VARIOUS PROCESSES FOR REGASIFICATION LNG TERMINALS VARIOUS PROCESSES FOR REGASIFICATION

What is Regasification? Processes for Regasification of LNG Conclusion Presentation Frame Gas Scenario in India LNG Chain What is Regasification? Processes for Regasification of LNG Conclusion

GROWTH OF GAS DEMAND IN INDIA Large supply deficit Industry using liquid fuels LNG import to reduce growing gap LNG a viable fuel in Indian market Gas Demand (MMSCMD) Source: Report of Working Group (XI Plan) of Government of India

PROJECTED DEMAND - SUPPLY GAP FOR NATURAL GAS Demand Supply Gap (MMSCMD) Years   2007-08 2011-12 DEMAND 179 281 SUPPLIES – DOMESTIC/PIPELINES 71 192 LNG Terminals Dahej 17.5 Dahej Expansion - Hazira 10.0 Kochi Dabhol Total LNG Imports  87 Total LNG + Domestic Gas 88.5 279  GAP 90.5 9 Source: Report of Working Group (XI Plan) of Government of India

WHAT IS LNG LNG Is Natural Gas Liquefied at –160 oC. NG is liquefied to make it suitable for transportation in LNG ships through sea routes where transportation of NG by pipeline route is not feasible / economical. During the Liquefaction process NG is purified to very high level. LNG is therefore environmentally friendly and efficient fuel. LNG is subsequently regasified at receiving terminal for use by the End users. LNG MOVIE

Vaporized LNG to Gas Consumers LNG CHAIN Gas Field Liquefaction Storage Transfer Loading Transportation (Loaded) Unloading Pumping Regasification Vaporized LNG to Gas Consumers Transport (Ballasted)

LNG TERMINAL LNG Vaporizers Metering LP PUMP HP PUMP SHIP LNG TANK BOG COMP. Metering RECONDENSOR UNLOADING/ VAPOR RETURN ARMS LNG Vaporizers LP PUMP HP PUMP SHIP LNG TANK

What is Regasification? It is the process of converting Liquefied Natural Gas in Liquid state to Gaseous state by adding heat.

Types of Vaporizers Open Rack Vaporizers (ORV) Submerged Combustion Vaporizers (SCV) Intermediate Fluid Vaporizers (IFV) Hydrocarbon Mixture (Rankine Cycle) Glycol / Methanol Water System Ambient Air Vaporizers (AAV)

Open Rack Vaporizers (ORV) RLNG Sea Water LNG To Sea The term "open rack" is used because the panels are suspended in a rack, facilitating access for maintenance.

Open Rack Vaporizers (ORV) - Highlights The construction and operation is very simple. No control. high turndown ratio. reliable considering safety aspects. capital-intensive. Environmental issues need to be addressed High maintenance.

Submerged Combustion Vaporizers Fuel Gas RLNG AIR LNG

Submerged Combustion Vaporizers Highlights Simple and compact design. Large load fluctuations. lower capital cost Used only where ambient temp. is very low 1.5% fuel consumption green house effect. The control is more complicated.

Intermediate Fluid Vaporizer with Rankine Cycle

Intermediate Fluid Vaporizer with Rankine Cycle Highlights It uses the cold heat of LNG for Power generation. Power Generation is free of any green house effect. The Capital cost is much higher. The process is complicated and requires lot of controls. Large turndown ratio is not possible. Start-up requires more time.

Glycol-Water Intermediate Fluid Vaporizer RLNG Air Heater GW Pump Water Collection STV Water to different users Water Pump LNG Glycol Water Circulation

Glycol-Water Intermediate Fluid Vaporizer Highlights The capital cost higher than SCV’s but lower than ORV’s. Minimum operating cost Simple operation Most effective where ambient temperature is high Large Space requirement. Special Design Consideration Recirculation of Cold air Generation of Fog Removal of condensed water

Selection of Vaporizers For Dahej LNG Terminal

General Weather Conditions at Dahej Generally warm & Humid Atmosphere Average Maximum Temperature 37 deg C Minimum Temperature 13 deg C Average Temperature 25 to 30 deg C Humidity 60 to 90 % (avg. 70%) Sea Water High Turbidity High Copper High Iron ion concentration

SELECTION OF REGASIFICATION SCHEME AT DAHEJ Open Rack Vaporizers (ORVs) Not Feasible. Submerged Combustion Vaporizers (SCVs) not desirable. Advantage of using high ambient temperature.

LNG TERMINAL DAHEJ AIR HEATER Metering FUEL GAS STV SCV GW PUMP STV WATER PUMP HW / GW EXCHANGER FOR BACKUP BLOWER BOG COMP. RECONDENSOR UNLOADING/ VAPOR RETURN ARMS GTG LP PUMP HP PUMP SHIP LNG TANK

AIR HEATERS & STVs –AT DAHEJ 7 STVs / Air Heaters with 112 fans-16.4 MW each Use of SCVs only if ambient heat is in-sufficient (extreme winter months)

Design Issues Recirculation of Cold air Generation of Fog Removal of condensed water

AIR HEATER COMPUTATIONAL ANALYSIS MODEL - ORIGINAL CONCEPT Detailed investigations were carried out to predict air circulation and to verify the performance of air heaters. 3D calculations were performed simulate air flow behaviour. It was observed that taking air humidity into account improves air heater performance, due to heat released by condensed vapours. Simple and efficient means of condensed water removal are required to prevent carry-over of water with the flowing air. Large amount of condensed water is going to be recovered.

AIR HEATER COMPUTATIONAL ANALYSIS MODEL RESULTS - ORIGINAL CONCEPT We observed that recirculation can occur and led to decrease air heater performance. Recirculation is mainly caused by confluence of streams comming from parallel units . The simplest and most efficient solution for minimizing cold air recirculation is to place different unit not parallel to each other.

AIR HEATER COMPUTATIONAL ANALYSIS MODEL - REVISED CONCEPT Detailed investigations were carried out to predict air circulation and to verify the performance of air heaters. 3D calculations were performed simulate air flow behaviour. It was observed that taking air humidity into account improves air heater performance, due to heat released by condensed vapours. Simple and efficient means of condensed water removal are required to prevent carry-over of water with the flowing air. Large amount of condensed water is going to be recovered.

AIR HEATER COMPUTATIONAL ANALYSIS MODEL RESULTS - REVISED CONCEPT Detailed investigations were carried out to predict air circulation and to verify the performance of air heaters. 3D calculations were performed simulate air flow behaviour. It was observed that taking air humidity into account improves air heater performance, due to heat released by condensed vapours. Simple and efficient means of condensed water removal are required to prevent carry-over of water with the flowing air. Large amount of condensed water is going to be recovered. Ambient Temp 21 deg C Zero Wind

CONCLUSIONS USE of STVs & Air Heaters offer most economical & Eco friendly regasification scheme for warm & Humid places Cold Air Re-circulation cannot be avoided but effect can be minimized by Computational Analysis Modeling Fogging can be considerably reduced by selecting a layout based on the above analysis

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