Hearing of E. coli outbreaks usually makes us reconsider our fast-food dining choices. Other possible, friendlier uses for the pesky bacteria, though, could show the way to clean energy production, making a “gasoline-like biofuel,” according to Harvard Medical School and Wyss Institute researchers. According to Harvard’s news release, “New lines of engineered bacteria can tailor-make key precursors of high-octane biofuels that could one day replace gasoline, scientists at the Wyss Institute for Biologically Inspired Engineering at Harvard University and the Department of Systems Biology at Harvard Medical School report in the June 24 online edition of Proceedings of the National Academy of Sciences. “’The big contribution is that we were able to program cells to make specific fuel precursors,’ said Pamela Silver, Ph.D., a Wyss Institute Core Faculty member, Professor of Systems Biology at Harvard Medical School, and senior author of the study.” Gasoline has yet to be knocked off its top-fuel pedestal because synthetic, cleaner alternatives are often less powerful. …
Anti-freeze Could Lower Cost of Solar Cells
We’ve examined many attempts to make solar cells, batteries and fuel cells less expensive and to use abundant, easily found materials in their manufacture. Engineers at Oregon State University in Corvallis, Oregon may have crafted a process to manufacture budget solar cells with anti-freeze and relatively cheap metals as key components. Ethylene glycol, found in many automotive antifreeze products, acts as a low-cost solvent “that functions well in a ‘continuous flow’ reactor,” according to OSU, “an approach to making solar cells that cost less and avoid toxic compounds, while further expanding the use of solar energy.” The last sentence stopped your editor cold, since ethylene glycol is a neurotoxin, playing havoc with brains, livers and kidneys. Reading the researchers’ paper published in Material Letters and available online, perhaps the effects of flowing the cells’ metallic materials through a meso-fluidic reactor with the antifreeze neutralizes the toxins, but that isn’t spelled out clearly (at least for your non-chemist editor). “Metallic materials” refers …
Vanadium Oxide/Lithium Batteries Offer Promise of High Power, Long Life
Henry Ford once brought a French metallurgist to Detroit, part of his plan to build cars with lighter, stronger steel. Vanadium, which the French used in their automobiles, offered him the chance to make the Model T lighter and stronger, and its part in the car’s alloyed steel gave the Model T the longevity which followed it through one of the longest production runs in history. Now battery researchers are looking at another quality of this mineral, its ability to form a superior cathode for batteries that “could supply both high energy density and significant power density. Combined with graphene, the wonder material du jour, vanadium oxide (VO2) could couple longevity echoing the Model T’s with charge and discharge rapidity similar to a supercapacitors. Materials scientist Pulickel Ajayan at Rice University created ribbons of vanadium oxide (VO2) thousands of times thinner than a sheet of paper, and combined those with atom-thick ribbons of graphene to form cathodes which were built …
New “Leaf” Turns Over More Energy
Scientists have been working on imitating nature’s ability to photosynthesize the sun’s energy, much as plants turn that energy into food for their health and growth. Daniel Nocera, for instance, created an artificial leaf that split water into oxygen and hydrogen that could fire up a small fuel cell and run an electric light. According to a Science Pub lecture your editor recently attended, an eight-ounce glass of water can power a 60-Watt bulb for 20 hours. Nocera, in a Pop! Tech talk, claims an Olympic-size swimming pool could supply all the world’s energy needs. Nocera now works at Harvard, but researchers at Massachusetts Institute of Technology (MIT), his former home, are taking his work further, detailing all the limitations that keep his “artificial leaf” from giving off more storable energy. As explained in the MIT press release, “The original demonstration leaf, in 2011, had low efficiencies, converting less than 4.7 percent of sunlight into fuel… But the team’s new …
A Layer of Graphene, A Layer of Nanowires…
Combine nano-anything with graphene, and that seems to describe most of what’s driving physics and chemistry laboratories at our major universities. The blog reported last week on Princeton researchers who’ve created a thin, flexible solar cell that absorbs 96-percent of received light and draws energy from off-axis and varied wavelengths of light. MIT researchers, too, have created a thin, flexible solar cell, but one based on layers of flexible graphene sheets, each coated with a layer of nanowires. Besides flexibility, these sheets offer transparency, enabling their use on windows as well as other surfaces. David Chandler, reporting for MIT states that the new cells may prove to be far less expensive than today’s silicon equivalents, which require high-purity silicon that undergoes crystallization and extremely thin slicing. Alternatives use indium tin oxide (ITO), itself an expensive substitute for or adjunct to silicon. Nanostructured cells such as that from Princeton may allow lower-priced material, although one version uses a gold foil top layer. Silvija …
Fast Food for an Energy-Hungry Economy
Phil Savage, an Arthur F. Thurnau professor and a professor of chemical engineering at the University of Michigan, with Julia Faeth, a doctoral student in Savage’s University of Michigan laboratory, have unveiled a fast-cooking process that converts 65-percent of wet algae feedstock into biocrude in one minute. Considering that nature takes millennia to convert ancient flora and fauna into the raw materials of our energy economy, this decidedly quicker process might capture even the shortest of attention spans. The team investigated the hydrothermal liquefaction (HTL) of wet Nannochloropsis species algae, something like pressure cooking your vegetables, for a mere minute. This was enough to create a form of at least a biofuel precursor. The video exposes Dr. Savage’s skeptical view of electrical aircraft. As the University’s news item explains, “An hydrothermal process is one that involves water at elevated temperatures and pressures; hydrothermal liquefaction (HTL) is one of a number of methods for converting biomass conversion to biofuels or biofuel …
Going Over to the Dark Side
The University of Texas at Austin’s press release spells out the quantum-like behavior of photons striking solar cells, and provides some insight into why obtaining higher efficiencies so far has perplexed researchers. “AUSTIN, Texas — The efficiency of conventional solar cells could be significantly increased, according to new research on the mechanisms of solar energy conversion led by chemist Xiaoyang Zhu at The University of Texas at Austin. “Zhu and his team have discovered that it’s possible to double the number of electrons harvested from one photon of sunlight using an organic plastic semiconductor material. “’Plastic semiconductor solar cell production has great advantages, one of which is low cost,’ said Zhu, a professor of chemistry. ‘Combined with the vast capabilities for molecular design and synthesis, our discovery opens the door to an exciting new approach for solar energy conversion, leading to much higher efficiencies.’” Zhu and his team published their discovery December 16 in the journal Science, under the title …
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