The LPG Recovery Plant: Designed and commissioned by The Randall Corporation of USA, in 1982 Production capacity : 55000 MT of LPG 25000 MT of Condensate Gas throughput : 2.21 MMSCMD Feed Gas Pressure : 14 Kg/ Cm2 g Residue Gas Pressure : 11.2 Kg/ Cm2 g Water content : Saturated LPG Quality : To conform IS-4576:1999 specification
Feed gas composition (mole%) COMPONENT DESIGN PRESENT FLUCTUATION N2 0.26 0.93 0.44 CO2 1.10 0.64 1.15 C1 86.80 86.58 88.99 C2 6.50 3.75 4.31 C3 3.30 2.16 2.39 i- C4 0.72 0.48 0.56 n-c4 0.86 0.65 0.83 i- C5 0.18 0.23 0.31 n-c5 0.13 0.17 0.26 C6 + 0.15 0.39 0.77
Production profile Fin. Year : 1992 2004 2006-2010 2011-2012 * LPG (MT) : 50417-55780 43750-48165 50500 COND (MT) : 23470 27905 23630 25615 29000 LPG (TPD) : 148.68 160.24 129.82 135.80 150.77 COND (TPD) : 69.45 78.61 70.12-75.36 86.53 Low production was attributed mainly due to change in feed gas composition, more particularly decline in propane and butane content from the year 2006-07. * April May 2011
PRODUCTION PROFILE 1992-2004 60000 55780 54610 54320 50000 MT 40000 30000 20000 24750 25350 10000 0 1992-93 1993-94 1994-95 1995-96 1996-97 1997-98 1998-99 1999-00 2000-01 2001-02 2002-03 2003-04 FINANCIAL YEAR LPG PRODUCTION CONDENSATE PRODUCTION
PRODUCTION PROFILE 2006-2010 MT 60000 48165 47610 50000 43750 44950 45010 40000 30000 23630 25615 25295 24150 25170 20000 10000 0 2006-07 2007-08 2008-09 2009-10 2010--11 FINANCIAL YEAR LPG PRODUCTION CONDENSATE PRODUCTION
RATE OF PRODUCTION 1992-2004 TONNES PER DAY 250.00 200.00 150.00 100.00 50.00 0.00 1992-93 1993-94 1994-95 235.73 235.16 231.58 1995-96 1996-97 1997-98 1998-99 1999-00 2000-01 2001-02 2002-03 2003-04 FINANCIAL YEAR LPG PRODUCTION RATE TOTAL LIQUID PRODUCTION RATE CONDENSATE PRODUCTION RATE
RATE OF PRODUCTION 2006-2011 TONNES PER DAY 237.73 250.00 199.94 203.25 210.71 208.76 210.12 200.00 150.87 150.00 100.00 86.86 50.00 0.00 2006-07 2007-08 2008-09 2009-10 2010--11 2011-12 LPG PRODUCTION RATE TOTAL LIQUID PRODUCTION RATE FINANCIAL YEAR CONDENSATE PRODUCTION RATE
Need Of The Hour To find out ways and means to enhance the LPG production from the available feed gas or from the new gas finds which was under development, in order to sustain the market demand in the northeast.
Action initiated for enhancement of LPG Production Awarded a consultancy service to EIL on 26.10.2006 to prepare Techno Economic Feasibility Report (TEFR) with additional recovery of propane and/ or spiking of butane in OIL s LPG Recovery Plant at a cost of Rs 36.00 Lakh. Report submitted by EIL on 12.03.2007 and a presentation was given to OIL Directors on 21.03.2007. Further study was carried out by EIL for recovery of propane without considering the limitations of existing plant and equipment and with no butane injection.
Action initiated for enhancement of LPG Production On 25.04.2007 EIL presented their findings to OIL Directors wherein the following case studies over base case towards maximizing propane recovery have emerged. Base case: Simulation was carried out on existing plant operating data of 08.11.2006 Throughput : 79 MMSCFD Butane content : 1.20 % Propane recovery :69.7% over the feed content. LPG production : 135 tones per day (45000 MT) Propane : Butane : 50.6:49.4 by weight.
Modified Case : Maximization of Propane recovery Recycling a part of product condensate (NGL) through deethanizer and debutanizer. Additional column height of deethanizer (about 1.5 meter) Small supplementary condenser and re-boiler A manhole has to be provided for inspection of the tower. Propane recovery : 87 % Additional LPG production : 6166 TPA Propane: Butane : 56:44 by weight. Expected plant downtime : 3-4 weeks Project cost: Rs 2-3 Crore Net Annual revenue : Rs.1520 Lakh based on LPG price @ 27000/MT Investment will be returned in 100 days.
