Monthly Archives: June 2012

Purdue university votes for sorghum biofuel

Researchers from Purdue University believe that sorghum should be considered as the next generation biofuel. Their article is published online in the journal Biofuels, Bioproducts & Biorefining.

Next generation biofuels are biofuels produced from sustainable feedstocks. Many of these biofuels are currently under development such as algae fuel, biohydrogen, biomethanol, DMF, BioDME, Fischer-Tropsch diesel, biohydrogen diesel, mixed alcohols and wood diesel. Purdue University scientists believe sweet and biomass sorghum are environmentally sustainable, easily adopted by producers and take advantage of existing agricultural infrastructure, which could make them the next big thing.


Sorghum is a kind of grass that was originally cultivated during ancient times in Egypt. The largest producers of sorghum in the modern era are still in Africa, although the crop has spread to southern Asia and the Americas as well. Sorghum is a tall plant, it grows over 6 ft (2 meters), although many varieties designed for cultivation are dwarf breeds, specially designed for easy harvest. Sweet sorghum is grown especially for the manufacture of syrup, but can also provide grain and fibers. Sorghum can tolerate heat well and is therefore suitable to be grown in dry areas. It can produce twice as much of bio-ethanol than sugar cane when using the same amount of water.

Another benefit is that sweet and biomass sorghum uses less nitrogen than corn. Corn has been bred to produce a maximum amount of seed, requiring a lot of nitrogen. But sorghum could be genetically developed in a way that maximizes cellulose, minimizes seeds and therefore, minimizes inputs. Sorghum could fit in with a normal crop rotation, unlike the perennials that would take up a field for a decade or longer, such as switchgrass or Miscanthus. Farmers are familiar with the crop and an infrastructure for sorghum production and processing already exists, making it a more cost-effective option.

According to Purdue researchers sorghum is not the ultimate answer to the problems facing the world of biofuels. They do think it deserves more attention as biofuel than it is getting now. Bringing sorghum back as a biofuel crop could also have an economic impact on poorer rural areas, that way it could be twice as useful.

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Why not paint them blue?

Photo by Booyia

Last year we wrote a piece about painting your roof white in order to make it more energy efficient. White roofs absorb less heat than dark roofs, so it will help you keep your house cool. It’s even reckoned to reduce peak rooftop temperatures in summer by an average of 43 degrees Fahrenheit (about 24 degrees C) according to a study that came out earlier this year. Now Researchers at Oregon State University have discovered a chemical compound, a “cool blue” pigment that also has notable heat reflecting properties.

Lighter pigments are generally better when it comes to reflecting heat than dark colors. They usually absorb more heat. But some compounds, like this one discovered at Oregon State University, have dark tones but also the ability to reflect heat in the infrared spectrum, which is responsible for most of the heat energy absorbed from sunlight. The scientist came across this ‘cool blue’ by accident while they were doing research on manganese compounds for their electrical properties. The pigment has infrared heat reflectivity of about 40 percent, which is significantly higher than most blue pigments now being used according to professor Subramanian from Oregon State University. Existing blue pigments are found to be toxic, expensive or decay quickly. Going back as far as the times of the Egyptians, the Han dynasty and Mayan cultures people have expiremented with blue pigment. But this one is apparently more durable, safe for the environment and easy to produce. The compound is now being cleared for a patent.

The pigment could be used on the roofs and walls of buildings to help reduce heat absorption with several energy efficiency benefits. In addition to easing the heat island effect in heavily populated areas they think it would lower peak energy demand and and reduce air pollution from power plant emissions. It is less affected by thermal degradation and more aesthetically pleasing than traditional roofing materials colors. Painting your roof white might not be to everyones liking and is not always a possibility due to zoning laws and regulations, so blue could be a good alternative in the nearby future. The university is momentarily looking for liscensing partners.


First solar intercontinental flight becomes reality

Last Tuesday a solar energy plane flew from Europe to North Africa, completing the world’s first intercontinental flight powered by the sun.

The plane, the Solar Impulse, is a 100% solar-powered Swiss plane is derived from a project with the same name being undertaken at the École Polytechnique Fédérale de Lausanne. The single-seat aircraft is fitted with 12,000 solar cells across a wingspan of sixty-four metres, but only weighs as much as the average family car, according to organizers. It charges 400kg lithium polymer batteries during the day and can fly after dark on the power. The project, started in 2003, is led by Bertrand Piccard, who piloted the flight on Tuesday, along with André Borschberg.

The Solar Impulse took off from Madrid in Spain, before crossing the Mediterranean and landing in Morocco, after an almost 20-hour trip. It made its first international flight last month when it completed a 13-hour flight from the western Swiss town of Payern to Brussels.

The plane can only fly in perfect weather and has succeeded in climbing to 28,000 feet. With an average flying speed of 70 km/h, this doesn’t make it the perfect alternative for commercial jets. “The question is not to use solar power for normal aeroplanes,” Piccard told Sky News. “The question is more to demonstrate that we can achieve incredible goals, almost impossible goals, with new technologies, without fuel, just with solar energy, and raise awareness that if we can do it in the air, of course everybody can do it on the ground.”

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Hydrodynamic forces to clean water

The Palo Alto Researh Centrer (PARC) has developed a new filterless technology for making clean water in wastewater plants. 

The Palo Alto Research Center, set up in 1970 by Xerox, is a research and development company responsible for important developments such as laser printing, Ethernet, the modern personal computer and graphical user interface (GUI). After three decades as a division of Xerox, PARC was transformed in 2002 into an independent, wholly owned subsidiary R&D company in Sillicon Valley. It has a few areas of focusincluding clean technology and solar.  Now they’ve made a breakthrough in clean water technology. They have been using Xerox’s know-how in working with small pieces of plastic, namely the bits of toner inside a printer, and applying that to figuring out how to take dirt out of water. 

The technology developed by PARC is called Hydrodynamic Separation (HDS). The separation solution is based on a simple concept: the system pumps water through a spiral tube to seperate unwanted particles. Controlled by centrifugal and hydrodynamic forces these particles are moved towards one wall of the tube where they can be split off to a waste stream. This enables a continuous flow seperation of clean effluent from the waste stream. The system is said to be capable of high rates of flow, use low energy (or use a gravity-fed source), and because of its compact size and modular design, can be scaled up or down to fit the site.

According to PARC This separation system could transform the ways in which water is treated for various uses including: desalination pre-treatment, produced water treatment, algae de-watering, cooling tower water treatment.Parc plans to work with partners to scale up and commercialize this water treatment technology. 

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