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Green Chemistry

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'Green chemistry' using carbon dioxide, low-cost catalysts: New way of producing potent carbon–boron synthetic reagents

January 25th, 2013 in Chemistry / Materials Science
‘Green chemistry’ using carbon dioxide, low-cost catalysts: New way of producing potent carbon–boron synthetic reagents



In a new demonstration of ‘green chemistry’, researchers have used copper catalysts to turn waste carbon dioxide (CO2), alkyne molecules and boron complexes into a uniquely shaped ring system suitable for organic synthesis

Because carbon dioxide (CO2) gas is a freely available resource, there are concerted efforts worldwide to convert this molecule into a chemical feedstock. Zhaomin Hou and colleagues from the RIKEN Advanced Science Institute in Wako have made important progress toward this goal by developing the first protocol for attaching both CO2 and boron atoms to unsaturated carbon–carbon triple bonds. This procedure uses inexpensive organic–copper catalysts to construct valuable 'building blocks' for chemists under mild, one-pot conditions.

The strong double bonds inside CO2 make this molecule particularly inert and hard to use in most chemical reactions. Current tactics have focused on using transition metals to catalyze addition of electron-rich organic 'nucleophiles' to CO2's central carbon atom. This technique has successfully generated simple carboxylic acids. However, production of more complex substances containing non-hydrocarbon atoms has remained mostly out of reach.

Hou and his team used a groundbreaking approach to help turn CO2 into organoboron reagents—valuable synthetic compounds because of the wide number of transformations possible at carbon–boron bonds. First, they turned alkynes, molecules with carbon–carbon triple bonds, into nucleophiles. Nucleophilic species are highly reactive with many types of chemical groups but they are also difficult to control. To achieve necessary precision, the team used N-heterocyclic carbene (NHC) copper complexes, a hybrid organic/inorganic system with a strong track record of catalyzing CO2 additions.

X-ray experiments revealed that the strategy had paid off: NHC–copper complexes could indeed catalyze the addition of CO2 and diborane molecules to alkynes through a three-step catalytic insertion process. This reaction generates a final product with a unique, previously unknown cyclic structure containing a boron atom, a carbon–carbon double bond and a carboxyl group that the authors termed 'boralactone'.

By tweaking the structure of the NHC–copper catalyst, the researchers were able to apply the technique to a wide range of alkyne-type molecules with no side reactions. Intriguingly, the catalyst delivered the same geometric arrangement—high regio- and stereoselectivity—no matter which substituents were attached to the carbon triple bond. Hou explains that this advantageous behavior occurs because the diborane–catalyst complex always attacks the alkyne bond from a specific direction due to electronic interactions. Furthermore, the cyclic boralactone helps to drive this selectivity.

"Our reaction may serve as an attractive method for the synthesis of multifunctional alkenes, as it uses CO2 and easily available alkynes as building blocks with a relatively cheap copper catalyst," concludes Hou.

More information: References:
Zhang, L., Cheng, J., Carry, B. & Hou, Z. Catalytic boracarboxylation of alkynes with diborane and carbon dioxide by an N-heterocyclic carbene copper catalyst. Journal of the American Chemical Society 134, 14314–14317 (2012). pubs.acs.org/doi/abs/10.1021/ja3063474

Ohishi, T., Nishiura, M. & Hou, Z. Carboxylation of organoboronic esters catalyzed by N-heterocyclic carbene copper(I) complexes. Angewandte Chemie International Edition 47, 5792–5795 (2008). onlinelibrary.wiley.com/doi/10.1002/anie.200801857/abstract

Provided by RIKEN

"'Green chemistry' using carbon dioxide, low-cost catalysts: New way of producing potent carbon–boron synthetic reagents." January 25th, 2013. http://phys.org/news/2013-01-green-chemistry-carbon-dioxide-low-cost.html




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New Era in Aviation Begins: Continental, Alaska Air Fly on Biofuels

SustainableBusiness.com News


A new era in aviation begins this week as the first commercial flights run partially on algae-based and cooking oil-based jet fuels. 

