Liquefied Natural Gas in Mobile Applications—Opportunities and Challenges

Abstract

Liquefied natural gas (LNG) is one of the most influential fuels of the 21st century, especially in terms of the global economy. The demand for LNG is forecasted to reach 400 million tonnes by 2020, increasing up to 500 million tonnes in 2030. Due to its high mass and volumetric energy density, LNG is the perfect fuel for long-distance transport, as well as for use in mobile applications. It is also characterized by low levels of emissions, which is why it has been officially approved for use as a marine fuel in Emission Control Areas (ECAs) where stricter controls have been established to minimize the airborne emissions produced by ships. LNG is also an emerging fuel in heavy road and rail transport. As a cryogenic fuel that is characterized by a boiling temperature of about 120 K (−153 °C), LNG requires the special construction of cryogenic mobile installations to fulfill conflicting requirements, such as a robust mechanical construction and a low number of heat leaks to colder parts of the system under high safety standards. This paper provides a profound review of LNG applications in waterborne and land transport. Exemplary constructions of LNG engine supply systems are presented and discussed from the mechanical and thermodynamic points of view. Physical exergy recovery during LNG regasification is analyzed, and different methods of the process are both analytically and experimentally compared. The issues that surround two-phase flows and phase change processes in LNG regasification and recondensation are addressed, and technical solutions for boil-off gas recondensation are proposed. The paper also looks at the problems surrounding LNG installation data acquisition and control systems, concluding with a discussion of the impact of LNG technologies on future trends in low-emission transport.

Modelling of Boil-Off and Sloshing Relevant to Future Liquid Hydrogen Carriers

“…U if is, by definition, independent of any changes caused by sloshing. Thus, for any SSF value around the design point, a corresponding temperature of vapour, hence BOR, can again be determined using Equations (8) and (9). The dependency of SSF on external weather conditions and ship velocity may also be defined using existing data and relationships from the literature, as will be shown later.…”

“…Two examples of cryogenic liquid fuels are liquified natural gas (LNG) and liquid hydrogen (LH2) [7]. On the one hand, LNG is commonly transported by and used to propel energy carrier ships [8], with LNG ships having a lower carbon dioxide (CO 2 ) equivalent emission due to propulsion than conventional oil-powered ships [9]. These ships cannot be carbon-neutral unless the CO 2 is captured during the voyage [10].…”

An Integral Method for Natural Convection of Van Der Waals Gases over a Vertical Plate

“…The liquefaction of gases is important when storing and transporting this type of fuel. In its liquefied form, natural gas occupies only about 1/600 of its gaseous volume; therefore, it is easier and more economical to transport it [1][2][3].…”

Impact of Compressed Natural Gas (CNG) Fuel Systems in Small Engine Wood Chippers on Exhaust Emissions and Fuel Consumption

“…Natural gas in the form of liquid LNG is the fuel of choice for long-distance maritime transport and heavy rail transport, where it is considered a low-emission fuel [16]. The use of this fuel requires special fuel supply facilities [16,17] as it is a cryogenic fuel with a boiling point of approximately 120 K (−153 • C) [16]. LNG is a popular fuel for sea vessels due to its low cost and environmental friendliness [18].…”

“…Figure16. Comparison of exhaust emissions of the designs tested with the exhaust emission limits in the European Union; (a) the emission limit value and the emissions during shredding processes; (b) the value of the difference between the emission limit value in the EU and that produced during shredding expressed as a percentage, where: A-gasoline fuel supply system, B-CNG fuel supply system.…”