Compressed Natural Gas vs. Liquefied Petroleum Gas. The difference between the two, and some good general knowledge

1. CNG vs. LPG

2. Introduction /
History
 LPG has been used since the 1940’s in
automobiles
 CNG has been used since the 1930’s in
automobiles
 A diesel locomotive was retrofitted with CNG
around 2002
 LPG’s largest use is in cooking and heating
 CNG is mostly compressed methane
 LPG is propane and butane
 LPG is replacing chlorofluorocarbons as
propellants in aerosols

3. CNG / LNG Operation
METHANE IS
COMPRESSED TO 2,900-
3,600PSI AND STORED
IN A SPECIAL TANK
LIQUIFIED NATURAL
GAS (LNG) GOES
THROUGH A CRITICAL
COOLING TO
CONDENSE IT INTO A
LIQUID
LNG TAKES UP LESS
STORAGE SPACE
LNG ENERGY
INEFFICIENT
LNG IS USED FOR
EXTENDED RANGE
REQUIREMENTS
CNG CONTAINS ABOUT
42% THE ENERGY
DENSITY OF
PETROLEUM

4. LPG Operation
STORAGE IS AROUND
320PSI
TANKS ARE FILLED TO
85% FOR THERMAL
EXPANSION
LOW CARBON
CONTENT
LOW OIL
CONTAMINATION
OPERATE AS BI-FUEL
WORKS WELL WHEN
USED WITH DIESEL
(WEAR)

5. Pros and Cons of CNG
Pro
 Better emissions than petrol
 Lower cost per mile
 Eco-friendly
 Efficient combustion
 Lighter than air
 Less oil contamination
Con
 High pressure
 Comes through pipeline
 Measured in KG
 Slow fill time
 Expensive conversion
 Hard to find refueling station
 Lower power than gasoline

6. Pros and Cons of LPG
Pro
 Better emissions than gasoline
 Low pressure
 Easy to find refueling station
 Quick refueling
 Good power production
 Low oil contamination
 Efficient combustion
 Very Eco-Friendly
Con
 Heavier than air
 Hotter combustion
 Less power than gasoline
 Requires heavy duty cooling system
 Requires special fuel system

7. Similarities Between
CNG and LPG
 High octane ratings
 More fuel consumption
 Lower emissions
 Efficient combustion
 Low oil contamintation
 Eco-friendly
 Conversion cost

8. Performance
Applications
 Similar octane ratings
 Bi-fuel
 Low cost
 Already used for many diesel engines to
increase boost
 Temperature decreases as pressure drops
 Increased efficiency and power when used in
combination with other fuels