Processing and history of Lng-Presentation.ppt
- 1. PRESENTATION SAFETY FEATURES OF LNG HANDLING BY AS.BHAVE.DGM(F&S) GAIL (India) Limited (Bhubaneswar & Cuttack)
- 2. History Of LNG Transportation • 1912 first LNG plant built in West Virginia. • 1959, cargo ship carried 5000 cub meters of LNG between Lake Charles and UK demonstrating feasibility of water borne transportation. • 1965, first commercial cargo sailed to France. • 2004, first LNG ship arrived at Petronet LNG Limited, Dahej, Gujarat, India.
- 3. What is LNG *LNG is natural gas that has been processed to remove impurities such as sulphur, ammonia, moisture, CO2 and heavy hydrocarbons and then condensed into a liquid at atmospheric pressure by cooling it to approximately -162 degrees Celsius. *LNG is about 1/600th the volume of natural gas. • Cost efficient to transport over long distances
- 4. 1.What is LNG • where pipelines do not exist or where moving natural gas by pipelines is not possible or economical, it can be transported by LNG vessels.
- 5. Supply Of LNG LNG is supplied from : 1.Algeria. 2. Australia. 3. Brunei. 4. Indonesia. 5. Libya 6. Malaysia. 7. Nigeria 8. Oman 9. Qatar. 10. Trinidad & Tobago The Pacific basin is the largest LNG producing Region in the world, supplying nearly half (49%) of all global exports.
- 6. Supply of LNG – 2002-Worldwide • Indonesia -Supplied 21%. • Qatar - Exported 23%. • Algeria - Exported 29%. • LNG terminals – 40. • Japan,South Korea,United States, and number of European countries import LNG. Algeria is major supplier to Europe & United States.
- 7. BASICS OF LNG • It is Liquid form of Natural Gas. • Natural gas is converted to liquid to reduce its storage volume. • It is safer, easier, and less expensive to transport and store than natural gas. • Weighs less than one-half that of water. • It is Odorless, colorless,non-corrosive,and non toxic.
- 8. PROPERTIES OF LNG • Primarily composed of methane (90-95%), ethane,propane and heavier hydrocarbons. • Stored in liquid state in tanks that have double - wall construction with insulation between the walls.
- 9. CARBON EMISSIONS • More efficient than other fossil fuels & leads to lower carbon emissions. Carbon emissions for natural gas used in single cycle gas turbine for power generation are: • 22% lower than fuel oil. • 43% lower than coal. • 45% lower than wood and wood waste.
- 10. 2.COMPOSITION OF LNG COMPOSITION MOLE% Methane 89.49% Ethane 6.33% Propane 2.49% Butane 1.26% Pentane 0.09% Nitrogen 0.34%
- 12. Liquefaction • When cooled to -1620 C, it becomes clear, colorless,odorless liquid. During Liquefaction : • Natural gas cooled below its boiling point, removing most of the compounds such as low concentrations of hydrocarbons,water, CO2,N2,O2, and some Sulphur compounds.
- 13. After Liquefaction • LNG is loaded to a tanker ship via loading line and loading arms. • The loading rate is driven by keeping the ship loading time as short as possible by the cool down time of the ship tanker material.
- 14. Transportation 1.Transported in double-hulled ships designed specifically to handle low temperature. 2.Insulated to limit amount of LNG to boil off or evaporate. 3. Boil off gas is used to supplement fuel for the carriers. 4. LNG carriers are 1000 ft long, and require a minimum depth of 40ft (12 mtrs.) when fully loaded. 5. There are 136 ships which transport more than 120 MMTPA of LNG every year.
- 15. LNG STORAGE • Each Tank is double integrity type. • Has a gross capacity of 1,60,000 m3 . • Diameter – 75m ; Height – 40m on shell with a domed roof. • Consists of 9% nickel steel inner tank with suspended Aluminium deck and a pre stressed reinforced concrete outer tank with a carbon steel roof.
- 16. LNG STORAGE • Annular Space is filled up with Perlite insulation to minimize heat leaks into the tanks. • The tank base insulated with foam glass blocks to minimize heat ingress from the ground. • Base heating elements are installed beneath the base insulation to maintain the ground temperature at or above 50 C.
- 17. LNG STORAGE • Each tank has a set of low pressure pumps, these pumps are used to transfer LNG from storage tanks to the gasification plant via the boil – off gas condenser, and concurrently to circulate a stream of LNG through the transfer lines to keep them cool when not unloading a ship. Vapor in the tanks generated by the tank filling or heat ingress is removed on pressure control to one of two centrifugal boil-off gas compressors.
