EFFICIENCY IMPROVISATION OF THE PROCESSING UNITS IN THE ONGC URAN PLANT

By Aditya Oak

Introduction to ONGC(oil & natural gas corporation ltd)

• Formed in 14th august 1956

• Most valuable company of India

• Market value 85000 crores

• contributes over 84% of India’s Oil & gas production

• Every LPG cylinder consumed in India comes from ONGC

• one tenth India’s refining capacity is handled by ONGC

Location of Uran

BHN

Heera

26”

30”

24”

26”

URAN

210 km

85 km

About Uran plant

• One of the most important installations of ONGC

• Handles 50% of the Indian oil production

• 5.5 km area & more than 1000 employee work there.

• The Uran plant has several units. They are listed as follows:-1.CFU (Condensate Fractionation Unit)2.GSU (Gas Stabilization Unit)3.EPRU (Ethane, Propane Recovery Unit)4.LPG unit5.CSU (Crude Stabilization Unit)6.Co-generation plant (Co-Gen)7.FGRU (Flare Gas Recovery Unit)

Function of Uran plant

• Stabilization of the crude and transportation of it to the refinery.

• Processing the natural gas for producing LPG, Naphtha, C2-C3.

• The primary objective is to maximize the production of LPG.

Objective of study

• To study all processes going on in Uran ONGC plant. 

• To find out recovery factor for following processing units in Uran plant:

1.LPG I2.LPG II 3.EPRU

•  To observe changes in efficiency of each unit using recovery factor and find out possible reasons to these changes.

• To suggest solutions to problems faced and solutions for process improvisation in order to increase the total production of LPG as well as to increase the life of the equipments of the unit and analyze the cost benefits

OFFSHORE

GSU

I & II

LPG

I &II

EPRU

S/C

II & III

OFFSHORE

LPG

LAN

C2C3

LEAN GAS

CSUSTABILIZED OIL TO REFINERY

MUMBAI REGION OFFICE

URAN ASSET

FINANCEHR MM

CORPORATE OFFICE - DELHI

CFU

I & II

LAN

COGEN & UTILCONSUMERS

MSEB

MIDC

POWER

WATER

POWER STEAM

GAS

COND

OIL

HP BP IOC

IOTL

IPCL

GAIL

HP BP IOC

HL PROCESS MAP OF URAN

PPCL

GPG

OPG

Recovery factor

• Concept widely used in chemical industry

• Used for calculating the efficiency of the unit

• Output/input

• Gives the amount of valuable product extracted from the given unit input of raw material

Sample calculation

• For a given day

input for lpg 1 unit = 5.4184 MMSCMD

lpg produced = 863 cubic M

recovery factor = 863/5.4184 M3/MMSCMD

= 159.377 M3/MMSCMD

similarly RF of each day for each year is calculated and mean of it gives the average RF of the unit per year.

Analysis(graph for 2 lpg production unit)

