is the major source of raw water obtained by the refinery. The water intake across for last six months as follows: Table 3: Water withdrawn/ sourced from PHE Amount of Water in m3


Cumulative 525674 473296 441980 384850 265740 273854 394232 Hourly 730 657 594 517 357 380 539 Figure 7: Average water sourced from PHE on monthly basis

Figure 8: Average water sourced from PHE on hourly basis

525674

473296 441980

384850

265740 273854

394232

0

100000

200000

300000

400000

500000

600000


Wat

er w

ithd

raw

n m

3/m

onth

Water sourced PHE

730 657

594 517

357 380

539

0

200

400

600

800


wat

er s

ourc

ed in

m3/

hr Water sourced from PHE on hourly basis in m3



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14

HFC tube well Raw water is also sourced from the HFC tube well depending upon demand. The water sourced through HFC tube well is as follows: Table 4: Water sourced through HFC tube well Amount of Water in m3


Cumulative 64623 61957 62013 71614 66983 50524 62952 Hourly 90 86 83 96 90 70 86 Figure 9: Total water sourced from HFC tube well on monthly basis

Figure 10 : Average water sourced from HFC tube well on monthly basis

64623 61957 62013

71614 66983

50524

62952

0

10000

20000

30000

40000

50000

60000

70000

80000


Wat

er w

ithd

raw

n in

m3/

mon

th

Water Withdrawn from HFC tube well

90 86 83

96 90

70

86

0

20

40

60

80

100

120


Wat

er w

ithd

raw

n m

3/hr

Water withdrawn from HFC tubewell



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Total raw water withdrawn Total water withdrawn from three sources is cumulated and presented below. The total raw water withdrawn is as follows: Table 5: Total raw water withdrawn Amount of Water in m3


Cumulative 709948 631354 584849 545178 436999 434270 557100 Hourly 986 877 786 733 587 603 762

Figure 11: Total raw water withdrawn per month (cumulative for three source)

Figure 12: Average hourly water withdrawn from three sources

709948

631354 584849

545178

436999 434270

557100

0

100000

200000

300000

400000

500000

600000

700000

800000


wat

er w

ithd

raw

n m

3/m

onth

Total water withdrawn m3/month

986 877

786 733

587 603

762

0

200

400

600

800

1000

1200


Wat

er w

ithd

raw

n m

3/ho

ur Average water withdrawn m3 /hour



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Analysis and synthesis Data information presented in the section above resembles that maximum water is sourced from PHE followed by in-house tube well and HFC tube well. Based on the average hourly water withdrawn the share of different source from which raw water is being withdrawn presented as follows:

Figure 13:Source wise water withdrawn

2.3. Water Consumption Water use across the refinery can be categorized both under consumptive and non-consumptive usage pattern. Consumptive use refers to water that is drained/discharged to the atmosphere or that is incorporated in the products/process. Evaporation and windage losses in a cooling tower and the discharge of process steam into the atmosphere are few cases of consumptive use across the refinery. The discharge of once-through cooling water, cooling-tower blow down, and discharge to waste of the condensate from a steam trap and effluents are non-consumptive uses. The sum of consumptive uses and effluents equals the water requirement.

Tube well 18%

PHE/JUSCO 71%

HFC well 11%

Source wise water withdrawn



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Figure 14: Water consumption

As per the technical information provided by the plant the typical consumption of water in the refinery is around 36,000 m3/day. Utility units like cooling tower, DM plant consumes the major share of water followed by drinking/ domestic water, service water, fire fighting water make up and process units. The water consumptions and its share in the total consumption are presented below.

Table 6: Segregation of water consumption Unit Water Consumption (m3/day)

Cooling tower make up 16800

DM water production 10800

Drinking / domestic 1920

Service water 1200

Fire fighting water make 3840

Process unit 1440

The graphical clearly evident that utilities like cooling tower and DM plant are the major water consumers. Both of these utilities consume 77% of the total in-house water requirement of the refinery. The process unit to that extent only shares 4% of the total water being consumed. Raw water Consumption Raw water consumption can broadly be categorized under the following heads:

1. Cooling tower makeup 2. Service Water 3. DMF make up 4. Fire tank make up 5. Drinking water

Cooling tower make up

47%

DM plant 30%

Drinking / domestic 5%

Service water 3%

Fire fighting water make up

11%

Process unit 4%

WATER CONSUMPTION



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6. DM plant input7. TPS RO raw water consumption8. PHE makeup to DMP

Raw water consumed across the last two quarter is tabulated below and compared with the total water consumed: Table 7: Raw and total water consumed Amount of Water in m3


Total raw water intake Cumulative 709948 631354 584849 545178 436999 434270 557100Hourly 986 877 786 733 587 603 762

Water Reuse Hourly 691 668 621 699 772 778 704

Analysis Out of 762 m3 of raw water intake the amount of water reused is 704 m3 (> 92%) on an average.

2.4. Effluent generation and reuse Refinery consumes large volume of water with a significant amount being consumed for cooling. Refineries generate a significant amount of wastewater with and without hydrocarbon contamination. The process waste water originates from the process like fractionation, cracking, reforming, polymerization and alkalizations. Wastewater also include water rejected from boiler feed-water pre-treatment processes (or generated during regenerations), cooling tower blow-down, or that leaves the refinery. The major pollutant in the waste water includes oils and chemicals (acids, alkalies, sulphides and phenolics). Contaminated wastewater is typically sent to ETP unit that is located at the facility. Cooling tower blow down water and wastewater from raw water treating receives treatment at the wastewater treatment plant (WWTP) before discharge. Water that has not been in direct contact with hydrocarbons for example, water used for bearing cooling, condensate drain which has only minimal contamination can be a source for reuse and is discussed in the water conservation section.

Process Waste Water Water that is generated in the process units is represented by the following categories:

De-salter effluent;Sour water;Tank bottom draws; andSpent caustic.

De-salter effluent Inorganic salts are present in crude oil as an emulsified solution of salt (predominantly sodium chloride). The source of the aqueous phase is the naturally occurring brine that is associated with



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the oil field from where the crude is extracted. The amount of water received at the refinery with the crude varies widely but an approximate range would be 0.1 2.0% volume. The salts contained in the aqueous phase are variable and range from 10 to 250 pounds per thousand barrels (p.t.b.) of crude. The salts are present mostly in the form of chlorides of sodium, magnesium and calcium. Typically, the first operation in a refinery crude unit is desalting, which is used to wash out the salt present in the crude. The most important reasons for removing the salts from the crude are to: Prevent plugging and fouling of process equipment by salt deposition; and Reduce corrosion caused by the formation of HCl from the chloride salts during the

processing of the crude. Sour Water Steam is used in many processes in refineries as a stripping medium in distillation and as a diluent to reduce the hydrocarbon partial pressure in catalytic cracking and other applications. The steam is condensed as an aqueous phase and is removed as sour water. Since this steam condenses in the presence of hydrocarbons, which contain hydrogen sulphide (H2S) and ammonia (NH3), these compounds are absorbed into the water at levels that typically require treatment. The typical treatment for sour water is to send it to a stripper for removal of H2S and NH3. Steam is used to inject heat into the strippers. High performance strippers are able to achieve < 1 ppm H2S and < 30 ppm NH3 in the stripped sour water. With these levels, the stripped sour water is an ideal candidate for recycle/reuse in the refinery.

Tank Bottom Draw: The incoming crude to refineries normally contains water and sediments (mud) that are picked up when the oil is extracted from the wells this is referred to as bottom sediment and water (BS&W). When the crude is stored in large tanks, the BS&W settles to the bottom and must be periodically removed to prevent a buildup of this material which would otherwise result in a loss of storage capacity. Water draws are normally sent to either the wastewater treatment or to a separate tank where the solids are separated from the oil and water.

