[Due to the increasing size of the archives, each topic page now contains only the prior 365 days of content. Access to older stories is now solely through the Monthly Archive pages or the site search function.]
Study: natural gas heavy-duty trucking fleet could benefit economy, but has mixed environmental effects
February 20, 2015
Switching from diesel fuel to natural gas may hold advantages for the US heavy-duty trucking fleet, but more needs to be done to reach the full environmental benefits, according to a new white paper released by the Institute of Transportation Studies at the University of California, Davis, and Rice University.
The recent shale-driven emergence of natural gas as an abundant, inexpensive fuel in the US has raised the possibility of a “momentous shift” in the level of natural gas used in transportation. The cost advantage of natural gas over diesel fuel is particularly appealing for vehicles with a high intensity of travel and thus fuel use. In the paper, the team investigated the possibility that natural gas could be utilized to provide fuel cost savings, geographic supply diversity and environmental benefits for the heavy-duty trucking sector—and whether it can enable a transition to lower carbon transport fuels.
MHI completes development of next-generation LNG carrier; apple-shaped tanks and hybrid propulsion
November 29, 2014
|Sayaringo STaGE. Click to enlarge.|
Mitsubishi Heavy Industries, Ltd. (MHI) has completed development of the “Sayaringo STaGE,” a next-generation LNG (liquefied natural gas) carrier. The Sayaringo STaGE was developed as a successor to the Sayaendo (earlier post), the company’s LNG carrier evolved from carriers with Moss-type spherical tanks that offer a high level of reliability. (Moss-type LNG carriers use independent spherical cargo tanks supported by a cylindrical skirt integrated with the hull and covered with a hemispherical steel cover attached to the main deck.)
While the Sayaendo (sayaendo = peas in a pod in Japanese) features a peapod-shaped continuous cover for the Moss spherical tanks that is integrated with the ship’s hull, in lieu of a conventional hemispherical cover, the new Sayaringo (ringo being the Japanese word for “apple”) STaGE adopts apple-shaped tanks, resulting in nearly a16% increase in LNG carrying capacity without changing the ship’s width. Further, a hybrid propulsion system has boosted fuel efficiency by more than 20% compared to the Sayaendo (and more than 40% vis-à-vis earlier carriers).
US MARAD study finds marine use of natural gas substantially reduces some air pollutants and slightly reduces GHG emissions
August 26, 2014
A recently released total fuel cycle analysis for maritime case studies shows that natural gas fuels reduce some air quality pollutants substantially, and reduce major greenhouse gas (GHG) emissions slightly, when compared to conventional petroleum-based marine fuels (low-sulfur and high-sulfur). The study was released by the US Department of Transportation’s (DOT) Maritime Administration (MARAD) and was conducted through a cooperative partnership with the Maritime Administration, the University of Delaware and The Rochester Institute of Technology.
They also found that the upstream configuration for natural gas supply matters in terms of minimizing GHG emissions on a total fuel cycle basis, and that the current infrastructure for marine fuels may produce fewer GHGs. Continued improvements to minimize downstream emissions of methane during vessel-engine operations will also contribute to lower GHG emissions from marine applications of natural gas fuels.
KAIST researchers develop box-shaped pressure vessel for storage and transportation of pressurized gases and fluids
March 25, 2014
|Scaled-down model of prismatic pressure vessel. Click to enlarge.|
Professors Pål G. Bergan and Daejun Chang and of Ocean Systems Engineering at Korea Advanced Institute of Science and Technology (KAIST) have developed a box-type, large-size pressure vessel for the storage and transportation of liquids such as liquefied petroleum gas (LPG), compressed natural gas (CNG), or liquefied natural gas (LNG). The project was sponsored by POSCO, a multinational steel-making company based in Pohang, Republic of Korea.
Pressure vessels have many applications and are widely used within the petrochemical, energy, and other industrial sectors where the transport and storage of many types of pressurized gases and fluids are essential. Pressure vessels must be designed, manufactured, installed, and operated strictly in accordance with the appropriate codes and standards since they can, in cases of leak or rupture, pose considerable health and safety hazards.