CNG (Compressed Natural Gas) is measured by converting its volume or mass into gasoline gallon equivalents (GGE) or diesel gallon equivalents (DGE) for transportation purposes. This standardization allows for easy comparison with traditional fuels.
Understanding Gasoline and Diesel Gallon Equivalents
- GGE (Gasoline Gallon Equivalent): This unit equates the energy content of a quantity of CNG to that of one gallon of gasoline.
- DGE (Diesel Gallon Equivalent): This unit equates the energy content of a quantity of CNG to that of one gallon of diesel.
Conversion Factors
The reference material provides specific conversion factors for CNG. Here's a breakdown:
| Unit | Equivalent |
|---|---|
| 1 GGE of CNG | 139.31 cubic feet |
| 1 GGE of CNG | 6.38 pounds |
This means if you have 139.31 cubic feet of CNG or 6.38 pounds of CNG, you have the energy equivalent of one gallon of gasoline.
Practical Application
CNG is usually sold by the GGE or DGE. This approach provides several benefits:
- Standardization: It allows consumers to easily compare the cost of CNG with gasoline or diesel.
- Energy Equivalence: It ensures a fair comparison based on the energy content of each fuel type.
- User-Friendly: The use of gallon equivalents makes fuel consumption and cost calculations simpler.
How It's Measured in Practice
- Volumetric Measurement: CNG is initially measured in cubic feet.
- Mass Measurement: CNG is also measured by weight, in pounds.
- Conversion: The measured cubic feet or pounds are then converted into GGE or DGE using the conversion factors mentioned earlier.
- Sale: The CNG is sold by GGE or DGE at the pump.
Example
Let's say a vehicle consumes 278.62 cubic feet of CNG. To find the GGE, divide the cubic feet by 139.31.
- 278.62 cubic feet / 139.31 cubic feet/GGE = 2 GGE
This would mean the vehicle used 2 GGE of CNG. Similarly, if a vehicle consumes 12.76 pounds of CNG, it would equate to 2 GGE.
- 12.76 pounds / 6.38 pounds/GGE = 2 GGE
Summary
Measuring CNG involves converting its volume (cubic feet) or mass (pounds) into gasoline or diesel gallon equivalents (GGE or DGE). This standard ensures a fair and understandable way to compare CNG with traditional fuels. The conversion of 1 GGE of CNG is equal to 139.31 cubic feet or 6.38 pounds.