Effluent Collection The liquid waste water generated from different units/area in the refinery is segregated into three basics streams. 1. Oily sewer: This system comprising of underground piping network collects the oily water

and delivers it to effluent treatment plant. 2. Storm water sewer: Open channel network 3. Domestic sewerage Effluent Treatment The waste water obtained from across the plant facility is treated in two number of effluent Treatment Plants. The effluent treatment plant broadly comprises of 1. Effluent Tank 2. API (for old ETP) and TPI (new ETP)



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Table 8: ETP capacities ETP Designed Capacities Old ETP Peak flow of 840m3/hr for 4 hrs and 540m3/hr for 24 hrs Enhanced Capacity with new ETP 790m3/hr in dry weather and 1100 m3/hr in wet weather 3. Equalisation Tank 4. Bio Tower and Bio tower feed swamp 5. Aeration Tank 6. Clarifier Working Principle The old ETP works on the method of chemical coagulation, flocculation and sedimentation along with oxidation of both organic and inorganic by chlorine. The physical and chemical treatment is followed by biological treatment under aerobic conditions.

Capacity Utilization Table 9: Effluent Treatment (Based on September 2014 data during audit) Effluent Treatment Plant Throughput (m3/hr) Reuse (m3/hr) % Reuse OLD ETP 434 255 58.80 New ETP 529 454 85.85 Total 963 709 73.7



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Water Inventory The plant water inventory is presented as follows1:

18%

3%

13%

26%

7%

5%

6%

7%

1%

5%

4%

1%

3%PHE/HFC/TW water losses

Drinking water

RO-3 Permeate

PHE/HFC/TW water for service water

PHE/HFC/TW water to HRSCC

Cooling tower makeup GTCT

PHE/HFC/TW -fire water

DM Plant input

Cooling tower makeup TPSCT

Cooling tower makeup PCT

Cooling tower makeup DHDSCT

Cooling tower makeup OHCUCT

Input for TPS RORefinery

PHE/JUSCO

HFC

Tubewell

ETP-Old

ETP-New

2.5.

Pla

nt W

ater

Bal

ance

Dia

gram

112

Loss

22

53

Loss

25CT

1511

0CT

3953

189

Reje

ct25

LOSS

132

27

225

12

RO1.

12.

11.

1.1

306

2.1.

116

52.

1.1

530

695

642

2.2

1.2

2.2.

153

1.2.

147

92.

2.2

225

1.2.

253

2.2.

316

41.

2.3

110

2.2.

49

642

2.3

Tota

l 45

1.26

9915

2.4

Loss

243

2.5

Tota

l 69

4

RO to

CT

RO to

DM

RO to

MBF

RO

for

Inta

ke to

RO

ETP

old

ETP

new

Tota

l Int

ake

Cons

umpt

ion

HRS

CC I/

L in

m3/

hr71

8

RO-1

+RO

3

RO fe

ed ta

nk in

m3/

hr

Clar

ifie

r O/L

in m

3/hr

9164

MBF

tank

m3/

hr

Back

was

h RO

fe

ed ta

nk

45

14Ef

flue

nt G

ener

atio

n in

m3/

hr98

9

336

Fire

Wat

er in

m3/

hr11

4

PDA

Scr

b in

m3/

hr31

Loss

from

ove

r flo

w a

nd d

rain

in

m3/

hr

RO ETP

Tota

l Los

s CT

434

ETP

Old

TW

P in

m3/

hrET

P ne

w i

n m

3/hr

530

RO to

CT

RO U

NIT

Evap

orat

ion

Loss

1.

1.2

Tota

l Los

s CT

Mak

e U

p Ra

w W

ater

Cool

ing

Tow

er

Blow

Dow

n

RO -3

pro

cess

tank

in

m3/

hr

RO fl

ashi

ng in

m

3/hr

RO -2

pro

cess

in

m3/

hr

104

Rive

r /op

en d

rain

in

m3/

hr89

Tota

l Los

s

RO -1

pro

cess

in m

3/hr

541

RO -1

per

mat

e ta

nk in

m

3/hr

462

306

75

Serv

ice/

Dri

nkin

g in

m3/

hr

DM

F fe

ed ta

nk in

m3/

hr

BELC

O in

m3/

hr

25 40 95

Bear

ing

Cool

ing

wat

er i

n m

3/hr

208

ETP

in m

3/hr

200

PDA

in m

3/hr

TTP

in m

3/hr

CT B

W in

m3/

hr

35 0

Des

alte

r in

m3/

hr

5Ta

nks

in m

3/hr

R E F I N E R Y P R O C E S S

Fire

wat

er in

m3/

hr

Raw

wat

er to

fire

tank

in

m3/

hr0

TPS

RO ra

w w

ater

co

nsum

ptio

n in

m3/

hr36

PHE

mak

eup

to D

MP

in m

3/hr

0141

Ser

vice

wat

er+

HRS

CC+D

MFm

ake

up+

Fire

ta

nk(A

)in

m3/

hr

DM

pla

nt in

put(

Raw

wat

er) i

n m

3/hr

252

Tota

l Fre

sh

Wat

er/R

aw W

ater

in

take

from

PH

E/JU

SCO

, HFC

w

ell a

nd T

ube

wel

l A

vera

ge W

ater

inta

ke in

m3 /h

r (A

vera

ge :

Apr

il 20

14- S

ep 2

014)

762

Cool

ing

Tow

er (P

CT, D

HD

S,

TPS,

OH

CU. G

T) in

m3/

hr47

9

79D

rink

ing

Wat

er i

n m

3/hr

WA

TER

AU

DIT

AT

HA

LDIA

REF

INER

Y

RE

POR

T V

ER

SIO

N: 4

,Apr

il 20

15

Page23

The

wat

er b

alan

ce o

f the

pla

nt is

pre

pare

d ba

sed

on th

e da

ta in

form

atio

n ov

er th

e to

tal a

mou

nt o

f wat

er in

put (

raw

and

trea

ted

wat

er)

efflu

ent g

ener

ated

and

trea

ted.

The

wat

er in

take

and

con

sum

ptio

n fr

om v

ario

us so

urce

for t

he m

onth

of A

pril

and

Sept

embe

r 201

4 an

d th

e ef

fluen

t bal

ance

for t

he m

onth

of S

ep 2

014w

as u

sed

to d

evel

op th

e w

ater

bal

ance

of t

he p

lant

. The

wat

er in

take

and

con

sum

ed a

re

outli

ned

belo

w:

Para

met

er

Apr

il-14

May

-14

June

-14

July

-14

Aug

ust-1

4Se

ptem

ber-1

4A

vera

ge

M3 /h

rR

aw w

ater

Gen

erat

ion:

H D

A (P

HE/

JUSC

O)

730

657

594

517

357

380

539

HFC

90

8683

9690

7086

Tube

wel

ls16

613

310

911

914

015

313

7T

otal

Raw

Wat

er R

ecei

pt:

986

877

786

733

587

603

762

Perm

eate

in ta

nk4

1-1

.31

0.1

-0.0

51

Rec

ycle

d E

TP

wat

er S

tatu

s:R

O-1

per

mea

te fr

om E

TP to

CT'

s0

21

2791

110

39R

O-1

per

mea

te t

o D

MP

RW

T16

521

626

624

622

722

722

5R

O-3

INPU

T 10

410

386

107

104

9410

0R

O-0

1 pe

rmea

te fo

r RO

flus

hing

911

98

99

9T

OT

AL

RO

-1 W

AT

ER

OU

TPU

T27

833

236

338

843

244

037

2

RO

wat

er C

onsu

mpt

ion:

DM

pla

nt in

put(t

hrou

gh E

TP R

O)

165

214

264

246

227

227

224

TPS

RO

per

mea

te57

358

20

117

Coo

ling

tow

er m

ake

up (t

hrou

gh T

TP R

O)

02

127

9111

039

ETP

RO

3 IN

PUT

TO M

B-0

6/07

//DM

RA

W T

AN

K95

9281

104

9990

94T

otal

RO

wat

er c

onsu

mpt

ion

317

343

354

380

418

428

373

Coo

ling

tow

er m

ake

up( D

HD

SCT)

380

382

367

372

319

300

353

Coo

ling

tow

er m

ake

up( O

HC

UC

T)67

6862

6268

7166

Ro-

02 to

OH

CU

CT/

DH

DS

CT

1413

1319

1414

15

WA

TER

AU

DIT

AT

HA

LDIA

REF

INER

Y

RE

POR

T V

ER

SIO

N: 4

, Apr

il 20

15

Page24

Para

met

er

Apr

il-14

M

ay-1

4 Ju

ne-1

4 Ju

ly-1

4 A

ugus

t-14

Sept

embe

r-14

Ave

rage

M

3 /hr

Coo

ling

Tow

er m

ake

up (P

CT)

