Final answer:
Gaseous and liquid fuels are more convenient than solid fuels in applications such as transportation and electricity generation. Challenges exist for storage and economic viability, especially for hydrogen fuel-cell vehicles. The liquefaction of natural gas is particularly important for storage and transport.
Step-by-step explanation:
Applications of Gaseous and Liquid Fuels
Transportation is a sector where gaseous fuels like natural gas and liquid fuels such as gasoline are more convenient than solid fuels. Gases can be compressed or liquified (e.g., LNG, Liquefied Natural Gas) and liquid fuels are easier to transport and pump into vehicles. Fuel-cell vehicles (FCVs), which use hydrogen, offer efficient nonpolluting alternatives but face challenges due to economic viability and hydrogen storage issues.
Another application of liquid fuels is in the generation of electricity through biofuels, but due to their rarity, this use is less common. Additionally, the conversion of coal to gas or liquid forms is crucial as it makes the mining and transport of these energy sources safer and more efficient. The production of synthesis gas (syngas) from coal also helps in reducing sulfur emissions when these gases are used for energy.
Liquefaction plays a critical role in the storage and shipment of fossil fuels. Liquefied Natural Gas (LNG) is a method to efficiently store and ship methane by cooling and compressing it, greatly reducing its volume and making international transport economically feasible.