What distinguishes CNG from LNG?

CNG, or compressed natural gas, is specifically defined as natural gas that has been compressed to a high pressure, allowing it to be stored and used efficiently for various applications, particularly in transportation. LNG, on the other hand, stands for liquefied natural gas, which is natural gas that has been cooled to very low temperatures, transforming it into a liquid state for ease of storage and transport, particularly over long distances. Therefore, the distinguishing factor is the physical state and method of storage: one is in a compressed gaseous state, and the other is in a liquid state.

The other options mischaracterize either the states or characteristics of CNG and LNG. For instance, CNG is gaseous, while LNG is indeed in a liquid state; thus, the descriptions of their states are reversed in the first option. The second option inaccurately matches the processes, stating that CNG is cooled, which is contrary to the process of LNG production. Finally, while some regard CNG as having potential renewable sources, LNG does not inherently possess a designation as non-renewable; both can be derived from non-renewable resources, thus making statements about their renewability too simplistic and not universally applicable.