Vehicle chassis of one of the UML research projects (General Atomics). Click to enlarge.

A 10-year US program to develop low-speed urban magnetic levitation (UML) technology has demonstrated that such systems are feasible to consider as alternatives in the US, but that the initial infrastructure costs and availability of safety and operationally certified maglev technologies are “intimidating”, according to a assessment report prepared by Science Applications International Corporation (SAIC) and sponsored by the Federal Transit Administration (FTA).

Maglev—a transportation technology in which trains are supported by magnetic forces without any wheels contacting rail surfaces—promises several attractive benefits including the ability to operate in challenging terrain with steep grades, tight turns, all-weather operation, low maintenance, rapid acceleration, quiet operation, and superior ride quality, among others. For urban alignments, maglev potentially could eliminate the need for tunnels and noise abatement, resulting in significant cost savings.

However, the results of multiple projects sponsored as part of the program indicated that substantial up-front costs exist. Most large urban areas in the United States have already invested in some type of mass transit system (subway or light rail) and urban maglev poses a fundamental change in technology that is viewed as being both a major risk and cost-prohibitive by transit agencies and investors, according to the report.

While maglev trains are in use throughout the world, those systems are primarily high-speed test environment systems where speeds reach in excess of 250 miles per hour. Low-speed urban maglev faces a much different set of operating circumstances than high-speed magnetic levitation systems, and the successful introduction of such a system to an urban environment presents different challenges, according to the report. Some of the challenges faced by urban maglev include:

• Slower speeds, due to the short distances between stops. Urban maglev should require a maximum speed of about 100 mph.

• Obtaining rights of way in an urban area will be very challenging.

• US safety standards are in many instances much more demanding than standards in other countries. Adapting a foreign system to run in the United States will require careful scrutiny of all safety requirements to determine if it is economically feasible to actually adapt the system.

In 1999, the FTA initiated the Low-Speed Urban Magnetic Levitation (UML) Program to develop magnetic levitation technology that offers a cost effective, reliable, and environmentally sound transit option for urban mass transportation in the United States.

The basic functions of maglev technology include:

• Levitation or suspension of the transit vehicle from the guideway. The two principal means of levitation are electromagnetic suspension (EMS) and electrodynamic suspension (EDS).

  EMS is an attractive force levitation system whereby electromagnets on the vehicle interact with and are attracted to magnetic-attractive components on the guideway. EMS is made especially practical by continuing advances in electronic control systems that precisely maintain the air gap between vehicle and guideway, preventing contact and optimizing power usage. An attractive feature of EDS, according to the report, is its inherent ability to compensate for variations in payload weight, dynamic loads, and guideway irregularities through rapid changes in the magnetic field (via the control system) resulting in the maintenance of the proper vehicle-guideway air gaps.

  Electrodynamic suspension (EDS) employs magnets on the moving vehicle to induce currents in the guideway. A key technical property of EDS is that the repulsive forces produced are inherently stable because the magnetic repulsion increases as the vehicle-guideway gap decreases. Usually the vehicle must be equipped with wheels or other forms of support for takeoff and landing because an EDS levitation design will not operate at speeds below approximately 20 mph. EDS performance has progressed with advances in materials research, cryogenics, and the potential application of superconducting magnet technology.

• Forward or reverse propulsion. Two types of propulsions systems are employed using magnetic technologies. Both rely on the principle of stator motor design and magnetic induction to create propulsive physical forces. Long-stator propulsion uses an electrically powered linear motor winding in the guideway; short-stator propulsion uses a linear induction motor (LIM) winding onboard the vehicle and a passive guideway with a magnetically receptive material (e.g., ferromagnetic aluminum, copper, etc.) installed along the rail surface. The LIM is heavy and reduces vehicle payload capacity, typically resulting in higher operating costs and lower revenue potential compared to the long-stator propulsion. However, the guideway costs are less.

• Vehicle guidance. Guidance systems are required in all degrees of freedom in order to steer or guide the vehicle safely along the guideway under all operating speeds and conditions. The guidance system can be the result of direct application of the magnetic forces necessary to meet ride requirements and can be used in either an attractive or repulsive manner. Similarly, certain design concepts allow for the same magnets on board the vehicle which supply levitation to be used concurrently for guidance. This approach is more complicated, but if successful can reduce vehicle weight.

FTA funded five projects under the UML program:

• The General Atomics Urban Maglev Project (General Atomics, San Diego, CA as the lead company) to develop a system based on permanent magnets.

• Maglev 2000 of Florida Corporation to establish the feasibility of a superconducting electrodynamics suspension (repulsive force) technology.

