Best of 2011: Hydrogen Fuel Breakthrough Uses Bacteria
As we head into the new year, Energy Digital will be posting some of best stories from 2011 all week. Happy Holidays to all of our readers!
Penn State researchers have discovered a low-energy way to harvest hydrogen fuel that may offer a limitless supply of the clean-burning power source. Hydrogen is a dream fuel that was not so long ago touted as the best alternative to a fossil fuel powered society. It holds more stored energy than any fossil fuel, such as coal, natural gas or oil, and its byproduct isn’t poisonous carbon monoxide or dioxide, but rather chemically pure water. The only problem in propagating this miracle fuel is that, since hydrogen does not naturally occur on earth, it has traditionally required excessive energy to generate the fuel through means such as electrolysis, where an electrical current is passed through water to break apart oxygen and hydrogen molecules. The Penn State researchers, however, may have found the answer, and it lies in bacteria.
Bacteria have been a cornerstone in the quest for alternative fuels such as biodiesel and ethanol, yet few have examined the possibility of bacterial hydrogen generation. But in 2009, researchers discovered a special strain of bacteria that splits water molecules. The only problem is that the bacteria need a small electrical charge to activate, again requiring excess energy to produce energy. But the Penn State team led by professor of environmental engineering Bruce E. Logan has found a way to excite the bacteria using an electrochemical reaction between saltwater and freshwater.
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The process is simple. Desalinating water, that is, removing salt from saltwater, requires extensive energy. So, the researchers hypothesized that adding salt to freshwater would have the opposite effect, and essentially create energy. “If you think about desalinating water, it takes energy,” says Logan. “If you have a freshwater and saltwater interface, that can add energy. We realized that just a little bit of that energy could make this process go on its own.”
Logan’s team created cells that separate freshwater and saltwater with a membrane that allows ions to pass through, but not water molecules. The ions from the saltwater pass through the membrane toward the freshwater to balance osmotic forces, thus creating a charge. While the energy produced is relatively small, it can be generated 24 hours a day and is sufficient enough to activate the hydrogen splitting bacteria.
The researchers set up a series of cells with the final anode being used to host the bacteria. The bacteria were supplied with a feedstock of acetate and the results are impressive. The cells were between 58 and 64 percent efficient and produced between 0.8 to 1.6 cubic meters of hydrogen for every cubic meter of liquid run through the cell each day. The researchers estimate that only about one percent of the energy produced in the cell was needed to pump water through the system.
This technology may potentially offer an unlimited supply of hydrogen; however, there are two problems to contend with. First, the cells require an expensive platinum-based cathode to operate at high efficiencies. Cheaper molybdenum cathodes can be substituted, but efficiency is reduced dramatically. The second problem is the requirement of a feedstock for the bacteria. This is the problem also facing most other forms of biofuel production as well. However, the bacteria used aren’t particularly picky when it comes to the source of acetate they require. In fact, wastewater could hypothetically contain enough feedstock to run the system. Essentially, these cells could be connected to a sewage line and continually produce hydrogen so long as there’s a local source of saltwater available.
Itronics successfully tests manganese recovery process
Itronics - a Nevada-based emerging cleantech materials growth company that manufacturers fertilisers and produces silver - has successfully tested two proprietary processes that recover manganese, with one process recovering manganese, potassium and zinc from paste produced by processing non-rechargeable alkaline batteries. The second recovers manganese via the company’s Rock Kleen Technology.
Manganese, one of the four most important industrial metals and widely used by the steel industry, has been designated by the US Federal Government as a "critical mineral." It is a major component of non-rechargeable alkaline batteries, one of the largest battery categories sold globally.
The use of manganese in EV batteries is increasing as EV battery technology is shifting to use of more nickel and manganese in battery formulations. But according to the US Department of Interior, there is no mine production of manganese in the United States. As such, Itronics is using its Rock Kleen Technology to test metal recoverability from mine tailings obtained from a former silver mine in western Nevada that has a high manganese content.
In a statement, Itronics says that its Rock Kleen process recovers silver, manganese, zinc, copper, lead and nickel. The company says that it has calculated – based on laboratory test results – that if a Rock Kleen tailings process is put into commercial production, the former mine site would become the only primary manganese producer in the United States.
Itronics adds that it has also tested non-rechargeable alkaline battery paste recovered by a large domestic battery recycling company to determine if it could use one of its hydrometallurgical processes to solubilize the manganese, potassium, and zinc contained in the paste. This testing was successful, and Itronics was able to produce material useable in two of its fertilisers, it says.
"We believe that the chemistry of the two recovery processes would lend itself to electrochemical recovery of the manganese, zinc, and other metals. At this time electrochemical recovery has been tested for zinc and copper,” says Dr John Whitney, Itronics president.
“Itronics has been reviewing procedures for electrochemical recovery of manganese and plans to move this technology forward when it is appropriate to do so and has acquired electro-winning equipment needed to do that.
"Because of the two described proprietary technologies, Itronics is positioned to become a domestic manganese producer on a large scale to satisfy domestic demand. The actual manganese products have not yet been defined, except for use in the Company's GOLD'n GRO Multi-Nutrient Fertilisers. However, the Company believes that it will be able to produce chemical manganese products as well as electrochemical products," he adds.
Itronics’ research and development plant is located in Reno, about 40 miles west of the Tesla giga-factory. Its planned cleantech materials campus, which will be located approximately 40 miles south of the Tesla factory, would be the location where the manganese products would be produced.
Panasonic is operating one of the world's largest EV battery factories at the Tesla location. However, Tesla and other companies have announced that EV battery technology is shifting to use of nickel-manganese batteries. Itronics is positioned and located to become a Nevada-0based supplier of manganese products for battery manufacturing as its manganese recovery technologies are advanced, the company states.
A long-term objective for Itronics is to become a leading producer of high purity metals, including the U.S. critical metals manganese and tin, using the Company's breakthrough hydrometallurgy, pyrometallurgy, and electrochemical technologies. ‘Additionally, Itronics is strategically positioned with its portfolio of "Zero Waste Energy Saving Technologies" to help solve the recently declared emergency need for domestic production of Critical Minerals from materials located at mine sites,’ the statement continues.
The Company's growth forecast centers upon its 10-year business plan designed to integrate its Zero Waste Energy Saving Technologies and to grow annual sales from $2 million in 2019, to $113 million in 2025.