What is Compressed Natural Gas (CNG)?

Compressed Natural Gas (CNG) is a fossil fuel substitute made by compressing natural gas, which primarily consists of methane. This gas is stored at high pressure to reduce its volume, making it more efficient for storage and transportation. CNG is often used as an alternative to traditional fuels in vehicles, providing a cleaner-burning option that results in lower emissions compared to gasoline or diesel.

The option emphasizing that CNG is made by compressing natural gas captures the essential process involved in its production and use. Unlike other forms of fossil fuels that may be either liquid or solid, CNG maintains the gaseous properties of natural gas while being compressed for efficiency. This unique aspect is key to understanding how CNG can be utilized as an energy source in various applications, including transportation and heating.

This distinction also clarifies why the other options do not accurately represent CNG. For instance, CNG is not a liquid or solid; therefore, referring to it as a liquid fossil fuel or a solid form of natural gas is incorrect. Additionally, CNG is not classified as a renewable energy source, as it derives from fossil fuels, which are finite in nature.