• The Colorado Department of Transportation partnered with Sandia National Laboratories, Colorado Intermountain Fixed Guideway Authority, and Maglev Technology Group, LLC to develop of a low-speed maglev to link Denver International airport with Vail, about 140 miles away.

• Maglev Urban System Associates of Baltimore, MD to explore the viability of bringing to the United States a Japanese-developed low-speed maglev technology that has undergone more than 100,000 kilometers of testing.

• MagneMotion, Inc. to lead the development of a key Maglev technology for implementation in transportation systems serving traffic-congested urban areas. A principal element of the MagneMotion urban maglev system is the use of the company’s linear synchronous motor technology to propel bus-sized vehicles that can operate with short headway under automatic control.

All of these teams focused on four main areas: systems studies; base technology development; route-specific requirements; and a preliminary design for a full-scale system concept.

The principal lesson learned from the perspective of the overall project execution was that, as with most research efforts, there will be unexpected challenges and obstacles during the course of the projects. Each project team identified different challenges, such as gaining cooperation with State, city, and local stakeholders for alignment issues; obtaining details on already operating systems that were not considered proprietary; and underestimating the technical challenges of super cooling magnets.

In addition, while the very nature of this research program draws creative individuals who are interested in solving complex problems, but very often are not as concerned about following sound project management principles, let alone Federal guidelines for submitting required reports on time. The lesson learned from the program in this regard was the value of requiring someone on the project team to provide a project plan with enough detail that FTA could determine when the project had drifted and enough detailed updates to determine whether progress has been achieved.

—FTA Low-Speed Urban Maglev Research Program Lessons Learned

Resources

• FTA Low-Speed Urban Maglev Research Program Lessons Learned

GM is holding an Advanced Technology Briefing today from 8am to 1pm EDT, and is offering a blogcast of the event, which begins with a Volt/Voltec mule drive prior to an announcement.

One of GM’s subject matter experts (SME) in the area will be available from approximately 8:45-9:30 am for a live chat, with the announcement and press conference to follow.

The live content and chat access will be available on the GM FastLane blog site or via the window below.

<a href=”http://www.coveritlive.com/mobile.php?option=com_mobile&task=viewaltcast&altcast_code=514f6e310d” >GM Advanced Technology Announcement</a>

The international airline industry is committed to achieving carbon-neutral growth by 2020, said Giovanni Bisignani, IATA’s Director General and CEO in his State of the Industry address at the 65th IATA Annual General Meeting and World Air Transport Summit in Kuala Lumpur.

Two years ago we set a vision to achieve carbon-neutral growth on the way to a carbon-free future. Today we have taken a major step forward by committing to a global cap on our emissions in 2020. After this date, aviation’s emissions will not grow even as demand increases. Airlines are the first global industry to make such a bold commitment.

—Giovanni Bisignani

The commitment to carbon-neutral growth completes a set of three sequential goals for air transport: (1) a 1.5% average annual improvement in fuel efficiency from 2009 to 2020; (2) carbon-neutral growth from 2020 and (3) a 50% absolute reduction in carbon emissions by 2050.

To achieve these goals, the air transport industry is focusing on a cross-industry four-pillar strategy on climate change consisting of improved technology; effective operations; efficient infrastructure; and positive economic measures.

In 2009 the carbon footprint of air transport is expected to shrink by 7%. Of this, 5% is due to the recession and 2% is directly related to efficiency gains.

Bisignani noted that the airlines’ commitment needed to be matched by governments.

We are ambitious, but our success will be contingent on governments acting effectively. ICAO must set binding carbon emissions standards on manufacturers for new aircraft. A legal and fiscal framework to support the availability of sustainable biofuels must be established. And governments must work with air navigation service providers to push forward major infrastructure projects such as a Single European Sky, NextGen in the US or fixing the Pearl River Delta in China.

—Giovanni Bisignani

IATA reiterated its call for a global sectoral approach for aviation in the successor to the Kyoto Protocol. Under such an approach, aviation’s emissions would be capped and accounted for globally, not by state. IATA would work with the International Civil Aviation Organization (ICAO) to ensure compliance.

High-pressure CH4 isotherms for COFs measured at 298 K. Credit: ACS. Click to enlarge.

COFs (covalent organic frameworks)—thermally stable and highly functional crystalline organic networks—are among the most porous and the best adsorbents for hydrogen, methane, and carbon dioxide, according to a new study by Professor Omar Yaghi and postdoc Hiroyasu Furukawa at the Center for Reticular Chemistry at UCLA. A paper on their findings was published online 4 June in the Journal of the American Chemical Society.

Yaghi and his colleagues have been at the forefront of inventing new classes of crystalline porous materials: metal organic frameworks (MOFs), and then COFs, reported in the journal Science in 2007. (Earlier post.)