- 18. LNG STORAGE • If LNG vapors are not released, the pressure and temperature within the tank will continue to rise. The temperature within the tank will remain constant by allowing the boil off gas to escape from the tank. This is known as auto-refrigeration. The boil-off gas is collected and used as a fuel source in the same facility.
- 19. BIRDS EYE VIEW OF LNG STORAGE
- 20. LNG GASIFICATION • LNG is converted back to gas at the terminal, which is supplied as fuel (or) connected to natural gas pipelines that transport the gas to where it is needed.
- 21. PROCESS FLOW CHART OF LNG PLANT Ship Unloading Blowers Primary Pumps Unloading Arms Jetty Ship Pumps Send-out Pumps Boil off Gas Condenser Flare Boil off Comp. From the sea Pipeline To the Sea Seawater Pumps Vaporizers Metering Pressure Control
- 22. PROPERTIES OF LNG BOILING POINT -1620 C SPECIFIC GRAVITY 0.466@ (-1620 C) SPECIFIC GRAVITY 0.555@ (As a Gas) Air Specific Gravity 1.0 RLNG is Lighter than Air
- 23. PROPERTIES OF LNG • LNG is odourless,colorless,non-corrosive & non - toxic. • Stable Hazardous polymerization will not occur. • It acts as a simple asphxiants and may cause death due to lack of oxygen. • Non carcinogenic.
- 24. TYPES OF LNG STORAGES LNG tanks are employed in a variety of types throughout the world according to social needs and the site environment. • Storage Tanks are broken down to two categories mainly: • In-ground/under ground storage tanks. • Above ground storage tanks.
- 25. TYPES OF LNG STORAGES • In – ground/under ground storage tanks do not need to be surrounded by a dike and legally required space between tanks as well as the necessary distance from items to be protected is relatively small. The roofs of in- ground LNG storage tanks are only a part visible from the surface making the tanks a difficult target for terrorists. The tanks are not obtrusive to environment. The tank would not leak onto the ground.
- 26. TYPES OF LNG STORAGES • Tokyo gas has constructed a new underground tank, which is totally buried in the ground, at its LNG Terminal in Yokohama. The dome roof of the tank is covered with over one meter of earth making it completely invisible from the surface space. An earthquake situation the seismic motion is not amplified for in-ground/ underground storage tanks as compared to above ground structures making them safer in earthquake prone regions.
- 27. BIRD’S EYEVIEW OF IN-GROUND LNG STORAGE TANKS
- 28. BIRD’S EYEVIEW OF UNDER-GROUND LNG STORAGE TANKS
- 29. BIRD’S EYEVIEW OF ABOVE-GROUND LNG STORAGE TANKS
- 30. LNG TERMINAL COSTING • In LNG Terminal above ground tanks are erected. • The main cost components of LNG unloading facility is primarily the cost of LNG storage around 45% of total cost balance send-out (24%),utilities (16%), general facilities (4%) and jetty (11%).
- 31. Myth and Legend • “Catastrophic release of LNG creates a BLEVE -- boiling liquid expanding vapor explosion” NOT TRUE NOT TRUE – In laboratory and open ocean combustion tests, there have been no documented cases of LNG BLEVEs
- 32. LNG TANK INSULATION • LNG Tank Insulation plays a very major role in handling of LNG at -1620 C. In order to safe guard the system against heat transfer the following specialized insulation material used in between the inner & outer tank as well as on deck roof and related piping.
- 33. LNG TANK INSULATION • Glass Fibre Resilient Blankets. • Perlite Ore – Expanded Form. • Foam Glass. • Polyisocyanurate (PIR) Buns. • Cellular Glass Insulation. • Outer Concrete Wall. • The insulation acts as a barrier between LNG & outside environment which is prone to have any type of ignition source.
- 35. TYPES OF LNG TRANSPORTATION • LNG is transported in • Road Trucks. • Rail Tankers. • Ship Carriers. depending on distance and quantity to be transported.
- 36. TYPES OF LNG TRANSPORTATION • In the US, (Department of Transportation) (DOT) regulates the transportation of LNG as well as the driver’s of the trucks. • The double walled trucks are like “thermos bottles” on wheels. • They transport LNG at -2500 C. • LNG can be stored for three days in the tanks of the trucks without losing any LNG
- 37. TYPES OF LNG TRANSPORTATION through the boil-off process. • The inner tanks of the trucks are made of thick aluminum designed to withstand up to 100 pounds of pressure (6.8kg/cm2 ). • There is a steel outer shell around the outside of the inner tank. • The tanks are designed to withstand most accidents that may occur during LNG transportation.