70

21

7

6 6

15

21

Coo

ling

Tow

er M

ake

up( T

PS C

T)

40

35

25

33

34

40

34

Serv

ice

wat

er+

HR

SCC

+DM

Fmak

e up

+ Fi

re ta

nk(A

) 16

5 13

6 20

7 16

2 84

90

14

1 D

rinki

ng w

ater

81

80

77

79

79

78

79

D

M p

lant

inpu

t(Raw

wat

er)

83

47

23

10

1 0

27

Raw

wat

er to

Fire

Tan

k 0

0 0

0 0

0 0

TPS

RO

raw

wat

er c

onsu

mpt

ion

119

74

16

7 0

1 36

PH

E m

akeu

p to

DM

P 0

0 0

0 0

0 0

Tot

al R

aw w

ater

con

sum

ptio

n 10

04

842

785

732

590

594

758

TO

TA

L C

ON

SUM

PTIO

N

1264

11

51

1130

11

09

1008

10

22

1114

T

PS R

O p

lant

per

mea

te

57

35

8 4

0 0.

6 17

R

w fl

ow

119

75

17

7 0

1.1

36

Rec

over

y 48

%

47%

47

%

52%

0%

54

%

48%

T

TP

RO

PL

AN

T O

UT

PUT

DE

TA

ILS:

HR

SSC

I/L

flow

=ET

P+R

aw W

ater

57

8 62

9 58

3 60

5 67

7 71

8 63

2 U

F flo

w

463

499

479

487

543

585

510

RO

-1+R

O-2

per

mea

te

287

335

366

400

437

445

378

RO

-3 IN

PUT

from

ETP

to D

M p

lant

/Raw

tank

95

92

81

10

4 99

90

94

R

O-1

per

mea

te to

DM

P 16

5 21

4 26

4 24

6 22

7 22

7 22

4 R

ecov

ery

62%

67

%

76%

82

%

80%

76

%

74%

CHAPTER 3: Water utilization 3.1. Cooling Tower Cooling tower is most important utility in the refinery that functions as an inexpensive and dependable means of removing low grade heat from water. The purpose of cooling system is to remove undesirable heat so that optimum temperature and pressure is maintained. Hot water from heat exchanger and process is sent to the cooling tower which after heat exchange ( in multi cell cooling tower) is sent back again to the heat exchangers or other units. Cooling water circulates in a closed circuit. The mechanical draft cooling tower uses large fans to force or suck air through circulated water. The water falls downward over fill surface which helps to increase the contact time and thereby maximizes heat transfer between two. In addition, formation of droplets increases the contact surface of the falling water, which in turn helps in releasing the heat contained in water. The water lost in the process of cooling due to evaporation is replenished through makeup water. The IOCL has the following cooling tower with the following specification.

Table 10: Cooling Tower specification Cooling Tower Recirculation Rate (m3/hr) System Hold Up Max. Blow Down Rate

Specification Operational (m3) PCT 18000 14500 4000 110 M3/Hr

DHDS 21000 17500 4000 350 - 400 M3/Hr TPS 5400 5000 1100 60 - 80 M3/Hr

OHCU 8500 8500 1700 75 M3/Hr GT 1000 1000 254 7 M3/Hr

The major water losses in a cooling tower are 1. Blow-down: Blow-down is facilitated to controls the buildup of dissolved solids by replacing

the more highly concentrated system water with an equal volume of fresh, less concentrated make up water. Blow down is a function of cycle of concentration (COC). COC is the ratio of the solids level of circulating water to that of makeup water. Solids level in makeup water gets concentrated in circulating water due to evaporation. Since only the water can evaporate and dissolved solid remains in the liquid phase, the evaporation process causes an increase in the concentration of dissolved solids in the re-circulating cooling water.

2. Evaporation: Loss of water by conversion into vapour form through cooling tower during cooling process

3. Drift loss: A small portion of cooling water lost through cooling tower apart from blow-down.

Estimation of theoretical water requirement Evaporation rate: Re-circulating rate × Delta T/ 560 Blow down + Windage: Evaporation rate / (COC-1)



Page

26

Make up water rate: Evaporation +Blow down +Windage +Leakage Un-accounted loss: Actual makeup water - Theoretical make up water Estimation of water saving through increased COC 1. Process Cooling Tower Process cooling tower is a cross flow induced draft cooling tower comprising of 9 cells. The cooling tower comprises of PVC splash fills and wooden tower frame material. The cooling tower is designed for recirculation rate of 18000m3/hr with designed delta T of 100C and system hold up capacity of 4000 m3. However the cooling tower is currently operating at recirculation rate of 14500 m3/hr , 4 0C delta T and COC of 2.1. Approx. 180-200 m3/hr of raw water is required to make-up the losses due to evaporation, drift and system leakage in PCT.

Table 11: Estimation of water saving through increased COC in PCT cooling tower System Parameters Actual Unit Proposed

COC -5 Proposed COC -7

Recirculation Rate : 14500 m3/hr 14500 14500 Average COC : 2.1 5 7 Delta T Across CT : (conservative as against 10 0C designed)

4 Deg. C

4 4

Evaporation from CT : 98 m3/hr 98 98 Blow Down Loss 89 m3/hr 25 16 Total makeup 187 m3/hr 123 114 Reduction in make up m3/hr 65 73 Annual water saving m3 565899 637449

2. TPS Cooling tower TPS is a counter flow induced draft cooling tower comprising of 3 cells. The cooling tower comprises of PVC filming fills and wooden tower frame material. The cooling tower is designed for recirculation rate of 5400m3/hr with designed delta T of 120C and system hold up capacity of 1100 m3. However the cooling tower is currently operating at recirculation rate of 5000 m3/hr , 1 0C delta T and COC of 1.34.



Page

27

Approx. 35-40 m3/hr of raw water is required to make-up the losses due to evaporation, drift and system leakage in TPS.

Table 12: Estimation of water saving through increased COC in TPS cooling tower System Parameters Actual Unit Proposed


Recirculation Rate : 5000 m3/hr 5000 5000 Average COC : 1.34 5 7 Delta T Across CT : 1 °C 1 1 Evaporation from CT : 9 m3/hr 9 9

Blow Down 26 m3/hr 2 1 Drift loss 35 m3/hr 11 10 Total loss 5000 m3/hr 24 25 Reduction in make up m3/hr 210488 Annual water saving m3 5000 3. DHDS Cooling Tower

DHDS is a counter flow induced draft cooling tower comprising of 7 cells. The cooling tower comprises of PVC packed fills and RCC tower frame material. The cooling tower is designed for recirculation rate of 21000m3/hr with designed delta T of 120C. However the cooling tower is currently operating at recirculation rate of 17500 m3/hr , 5 0C delta T and COC of 2.51. Approx. 275-300 m3/hr of raw water is required to make-up the losses due to evaporation, drift and system leakage in DHDS CT.

Table 13: Estimation of water saving through increased COC in DHDS cooling tower System Parameters Actual Unit Proposed


Recirculation Rate : 17500 m3/hr 17500 17500 Average COC : 2.51 5 7 Delta T Across CT : 5 °C 5 5 Evaporation from CT : 156 m3/hr 156 156 Blow Down 103 m3/hr 39 26 Total loss 260 m3/hr 195 182 Reduction in make up m3/hr 64 77 Annual water saving m3 564269 678332

CASE PRESENTATION: CII Excellence in Water Management 2008 UNIT: Reliance Industries Limited, Dahej Manufacturing Division. The unit has increased its cooling tower cycle of concentration from 5 to 7.5. The unit achieved an annual saving of 130km3 of raw water resulting in monetary saving of 10.5 lakhs.



Page

28

4. OHCU Cooling Tower DHDS is a counter flow induced draft cooling tower. The cooling tower is designed for recirculation rate of 8500m3/hr with designed delta T of 50C. However the cooling tower is currently operating at recirculation rate of 8500 m3/hr, 3 0C delta T and COC of 1.58. Approx. 110-120 m3/hr of raw water is required to make-up the losses due to evaporation, drift and system leakage in OHCU CT.