The road map towards implementation of the NGL Recycle Project Preparation of basic design engineering package (BDEP) Project management consultancy (PMC) Procurement and construction Installation and commissioning
ACTION PLAN Award of BDEP with extended deliverables to EIL on 26.05.2007 at a cost of Rs 75 lakh BDEP Report submitted on 15.02.2008 The total estimated cost works out to Rs. 624.75 lakh with following beak-up. --------------------------------------------------------------------------- 1. Equipment and Modification job : RS. 414.75 Lakh 2. Project Management Consultancy : Rs. 110.00 Lakh 3. Additional job : Rs. 100.00 Lakh --------------------------------------------------------------------------- TOTAL : Rs. 624.75 Lakh
ACTION PLAN LOA awarded to EIL for PMC on 10.05.2008 at a cost of Rs.135 lakhs. Procurement of equipment initiated. Tender document for LSTK job (NIT) prepared. The cost of LSTK has been increased from that was estimated in BDEP by EIL, R& D in 2007. Total cost of the project : Rs.1053 lakhs. (2010)
INNOVATIVE PROCESS Recycling one part of NGL (Condensate Product) as Deethanizer Feed Additional Propane can be retained at Deethanizer and subsequently Extra amount of LPG can be produced from Debutanizer top. Yield of the process : 15 Tones per day of additional LPG. (Expected) Specification of LPG : Composition C2 present Vapor pressure 56:44 of C3:C4 by Wt. 1% by Wt. 9.5 Kg/Cm 2 g at 40 o C
Modification Jobs : At a Glance PV 16.09 to be cut at top dished end. Weld 1.5 M height of column section. Steel lining at dished end and the new section. New distributor plate at top section. New reflux nozzle at top section One manhole at new section. Three hand hole for removal of packing at bottoms of section. One new nozzle for NGL recycle at middle section. Contd
Modification Jobs : At a Glance Replacement of Deethanizer reflux line from pump to the tower. Topping of packing if necessary. Replacement of PV 16-08 with new one. One NGL tank will be installed Two nos. of pumps for NGL recycle will be required. Three nos. of new heat exchangers will be installed. Deethanizer reflux condenser no2 Debutanizer reflux condenser no 2 Debutanizer feed pre heater HE 15.04 will be replaced with a new one. HE 15.05 will be replaced with a new one. Piping modification for new equipment and insulation
STATUS AS ON 01.06.2011 1. Pressure Vessels (3 Nos.) : Received. 2. Heat exchanger (6 Nos.) : Received. 3. NGL dosing pump (2 Nos.) : Received 4. Pressure Control Valves (8 Nos.) : Received. 5. Control Valves ( 4 Nos.) : Received. 6. Safety Relief Valves ( 2 Nos.) : Received 7. Column Internals : Delivery by 30.09.11. 8. LSTK job : NIT is ready 9. PMC Job : Extended up to 31.03.10 10. Expenditure incurred : Rs 3.00 Crore
EC 12-01 HE 15 09 HE 15 02 PV-16 06 CM 11-01 HE 15 08 PV 16 07 PV 10 08 PV 16 10 HE 15 10 HE 15 05 FC 2101 HE 15 01 RESIDUE GAS FC 2102 FC 2103 REFLUX PV 16 03 PV 16 04 EXP SEP HE 15 12 LPG INLET GAS HE 15 11 COLD SEP PV 16 01 PV 16 02 HE 15 13 HE 15 07 LPG RECOVERY PLANT PROCESS FLOW DIAGRAM Drawn by: SANCHITA BANERJEE : 29.11.2006 HE 15 03 PV 16 09 PV 16 11 HE 15 06 CONDENSATE
FROM DEEHYDRATOR NGL RECYCLE AT LPG PLANT FROM COLD SEP BOTTOM FROM EXP SEP TOP HE 1504 HE1502 REFLUX PV1609 TO COLD SEP HE1510 PV1608 HE 15101 EXP SEP NGL COLD SEP MODIFIED PORTION HE1512 LPG PRODUCT PM170102 HE1501 TO HE1511 FROM EXP SEP HE1503 HE 15103 HE1505 TO KOD He151 02 RESIDUE GAS RESIDUE GAS TO HE15102 INLET GAS FROM CM1101 PV1611 PV1610 NGL PV16101A/B HE1513 HOT OIL PM1703/04 PM17101A/B HE 1506 RESIDUE GAS CONDENSATE GASOLINE PRODUCT
Present consideration Plant can handle a total liquid (LPG + Condensate) of 250-255 tones per day About 40 MT of NGL will be recycled through Deethanizer and Debutanizer to produce about 17 MT of additional LPG at base case (total liquid will be 135+68+40+17 = 260 MT) Present production of liquid (152+ 88) 240 MT. A margin of only 15 20 MT left for NGL recycle and additional production of LPG. If LPG production goes to about 160 MT and above there will be hardly any margin left for NGL recycle. Further Deethanizer and Debutanizer are due for replacement in 2015 2017 as per health survey report by EIL While simulating the base case for enhancement of LPG production the limitation of existing equipment was not considered particularly the case for Debutanizer Rebioler. Replacement of equipment to be planned phase wise