Introduction
 Propane is one of the world’s most
common engine fuels
 Stations available worldwide
 High energy density
 Exceptionally safe
 U.S. imports about half of its petroleum
 Two thirds of petroleum is used for
transportation
 Propane use offsets petroleum imports
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Lesson 1:
Introduction to Propane
3
Objectives
 Describe what propane (LPG) is and how to
identify it
 Explain the basic history of propane
 Describe how propane may help public health
and the environment
 Explain how propane may help stimulate the
economy
 Describe what energy security is and how to
use propane to attain it
4
Definition of Propane
 Propane is:
 Identified as an alternative fuel
 Colorless
 Odorless
 Product of natural
gas production and
crude oil refining
Figure 1: Propane molecule. Source: NAFTC.
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 Propane usually contains:
 More than 90% propane
 Some butane
 Trace gases
 Easily converted and stored as a liquid
under pressure
 Can produce fewer emissions than
conventional gasoline
 Presents no immediate environmental
threats
6
Chemical Properties of Propane
 Gas at ambient temperatures; liquid below
-40°F or when under pressure
 One cubic foot of liquid = 270 cubic feet of
vapor
Figure 2: Propane tanks. Source: NAFTC.
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Specific Gravity
 Specific gravity of liquid propane = 0.504 (half
that of water)
 Specific gravity of propane vapor = 1.50 (one
and a half times as much as water)
 Leaked propane vapors will sink to the floor
Figure 3: The specific gravity of liquid propane is less than water, and the specific gravity of propane vapor
is greater than air. Source: NAFTC.
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Propane Color
 Colorless liquid or vapor
 Produces pale blue flame when ignited
Propane Smell
 Naturally odorless
 Odorants are added to aid in leak detection
9
Propane Identification
 Colorless, odorless; best identified by added
odorants
 Highly volatile; burns twice as hot as
conventional gasoline
Forms of Propane
 Naturally occurs as a gas
 Liquid quickly evaporates
 Liquid is less flammable,
less dangerous
Figure 4: Propane flame. Source: NAFTC.
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Propane Gas
 Heavier than air
 Tanks are usually pressurized up to around
300 psi or less
Liquefied Petroleum Gas (LPG)
 One gallon of liquid petroleum has about 75%
as much energy as one gallon of conventional
gasoline
 Liquid propane injection systems can return
higher fuel efficiency than conventional
gasoline ICEs
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Basic History of Propane
 Used as an alternative fuel for more than 60
years
 Dr. Walter Snelling first discovered propane in
1910
 Propane was used for cooking as early as
1912
 First propane powered car
introduced in 1913
 Original applications were
mostly farm equipment
Figure 5: Propane gas tank. Source: NAFTC.
12
 Used as a fuel for indoor vehicles
beginning in the 1950s
 RV industry relies on propane heavily
 Propane = $10 billion
industry in the U.S.
alone
Figure 6: Propane warehouse equipment. Source: NAFTC.
13
Did You Know?
Less than 2% of U.S. propane
consumption is used as a
transportation fuel.
Source: AFDC, 2011.
14
Propane Today
 U.S. consumes more than 15 billion gallons
of propane annually
 8.1 million households in the U.S. depend
on propane
 More than 270,000
vehicles in U.S.
Figure 7: Ford E250 Roush CleanTech propane conversion.
Source: AFDC.
15
 Direct from the OEM, purpose-built
vehicles utilize propane
 Conversion vehicles have been converted
from gasoline to utilize propane as a fuel
source
 Conversion kits are widely available for
light-duty vehicles
 Propane may be used in conjunction with
gasoline for bi-fuel applications
16
Comparison of LPG to Gasoline
 Propane is naturally gaseous
 Fuel economy is calculated in gasoline gallon
equivalent (GGE)
 Propane = high octane fuel
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Figure 8: Propane facts and figures. Source: NAFTC.
18
Energy Content
 Energy content is measured in British thermal
units (Btu)
 Propane = 47% more energy by mass when
compared to gasoline
Octane Rating
 Indicates how well the fuel combusts,
resistance to auto ignition
 Conventional gasoline octane rating = 87, 89,
93
 Propane octane rating = around 105
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Auto-Ignition Temperature
 Propane’s auto-ignition temperature = 855°F
(457°C)
 Auto ignition requires between 2.15% and
9.6% propane in the air
20
Why Consider Propane?
 Can produce fewer emissions than
conventional vehicles
 High energy output
 High octane = more complete combustion
 Propane generally costs about the same as
gasoline and diesel
21
Figure 9: LPG compared to conventional gasoline. Source: fueleconomy.gov.
22
Propane Benefits
 Propane = domestic resource
 90% of propane used in the
U.S. is produced domestically
 Promotes energy security
 Established infrastructure
 Longer vehicle service life
Figure 10: Propane production. Source: EERE.
