Gas companies often store their fuel sup- plies in liquid form and in large storage tanks. Liquid nitrogen is used to keep the temperature low enough for the fuel to remain condensed in liquid form. Although continuous cooling is expensive, storing a condensed fuel is more economical than storing the fuel as gas. Suggest a reason that storing a liquid is more economical than storing a gas.

Understanding the states or phases of matter is foundational in grasping why certain storage methods are advantageous for fuels. Matter can exist in three primary phases: solid, liquid, and gas. Solid matter has a fixed shape and volume due to tightly packed particles. Liquid matter has a definite volume but takes the shape of its container, as the particles are close but can move past one another. Gaseous matter, however, neither has a fixed volume nor shape; its particles are spread out and move freely. When debating fuel storage options, the space required by the different phases is critical. Liquid fuel, being denser than its gaseous form, occupies less space, allowing more fuel to be stored in a smaller area. This translates directly to savings in storage facilities and transportation logistics.

Moreover, considering safety and containment, liquids are generally easier to manage. Gases, due to their high kinetic energy and low density, require robust containment methods to prevent leaks and ensure safety, elevating the associated costs and complexities.

Matter density refers to the mass of a substance contained within a unit volume. It's an essential concept when discussing storage economy because denser substances allow for storing more mass in less space. Liquids tend to be denser than gases because their particles are packed closely together, with minimal space between them. Density impacts not just storage efficiency, but also the transportation and overall handling of fuels.

A higher density means that we can transport a greater amount of fuel in the same volume, reducing the number of trips and the logistics cost. This contributes to the economic advantage of storing fuels in their liquid phase despite the coolants' costs, like liquid nitrogen, required to maintain this dense phase.

The economic storage of fuels is a complex issue that includes factors such as storage space, cost of containers, temperature control, and transportation. Storing fuels in liquid form requires less space than in gaseous form, leading to savings in storage facility costs. The cost of continuous cooling, while significant, is often offset by the reduced volume requirements of the liquid fuel. Additionally, liquid storage is typically less complex and requires less maintenance than gas storage systems, which may include pressurization and constant monitoring.

Including economic considerations, we must also account for the volatility and energy content per volume. Liquids have a lower volatility and often higher energy content per liter, which improves fuel handling and contributes to efficient energy storage.

Liquid nitrogen plays a critical role in the storage of fuels, especially when it comes to liquefying natural gas or other hydrocarbons. As an extremely cold substance, liquid nitrogen is used to maintain the low temperatures required to keep fuels in liquid state. This process, known as cryogenic storage, is essential for substances that otherwise would occupy a much larger volume as gases at standard temperatures and pressures.

Liquid nitrogen is efficient for maintaining the specific temperature range needed for the storage of different fuels. Despite the initial setup and operational energy costs, the reduction in volume leads to long-term economic benefits. The use of liquid nitrogen also adds a layer of safety, as it can help mitigate fire risks inherently associated with fuel storage.