Natural gas is a combustible, odorless, and colorless hydrocarbon gas largely composed of methane. Natural gas is a very important commodity in modern civilization. However, most natural gas reserves exist in several countries requiring only small quantities for their own consumption while countries with large natural gas demands are constrained with limited resources and tight environmental regulations. Therefore, natural gas has to be transported across multinations route from exporting countries to importing countries. One of the most common way of transporting natural gas in long distance is through Liquefied Natural Gas (LNG). LNG is produced in liquefaction plant where the natural gas feed is processed to remove impurities and then liquefied at atmospheric pressure.

One of the most essential facilities of liquefaction plant is the fuel gas system. The function of this facility is to satisfy the plant energy demands. It is unique because the sources of fuel are coming from the plant itself. Fuel gas system is designed considering the availability of tail gas in the plant, equipment design requirements as the user of fuel gases, and these have to be balanced in such manner that no flaring occur. In this work, the problem of finding the optimal design of fuel gas networks is represented, modeled, and solved in a systematic way. Other challenging issues regarding the dynamic operations of the networks are also included.