And as airlines adopt biofuels, the first of many new "business categories" takes off - aviation biofuels broker - to arrange delivery of those fuels.

Today, Continental flew the first commerical flight on a blend of algae biofuels, and Alaska Airline Group announced that 75 commercial passenger flights in the US would be powered partly by used cooking oil, starting this Wednesday. 

Airbus estimates airlines may derive 30% of their fuel from plant-derived sources by 2030.

Airline executives and biofuel developers say they see huge potential for this new industry, but they need a reliable supply, which means supportive government policy to develop supply chains that can compete with petroleum.

Continental Flies from Houston to Chicago

Passengers on Continental's Flight 1403, departed at 10:30 AM running on a combination of Solazyme's (Nasdaq:SZYM) algae oil, which is refined into jet fuel, and conventional fuels. The Solajet fuel blend consists of 40% biofuel and 60% petroleum-based jet fuel. 

United Airlines, which owns Continental and is the world's largest airline, also signed a letter of intent with Solazyme to purchase 20 million gallons of algae-based jet fuel a year, starting in 2014. 

Solazyme, headquartered in south San Francisco, produced the world's first 100% algae-derived jet fuel for commercial and military applications. It manufactured the algae oil used on today's flight through a proprietary fermentation process, which was then refined into fuel near Houston using a process developed by Honeywell. 

"Today, roughly four months since the approval of hydroprocessed renewable fuels in commercial aviation, we are excited to see the deployment of these fuels on a domestic U.S. flight," says Air Transport Association of America) Vice President and Chief Economist John Heimlich. 

Continental says it's also improved fuel efficiency by more than  32% since 1994 by streamlining operations and investing in new airplanes that use 20% less fuel. And over 3600 alternative-fueled or zero-emission vehicles operate on the ground for United and Continental. 

75 Alaska Air Flights

Over the next two weeks, 75 flights between Seattle, Portland, Oregon and Washington DC will fly on 20% biofuel, starting on November 9. 

The biofuel used by Alaska Airlines and sister airline, Horizon Air, is a blend of used cooking oil. The company estimates the 20% blend will reduce greenhouse gas emissions 10%.

SkyNRG, an aviation biofuels broker, supplied the fuel, which is made by Dynamic Fuels, a $170 million joint-venture between Tyson Foods Inc. (NYSE: TSN) and Syntroleum Corp. (NASDAQ: SYNM). The company makes synthetic fuels from used cooking oil.

Saying he believes sustainable biofuels are key to aviation's future, Alaska Air Group CEO Bill Ayer comments, "Commercial airplanes are equipped and ready for biofuels. They will enable us to fly cleaner, foster job growth in a new industry, and can insulate airlines from the volatile price swings of conventional fuel to help make air travel more economical. What we need is an adequate, affordable and sustainable supply. To the biofuels industry, we say: If you build it, we will buy it."

"Aviation clearly needs a clean energy alternative to fossil fuels," says Boeing Commercial Airplanes Vice President of Environment and Aviation Policy Billy Glover. "In the U.S. and around the world, the industry is doing all it can to support sustainable biofuel development and maintain aviation's role in global economic growth. To make that happen we must develop regional supply chains, and that takes supportive government policies that encourage investment in the early stages of this emerging sector."

"Government policies supporting advanced biofuels are essential to ensure that the aviation biofuels industry reaches its full potential and is able to compete against foreign petroleum," says Bob Ames, Tyson Foods' vice president of renewable energy and member of the Dynamic Fuels management committee.

Alaska Air Group has been a partner in Sustainable Aviation Fuels Northwest, a 10-month regional stakeholder effort, which determed the Pacific Northwest has the feedstocks, delivery infrastructure and political will needed to create a viable biofuels industry.

In July, 2011, technical standards group ASTM International gave the airlines the go-ahead to incorporate biofuels into as much as 50% of the total fuel they use on passenger flights. They certified advanced biofuels as meeting the ASTM International specification for bio-derived aviation fuels, "Hydroprocessed Esters and Fatty Acids" (HEFA) fuel. 