Table 14: Estimation of water saving through increased COC in OHCU cooling tower System Parameters Actual Unit Proposed


Recirculation Rate : 8500 m3/hr 8500 8500 Average COC : 1.58 5 7 Delta T Across CT : 3 °C 3 3 Evaporation from CT : 46 m3/hr 46 46 Blow Down 79 m3/hr 11 8 Total loss 124 m3/hr 57 53 Reduction in make up m3/hr 67 71 Annual water saving m3 588023 621264 5. GT Cooling Tower

GT is a counter flow induced draft cooling tower. The cooling tower is designed for recirculation rate of 1000 m3/hr with designed delta T of 120C. However the cooling tower is currently operating at recirculation rate of 1000 m3/hr, 110C delta T and COC of 4.03. Approx. 20-30 m3/hr of raw water is required to make-up the losses due to evaporation, drift and system leakage in GT CT.

Table 15: Estimation of water saving through increased COC in GT cooling tower System Parameters Actual Unit Proposed


Recirculation Rate : 1000 m3/hr 1000 1000 Average COC : 4.03 5 7 Delta T Across CT : 11 °C 11 3 Evaporation from CT : 20 m3/hr 20 5 Blow Down 6 m3/hr 5 1 Total loss 26 m3/hr 25 6 Reduction in make up m3/hr 2 20 Annual water saving m3 13771 174111



Page

29

3.2. RO Unit The reclamation unit incorporates high rate clarification, filtration, ultrafiltration (UF) and reverse osmosis (RO) phases.

ETP Unit HRSC

DMF Feed Tank

DMF

Basket Stainer

Ultra Filter

RO Feed Tank

RO 1 MCF

RO 1 Process

RO 1 Permate

Tank

RO 2 Process Reject

Reject

River/ETP

Output

OHCU CT Makeup

CT raw water makeup

RO 3 Process/

Tank

Reject

DM Plant (Cation)

PHE Water



Page

30

The RO permeate obtained is used as boiler make-up water. The water balance of the RO section is presented below:

Following practices are recommended for membrane exchange A.) Low permeability necessitating a higher CEB frequency, higher energy consumption and lower plant availability. The permeability value has a basic tendency to fluctuate, which is due mainly to variable secondary effluent quality from upstream ETPs. Therefore, the maximum achievable permeability (average of the three highest daily values in the subsequent operational period - accomplished after regular or additional CEB;) may be used as a parameter for performance evaluation. B.) Trance Membrane Pressure should not exceed from designed parameter in order to avoid both intensified fouling and mechanical stress. C.) Membrane integrity - number of fiber breakages should not be too high in order to avoid Turbidity and an increased SDI. Nevertheless, the membrane elements with fiber breakages should be exchanged (or repaired) in order to maintain proper turbidity and SDI values, and subsequently to minimize the fouling potential of the RO membranes.

112

Loss 22

53

2 ROLoss 25 2.1

2.1.1 1652.1.1 530

6952.2

2.2.1 53CT 15 2.2.2 225

2.2.3 164CT 39 2.2.4 9

189 2.3 Total 451.2699152.4 Loss 2432.5 Total 695

Reject 25225

132LOSS

RO-1+RO3

RO to MBF RO for

RO to CTRO to DM

ETP newTotal IntakeConsumptio

Intake to ROETP old

9

DMF feed tank in m3/hr

RO flashing in m3/hr

RO feed tank in m3/hr

RO -1 process in m3/hr

River /open drain in MBF tank m3/hr

164 541 89

RO -1 permate tank in m3/hr

104

462RO -3 process tank

in m3/hr

434 530

RO -2 process in m3/hr

Effluent Generation in m3/hr 989

Clarifier O/L in m3/hr HRSCC I/L in m3/hr718

ETP Old TWP in m3/hr ETP new in m3/hr Backwash RO feed tank

45



Page

31

3.3. Process 3.3.1. Fuel oil block Process Description Fuel Oil block comprises of Crude Distillation Units (CDU I and CDU II), Catalytic Reforming Unit (CRU) and Kerosene Hydrodesulphurisation Unit (KHDS). CDU-I &II Water Use Scenario Water is majorly used mainly for the purpose of gland cooling and steam generation. Relatively small quantum of water is used, cleaning / product washing (service water), drinking and fire protection. Steam is used across these units for the purpose of heating and pumping (maintaining temperature and flow of hot streams). Crude oil received from crude storage tanks is heated to around 125 130°C by recovering process heat from the various hot streams in a series of heat exchangers. The temperature of crude is thereafter increased by heating it with medium pressure steam heater. Catalytic Reforming Unit (CRU) Water Use Scenario Water is majorly used across this unit for the purpose of gland cooling, cleaning (service water), drinking and firefighting. Steam is used across this unit for the purpose of heating and also maintaining temperature and flow of hot streams. Case Specific: 1. The reactor effluent after exchanging heat with the feed and subsequent cooling in water cooler is

sent to a High Pressure Separator Vessel. 2. The bottom stream from the stabiliser column, known as reformate, is cooled by exchanging heat

with the Cold feed and then with cooling water before routing to the MS Pool. Kerosene Hydro-desulphurization Unit (KHDS) Water Use Scenario Water is majorly used across this unit for the purpose of gland cooling, cleaning (service water), drinking and firefighting. Steam is used across these units for the purpose of heating and also maintaining temperature and flow of hot streams. Case Specific: 1. The reactor effluent is cooled in the feed preheat exchangers and water cooler and sent to a High

Separator Vessel 2. The stripper bottom (hydrotreated kero cut) is cooled in the feed/bottom exchangers and then in

water cooler and routed to respective storage tanks of Kerosene, ATF/RTF and MTO.



Page

32

Water supply Scenario Water required for the purpose of cooling is being supplied to units (CDU-I, CRU and KHDS) from DHDS and OHCU cooling tower. Recovered condensate is also being supplied for specific requirement. Water from OHCU cooling tower is supplied to CDU- 2 and from DHDS cooling tower to CDU-1 , CRU and KHDS. Water from cooling tower is supplied via main header to the units which is then subdivided to the respective locations depending upon the usage through sub headers.

Figure 155: Water supply network across FOB unit

CDU-1DHDS CT

CDU-2

OHCU CT CRU

KHDS

ETP



Page

33

Critical Observation 1. As indicated above a considerable amount of water

is being used for the purpose of bearing cooling. Pumps carrying hot and viscous fluid conduct some heat to its bearing. In-order to prevent bearing from damage this bearing is being cooled either by using water jacket or by injecting water (cooling water) on the bearing. The hot water is thereafter being drained to closed loop network which is being reused. The water used for the purpose of bearing cooling of the pumps are treated water and are least contaminated and can be reused. The water used for bearing quantified across the units are as follows:

FFigure 16: pump draining water to

drain in FOB Table 16: Water used in bearing cooling in CDU-2

Sl. No.

Pump/ Other device

Loss Sl. No.

Pump/ Other device

Loss ml/sec m3/hr ml/sec m3/hr

1 16PM26A 280.00 1.01 14 16PM109A 600.00 2.16 2 16PM26B 290.00 1.04 15 16PM109B 750.00 2.70 3 16PM26C 250.00 0.90 16 16PM02B 333.33 1.20 4 16PM03B 200.00 0.72 17 16PM02A 250.00 0.90 5 16PM107A 142.86 0.51 18 16PM01B 500.00 1.80 6 16PM08A 62.50 0.23 19 16PM107B 142.86 0.51 7 16PM10A 400.00 1.44 20 16PM106A 1000.00 3.60 8 16PM10B 333.33 1.20 21 16PM106B 1000.00 3.60 9 16PM110A 333.33 1.20 22 FIRE WATER 11.11 0.04

10 16PM104A 833.33 3.00 23 16PM26A 1566.67 5.64 11 16PM104B 250.00 0.90 24 16PM26B 1566.67 5.64 12 16PM105B 428.57 1.54 25 16PM26C 1566.67 5.64 13 16PM09A 600.00 2.16 26 Cooling Water

Back Lushing Line

33.33 0.12

Total quantity 49.41



Page

34

Table 17: Water used in bearing cooling in CDU-I

Sl. No.

