Silver News

In order to reduce air pollution, the U.S. government has mandated that sulfur in gasoline be reduced from the current 350 parts per million to 30 ppm by January 2005. Technologies to reduce sulfur are costly and complicated, but scientists at the University of Michigan may have an answer.

Reporting in the July issue of Science, chemical engineering professor Ralph Yang says that 'molecular sieves' containing adsorbent materials, imbedded with either copper or silver ions, bond strongly with sulfur compounds and eliminate them when added to fuel during the refining process.

The adsorbent material they used is the mineral zeolite, an alumino-silicate crystalline compound akin to clay. Copper or silver ions are then added to the zeolite. The combination is highly effective in taking out sulfur.

Yang claims that the sieves could reduce sulfur from hundreds of parts per million to less than 0.2, about 40 times more efficient than the best currently- used adsorbent materials. “After this treatment the fuel is essentially sulfur-free,” says Yang. He adds that the adsorbent materials are simple and cheap to produce, around $2 per pound. He says that the materials are selective in eliminating sulfur, and the process can be done at normal room temperature and pressure.

American Superconductor Delivers High Temperature Superconductor Ship Propulsion Motor to U.S. Navy American Superconductor Corporation has delivered to the U.S. Navy a 5-Megawatt high temperature superconductor (HTS) ship propulsion motor. The motor and its drive system successfully completed factory acceptance testing under U.S. Navy observation. “We are very pleased with the factory test results for this advanced electric ship propulsion technology, which confirmed that this HTS motor met or exceeded all of our performance requirements,” said Scott Littlefield, program manager at the U.S. Navy’s Office of Naval Research, in an official announcement. “American Superconductor’s successful development and delivery of this motor on-time and on-budget is noteworthy and adds to our confidence that their much more powerful 36.5-MW

HTS motor, now in design, will deliver similar results and provide the sort of power dense, highly efficient propulsion system the Navy will require for its next generation of surface ships.”

The motor is an improvement over conventional copper-wound rotor and permanent magnet motors because it is lighter, smaller, quieter, more durable and more efficient. These advantages result from the use of HTS wire in place of copper in the motor’s rotor coils.

Superconductivity allows certain materials, such as ceramics, to carry large electrical current without the resistance losses of conventional materials such as copper. Silver sheathing provides a protective and inert barrier for the ceramic and represents about half of an average electrical cable’s weight. HTS are used in electric power devices such as motors and generators, medical diagnostic technology and for electricity transmission in power lines. Superconducting power equipment typically will be half the size and have half the energy losses compared to conventional equipment.

Within the next decade, the superconducting wire market may consume 50 million ounces of silver or more every year. In 2001, the Department of Energy and seven industry teams announced projects worth $117 million to further develop high temperature superconductivity into the American marketplace.

In a related story, American Superconductor also announced that it will ship 18 miles of HTS wire to China for use in two electric power projects. China, which has the world’s second largest electric power generation capacity, is widely viewed as one of the world’s most important markets for HTS products, company officials said.

Silver News - Third Quarter 2003