NOV 26

Super-Efficient Solar Water Desalination

Written by on November 26, 2014


A novel approach to desalinating water could be very beneficial in providing fresh water for many parts of the world needing clean water.  This is a relatively inexpensive process which uses graphite to use solar energy far more efficiently than ever before.

Desalination is an important way to provide fresh water in many parts of the world, but it is usually an extremely energy intensive process.  In order to produce fresh water, the brackish water must be heated to produce steam, which leaves the salts behind.  Then, the steam is condensed to yield clean water.

Solar power would seem to be ideal for this application, but, until now, it has required intense concentration of sunlight in order to produce the heat needed to boil the water.

The method developed by Dr. Hadi Ghasemi at the University of Houston first microwaves graphite for a few seconds, causing it to fracture and pop “like popcorn.”  This material floats on top of a container of water and draws small amounts of water up through capillary action.  The pores in the material serve to further concentrate solar energy on those small amounts of water, causing it to steam.  Since the solar energy is concentrated on just the top layer, the rest of the water stays cool, so far less energy is needed to produce the steam.

This allows cheaper and simpler equipment to be used to concentrate the solar energy and makes for a simpler system to produce clean water.  And graphite is a cheap and plentiful material, which also makes this a promising technology.

via: BoingBoing and NPR

NOV 25

Better Cement for Construction with Less CO2

Written by on November 25, 2014


Greener cement for construction may be already well within reach, based on a new study carried out by researchers from MIT in the United States and CNRS in France.  While modern-day cement has its roots extending back to the mid-1700s, the ratios of the two main ingredients, calcium (from limestone) and silica (from clay), which are used to manufacture it can vary widely, and had not been studied to this extent before.

The potential reduction in carbon emissions from the production of cement could be as much as 60 percent, according to Dr. Roland Pellenq, the senior research scientist for the study.  The production of cement is presently one of the largest contributing industrial sources of CO2 in the atmosphere.  Consequently, changes in its manufacture could have significant and widespread benefits if a better production method is developed.

“In conventional cements, Pellenq explains, the calcium-to-silica ratio ranges anywhere from about 1.2 to 2.2, with 1.7 accepted as the standard. But the resulting molecular structures have never been compared in detail. Pellenq and his colleagues built a database of all these chemical formulations, finding that the optimum mixture was not the one typically used today, but rather a ratio of about 1.5.”  Production of cement at this ratio would, according to the researchers, allow significant reductions in CO2 emissions.  In addition to the emissions benefit, the researchers also found that cement produced at this ratio would be stronger and more fracture resistant.

Adaptation of this research will still take time to implement, as the new formulations will need to be studied by engineering standards organizations before this becomes the new standard for manufacture.

There could even be a synergistic benefit in this, by significantly reducing the carbon emissions in the production of the cement, and then further reducing emissions due to less cement being needed due to the improved strength of the material.

via: MIT Press Release

image credit: Phlat Phield Photos

NOV 23

Electric Turbochargers to Improve Engine Efficiency

Written by on November 23, 2014

In the ongoing quest to improve, electrically powered turbochargers may be the next step in increasing engine efficiency for automobile engines.  The first such to be included in a production model is slated to come in 2016 from Audi on its SQ7 SUV.

Turbo boost has been a popular way of increasing the power of an engine without increasing its size.   Ford’s EcoBoost is an example of this approach, using 3-, 4-, and 6-cylinder engines in vehicles which had previously used larger engines.  Turbocharging an engine increases the amount of air, and therefore fuel, being fed into the engine, providing better performance from a smaller-sized engine.

Conventional turbos use exhaust gasses to spin the turbine that forces more air into the engine.  This is efficient, but it produces “turbo lag” as the engine needs to increase speed in order to develop the boost.  But an electric turbo can respond almost instantaneously, providing added power without any delay.  Furthermore, as Green Car Reports notes, “a more responsive turbo will help the engine produce more low-end power, meaning drivers won’t have to venture higher into the rev range–and increase fuel consumption–as much.”

