The gradual rise of natural gas fuel trucks has given many people a glimmer of hope. Currently, the region with the largest sales volume of natural gas trucks in China is mainly the western region, which is rich in gas reserves. What are the differences between CNG and LNG natural gas fuels?
Differences Between the Two
Let’s briefly explain the English terms for these two fuels: CNG is the abbreviation for Compressed Natural Gas, while LNG is the abbreviation for Liquefied Natural Gas. The main component of both fuels is methane.
Characteristics of CNG Fuel Use:
Abundant Reserves
In 2006, China’s cumulative proven recoverable natural gas reserves reached 3.84 trillion cubic meters, with remaining recoverable reserves of approximately 3.09 trillion cubic meters.
Long History of Use
My country built its first CNG refueling station in 1988. By the end of 2006, my country had built over 730 natural gas vehicles and converted nearly 200,000 vehicles to CNG. With the construction of several national-level natural gas pipelines, such as the West-East Gas Pipeline and the Sichuan-East Gas Pipeline, CNG vehicle development is booming in Hefei, Nanjing, Wuhan, and Changsha.
CNG Advantages and Disadvantages at a Glance:
Advantages:
- Convenient Refueling.
- Lower Price: Compared to soaring diesel prices, CNG prices are relatively stable.
Disadvantages:
- Longer Refueling Time: CNG refueling takes longer. Filling a CNG cylinder of the same capacity takes twice as long as LNG, or even more.
- Lower Cylinder Loading Efficiency: Because CNG is stored in cylinders under high pressure, its cylinder loading efficiency is much lower than LNG’s.
- Short Driving Range, Suitable Only for Short-Distance Transportation. Generally, CNG-fueled vehicles are used in and around cities. Due to the limited cylinder capacity, more refueling stations are needed to meet the refueling demand.
LNG Advantages and Disadvantages at a Glance:
Advantages:
- Long Driving Range: LNG is liquefied natural gas. While improving gas quality, it overcomes the inherent disadvantages of CNG-fueled vehicles. Using LNG as fuel, a 335L LNG cylinder completely solves the vehicle’s range problem.
- High Cylinder Loading Efficiency: A 335L LNG cylinder weighs 225kg on its own, and 353kg when filled, equivalent to the weight of a fully fueled diesel vehicle. Furthermore, it is mounted on the vehicle frame, significantly lowering the vehicle’s center of gravity.
Disadvantages:
- Limited LNG Refueling Stations: The construction of LNG refueling stations in China is currently slower than that of CNG refueling stations, resulting in a significant shortage of LNG refueling stations. This is a major reason limiting the sales of LNG trucks.
- High Price: LNG is expensive for two main reasons. LNG production costs are very high. Natural gas is liquefied by deep cooling to -162°C, a process that consumes about twice the energy of producing a comparable amount of CNG.
| Fuel type | CNG | LNG |
| Advantages | Convenient refueling | Long driving range |
| Inexpensive | High cylinder loading efficiency | |
| Disadvantages | Long refueling time | Few LNG refueling stations |
| Low cylinder loading rate | Expensive | |
| Short driving range |
Advantages of Natural Gas Compared to Diesel:
In terms of fuel consumption, the retail price of diesel in China is currently higher than that of liquefied natural gas.