The fuels underwent rigorous testing and review by engine and airframe manufacturers, the U.S. military, the FAA and airlines, and were found to have identical characteristics to  conventional jet fuel -- but cleaner. 

These advanced biofuels are drop-in replacements for petroleum-based fuel, requiring no modification to engines or aircraft. Pilots operate the aircraft the way they've always done and passengers won't sense any difference - no friench fry smell! 

In May, Solazyme was the first algae-to-fuels company to list on a major public market.

Sir Richard Branson announced last month that he would soon begin a pilot to prepare Virgin Atlantic Airways to run on waste gas-based fuel by 2014. The fuel is made from recycled industrial gases, which are captured from industrial steel production, and then fermented and chemically converted into jet fuel. 

Meanwhile, the airline industry, House Republicans, and the Obama Administration are fighting the EU on its requirement to participate in its cap-and-trade program, starting January 2012.

In August, President Obama announced a $510 million public-private partnership to produce advanced drop-in aviation and marine biofuels.



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Twelve Principles of Green Chemistry *


  1. Prevention
    It is better to prevent waste than to treat or clean up waste after it has been created.
  2. Atom Economy
    Synthetic methods should be designed to maximize the incorporation of all materials used in the process into the final product.
  3. Less Hazardous Chemical Syntheses
    Wherever practicable, synthetic methods should be designed to use and generate substances that possess little or no toxicity to human health and the environment.
  4. Designing Safer Chemicals
    Chemical products should be designed to effect their desired function while minimizing their toxicity.
  5. Safer Solvents and Auxiliaries
    The use of auxiliary substances (e.g., solvents, separation agents, etc.) should be made unnecessary wherever possible and innocuous when used.
  6. Design for Energy Efficiency
    Energy requirements of chemical processes should be recognized for their environmental and economic impacts and should be minimized. If possible, synthetic methods should be conducted at ambient temperature and pressure.
  7. Use of Renewable Feedstocks
    A raw material or feedstock should be renewable rather than depleting whenever technically and economically practicable.
  8. Reduce Derivatives
    Unnecessary derivatization (use of blocking groups, protection/ deprotection, temporary modification of physical/chemical processes) should be minimized or avoided if possible, because such steps require additional reagents and can generate waste.
  9. Catalysis
    Catalytic reagents (as selective as possible) are superior to stoichiometric reagents.
  10. Design for Degradation
    Chemical products should be designed so that at the end of their function they break down into innocuous degradation products and do not persist in the environment.
  11. Real-time analysis for Pollution Prevention
    Analytical methodologies need to be further developed to allow for real-time, in-process monitoring and control prior to the formation of hazardous substances.
  12. Inherently Safer Chemistry for Accident Prevention
    Substances and the form of a substance used in a chemical process should be chosen to minimize the potential for chemical accidents, including releases, explosions, and fires.

* Anastas, P. T.; Warner, J. C.; Green Chemistry: Theory and Practice, Oxford University Press: New York, 1998, p.30. By permission of Oxford University Press.



Eastman Cleans Up Chemicals in Makeup



KINGSPORT, TN —  Eastman Chemical Company announced this week the first cosmetic and skin care ingredient made with a process that cuts out harsh acids and uses less energy and water.

Called GEM technology, the process also fits into Eastman's plan to have more-sustainable chemicals and materials account for two-thirds of revenue from new products.

GEM, which won a U.S. EPA Presidential Green Chemistry Challenge award in 2009, uses enzymes instead of acids and solvents to make a key group of cosmetic and personal care ingredients called esters. 

Using enzymes eliminates the use of harsher manufacturing techniques and also cuts energy and water use. Making esters with strong acids requires high temperatures and creates byproducts that have to be removed, requiring more energy. Solvents that are used to make esters, meanwhile, are potentially hazardous to people and the environment.

GEM requires lower temperatures, thus using less energy, and also doesn't produce any unwanted byproducts. Since there are no unwanted impurities, colors or odors that form during the process, there's no need for purification or other clean-up processes. 