This becomes a more viable option with the increased computerization of engine control systems, which can read the driving conditions and trigger small amounts of boost as needed.

Whichever kind of turbo is used, the benefits come from having a smaller engine, both in terms of the overall displacement of the cylinders, as well as the mass of the engine itself.  Smaller engines mean less weight the car has to move, which helps in efficiency.  And the smaller displacement means less fuel is routinely used, while the power that would have been available is still there, thanks to the boost of the turbo.

via:  Gas 2.0

image credit: Wikipedia/NASA


Nobel Prize Awarded for Blue LEDs

Written by on October 7, 2014

The Nobel Prize in physics this year has been awarded to three scientists, Isamu Akasaki, Hiroshi Amano, and Shuji Nakamura, for their work in the development of the blue LED.

LEDs were first developed in the early 20th Century, and the first practical, commercial LEDs were brought to the market in the 1960s.  However, the earliest LEDs were red or orange.  The development of blue LEDs was crucial to the ability to make “white light” LEDs, which combine blue, green, and red (or sometimes blue and yellow) to create an acceptable light source for general illumination.  The high efficiency of LED light bulbs and LED displays which we enjoy today stems from this research work.

As the Nobel committee noted, “As about one fourth of world electricity consumption is used for lighting purposes, the LEDs contribute to saving the Earth’s resources.”  With the increased use of LEDs for lighting, demand for electricity is reduced.  We salute these three as EcoGeeks of the highest order.

link: Nobel Foundation Press Release

image: CC BY-SA 3.0 by Gussisaurio/Wikimedia Commons


Fuel-Free Plastics Manufacturing

Written by on October 6, 2014


Plastics manufacturing is typically a double consumer of petrochemicals, using them for both feedstock for the products, as well as fuel to provide the needed energy for the process.  But a greener method from LightManufacturing provides a system with low initial costs and low operating costs to manufacture molded plastic objects without the need for any fossil fuels.  The process is even applicable with recycled plastic feedstock, making it an even greener process.

Using heliostats to concentrate and reflect the sun’s rays provides the heat imput needed in order to melt the plastic and make it moldable.  This eliminates the largest need for fossil fuel in the process.  But also, the molding equipment itself is powered from solar panels on the roof of the molding chamber, which allows the whole process to be completely off-grid and entirely solar powered.

In addition to the benefit of having plastic manufacturing without fossil fuels, this also could allow developing countries without an extensive power infrastructure to have this kind of manufacturing capacity domestically, instead of relying on imports for finished goods.

video link: Solar powered plastics molding

via: Solar Thermal Magazine


Navy Demonstrates Fuel From Seawater Production

Written by on May 7, 2014

A team of US Navy research scientists has developed a method to produce liquid fuel from seawater, using CO2 and hydrogen extracted from the ocean and then processed with a metal catalyst to produce liquid fuel. As a demonstration of the concept, an unmodified scale airplane has been flown with the seawater fuel.

The concentration of CO2 is about 140 times higher in seawater than it is in the atmosphere. Carbon dioxide and hydrogen are the two feedstocks needed to make hydrocarbons. The process relies on “an iron-based catalyst [which] has been developed that can achieve CO2 conversion levels up to 60 percent and decrease unwanted methane production in favor of longer-chain unsaturated hydrocarbons (olefins).” The process is claimed to be the first technology of this type with the potential for commercial implementation.

“The predicted cost of jet fuel using these technologies is in the range of $3-$6 per gallon, and with sufficient funding and partnerships, this approach could be commercially viable within the next seven to ten years.”

video clip: Flight with Seawater Fuel

image credits: U.S. Naval Research Laboratory

APR 16

Ontario Completely Off Coal

Written by on April 16, 2014

The Canadian province of Ontario has officially shut down its last coal burning power plant.

Power for the province now comes from “emission-free electricity sources like wind, solar, nuclear and hydropower, along with lower-emission electricity sources like natural gas and biomass.” The province had set a target of the end of 2014 to end its use of coal to generate electricity.

