Page 15 - CNG ESP Participant Guide2024
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Module 1: Properties and Characteristics of Natural Gas


            Lesson 1.3: How Natural Gas Compares with Liquid Fuels

             Properties of
             Natural Gas                Property            Gasoline           Diesel           Natural Gas
             Compared with         Source                  Petroleum          Petroleum         Natural Gas
             Gasoline and Diesel   Physical State            Liquid             Liquid              Gas
                                                               >1                >1                  <1
                                   Vapor Density
                                                        Heavier than air   Heavier than air    Lighter than air
                                   Ignition
                                                             580°F              410°F           900-1,080°F
                                   Temperature

                                   Flammability Range       1.4-7.7%           .6-7.5%             5-15%
                                                                                              5.66 pounds GGE
                                   Weight                  6 pounds           7 pounds
                                                                                               6.4 pounds DGE

                                   BTU Content/             125,000            140,000        125,000 per GGE
                                   Gallon or GGE/DGE                                          140,000 per DGE
                                   Octane Rating             85-94               N/A                130
                                   Cetane Rating              N/A               40-60                <0


             What is Octane?      ▪  Rating for the ability to resist detonation
                                       o  The higher the number, the higher the temperature required to ignite the fuel

             What is Cetane?      ▪  Rating of speed at which fuel begins to combust
                                       o  The higher the number, the faster (easier) the ignition begins

             What Technicians     ▪  Because natural gas is lighter than air, it rises when leaked and dissipates rapidly
             Need to Know         ▪  Natural gas will only burn in concentrations of 5-15% in air


             How CNG Compares
             to Gasoline and
                                         Property           Gasoline        Diesel              CNG

             Diesel
             Transportation and    Transported to            Truck          Truck          Transmission or
             Storage               Fueling Stations                                     Distribution Pipelines

                                   Stored at Fueling      Underground    Underground     Above ground ASME
                                   Stations               storage tanks   storage tanks   pressure vessels










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