- 38. TYPES OF LNG TRANSPORTATION • This pressurized tank does not use any pump for unloading. It uses a series of relief valves to release pressure as a safe measure. Additionally, tank pressure is used to transfer the LNG from the to the storage tank.
- 39. TYPES OF LNG TRANSPORTATION • Improvement has been done to this system by introducing railway tank containers in March 2000 by JAPEX. • This has reduced logistics cost & reaching customers in more distant areas. • By this method JAPEX has expanded the coverage of LNG Satellite System from the existing range of 250kms to 360kms from the LNG receiving terminals.
- 40. LNG TRANSPORTATION BY ROAD TRUCKS & RAIL TANKERS
- 41. LNG TRANSPORTATION BY ROAD TRUCKS & RAIL TANKERS
- 42. LNG TRANSPORTATION BY SHIP • Much safer than Road trucks and Rail tankers. • Large quantities & Long distances are covered by sea routes. • Ships are specially designed to consume the Boil off gases generated during the sailing as fuel to ship turbine, boiler etc.
- 43. LNG TRANSPORTATION BY SHIP • LNG Ships are of two types : • A) Kvaerner – Moss Spherical Tanks. • B) Membrane type (or) • IHI Prismatic Design. • LNG is transported at approximately 5 psi back pressure in a ship of approximately 1,00,000 m3 or larger capacity.
- 44. A PICTURE OF LNG SHIP
- 45. LNG TRANSPORTATION Has a proven safety record with 33,000 carrier voyages covering 60 million miles with no major accidents over a 40 period history.
- 46. LNG TRANSPORTATION • Eight marine incidents have resulted in spillage of LNG. • Seven incidents not involving spillage, two from grounding – no significant cargo loss. • LNG carriers are much more robust than typical crude, fuel and chemical tankers. The same can be seen in the cross section of the LNG tanker.
- 47. CROSS SECTION OF LNG TANKER
- 48. LNG SAFETY & HANDLING PROCEDURES • Natural gas is combustible in the range 5% to15% volume concentrations in air. Combustible mixtures in confined space will burn explosively. • LNG is cryogenic liquid • Physical contact/spillages constitute a personal/equipment hazard. • Avoid the direct contact/spillages.
- 49. LNG SAFETY & HANDLING PROCEDURES • When handling cryogenic gases and liquids, it is necessary to put on protective devices, e.g. mask, cryogenic gloves. • LNG pool vaporizes rapidly on water body surface (faster than an equal sized pool on land). Release of LNG into a body of water (or) onto water surface is usually followed by violent boiling of LNG in a process called eruption. LNG should never be discarded into water (or) surfaces of water.
- 50. LNG SAFETY & HANDLING PROCEDURES • LNG spill within a hull can cause brittle fracture during transportation. Cryogenics should be stored in Aluminum (or) SS containers to prevent leakage & brittle fracture. • LNG leakage forms white cloud formation with subsequently burn back. No one should be allowed inside white cloud or down stream of this gas.
- 51. LNG SAFETY & HANDLING PROCEDURES • At -1620 C the moisture present inside tanks,piping,pumps and so on can freeze & cause clogging inside systems. So these facilities are dried up with nitrogen until the dew point of complete drying cycle reaches -400 centigrade. • Quick introduction of LNG into piping, tanks cause intensive thermal contraction. This damage or destroy the facilities. So they should be gradually cooled to absorb contraction.
- 52. LNG SAFETY & HANDLING PROCEDURES • Bowing should be avoided by pre-cooling by cooled gas in a proper cool down speed. • LNG remains in a gaseous state, it reaches -900 C. Between -900 C and -960 C, it exhibits a mixed state of gas and liquid, below which all LNG is in a liquid state. The vapor pressure at -1610 C is 1kg/cm2 .
- 53. LNG SAFETY & HANDLING PROCEDURES • If LNG is trapped & sealed inside piping and vessels, heat leak from surroundings will cause expansion and volume increase 600 times due to evaporation which shall increase pressure. This could cause large scale disaster if equipment and piping are subject to pressure larger than design pressure. To prevent this, safety valves and specially designed disk-hole valves
- 54. LNG SAFETY & HANDLING PROCEDURES • are incorporated during the design stage on the LNG lines susceptible to liquid seal. • LNG is heated by atmosphere, increases its temperature and evaporates easily. If small amount of LNG are released into the air, LNG evaporates and dissipates instantly. However, below -1130C, it is heavier than air and crawls low to the ground.