23
Health Benefits
 Combustion can produce fewer harmful
emissions like:
 Particulate matter
 Carbon monoxide (CO)
 Fewer emissions = less smog formation =
less respiration problems
24
Environmental Benefits
 Propane vehicles can produce fewer
harmful emissions
 Spills rarely occur
 If spilled, propane rapidly
biodegrades in soil, water,
air
 Not considered a
greenhouse gas (GHG)
Figure 11: Propane vehicle emissions. Source: EERE.
25
Economic Benefits
 Most accessible alternative fuel
 Generally costs less than conventional
fuels
 Prices fluctuate seasonally – generally
higher in the winter months (October
through March)
26
Energy Security Benefits
 U.S. imports more than 50% of its oil; two
thirds is used for transportation
 97% of propane consumed in the U.S. is
produced in North America, 90% in the
U.S. alone
 Propane use will help offset reliance on
foreign oil supplies
27
Upon completing this lesson, can you:
 Describe what propane (LPG) is and how to
identify it?
 Explain the basic history of propane?
 Describe how propane may help public health
and the environment?
 Explain how propane may help stimulate the
economy?
 Describe what energy security is and how to
use propane to attain it?
28
Test Your Knowledge
1. Propane burns with what color flame?
2. At normal temperatures, propane is a
__________, but it can be liquefied under
moderate pressure.
3. True or False: Propane gas is lighter than
air.
4. True or False: Propane has been used as a
fuel for home heating and cooking for
decades.
29
Lesson 2:
Propane Manufacturing,
Infrastructure, and
Sustainability
30
Objectives
 Describe what propane is made from
 Explain how propane is manufactured and
produced
 Describe how propane is transported
 Explain how propane is distributed
 Describe the sustainability of propane – its
future and cost efficiency
31
Fuel Sources
 Propane = byproduct of refining oil or
natural gas
 About half of the propane produced in the
U.S. is from natural gas production, half is
from crude oil refining
 Propane is captured during these
processes
32
Manufacturing and Production
 Natural Gas Refining
 Propane, butane, ethane are removed from
raw natural gas
 Natural gas = mostly methane; propane is
heavier than methane
 Raw natural gas is chilled
 Propane condenses out of raw natural gas and
is collected
33
Crude Oil Refining
 Propane is removed through cracking
 Oil is heated, lighter propane molecules
evaporate and are collected
 Propane boils at -44°F (-42.2°C)
 One 42 gallon barrel of crude oil produces
about 1.5 gallons of LPG
34
Figure 12: Propane as a percentage of refined crude oil. Source: DOE.
35
Transportation and Distribution
 Stored and transported in large
pressurized tanks
 56,000 miles of pipeline
 More than 6,000 retail locations
 Portable tanks enable
delivery beyond pipelines
 Can be transported via
rail, pipeline, barge, truck
Figure 13: Multiple propane storage tanks. Source: EERE.
36
Figure 14: Schematic of a typical propane distribution route. Source: EIA.
37
Transporters
 Placards and/or other markings are required
for all bulk shipments
 Identified by number UN 1075
Figure 15: LPG transport placard UN1075. Source: USDOT, PHMSA.
38
Infrastructure
 Nearly every city and town in the U.S. has
a propane fueling station/propane source
 Nationwide infrastructure is already in
place
39
Figure 16: Propane fueling station. Source: AFDC.
40
Did You Know?
As of February 2012, the total number
of U.S. LPG fueling stations was at
2,670. This is more than the 2,512
E85 stations.
Source: AFDC.
41
LPG Fueling Stations
 Many items are the same/similar to
conventional fueling stations
 Most tanks are steel
 Certain materials must be used to prevent
premature wear
Figure 17: Propane Fueling Station. Source: NREL.
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LPG Fueling Station Safety Systems
 Fueling station systems closely resemble
conventional fueling stations
 Similar safety precautions/devices are in place
National Fire Protection Association
(NFPA)
Figure 18: NFPA 704 hazard placard for propane. Source: NAFTC.
43
Propane Sustainability
 Propane is derived from fossil fuels
 Propane can be utilized with minimal
modification to vehicles
 Propane is better for the environment
than conventional fuels
 Additional fueling stations must be built
 Bi-fuel vehicles will assist in this
development
44
Did You Know?
Propane is the only alternative fuel
with fueling stations located in every
state.
Source: AFDC.
45
The Future of Propane
 Propane is the most widely used alternative
fuel
 Propane prices are historically below prices
for conventional gasoline
 Limited worldwide supply
 Investigations are underway into producing
synthetic propane
46
Figure 19: Rising consumption of propane. Source: PERC.
47
Upon completing this lesson, can you:
 Describe what propane is made from?
 Explain how propane is manufactured and
produced?
 Describe how propane is transported?
 Explain how propane is distributed?
 Describe the sustainability of propane – its
future and cost efficiency?
48
Test Your Knowledge
1. Name two processes that are sources of
propane.
2. True or False: Propane is the only
alternative fuel that has a fueling station in
every state.
3. Propane accounts for what percentage of
products refined from crude oil?
4. True or False: LPG consumption is
predicted to rise over the next few years.