Unlike MOFs, COF structures are entirely composed of light elements (H, B, C, and O) that are linked by strong covalent bonds (B-O, C-C, and B-C) to make a highly porous class of materials. Indeed, one member of this class has the lowest density ever reported for a crystalline solid (0.17 g cm^-3 for COF-108). This has led us to investigate the potential use of COFs in the storage of some gases relevant to clean energy. Here we report the first adsorption studies of hydrogen, methane, and carbon dioxide in COFs and show that COFs rank among the highest performing materials in terms of their gas storage capacities.

—Furukawa and Yaghi (2009)

Furukawa and Yaghi classified seven different COFs into three groups based on their structural dimensions and corresponding pore sizes:

• Group 1: 2D structures with 1D small pores (9 Å for each of COF-1 and COF-6)
• Group 2: 2D structures with large 1D pores (27, 16, and 32 Å for COF-5, COF-8, and COF-10, respectively)
• Group 3: 3D structures with 3D medium-sized pores (12 Å for each of COF-102 and COF-103)

In dihydrogen, methane, and carbon dioxide isotherm measurements performed at 1-85 bar (0.1 to 8.5 Mpa) and 77-298 K (-196 to 25°C), the researchers found that Group 3 COFs outperform group 1 and 2 COFs, and rival the best metal-organic frameworks and other porous materials in their uptake capacities.

At 35 bar, COF-102 showed excess gas uptake of 72 mg g^-1 at 77 K for hydrogen; 187 mg g^-1 at 298 K for methane, and 1,180 mg g^-1 at 298 K for carbon dioxide).

Hydrogen. For hydrogen, the Group 3 COFs demonstrate one of the best performances in the class of physisorption materials, approaching the 2010 DOE system target at 77 K (6.0 wt % and 45 g of H₂ L^-1). More importantly, the researchers notes, the comparable H₂ uptake capacities of the group 3 COFs and MOFs indicate that H₂ uptake capacity is independent of the composition of the structure’s backbone and that design of high-affinity sites by metal doping is a promising pathway for enhancing hydrogen storage performance at ambient temperature.

Methane. The current storage target set by DOE is 180 cm³(STP) cm^-3 at 35 bar, which is comparable to the energy density of compressed natural gas at 250 bar.

Remarkably, [COF-102] CH₄ uptake at 35 bar is roughly 4 times larger than bulk CH₄ density at the same temperature and pressure. The values in cm³ cm^-3 units for COF-102 are well within the realm of the DOE target of 180 cm³ cm^-3 at 35 bar. It should be noted that the contribution of the packing factor of COF samples is important to determine practical uptake in a canister. The packing density is influenced by both shape and size of the materials and usually is below unity, although these numbers for COFs are not available here. Indeed, the actual volumetric uptake is 20-30% smaller compared to the present data if the packing density is 0.7.

—Furukawa and Yaghi (2009)

(Yaghi’s group has a long-standing collaboration with BASF to expand the use of methane as an automobile fuel; the company contributes to the research funding and has licensed MOF technology and is moving forward on commercialization.)

CO₂. Furukawa and Yaghi found that the relationship between the pore diameter and saturation pressure of COFs for storing CO₂ is similar to that of MOFs, indicating that gas adsorption behavior in COFs is substantively the same as that in MOFs. The high CO₂ storage capacity of COFs could be applicable to the short-term CO₂ storage and transport of CO2, although it is lower than certain other materials.

Resources

• Hiroyasu Furukawa and Omar M. Yaghi (2009) Storage of Hydrogen, Methane, and Carbon Dioxide in Highly Porous Covalent Organic Frameworks for Clean Energy Applications. J. Am. Chem. Soc., Article ASAP doi: 10.1021/ja9015765

The Himalayan glacier volume is reducing rapidly due to climate change, leading to cascading effect of alpine ecosystem there, according to a recent study by researchers at the Chinese Academy of Sciences (CAS).

The Greater Himalayas hold the largest mass of ice outside of the polar regions and are the source of the 10 largest rivers in Asia.

The cascading effects of rising temperatures and loss of ice and snow in the region are affecting water availability (amounts, seasonality), biodiversity (endemic species, predator-prey relations), ecosystem boundary shifts (tree-line shifting, high-elevation ecosystem changes) and global changes (monsoonal shifts, loss of soil carbon), found Xu Jianchu, researcher of Key Laboratory of Biodiversity and Biogeography, Kunming Institute of Botany, CAS.

The results were published in Conservation Biology, a journal of the Society for Conservation Biology. According to the study, climate change will also have environmental and social impacts that will likely increase uncertainty in water supplies and agricultural production across Asia.