Comparisons and Advantages of Marine CNG Transportation

Abstract

Summary Natural gas is becoming a more popular energy source worldwide and its use is expected to increase dramatically over the next 2 decades. Natural gas has been gaining wider significance as a result of sustained high oil prices, a need for energy diversification and security, the growing global awareness of environmental issues, and the development of new gas-related technologies. Traditionally natural gas has been delivered to markets using two main commercially proven methods—pipelines and liquefied natural gas (LNG). Each of these alternatives is highly capital intensive and requires considerable working terms regarding the quantities and distances to market. In other words, these two methods are economical only over a specified range of quantities and distances and not over the whole range, which opens the door to a number of alternative technologies that have the potential to make the development for smaller quantities to be transported to specific distances. The most advanced among these alternative technologies include onshore gas-to-liquid (GTL), floating LNG and GTL, natural-gas hydrates (NGH), adsorbed natural gas (ANG), and compressed natural gas (CNG). However, none of these has been developed yet and been proved on a commercial scale, although they have proved themselves viable on the basis of technical parameters. This paper will be concerned mainly with (1) marine CNG alternatives, which are currently in their final stages of commercialization, indicating the various available marine CNG technologies used worldwide; (2) the operating differences between LNG and CNG transportation; (3) technical and economic evaluation of both the obstacles facing the commercialization of marine CNG transportation and its advantages.