Pump/ Other device

Loss Sl. No.

Pump/ Other device


1 11B112 & 11B113

125.00 0.45 13 11PM-10, HSDCR pump

140.00 0.50

2 11PM115A, VB to IP

125.00 0.45 14 11PM04, Kerosine pump

60.00 0.22

3 Heat exchanger 11E23A

500.00 1.80 15 11PM-05B HSD/Kero

165.00 0.59

4 11E11A,T-HSD CRS-Stabiliser bottom

1000.00 3.60 16 11PM-05A, HSD/Kero

125.00 0.45

5 S/S-16/DO22/21, 11-PM-102B

165.00 0.59 17 11PM-05C, HSD/Kero

45.00 0.16

6 11PM-102C, S/S-16/DO33/36

340.00 1.22 18 11PM06A, JBO pump

250.00 0.90

7 11PM-102A, crude oil pump

110.00 0.40 19 11PM06B, JBO pump

165.00 0.59

8 11PM-01, crude oil pump

165.00 0.59 20 11PM07A, RCO pump

165.00 0.59

9 11PM08A 200.00 0.72 21 11PM07B, RCO pump

230.00 0.83

10 11PM-08B 200.00 0.72 22 11PM07C, RCO pump

390.00 1.40

11 11PM109A, Hydrocarbon

500.00 1.80 23 11PM-01 100.00 0.36

12 11PM109B, Kero CR pump

500.00 1.80

Total quantity 20.75 Table 18: Water used in bearing cooling in Unit 21, 22 and 23

Sl. No.

Pump/ Other device

Loss Sl. No.

Pump/ Other device


Unit 21 Unit 23 1 21PM01C, LUBE

oil, S/S-68 (I/B+O/B)

250.00 0.90 9 23PM03A (closed)

200.00 0.72

2 21PM01C Feed pump-S/S-2/PC 23/22F

350.00 1.26 10 23PM03B (working)

60.00 0.22

3 21PM01D Feed pump

290.00 1.04

4 21PM-02A Reboiler pump

250.00 0.90

5 21PM-02B Reboiler pump

330.00 1.19



Page

35

Sl. No.

Pump/ Other device

Loss Sl. No.

Pump/ Other device


Unit 22 6 JB22PM04B

(Lube oil reserver) 230.00 0.83

7 22PM-202A, Feed pump

250.00 0.90

8 22PM-202B, Feed pump

250.00 0.90

Total quantity 8.86 Table 19: Estimation of Bearing Cooling water in FOB Sl. No Name of the Unit Total Loss (m3/hr) 1 CDU - 2 49.41 2 Unit 21,22 and 23 8.86 Total 58.27 The above converts to financial loss of INR 0.83 crore : Table 20: Total financial saving Sl. No Name of the Unit Total Loss (m3/hr) Total financial saving (INR in Crore/year)

1 CDU - 2 49.41 0.52 2 Unit 21, 22 and 23 8.86 0.09

Total 58.27 0.61 2. Steam loss: Steam is used for process heating, facilitation of pumping operation and

generating power. The recovered condensate across steam traps are purest form of water and should be reutilized. We have observed that in most cases the condensate recovery system is non functional and as such most of the condensates at the outlet of the steam trap is being drained out without being recirculated through condensate recovery piping network. Proper monitoring of the steam system in the refinery will help minimize the production of excess steam and minimize/ eliminate the need for venting. Moreover insulation leakage and leakage across the steam piping network results in loss of steam to the atmosphere.



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3.3.2. Lube oil block comprises of the following units: Vacuum Distillation Unit (VDU) Propane De-asphalting Unit (PDA) Furfural Extraction Unit Solvent Dewaxing Unit SDU Hydro finishing Unit Visbreaker Unit Lube Catalytic Iso Dewaxing Unit Water Use Scenario Water is majorly used across these units for the purpose of cooling, cleaning (service water), drinking and firefighting. Steam is used across these units for the purpose of heating and also maintaining temperature and flow of hot streams. Water supply Scenario Water required for the purpose of cooling is being supplied to units from PCT cooling tower. Recovered condensate is also being supplied for specific requirement. Water from cooling tower is supplied via main header to the units which is then subdivided to the respective locations depending upon the usage through sub headers.

Critical Observation

Figure 17: Water is being supplied to Pump No SS-121 under maintenance

During the study it was observed that water supply is unregulated in most cases. Water is continued to be supplied to the pump and equipments even if the system is idle.



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1. A considerable amount of water is used for the purpose of bearing cooling. Water after

cooling the bearing or coupling is being directed to the drain. Since this water neither contaminated nor is polluted it can be reused or recycled easily instead of directing the same to ETP. The oil or grease ingression if any can be removed from the water using arrestor and recycled for same use or as cooling tower makeup water. The quantification of water used as bearing cooling across the subunits are as follows:

Table 21: Water used in bearing cooling in unit 39 Sl. No.

Pump/ Other device

Quantity Sl. No.

Pump/ Other device

Quantity ml/sec m3/hr ml/sec m3/hr

1 wax production to storage tank

3.00 0.01 9 HP Flare knockout drum

1.00 0.00

2 Steam Distribution Section(SDS)- 5

25.00 0.09 10 39 B 01 at Hydrogen knockout drum

5.00 0.02

3 Steam Condensate Section(SCS)- 8

10.00 0.04 11 Water vessel 50.00 0.18

4 39 C 02 Vacuum dry

10.00 0.04 12 Water vessel 50.00 0.18

5 SCS-5 20.00 0.07 13 39 B 01 at 39 KM 01B motor

30.00 0.11

6 SCS-4 25.00 0.09 14 SCS-10 20.00 0.07 7 SDS-3 0.50 0.00 15 SDS-9 30.00 0.11 8 SCS 2.00 0.01

Total quantity (m3/hr) 1.01 Table 22: Water used in bearing cooling in unit 84

Sl. No.

Pump/ Other device

Quantity Sl. No.

Pump/ Other device


1 84 PM 2A 750.00 2.70 8 84 PM 7A 20.00 0.07 2 84 PM 02 B 250.00 0.90 9 84 PM 18 B 1.00 0.00 3 84 PM 14 B 455.00 1.64 10 near pole no.

6F 6.00 0.02

4 VM condensate (near pole 21A)

5.00 0.02 11 84 PM 15 B 0.00 0.00

5 pole no. 21E 15.00 0.05 12 feed condenser (near 84 PM 1)

20.00 0.07

6 pole no. 21 F 23.00 0.08 13 feed condenser (near 84 PM 1) back side

0.00 0.00

7 84 PM 5A 16.00 0.06 14 84 GO 1A (feed filtration)

4.00 0.01

Total Quantity (m3/hr) 5.63



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38

Table 23: Water used in bearing cooling in unit 32 Sl. No.

Pump/ Other device

Quantity Sl. No.

Pump/ Other device


1 32KM01 (not operational)

1750.00 6.30 4 32P-110-C (SS-46-SP-46)

450.00 1.62

2 32-110D 1170.00 4.21 5 32P-110E 1150.00 4.14 3 32-PM-104

(centrifugal pump) 65.00 0.23 6 32-PM104 30.00 0.11

Total Quantity (m3/hr) 16.61 Table 24: Water used in bearing cooling in unit 31

Sl. No.

Pump/ Other device

Quantity Sl. No.

Pump/ Other device


1 31PM113 (125 centrifugal pump)- not working

200.00 0.72 4 31PM05R 100.00 0.36

2 31PM113R (125 centrifugal pump)

200.00 0.72 5 31PM103R 100.00 0.36

3 31PM06+B1PM06R

1000.00 3.60 6 31PM10 (Vacuum Residue)

625.00 2.25

Total quantity (m3/hr) 8.01 Table 25: Water used in bearing cooling in unit 37

Sl. No.

Pump/ Other device

Quantity Sl. No.

Pump/ Other device


1 37PM119A 30.00 0.11 2 37PM03 125.00 0.45 Total Quantity (m3/hr) 0.56

Table 246: Water used in bearing cooling in unit 33

Sl. No.