The Thunder Bay Generating Station was the last coal fueled power plant in the province. Now that it has burned the last of its coal supply, the plant will be converted to a biomass-fueled power plant.

image: CC 2.0 by Kyle MacKenzie

Hat tip to @TomMatzzie

APR 12

CETO Produces Wave Power and Freshwater

Written by on April 12, 2014

A new, grid-tied offshore wave energy project called CETO is being readied off the west coast of Australia, near Perth. Carnegie Wave Energy is installing what is called the “first operating wave energy array scheme in the world.” The installation will consist of three submerged buoys 11 meters (36 feet) in diameter, which will be anchored offshore. The buoys will create high pressure water which will be pumped to an onshore generating station to produce electricity.

In addition to producing power, the CETO technology incorporates an interesting synergy – it is also used to provide fresh water. The system provides for more efficient desalination of seawater, since the water is already being pumped onshore from the buoys. Once it has powered the turbines, some of the water can be diverted into conventional desalination equipment. For regions in need of water desalination, the combination is ideal, and additional energy is not required for pumping water in from the sea.

The submerged operation of the CETO buoys helps provide storm survival capacity for the buoys and keeps the bouys out of view to minimize visual impact.

In comparison to wind turbines, the CETO system is small-scale. Each buoyant actuator has a rated capacity of 240 kW, so the installation being built will have less than 1 MW of capacity, whereas many current wind turbines have individual capacities of several mwgawatts. Nonetheless, it is another step forward for another energy generating technology. Carnegie hopes to expand commercialization of this technology and is targeting having 1000 MW of capacity installed by 2020.


Nontoxic Flame Retardants from Whey

Written by on April 2, 2014

Whey is generally a waste byproduct from cheese- and yogurt-making. Producers need to find ways to dispose of it, and often it is discharged into wastewater systems. Research at the Polytechnic University of Turin is being done to explore the use of whey as a replacement for toxic compounds used as flame retardants.

Treated fabrics are kept from burning as readily because the casein from whey forms a layer of char on the surface when it is exposed to heat, which prevents the fire from spreading as readily. Tests on cotton and polyester materials often self-extinguished, and tests on cotton-polyester were also inhibited and burned more slowly.

While the tests have been promising, the process is not yet ready for commercialization because “the cheese-treated fabrics stink.” But, if the compounds that cause the odor can be removed, this can be a technology to remove more harmful chemicals from common use and make use of a waste product at the same time. And, it could give the word “cheesecloth” a whole new meaning.

image: CC BY-SA 3.0 by Oscar/Wikimedia Commons

via: Environmental Building News

MAR 27

Making Bio-Based Rocket Fuel

Written by on March 27, 2014

Rocket fuel is the latest in a long line of fuels being developed from bio sources instead of being produced from petrochemicals. Numerous other fuels have been developed from bio-diesel and synthetic gasolines to aviation fuels are now being made from microorganisms or from converting bio feedstocks. And now, scientists from the Georgia Institute of Technology and the Joint BioEnergy Institute have been able to produce a key component of JP-10 high energy fuel from bacterial sources.

Pinene is a component that is used in fuels that are used for missiles and rockets. It is found in tree sap, but it is primarily extracted from crude oil. Since only a small amount of pinene can be produced from each barrel of crude oil, it is expensive and difficult to obtain.

The researchers developed strains of E. coli which has been able to produce small quantities of pinene in the laboratory. There are still further steps to take before this becomes scalable and commercially viable, but the initial development has been the major milestone, and researchers on the project expect to be able to further improve the process as they continue their work.

There is also a much stronger economic drive to develop bio-based rocket fuel as compared to other fuels. At present, petroleum-based JP-10 costs about $25 per gallon, so a difference of a dollar or two per gallon could be significant, as well as being able to produce fuel for space travel without needing ot rely on petrochemical sources.

image: CC BY-SA 3.0 by Image courtesy of SpaceX/Wikimedia Commons

via: Solar Thermal Magazine