The technology creates half as much carbon dioxide emissions, uses about 60 percent less energy, generates almost no waste and uses no process water (it was previously only used during the purification stage), compared to other manufacturing techniques.

Eastman's first product to come out of the technology is GEM 2-ethylhexyl palmitate, an ingredient that can be used in color cosmetics and skin care products.

Eastman began working on GEM technology, previously referred to as Eastman's green biocatalytic process, in 2005 and molded it to follow the 12 principles of green chemistry, which call for using renewable raw materials, eliminating solvents where possible and making chemicals that will break down harmlessly in the environment.

Read more: http://www.greenbiz.com/news/2011/03/31/eastman-cleans-up-chemicals-makeup#ixzz1IHChVnAM




Mass. company making diesel with sun, water, CO2




CAMBRIDGE, Mass. – A Massachusetts biotechnology company says it can produce the fuel that runs Jaguars and jet engines using the same ingredients that make grass grow.

Joule Unlimited has invented a genetically-engineered organism that it says simply secretes diesel fuel or ethanol wherever it finds sunlight, water and carbon dioxide.

The Cambridge, Mass.-based company says it can manipulate the organism to produce the renewable fuels on demand at unprecedented rates, and can do it in facilities large and small at costs comparable to the cheapest fossil fuels.

What can it mean? No less than "energy independence," Joule's web site tells the world, even if the world's not quite convinced.

"We make some lofty claims, all of which we believe, all which we've validated, all of which we've shown to investors," said Joule chief executive Bill Sims.

"If we're half right, this revolutionizes the world's largest industry, which is the oil and gas industry," he said. "And if we're right, there's no reason why this technology can't change the world."

The doing, though, isn't quite done, and there's skepticism Joule can live up to its promises.

National Renewable Energy Laboratory scientist Philip Pienkos said Joule's technology is exciting but unproven, and their claims of efficiency are undercut by difficulties they could have just collecting the fuel their organism is producing.

Timothy Donohue, director of the Great Lakes Bioenergy Research Center at the University of Wisconsin-Madison, says Joule must demonstrate its technology on a broad scale.

Perhaps it can work, but "the four letter word that's the biggest stumbling block is whether it `will' work," Donohue said. "There are really good ideas that fail during scale up."

Sims said he knows "there's always skeptics for breakthrough technologies."

"And they can ride home on their horse and use their abacus to calculate their checkbook balance," he said.

Joule was founded in 2007. In the last year, it's roughly doubled its employees to 70, closed a $30 million second round of private funding in April and added John Podesta, former White House chief of staff under President Bill Clinton, to its board of directors.

The company worked in "stealth mode" for a couple years before it recently began revealing more about what it was doing, including with a patent for its cyanobacterium last year. This month, it released a peer-reviewed paper it says backs its claims.

Work to create fuel from solar energy has been done for decades, such as by making ethanol from corn or extracting fuel from algae. But Joule says they've eliminated the middleman that's makes producing biofuels on a large scale so costly.

That middleman is the "biomass," such as the untold tons of corn or algae that must be grown, harvested and destroyed to extract a fuel that still must be treated and refined to be used. Joule says its organisms secrete a completed product, already identical to diesel fuel or ethanol, then live on to keep producing it at remarkable rates.

Joule claims, for instance, that its cyanobacterium can produce 15,000 gallons of diesel full per acre annually, over four times more than the most efficient algal process for making fuel. And they say they can do it at $30 a barrel.

A key for Joule is the cyanobacterium it chose, which is found everywhere and is less complex than algae, so it's easier to genetically manipulate, said biologist Dan Robertson, Joule's top scientist.

The organisms are engineered to take in sunlight and carbon dioxide, then produce and secrete ethanol or hydrocarbons — the basis of various fuels, such as diesel — as a byproduct of photosynthesis.

The company envisions building facilities near power plants and consuming their waste carbon dioxide, so their cyanobacteria can reduce carbon emissions while they're at it.