- 55. LNG SAFETY & HANDLING PROCEDURES • Consequently, liquid Natural Gas is more dangerous. Emitted cryogenic gas condenses moisture in the air and creates white cloud which makes leakages easily detectable. The area covered by white clouds usually corresponds with critical explosion range (5-15%). Thus entry into the cloud covered areas and use of fire in that field must be prohibited.
- 56. LNG SAFETY & HANDLING PROCEDURES • During cool down of equipments/tanks, pockets in pipelines etc., heavier hydrocarbons, moisture and carbon dioxide condense and may clog the valves. Opening and closing of drain valves, therefore warrant special attention. If valves are stuck, they must be warmed with steam and other means before attempting to open them.
- 57. LNG SAFETY & HANDLING PROCEDURES • Stratification is phenomena in which vigorous evaporation of boil-off gases makes density different between top and bottom liquid there by roll over occurs. If the density of the incoming liquid is lower than that of the one already stored, input into storage tank through the bottom pipe would enable complete mixture of the two.
- 58. LNG SAFETY & HANDLING PROCEDURES • Conversely, if the density of the incoming liquid is higher than that of the one already in the tank, the top pipe would be used for input. As safety measure density from top to bottom is measured continuously at different heights and through jet mixing should carried out by circulation pumps.
- 59. HAZARDS & SAFEGUARDS IN HANDLING LNG • A) Fire & Explosion Hazards of LNG: • Extremely Flammable. Potential hazard resulting from spillage of large quantity of LNG include thermal radiation from vapor cloud fires as flash fires & pool fires.
- 60. POOL FIRE OF LNG
- 61. HAZARDS & SAFEGUARDS IN HANDLING LNG • If the vapor cloud is confined and/or the vapor contain large amount of heavier hydrocarbons (C2+) then the flame can accelerate and result in an explosion. Otherwise not. • If the liquid pool is unconfined and the inventory of LNG is large, the fire will continue to burn until all the fuel is exhausted by the pool fire. • Declare the entire area as a “No Smoking Zone”. Notify local fire brigade. • Keep Public away incase of Leak / Spill.
- 62. OCCUPATIONAL HAZARDS OF LNG • Inhalation: Inhalation of high concentrations may cause central nervous system depression such as dizziness, drowsiness, headache, and similar narcotic symptoms, but no long term effects. Numbness, a chilly feeling, and vomiting have been reported from accidents. May cause cardiac sensitization
- 63. OCCUPATIONAL HAZARDS OF LNG • Skin Contact: Not irritating. Direct contact to skin with pressurized vapor may cause freeze burns and frostbite. Signs of frostbite include a change in the color of the skin to gray or white, possibly followed by blistering. Skin may become inflamed and painful. • Skin Absorption: Unlikely
- 64. OCCUPATIONAL HAZARDS OF LNG • Eye contact: Not irritating. However, Contact with pressurized vapor may cause frostbite, freeze burns and permanent eye damage. • Swallowing : Unlikely • Physical contact or spillage constitutes a personal injury and equipment hazard.
- 65. SPECIAL FIRE FIGHTING PROCEDURES • Gas fires should not be extinguished unless flow of Gas can be immediately stopped. Shut off Gas source and allow Gas to burn out. If spill or leak has not ignited, water spray may assist in dispersing Gas or vapor to protect personnel attempting to stop leak. Take decision judiciously. • Use Breathing Apparatus Set • Use non sparking tools. • If LNG has spilled then dyke the liquid. • Disperse the vapors with water fog.
- 66. SPECIAL PRECAUTIONS • Use Leather, Cotton, Cryogenic Hand gloves. • Wear goggles or face shield. • Dry chemical, carbon dioxide, Halon or water. However, fire should not be extinguished unless flow of Gas can be immediately stopped. • Use Explosion Proof Oxygen Tester. • Ground equipments to prevent static sparks. Use non sparking tools to work on natural gas lines & equipments.
- 67. MYTHS & LEGENDS • MYTH: Catastrophic release of LNG creates a BLEVE – Boiling Liquid expanding Vapor explosion. NOT TRUE. • LEGEND : In laboratory and ocean combustion tests - there have been no documented cases of LNG BLEVE’S.
- 68. MYTHS & LEGENDS • MYTH : An LNG tanker is a floating bomb. NOT TRUE. • LEGEND : Liquefied Natural Gas tankers have been run aground, experienced loss of containment , suffered weather damage, been subjected to low temperature brittlement from cargo spillage, suffered engine room fires, and been involved in serious collisions with other vessels. No cases of Explosions Reported.
- 69. MYTHS & LEGENDS • MYTH: LNG explodes. NOT TRUE • LEGEND: In laboratory and ocean combustion tests - there have been no documented cases of LNG explosion.
- 70. THANK YOU