How to Turn Seawater to Drinking Water With the Push of a Button

MIT researchers have developed a portable desalination unit, weighing less than 10 kilograms, that can remove particles and salts to generate drinking water. The suitcase-sized device, which requires less power to operate than a cell phone charger, can also be driven by a small, portable solar panel, which can be purchased online for around $50. It automatically generates drinking water that exceeds World Health Organization quality standards. The technology is packaged into a user-friendly device that runs with the push of one button. Unlike other portable desalination units that require water to pass through filters, this device utilizes electrical power to remove particles from drinking water. Eliminating the need for replacement filters greatly reduces the long-term maintenance requirements. This could enable the unit to be deployed in remote and severely resource-limited areas, such as communities on small islands or aboard seafaring cargo ships. It could also be used to aid refugees fleeing natural disasters or by soldiers carrying out long-term military operations.

This is really the culmination of a 10-year journey that I and my group have been on. We worked for years on the physics behind individual desalination processes, but pushing all those advances into a box, building a system, and demonstrating it in the ocean, that was a really meaningful and rewarding experience for me,” says senior author Jongyoon Han, a professor of electrical engineering and computer science, and a member of the Research Laboratory of Electronics (RLE).

Joining Han on the paper are first author Junghyo Yoon, a research scientist in RLE; Hyukjin J. Kwon, a former postdoc; SungKu Kang, a postdoc at Northeastern University; and Eric Brack of the U.S. Army Combat Capabilities Development Command (DEVCOM). The research has been published online in Environmental Science and Technology.


How To Turn Seawater Into Fuel

For the first time, Rochester chemical engineers have demonstrated a ‘potassium-promotedcatalyst’s potential for use on an industrial scale. Now, the Navy’s quest to power its ships by converting seawater into fuel is nearer fruition.

University of Rochester chemical engineers—in collaboration with researchers at the Naval Research Laboratory, the University of Pittsburgh, and OxEon Energy—have demonstrated that a potassium-promoted molybdenum carbide catalyst efficiently and reliably converts carbon dioxide to carbon monoxide, a critical step in turning seawater into fuel.

Gulf of Aden, April 27, 2011- The Military Sealift Command fleet replenishment oiler USNS Joshua Humphreys (T-AO 188), left, refuels the amphibious assault ship USS Boxer (LHD 4) during a replenishment at sea. Boxer is underway supporting maritime security operations and theater security cooperation efforts in the U.S. 5th Fleet area of responsibility.

This is the first demonstration that this type of molybdenum carbide catalyst can be used on an industrial scale,” says Marc Porosoff, assistant professor in the Department of Chemical Engineering at Rochester. In a paper in the journal Energy & Environmental Science, the researchers describe an exhaustive series of experiments they conducted at molecular, laboratory, and pilot scales to document the catalyst’s suitability for scale-up.

If navy ships could create their own fuel from the seawater they travel through, they could remain in continuous operation. Other than a few nuclear-powered aircraft carriers and submarines, most navy ships must periodically align themselves alongside tanker ships to replenish their fuel oil, which can be difficult in rough weather.

In 2014, a Naval Research Laboratory team led by Heather Willauer announced it had used a catalytic converter to extract carbon dioxide and hydrogen from seawater and then converted the gases into liquid hydrocarbons at a 92 percent efficiency rate.

Since then, the focus has been on increasing the efficiency of the process and scaling it up to produce fuel in sufficient quantities.
The carbon dioxide extracted from seawater is extremely difficult to convert directly into liquid hydrocarbons with existing methods. So, it is necessary to first convert carbon dioxide into carbon monoxide via the reverse water-gas shift (RWGS) reaction. The carbon monoxide can then be converted into liquid hydrocarbons via Fischer-Tropsch synthesis.
Typically, catalysts for RWGS contain expensive precious metals and deactivate rapidly under reaction conditions. However, the potassium-modified molybdenum carbide catalyst is synthesized from low-cost components and did not show any signs of deactivation during continuous operation of the 10-day pilot-scale study. That’s why this demonstration of the molybdenum carbide catalyst is important.


How To Produce Uranium From SeaWater

For the first time, researchers at Pacific Northwest National Laboratory (PNNL) and LCW Supercritical Technologies have created five grams of yellowcake — a powdered form of uranium used to produce fuel for nuclear power production — using acrylic fibers to extract it from seawater.


This is a significant milestone,” said Gary Gill, a researcher at PNNL, a Department of Energy national laboratory, and the only one with a marine research facility, located in Sequim, Wash. “It indicates that this approach can eventually provide commercially attractive nuclear fuel derived from the oceans — the largest source of uranium on earth.”

That’s where LCW, a Moscow, Idaho clean energy company comes in. LCW with early support from PNNL through DOE’s Office of Nuclear Energy, developed an acrylic fiber which attracts and holds on to dissolved uranium naturally present in ocean water.

We have chemically modified regular, inexpensive yarn, to convert it into an adsorbent which is selective for uranium, efficient and reusable,” said Chien Wai, president of LCW Supercritical Technologies. “PNNL‘s capabilities in evaluating and testing the material, have been invaluable in moving this technology forward.”

The adsorbent material is inexpensive, according to Wai. In fact, he said, even waste yarn can be used to create the polymer fiber. The adsorbent properties of the material are reversible, and the captured uranium is easily released to be processed into yellowcake. An analysis of the technology suggests that it could be competitive with the cost of uranium produced through land-based mining.