Pump/ Other device

Quantity Sl. No.

Pump/ Other device

Quanity ml/sec m3/hr ml/sec m3/hr

1 33-PM-12A (hot water drain)

4.00 0.01 3 After steam trap nearby Redundan (33JBS-02A)

3.00 0.01

2 33E03 (valve leakage)

3.00 0.01

Total Quantity (m3/hr) 0.04 Table 27: Water used in bearing cooling in unit 35

Sl. No.

Pump/ Other device

Quantity Sl. No.

Pump/ Other device


1 35PM-102 220.00 0.79 4 35PM-01B Feed pump (not

50.00 0.18



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39

Sl. No.

Pump/ Other device

Quantity Sl. No.

Pump/ Other device


working) 2 Recycle com

(closed), Lube-CR case SP-150

330.00 1.19 5 35PM01A (working)

165.00 0.59

3 35KM-02B (working)

330.00 1.19

Total Quantity (m3/hr) 3.94 Table 28: Total water used for bearing cooling in LOB Sl. No Name of the Unit Total Quantity (m3/hr)

1 Unit 39 1.01 2 Unit 84 5.63 3 Unit 32 16.61 4 Unit 31 8.01 5 Unit 37 0.56 6 Unit 33 0.04 7 Unit 35 3.94

Total 35.8 The above converts to financial loss of INR 0.37 crore 2. Steam is used for process heating and facilitation of pumping operation. It was observed

steam leaking mostly due to insulation breakage, improper fixing of coupling/flanges and leakage across the steam piping network results in loss of steam to the atmosphere.

Figure 178: Steam condensate routed to drain

3. We have observed that in most cases due to the malfunction of condensate recovery system these condensates are drained out to the surface drain without being recirculated through condensate recovery piping network.



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Figure 19: Condensate drain across unit no 39

3.3.3. DHDS Block consists of the following process units DHDS Hydrogen Generation Unit (HGU) Sulphur Recovery Units , SWS and ARU Fluid Catalytic Cracking Unit (FCCU) VDU-2 MSQ Units Water Use Scenario Water is majorly used across these units for the purpose of cooling, cleaning (service water), drinking and firefighting. Steam is used across these units for the purpose of heating and also maintaining temperature and flow of hot streams. Water Supply Scenario Water required for the purpose of cooling is being supplied to units (HGU, DHDS, ARU, SWS, FCCU, VDU-II, MSQ ) from DHDS cooling tower. Water from cooling tower is supplied via main header to the units which is then subdivided to the respective locations depending upon the usage through sub headers. Critical Observation 1. A considerable amount of water is used for the purpose of bearing cooling. Water after

cooling the bearing or coupling is being directed to the drain. Since this water neither contaminated nor is polluted it can be reused or recycled easily instead of directing the same to ETP.

2. Lack of housekeeping resulting in loss of water from flanges



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41

Figure 20: Bearing cooling water drained to surface drain in Unit-82(VDU-2)

Table 259: Water used in bearing cooling in old HGU and DHDS (unit 24 and 25 )

Sl. No.

Pump/ Other device

Quantity Sl. No.

Pump/ Other device

Quantity m3/hr m3/hr

1 24 PM 1 B 0.72 4 25 PM 4 B 1.80 2 24 PM 4 B 3.42 5 25 PM 4 A 1.19 3 25 PM 7 B 1.19

Total quantity (m3/hr) 8.32 Table 3026: Water used in bearing cooling in VDU-II (U-82)

Sl. No.

Pump/ Other device

Quantity Sl. No.

Pump/ Other device


1 82 PM 3 A & B 0.54 10 82 PM 4 A 0.30 2 82 PM8 B 0.54 11 82 PM 4 B 0.14 3 82 PM 8 A 1.62 12 82 PM 6 A 1.35 4 82 PM 10 B 0.65 13 82 PM 6 B 1.62 5 82 PM 10 A 0.72 14 82 PM 5 A 3.60 6 82 PM 9 B 2.16 15 82 PM 5 B 2.16 7 82 PM 9 A 2.88 16 82 PM 1 C 0.54 8 82 PM 7 B 0.72 17 82 PM 1 A 0.90 9 82 PM 7A 1.08

Total quantity (m3/hr) 21.52 Table 31: Water used in bearing cooling in MSQ units

Sl. No.

Pump/ Other device

Quantity Sl. No.

Pump/ Other device


1 85 K 21 A 0.45 17 85 PM 24 B 1.19 2 85 PM 4A 1.19 18 85 PM 24 A 0.20



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42

Sl. No.

Pump/ Other device

Quantity Sl. No.

Pump/ Other device


3 85 PM 4 B 1.19 19 85 PM 87 A (condensate)

0.01

4 85 PM 80 A 0.90 20 86 PM 3 B 0.90 5 85 PM 80 B 1.19 21 86 pm 3 A

(stand by) 0.90

6 85 PM 29 A 1.19 22 86 PM 1 B 0.72 7 85 PM 29 B 0.45 23 86 PM 1A 0.72 8 85 PM 3 A 1.80 24 86 PM 8A 0.96 9 85 PM 3 B 0.51 25 86 PM 7 A 0.54

10 85 PM 2 A 0.90 26 86 PM 7 B 0.04 11 85 PM 2 B 0.90 27 86 K 1 B 0.51 12 85 PM 1 B 1.19 28 87 PM 2A 0.72 13 85 PM 1 A 1.19 29 87nPM 53 B 0.60 14 85 PM 22 B 0.15 30 87 PM 51 B 0.72 15 85 PM 21 A 0.72 31 87 Pm 56A 0.16 16 85 PM 21 B 0.90

Total quantity (m3/hr) 23.71

Table 32: Water used in bearing cooling in FCCU

Sl. No.

Pump/ Other device

Quantity Sl. No.

Pump/ Other device


1 17 KM 1 A 0.90 12 18 PM 2 A 0.54 2 17 KM 1 C 0.30 13 Fire water 13 F 0.59 3 18 PM 29 A 1.26 14 18 PM 32 A 0.52 4 18 PM 12 A 0.72 15 18 PM 40 & 34

B 0.23

5 18 PM 12 B 1.08 16 18 PM 37 A 1.19 6 18 PM 14 B 2.38 17 18 PM 11 B 0.36 7 18 PM 15 A 2.70 18 18 PM 25 A 0.11 8 18 PM 15 B 2.70 19 18 PM 28 A 0.07 9 18 PM 16 B 0.59 20 18 PM 28 B 0.29

10 18 PM 16 A 0.59 21 18 PM 31 A 0.11 11 18 PM 2 B 1.80

Total quantity (m3/hr) 19.03 Table 33: Water used in bearing cooling in ARU and SWS unit

Sl. No.

Pump/ Other device

Quantity Sl. No.

Pump/ Other device


1 29 PM 51 B 0.04 2 29 PM 51 A 0.04 Total quantity (m3/hr) 19.03



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43

3.3.4. OHCU Block consists of the following process units Once Through Hydrocracker (OHCU) Hydrogen Unit(new) Table 34: Water used in bearing cooling in OHCU Block

Sl. No.

Pump/ Other device

Quantity Sl. No.

