LNG Hazards. LNG Hazards – Introduction Liquefied Natural Gas Facilitates transportation and storage of natural gas 600:1 vapor to liquid ratio Natural.

LNG Hazards

LNG Hazards – Introduction

• Liquefied Natural Gas

• Facilitates transportation and storage of natural gas

• 600:1 vapor to liquid ratio

• Natural gas is refrigerated to cryogenic temperatures to liquefy it

• Liquefaction and vaporization facilities

LNG Hazards – LNG Properties

• Mostly methane with small amounts of propane, ethane and other materials

• Very flammable Flammability range of 5% to 15%

• Cryogenic at ~ -260 ºF

• Near atmospheric pressure in most cases

• Heavier than air below ~ 170 ºF

LNG Hazards – Types of Facilities

• Liquefaction At source of fuel Converts natural gas to LNG

• Base Load Main receiving point for large shipments of LNG Vaporization facility

• Peak Shaving Liquefies natural gas during off season, stores it and vaporizes it

during high demand periods Liquefaction and vaporization processes

LNG Hazards – Types of Facilities

• Distribution Relatively small operation Receives shipments of LNG Normally by tanker truck May supply remote town or specific facility

• Vehicle Fueling Similar to Distribution facility but for refueling vehicles only

LNG Hazards – Typical Hazards

• Storage Tank Diked Areas Typically earthen banks Containment in case of tank

leak or rupture Very large areas

• Storage Tank Relief Valves Located on top of storage

tanks Fire hazard due to lightning

strikes Manual fire fighting not

practical

Need LNG storage tank diked area picture

LNG Hazards – Typical Hazards

• Pump Skids and/or Areas May be inside storage tank

dike May be in pit outside of dike Potential for large fire due to

LNG flow rates

• Vaporizers Many different type

• Direct fired• Remote heat source• Ambient air• Water bath

LNG Hazards – Typical Hazards

• Loading / Unloading Hazards Truck loading/unloading Loading arms for transfer from

ship at marine terminals

• General Plant Areas Process piping Pipe racks Typical plant hazards

Need LNG truck loading rack area picture

LNG Hazards – Typical Hazards

• Enclosed Areas Computer rooms Control rooms Buildings enclosing equipment

LNG Hazards – Protection Objectives

• Dikes to Control LNG Flow Collection Pits in Safe

Location

• Natural Gas Vapor Control• Flame Extinguishment• Heat Flux Control• Separation

Between Hazards Between Hazards and

Facilities

LNG Hazards – Detection Methods

• Flammable Gas• Flame• Heat

Spot detectors Linear detectors

• Video

Need Gas Detector Slide

LNG Hazards – Agents

• Sprinkler Building sprinkler

systems Equipment / piping heat

protection• Cooling of

equipment/piping• Will not extinguish

natural gas fires Vapor control

• Prevent downwind drift

• Warm vapors

LNG Hazards – Agents

• Water Fog / Spray Vapor control

• Warms vapors to prevent downwind travel

Heat control• Used to control

heat flux• Protect fire fighters

and/or exposures to a fire

LNG Hazards – Agents

• High Expansion Foam Typically used for diked

areas Required containment Vapor control

• Natural gas vapor forms chimneys that warms vapor

Fire control• Natural gas vapor forms

chimneys that reduces flame size

LNG Hazards – Agents

• Dry Chemical Extinguishes natural

gas fires Portables & hose-lines

• General plant protection

High capacity monitors• Specific hazards

Fixed nozzle systems• Specific hazards• Automatic actuation

LNG Hazards – Agents

• Clean Agents Indoor total flood systems

only• Computer rooms• Control rooms• Hazardous enclosures• Normally occupied areas