2004-05 2005-06 2006-07 2007-08 2008-09150

155

160

165

170

175

180

185

190

LPG ILPG II

Analysis lpg 1

2004-05 2005-06 2006-07 2007-08 2008-09145

150

155

160

165

170

175

RF

RF

2004-05 2005-06 2006-07 2007-08 2008-090

5

10

15

20

25

30

NW

NW

Analysis lpg 1

2004-05 2005-06 2006-07 2007-08 2008-09286000

288000

290000

292000

294000

296000

298000

300000

302000

prod

prod

Analysis lpg 2

2003-04

2004-05

2005-06

2006-07

2007-08

2008-09

165

170

175

180

185

190

L2RF

L2RF

2003-04

2004-05

2005-06

2006-07

2007-08

2008-09

0

5

10

15

20

25

30

NW

NW

Analysis lpg 2

2003-04 2004-05 2005-06 2006-07 2007-08 2008-09270000

280000

290000

300000

310000

320000

330000

340000

350000

360000

370000

production

production

Analysis of EPRU unit

2004-05 2005-06 2006-07 2007-08 2008-09340

350

360

370

380

390

400

410

EPRURF

EPRURF

2004-05 2005-06 2006-07 2007-08 2008-090

2

4

6

8

10

12

NW

NW

Analysis of EPRU

2004-05 2005-06 2006-07 2007-08 2008-091020000

1040000

1060000

1080000

1100000

1120000

1140000

1160000

1180000

1200000

production

production

Effect of climatic conditions on RF

• For lpg 1

summer rainy wnter150

152

154

156

158

160

162

164

166

168

RF avg

RF avg

Effect of climatic conditions on RF

• For lpg 2

summer rainy winter177

178

179

180

181

182

183

184

185

186

RF avg

RF avg

Effect of climatic conditions on RF

• For EPRU

summer rainy winter376

377

378

379

380

381

382

383

384

385

RF avg

RF avg

Conclusions

• LPG 1 being the oldest unit is showing some drop in the efficiency.  

• Heat exchanger tends to get fouling frequently due to constant usage and heavy duty. Hence it shows drop in efficiency over the period of time.

• The gas turbine used in LPG 1 unit for compression purpose shows a serious drop in the efficiency in summers while the electrical motors in LPG unit is showing a very constant performance.

Conclusions

• The new modification in the equipment of EPRU unit has reduced the RF of the unit for (c2-c3) but it has helped in increasing the production of LPG. The objective of the plant has been achieved due to this modification.

• Summer season affects the overall productivity of the Uran plant.

• The plant requires periodic maintenance of the cooling units in Uran plant.

• The resources like human, software, electricity, water are not been used properly and effectively.

Recommendations

• Periodic shut down of LPG 1 plant for maintenance of heat exchangers at least once a year. 

• shut down should be taken just before summer to give maximum effect of maintenance.

• Heat exchangers of LPG1, LPG 2 and EPRU should be thoroughly inspected on regular basis. This should be done at least 2 times a year. Employees should be trained for resource management.

Recommendations

• Employees working on plant should have proper training and full time access to production and design related software’s such as HYSYS.

• Production of key products should be flexible so that the production volume can be controlled depending upon the demand of the products.

• Replace the gas turbine used in the LPG 1 unit with electrical

motors.

Cost benefits

• LPG subsidized selling price - Rs. 15763.59 per metric ton

• Density: 0.55 tons per cubic meter

• Average production per day: 1000 cubic meter per day

• Electricity Cost of 1 KWH: Rs. 3.25 Consumption of electricity by LPG gas turbines: 2.65 MWH

• Unprocessed gas Selling price: Rs. 3.2 per cubic meter

• Maintenance cost of 6 heat exchangers: Rs. 10, 00,000

Cost benefits

• Formula for calculating profit from LPG 1 plant due to annual maintenance

• Net profit (after maintenance) = {Profit gained by improved recovery Factor}+ {unprocessed gas sales} + {electricity savings} - {production loss due to shut down} – {Maintenance cost of heat exchangers}

• Profit gained by improved recovery Factor for LPG=23, 31,

16,592.4 Rs

• Profit gained by improved recovery Factor for Naphtha =6, 85, 18,296 Rs

• Unprocessed gas sales for 5 days = 41, 60,000 Rs

Cost benefits

• Electricity saved in 5 days = 10, 33,500 Rs

• Production loss of LPG per day = 86, 69,974.5 Rs

• Production loss of Naphtha per day = 4943600 Rs

• Net profit (after maintenance) per year is 30, 16, 34,888.4+41,60,000 +10,33,500-6,80,67,872.5-10,00,000 = Rs. 23,77,60,515.9

Biblography

• www.ongc.com • Journal for petroleum technology • ONGC performance report • Chemical engineering world magazine • Chemical weekly

• Maintenance engineering and management ; Author:sushil kumar shrivastav

THANK YOU