Pump/ Other device


1 91 PM 2 A 0.54 29 91 PM 13 B 7.20 2 91 PM 2 B 4.79 30 91 PM 13 A 3.60 3 91 PM 42 B 0.45 31 91 PM 12 A 3.60 4 91 PM 43 0.04 32 91 PM 12 B 4.68 5 91 PM 44 0.04 33 91 PM 9 A 4.32 6 91 PM 19 B 0.27 34 91 PM 9 B 3.60 7 91 PM 19 A 0.54 35 91 PM 14B 0.54 8 91 PM 22 B 1.08 36 91 PM 17 B 1.44 9 91 PM 22 A 0.90 37 91 PM 17 A 1.44

10 91 PM 20 B 0.14 38 92 PM 15 A 0.72 11 91 PM 20 A 0.36 39 92 PM 14 A 0.54 12 91 PM 18 B 0.36 40 92 PM 14 B 0.36 13 91 PM 18 A 0.54 41 92 PM 2 A 0.27 14 91 PM 3 B 0.54 42 92 PM 11 A 0.27 15 91 PM 3 A 0.54 43 92 PM 11 B 0.27 16 91 PM 6 B 0.54 44 92 PM 13 A 0.90 17 91 PM 6 A 0.54 45 92 PM 13 B 0.72 18 91 PM 7 B 0.90 46 92 PM 1 B 1.08 19 91 PM 4 B 0.54 47 92 PM 12 C 1.19 20 91 PM 4 A 0.09 48 92 PM 12 B 0.59 21 91 PM 26 B 0.36 49 92 PM 12 A 0.90 22 91 PM 26 A 0.54 50 92 PM 16 B 1.19 23 91 PM 5 B 2.16 51 92 PM 16 A 0.90 24 91 PM 5 A 1.73 52 92 PM 22 A 0.01 25 91 PM 10 B 1.08 53 92 PM 21 B 0.04 26 91 PM 10 A 1.62 54 92 PM 21 A 0.01 27 91 PM 16 B 3.60 55 92 K 1 A 0.07 28 91 PM 16 A 2.52

Total quantity (m3/hr) 40.45



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44

Table 35: Total water used for bearing cooling in all the units Sl. No Name of the Unit Total Quantity (m3/hr)

1 CDU - 2 49.41 2 Unit 21,22 and 23 8.86 3 DHDS (24,25) 8.32 4 VDU (82) 21.52 5 FCCU (17,18,19) 19.04 6 ARU & SWS 0.07 7 OHCU (91,92) 40.45

Total 143.1 The above quantity converts to financial amount of INR 1.6957 crore Table 36: Estimation of financial amount Sl. No Name of the Unit Total Loss (m3/hr) Total financial saving (INR in Crore)

1 CDU - 2 49.41 0.52 2 Unit 21, 22 and 23 8.86 0.09 3 DHDS (24,25) 8.32 0.08 4 VDU (82) 21.52 0.20 5 FCCU 19.04 0.18 6 ARU & SWS 0.07 0.0007 7 OHCU (91,92) 67.79 0.625

Total 143.1 1.6957

3.4 DM Plant The DM plant is the most critical unit in a process industry requiring treated water either for process or for generation of high pressure steam. The DM plant through use of ion exchange technique results in fixation of ionic impurities of water in a dynamic manner, on the ion exchange resin beds, to improve the quality of water progressively, until completely demineralised water, having the highest degree of chemical purity is achieved. The existing DM plant includes five demineralization chains in parallel, with array of essential accessories. Each demineralization chain consists of two cation units in series ( Strong acid cation + Weak acid cation ) , one (common) degasser unit, one weak base anion unit, one strong base anion unit and one mixed bed unit. The cation units contain strongly acidic cation exchange resin beds and weak acid cation exchange resin beds which accommodated all the metallic ions of the influent water and in exchange, release hydrogen ions in equivalent amount. Thus the mineral salts of the water are converted into corresponding acids leaving practically no metal ions in the effluent from cation units. Water balancing for the DM utility is presented below. Water generation and condensate recovered from different units and directed to DM plant are as follows:



Page

45

Table 37: DM Water generation & Condensate recovery from different units Sl. No.

DM Water generation & condensate receiving form different unit

Unit/Area Tag Number

DM water in m3/hr

DM water in m3/month

1 DM Water from DM Plant/tank DM Plant 55FI-06 371 267120 2 DM Water from MB-6 99FI-

0601 0 0

3 DM Water from MB-7 99FI-0602

0 0

4 Total Condensate recovery from Units Different Unit 51FI-21 145 104400 Total DM water Generation + condensate Received 516 371520 DM water supply to units and processes: Table 278: DM water supply to units and processes Sl. No.

DM Water Consumption in Unit Unit/Area Tag Number

DM water in m3/hr


1 Dearator No.-1 Make Up Flow TPS 51FI-29A 46 33120 2 Dearator No.-2 Makeup Flow 51FI-29B 38 27360 3 Unit Feed pump flow 51FI-22 11.05 7956 4 TPS Area dosing pump + Caustic

Preparation No Tag 1.75 1260

5 OHCU DM Water Tank 92T01 OHCU 92FI-4101 105 75600 6 OHCU Stand By DM Water Tank 91T02 No Tag 0 0 7 OHCU Unit-91 DM consumption as wash

water 91FIS-701 14 10080

8 92P-16A/B Pump Jacket Cooling No Tag 3 2160 9 SRU-IV DM Water For Process SRU-IV 95FI-5201 0 0

10 DM Water To Hydrogen Unit Tank No.-24T01

OLD HGU 24FI-3201 0 0

11 DM Water Flow to HRSG-1&2 Tank No.59-T01

GT/HRSG 59FI-51A 108 77760

12 DM Water Flow to HRSG-3 Tank No.59-T05C

59FI-9822C 40 28800

13 DM Water through VDU-2 finally reach to HRSG/Dearator-1/2

59FC-11A 75 54000

14 HRSG area dosing pump No Tag 2 1440 15 Ammonia dosing near VDU-2 No Tag 0.5 360 16 DM Water flow to FCCU Tank no. 18-T11 FCCU/MSQ 18FI-6601 18 12960 17 DM Water flow to MSQ 85FI-2201 27 19440 18 DM Water to ARU UNIT-29 No Tag 1 720 19 DM Water used for Process Steam in

LOB/Unit-37 LOB/Unit-37 37FI-01 6 4320

20 37FI-706 0.43 309.6 21 37FI-705 0.46 331.2



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Sl. No.

DM Water Consumption in Unit Unit/Area Tag Number

DM water in m3/hr


22 37FI-708 3.3 2376 23 DM Water to maintain level

31B105,31H01A& 31H01B LOB/Unit-31 31FI-34 3.7 2664

24 DM Water To Maintain Level of C-03 LOB/Unit-84 FC-2401 3.85 2772 25 DM Water flow to Tank 32-B11 LOB/Unit-32 No Tag 1 720 26 DM Water to Vessel 39B08 LOB/Unit-39 39FI-801 1 720 27 DM Water filling in DM Water Storage

Tank in T/Hr 5.96 4291.2

Total Consumption 516 3,71,520 DM Plant water balance diagram

16.90%

1.40%

67.25% 15.50%

46.50%0.02%

0.50%32.72%

19.10%

0.10%Hydro test/ Chem

prepn/Alkali boilout

DM Plant

DM Water Produced

DM water from Tank

DE oily condensate

To Deaerator

FOB and LOB

DHDS and FCC

GT

TG make up

OHCU and HGU



Page

47

CHAPTER 4: WATER CONSUMPTION REDUCTION OPPORTUNITIES

4.1. Water conservation across Process Units Critical observation 1. Bearing cooling and jacket water is being directly drained to surface drain 2. Water and steam being always injected to the backup pump so as to facilitate zero down time

at the same rate at which it is injected when at use. 3. Water loss from valve, coupling and flanges 4. Steam leaks from valves, coupling and flanges Recommendation 1. Recycle of pump bearing cooling water and jacket cooling water should be undertaken. The

water that is being drained out after each pump can be collected in existing or newly constructed pit near the unit. The water stored in this storage pit can be pumped again to bearing cooling water piped network of the particular units or to cooling water return line.

2. Condensate recovery should be maximized: . Best practices towards condensate recovery are outlined as follows: The refinery should monitor the condensate balance in the refinery on an ongoing basis

and efforts should be made to maximize recovery. The quantity of blow-down taken at each boiler or steam generator in the refinery should

be monitored and minimized. The blow-down from each location or a group of locations should be collected and sent to

a flash drum where the pressure is let down to atmospheric pressure before being discharged. The flashed blow-down should then be cooled with a heat exchanger. This will prevent deterioration of the sewers and also avoid heating and vaporizing of any hydrocarbons that might be present in the sewer. The discharge should not be cooled by directly adding water (such as utility water) because this could require the addition of a substantial quantity of water to adequately cool the stream. This will also result in an increase of the total flow of wastewater to the treatment plant.

