Full-Spectrum Solar-Generated Hydrogen

Dean Sigler Hydrogen Fuel, Solar Power, Sustainable Aviation Leave a Comment

Osaka University researchers have created a new material based on gold and black phosphorus to produce clean hydrogen fuel using the full spectrum of sunlight.  Most solar apparatus used in “water splitting” rely on materials such as titanium dioxide.  These are limited to obtaining energy from the ultraviolet (UV) part of the solar spectrum, however.  The rest of the spectrum is wasted. Osaka’s team “developed a material to harvest a broader spectrum of sunlight,” using a three-part composite.  The different parts maximize absorption of light and enhance the efficiency of the unit for water splitting.  The core, a “traditional” semiconductor of lanthanum titanium oxide (LTO) is coated with tiny nanoparticle specks of gold.  The gold-covered LTO is then mixed with ultrathin sheets of black phosphorus (BP), which acts as a light absorber. Bonding the gold-coated LTO to the BP layer makes a serendipitous combination.  Team leader Tetsuro Majima says. “BP is a wonderful material for solar applications because we can …

Corn Stalks and Cobs Into Clean Hydrogen

Dean Sigler Electric Powerplants, Sustainable Aviation Leave a Comment

Hydrogen has several demerits in coming to the energy market.  A primary issue for H2 critics – that hydrogen requires more energy to produce than it gives back – may have been answered by Dr. Percival Zhang of Virginia Tech’s Department of Biological Systems Engineering, which is in both the College of Agriculture and Life Sciences and the College of Engineering.  We’ve covered his work before, usually in terms of turning corn into biofuels or in finding biological ways to produce hydrogen with low energy input. Part of his exploratory mandate comes from his ECHo cycle.  “I wish to suggest constructing the electricity-carbohydrate-hydrogen (ECHo) cycle… could meet four basic needs of humans: air, water, food and energy, while minimizing environmental footprints. In it, electricity is a universal high-quality energy carrier; hydrogen is a clear electricity carrier; and carbohydrate is a hydrogen carrier, an electricity storage compound and sources for food, feed and materials. By using this cycle, we could replace …

As Common As It Gets – But Hard to Get

Dean Sigler Electric Powerplants, Sustainable Aviation Leave a Comment

Since Michael Faraday first split water into hydrogen and oxygen in 1820, scientists have puzzled over how to do this economically in large quantities.   The Blog continues to run stories about “artificial leaves,” low-energy approaches to dividing the hydrogen in water from the oxygen, and doing so economically.  The current most widely-used approach to capturing hydrogen is pulling it from natural gas via several processes.  The Office of Energy Efficiency and Renewable Energy explains the process on its web site. Steam-methane Reforming In steam-methane reforming, “high-temperature steam (700°C–1,000°C) is used to produce hydrogen from a methane source, such as natural gas. In steam-methane reforming, methane reacts with steam under 3–25 bar pressure (1 bar = 14.5 psi) in the presence of a catalyst to produce hydrogen, carbon monoxide, and a relatively small amount of carbon dioxide. Steam reforming is endothermic—that is, heat must be supplied to the process for the reaction to proceed.” In a “’water-gas shift reaction,’ the carbon …

H2, Where Are You?

Dean Sigler Electric Powerplants, Sustainable Aviation Leave a Comment

Elon Musk publicly disdains hydrogen-powered automobiles, but then he has $5 billion riding on his battery megafactories and continued success with his Tesla line of automobiles.  Others with a more disinterested point of view discuss H2’s difficulties – and its promise as a vehicle fuel. America, for instance, has a mere 128 hydrogen fueling stations, and the European Union only 143 as of February 2012.  Even with planned expansion of this infrastructure (California is spending $180 million in private and public funds on a planned 46 stations), the landscape might not be ready for large numbers of fuel cell vehicles for a decade or more. For comparison, there are about 29,000 battery-charging stations in the U. S., with both government and private enterprise offering such services.  The Kohls store and all Walgreens Pharmacies in my area have plug-in stations for EVs, for instance, and the I-5 freeway, from British Columbia to Baja, California, has stations every 25 to 50 miles.  With battery-powered EV and …

Cambridge, MIT Chasing Room-Temperature Hydrogen

Dean Sigler Electric Powerplants, Sustainable Aviation 1 Comment

News from Cambridge University shows some promise for inexpensive production of hydrogen, an elusive process considering the lightest element in creation is also the most common, said to make up 90 percent of the visible universe.  On earth, it readily combines with oxygen to form water, a handy thing to have around for the benefit of our species. Getting hydrogen out of the water so that we can burn it in our cars and airplanes is a frustrating process, though, often requiring more energy for the extraction than can be obtained from its combustion. According the National Renewable Energy Laboratory, “To make [hydrogen] usable in fuel cells or otherwise provide energy, we must expend energy or modify another energy source to extract it from the fossil fuel, biomass, water, or other compound in which it is found. Nearly all hydrogen production in the United States today is by steam reformation of natural gas. This, however, releases carbon dioxide in the …