Monday, June 22, 2015

Article: MIT Students Create A Brick That Could End Pollution From Dirty Brick Kilns

We use a lot of bricks. Making them, though, is pretty bad. The Eco BLAC brick is made with waste ash and requires no firing at all. India's brick industry, spread out over 100,000 kilns and producing up to 2 billion bricks a year, is a big source of pollution. To fire to hot temperatures, the ki...

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UCLA discovers how solar cells' charges can last for weeks


30,000 Lux

Solar cells have always been inspired by photosynthesis, so it's only natural for researchers to take cues from different aspects of the energy-making process. A team of UCLA chemists, for instance, have developed a way that will allow solar cells to keep their charge for weeks instead of just a few seconds like current products are capable of. According to Sarah Tolbert, UCLA chem professor and one of the study's authors, they looked into plants' nanoscale structures that can keep negatively charged molecules separated from positively charged ones. "That separation is the key to making the process so efficient," she said.

The team has discovered that in order to mimic those nanoscale structures in plastic solar cells (which are potentially cheaper to make than silicon-based ones), they need to use two components: a polymer donor and a nano-scale fullerene acceptor. The team describes the process as follows:

The UCLA technology arranges the elements more neatly -- like small bundles of uncooked spaghetti with precisely placed meatballs (see image below). Some fullerene meatballs are designed to sit inside the spaghetti bundles, but others are forced to stay on the outside. The fullerenes inside the structure take electrons from the polymers and toss them to the outside fullerene, which can effectively keep the electrons away from the polymer for weeks.

In short, those two can form the right "noodle and meatball" structure to keep different charges away from each other for days to weeks, greatly improving a cell's capability to retain power. It's also a plus that the components can auto-assemble, simply by putting them in water. The ability to store energy is a big deal for solar energy systems, since they need to be able to save enough power to use at night or during days when the sun isn't shining as brightly. UCLA's technology isn't quite ready yet, but Tolbert and her team are already trying to figure out how to incorporate it into real solar cells.

[Image credit: Jason A. Samfield/Flickr, UCLA Chemistry]

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Source: UCLA, Science


Friday, June 5, 2015

High-yield yeast converts 97 percent of a plant's sugars to biofuel


Operations At Usina da Mata Ethanol, Sugar and Energy Plant As Brazil Expands Ethanol Tax Credit

The Department of Energy's BioEnergy Science Center announced a major breakthrough in the biofuel field yesterday: a newly developed strain of yeast capable of producing more than three times the amount of fuel from plant matter as the current record holder. The Center has teamed with Mascoma LLC to develop the new strain, dubbed C5 FUEL. Existing biofuel yeast strains generally only convert about 30 percent of a plant's sugars and cannot effectively convert tough xylose sugars. C5 however can ferment up to 97 percent of plant sugars into ethanol, including the xylose that other strains can't break down. What's more, it does all that in just 48 hours as opposed to the multiple days or weeks that other strains require.

Update: The headline of this post has been updated to clarify that it's 97 percent of a plant's sugars the team is claiming to convert into biofuel, not 97 percent of the entire plant.

The BESC team presented its findings at the 31st International Fuel Ethanol Workshop in Minneapolis on Thursday morning. They hope that the discovery will help make ethanol-based biofuels more accessible to the consumer market. "Driving down the cost to develop, verify and consolidate bioprocessing was at the heart of the BESC effort when we began in 2007, and this achievement allows us to advance to the next challenge," BESC Director Paul Gilna said in a statement. "This accomplishment represents a clearly impactful example of how our partnering with industry can accelerate the translation of our research capabilities and findings into commercial products." Up next, the BESC hopes to perform the same biochemical gymnastics with thermophilic bacteria, which would produce fuel directly from biomass in just one step.

[Image Credit: Bloomberg via Getty Images (Top) - ORNL (inline)]