Perform steam trap surveys and implement recommendations for repair and replacement Install new steam traps and return the condensate to the boiler house

3. The effective way to reduce freshwater consumption is to maximize the recycle and reuse of

the treated wastewaters. In the Refinery, the extent of wastewater generation and their quality depends on the type of pollutants and composition. One of the broad categorization is that the wastewater can be segregated as on the basis of total dissolved solids and is subjected to the pre-treatment/treatment of the specific pollutants. The treated wastewater can thereafter be used in the cooling towers where maximum consumption is for cooling water and next maximum utilization through Tertiary Treatment Plant. The waste water generated from some of the units can be pre-treated prior to discharge to waste water treatment.



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48

Desalter oil / water separation techniques may be upgraded from the existing ETP configuration.

Primary Treatment in ETP: To upgrade the API system because Emulsified or dissolved oil that is usually

present which cannot be removed by an API system High pH at the API separator can stabilize emulsions. Spent caustic streams should be

either neutralized or routed directly to equalization in order to reduce pH at the API separators.

Use of DAF versus IAF based on the influent conditions and the required outlet condition may be decided. Advantages of IAF technique are compact size, low capital cost and the effective removal of free oil & suspended materials.

The possibility for installing the Equalization & Holding tank in downstream of the DAF may be evaluated to protect the downstream equipment (basically Biological System) from wide variations in flow and concentration.

Secondary treatment: Activated sludge with Powdered Activation Carbon (PACT) Treatment may be

adopted for better efficiency: In this treatment system both Biological oxidation and carbon absorption occur simultaneously, thus enhancing the removal of contaminants in the waste water. Most of the carbon is recycled with the activated sludge.

Aerated lagoons system can be developed in the Guard pond to enhance biological treatment

Tertiary Treatment: Chemical oxidation can be enhanced by the use of UV light as a catalyst Chemical oxidant (Hydrogen Per-oxide, Chlorine dioxide etc.) must be prepared

afresh to maintain reactivity 4. Complete mixing of returned sludge in Aeration tank, use of Ferro bacteriological process or

multistage activated sludge systems or UNOX (Pure oxygen input instead of air) process for aeration may be provided for better treatment of wastewater.

5. Reducing leaks and over flows from overground and underground fire water lines. 6. As a practice, waste water obtained across the plant is directed towards the ETP for

treatment. The degree of treatment is function of the level of contamination. In the current practice of handling waste water, even the water with lower level of contamination gets highly contaminated in contact with hydrocarbon. It is therefore recommended that separate infrastructure be planned to treat water with different level of TDS or at-least broadly segregating the waste water as low and high TDS contained and facilitating treatment.



Page

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Water/ condensate with oil contamination and TDS below 500 mg/l and the chloride content below 300 mg/l can be treated easily and used for cooling water make up or fire water. The oily wastewater from the crude unit, desalters containing dissolved salts such as sodium chloride, neutralized spent caustic and contaminated cooling water blow-down can be considered for rigorous treatment.

4.2 Cooling Tower Critical observation 1. Drift eliminators at the top of the tower minimize the amount of water lost. Drift eliminator

as seen in PCT and TPS cooling tower is underperforming. 2. Mist eliminator (Used to minimize the amount of water carried out by wind at the top of the

tower) in PCT and TPS cooling tower are damaged Fills (Fills are wooden or plastic splash plates designed to increase the amount of water surface exposed to the surrounding air. Splash fills breaks the falling water into finer droplets) in PCT and TPS cooling tower are damaged in many areas .

3. Cooling towers louvers (louvers allow proper air passage & to control loss of water spillage through cooling tower) are damaged in many areas.

4. Biological growth/algae formations are observed. Such growth reduces cooling tower efficiency.

Recommendation 1. Repair and replace drift eliminator. While replacing the drift eliminator it is recommended to

replace the same with rigid PVC made eliminator. These standard drift eliminators are cellular multipass type, with a wave sheet between each corrugated sheet to impart extra structural integrity for beam strength and durability.

2. Repair and replace mist eliminator. 3. Fills to be repaired in PCT and TPS cooling tower and other cooling tower. 4. Louvers to be repaired in PCT and TPS cooling tower and other cooling tower. 5. It is recommended to install FRP based louvers if possible. These louvers reduce by far the

need for anti-biocide chemicals to overcome the biocide and algae problem created by the sun; the louvers serve as a filter to prevent any particles (e.g., birds or plastic bags) from entering the tower, as well as reducing noise by three decibels.

6. Dosing of chlorine or biocides as part of advanced cooling water treatment in the cooling water system should be done to take care of biological growth

7. Cooling towers are normally designed for a COC of around 5. By increasing COC, the blow down quantity can be reduced by external water treatment and adding water treatment chemicals, COC of even 10 can be reached. Increasing COC can result in significant saving of water. However since the plant is operating at COC level of 2 it is recommended to improve the COC to at least at the level of 5.



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4.3 DM Plant Critical Observation 1. There are leakage across different couplings /flanges leading to water loss 2. Water leakage from across seal of pumps 3. Tank overflow Recommendation towards water conservation 1. Continuous monitoring and vigilance to identify leaks and measures undertaken to ascertain

that there is no leak in the system. 2. Demineralization by the ion exchange process generates strong effluents which require

dilution with fresh water or other streams low in dissolved solids prior to discharge. However water can be recovered from the effluents generated in a DM plant by installing a water recovery plant for reuse in the plant. Some plants use the strongly acidic effluents in cooling water for pH control in place of acid.

4.4 Monitoring Recommendation 1. The detailed record of raw water intake at refinery (for processes, CT, makeup, fire water,

green belt development and sanitary and drinking purpose) as well as township complex and wastewater generation from different sources should be maintained on daily/regular basis w.r.t. flow rates and characteristics. These details will be useful in preparing comprehensive water balance at the site and also for identification and implementation of reuse/recycle practice of treated effluent at project site leading to mitigation of effluent discharges.

2. Frequent in house water audit be undertaken.



Page

51

CHAPTER 5: CONCLUSION The basis of the effective conservation of water is not only about reducing water loss, monitoring and verification but establishing the framework of integrated water management. Effective utilisation and management of water resources needs a foresight of the critical challenges of competing water demand in light of extrinsic factors like regional water quality & availability, regional policies & regulations, socio-economic setup, and stakeholders (Govt. agencies, local community, including the industrial value chain etc.) views and a multifarious approach towards not only improving the in-plant water use efficiency, but also to foresee beyond the paradigm of in-situ water management. This calls for a holistic approach towards management of water resources necessitating formulation of an integrated water management framework, as a first step, with responsive corporate water policies and programs in order to respond to the potential challenges related to water within and outside the plant boundaries. It is also recommended to implement integrated water management framework: An integrated water management framework is an essential step towards effective water management and conservation. The water management framework needs to be integrated within the sustainability and resource conservation policy of the organisation. The effective steps towards integrated water management framework are outlined below:

Water use mapping Water quality assessments Availability/ Supply Assessment Regulatory risk assessment Stakeholder need assessment

Assessment

Set benchmark for the water usage Making the source sustainable Reducing specific water consumption and implementing conservation interventions Aiming for zero liquid discharge Integrating ICT for efficienct water use planning

Identify Intervention

Prioritizing material issues Sensitize and capacitate internal stakeholders Engaging with community Implement high priority interventions

Prioritise and implement

Develop systems for internal audit Conduct external audit Evaluate and benchmark performance Take remedial measures

Monitor and evaluate



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52

Monitoring/Measurement Monitoring and measurement are two most important things in effective industrial water management. Good water management requires accurate water measurement. Some benefits of water measurement are:

Accurate accounting and good records help allocate equitable shares of water between competitive uses both on and off the plant.

Good water measurement practices facilitate accurate and equitable distribution of water. Proper recording and monitoring leads to develop a clear Water balance which is the

primary key to water conservation programme For effective water use it is important to integrate integrated water management tools discussed above in with planning which will include Management Information System and, Decision Support System, etc. Adopting of effective water management framework will help in reducing water consumption and improving specific water consumption. This will not only enhance the industrial sustainability but will also lower the unprecedented stress on the finite and fragile water resources that are on the verge of depletion on account of overexploitation coupled with mismanagement.

Annexure - IV

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