49
Lesson 3:
Propane Vehicles
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Objectives
 Explain the differences between propane
vehicles and conventional vehicles
 Describe the basic evolution of LPG for
vehicles and subsequent component
technologies
 Describe the performance of propane vehicles
 Explain how to maintain propane vehicles
 Describe the propane vehicles used today
51
Differences Between Propane and
Conventional Vehicles
 Attaining optimal compression ratio
 Compression ratio for most gasoline
vehicles = 10:1
 Compression ratio best for propane
vehicles = 11:1
 Propane sulfur content
 Propane vehicles contain many of the same
components as conventional vehicles
52
Types of Propane Vehicles
 Dedicated
 Propane is the sole source of fuel
 Depending upon storage capacity, driving range
may be limited when compared to conventional
gasoline vehicles
 Bi-fuel
 Utilize propane or another fuel (typically
gasoline) independently
 Are equipped with separate fuel tanks
53
Figure 20: Bi-fuel propane vehicle. Source: AFDC.
54
Propane Conversions
 Gasoline vehicles converted to utilize propane
 Majority of propane vehicles today are
conversions
 Conversions are relatively simple
 Conversion kits may cost from $4,000 to
$12,000
55
Propane Vehicle Components
 Fuel Management System
 Vapor injection vs. liquid injection
 Fuel is stored in liquid form at low pressure
 Older Vapor Systems
 Utilization of throttle bodies/carburetor
systems
 Commonly seen in older forklift/stationary
applications
 Liquid fuel is vaporized before injection
56
Regulator
 Determines how much fuel to sent to the
engine
 May be combined with vaporizer in one device
Vapor Injectors
 Multipoint vapor injectors
 Gaseous fuel flow properties
vs. liquid fuel
 Available around the turn of
the 21st century
Figure 21 Propane regulator. Source: NAFTC.
57
Newer Fuel Injection Systems: Liquid
Propane Injection
 Produced since the early 2000s – mainly for
fleet applications
 Density of liquid fuel
 Nearly identical to gasoline multipoint
injection systems
 Fuel is introduced into the intake in liquid
form
58
Figure 22: Liquid propane fuel injection system on Chrysler beta vehicle. Source: NAFTC.
59
Fuel Storage System
 One or more steel fuel storage tanks
 Tanks are 20 times more puncture resistant
than conventional gasoline tanks
 Tanks include manual shutoff for
removal/servicing
60
 Tanks may be located in the vehicle’s trunk,
under a side panel, on the frame
 Will increase the weight of retrofitted vehicles
Figure 23: Propane fuel tanks. Source: EERE.
61
Pressure Relief Valve
 All propane tanks are fitted with a pressure
relief valve (NOT a pressure relief device)
 Only releases a certain amount of fuel, not the
entire amount in the tank
 Must be vented to the
outside of the vehicle
Figure 24: Pressure relief valve. Source: NAFTC.
62
Solenoid Shutoff Valve
 Ensures that fuel does not flow when the
vehicle is not in use
Fuel Lock
 Stops the flow of fuel if contaminants are
present in the fuel system
63
Propane Vehicle Modifications and
Conversions
 Gasoline conversions may require state
emissions certification
 Calibrations will need to be made by a
trained professional
 Several companies offer aftermarket
conversion kits
64
Propane Vehicle Performance
 Comparable performance with increased
fuel economy
 1.3 gallons of propane = 1 gallon of
gasoline
 Larger fuel storage tanks may be required
 Vehicles designed to utilize propane do so
most efficiently
65
Propane Vehicle Safety
 Tanks are built to withstand extreme
pressures
 Tanks are designed to be filled to 80%
capacity
 Tank explosion is highly unlikely
 Propane tank = 20 times more puncture
resistant than a conventional gasoline tank
66
Propane Vehicle Maintenance
 Regular maintenance is required as with
conventional vehicles
 Bi-fuel vehicles have two fuel systems to
service
 Properties of LPG may help extend oil life
67
Propane Vehicles in Use Today
 Most propane vehicles are conversions
 Propane vehicles typically have lower
maintenance costs
 Cold start problems may be an issue
 Heavy-duty vehicles available
 Currently used worldwide
68
Figure 25: Countries ranking highest in LPG-fueled vehicles. Source: EERE.
69
Upon completing this lesson, can you:
 Explain the differences between propane
vehicles and conventional vehicles?
 Describe the basic evolution of LPG for
vehicles and subsequent component
technologies?
 Describe the performance of propane
vehicles?
 Explain how to maintain propane vehicles?
 Describe the propane vehicles used today?
70
Test Your Knowledge
1.
List three types of propane fuel delivery
systems that have been used over LPG’s history
2. Propane tanks are normally filled to what
percentage of total tank volume?
3. True or False: Propane fuel delivery systems
have evolved much like gasoline fuel delivery
systems for conventional ICEs.
4. True or False: The U.S. currently leads
countries in the use of the most LPG fueled
vehicles.
71