The flat, solar-panel style "bioreactors" that house the cyanobacterium are modules, meaning they can build arrays at facilities as large or small as land allows, the company says. The thin, grooved panels are designed for maximum light absorption, and also so Joule can efficiently collect the fuel the bacteria secrete.

Recovering the fuel is where Joule could find significant problems, said Pienkos, the NREL scientist, who is also principal investigator on a Department of Energy-funded project with Algenol, a Joule competitor that makes ethanol and is one of the handful of companies that also bypass biomass.

Pienkos said his calculations, based on information in Joule's recent paper, indicate that though they eliminate biomass problems, their technology leaves relatively small amounts of fuel in relatively large amounts of water, producing a sort of "sheen." They may not be dealing with biomass, but the company is facing complicated "engineering issues" in order to recover large amounts of its fuel efficiently, he said.

"I think they're trading one set of problems for another," Pienkos said.

Success or failure for Joule comes soon enough. The company plans to break ground on a 10-acre demonstration facility this year, and Sims says they could be operating commercially in less than two years.

Robertson talks wistfully about the day he'll hop into the Ferrari he doesn't have, fill it with Joule fuel and gun the engine in an undeniable demonstration of the power and reality of Joule's ideas. Later, after leading a visitor on a tour of the labs, Robertson comes upon a poster of a sports car on an office wall, and it reminds him of the success he's convinced is coming. He motions to the picture.

"I wasn't kidding about the Ferrari," he says.





Turning bacteria into butanol biofuel factories

By Robert Sanders, Media Relations | March 1, 2011

BERKELEY —Michelle Chang's biofuels lab

Graduate student Brooks Bond-Watts and post-doctoral fellow Jeff Hanson examine cultured E. coli used to produce the biofuel n-butanol. (Photo by Michael Barnes)

University of California, Berkeley, chemists have engineered bacteria to churn out a gasoline-like biofuel at about 10 times the rate of competing microbes, a breakthrough that could soon provide an affordable and “green” transportation fuel.

The advance is reported in this week’s issue of the journal Nature Chemical Biology by Michelle C. Y. Chang, assistant professor of chemistry at UC Berkeley, graduate student Brooks B. Bond-Watts and recent UC Berkeley graduate Robert J. Bellerose.

Various species of the Clostridium bacteria naturally produce a chemical called n-butanol (normal butanol) that has been proposed as a substitute for diesel oil and gasoline. While most researchers, including a few biofuel companies, have genetically altered Clostridiumto boost its ability to produce n-butanol, others have plucked enzymes from the bacteria and inserted them into other microbes, such as yeast, to turn them into n-butanol factories. Yeast and E. coli, one of the main bacteria in the human gut, are considered to be easier to grow on an industrial scale.

While these techniques have produced promising genetically altered E. coli bacteria and yeast, n-butanol production has been limited to little more than half a gram per liter, far below the amounts needed for affordable production.

Chang and her colleagues stuck the same enzyme pathway into E. coli, but replaced two of the five enzymes with look-alikes from other organisms that avoided one of the problems other researchers have had: n-butanol being converted back into its chemical precursors by the same enzymes that produce it.

The new genetically altered E. coli produced nearly five grams of n-buranol per liter, about the same as the nativeClostridium and one-third the production of the best genetically altered Clostridium, but about 10 times better than current industrial microbe systems.

“We are in a host that is easier to work with, and we have a chance to make it even better,” Chang said. “We are reaching yields where, if we could make two to three times more, we could probably start to think about designing an industrial process around it.”

butanol biosynthetic pathway

The enzyme pathway by which glucose is turned into n-butanol is set against the silhouette of an E. coli bacterium. The pathway, taken from Clostridium bacteria and inserted into E. coli, consists of five enzymes that convert acetyl-CoA, a product of glucose metabolism, into n-butanol (C4H9OH).

“We were excited to break through the multi-gram barrier, which was challenging,” she added.

Among the reasons for engineering microbes to make fuels is to avoid the toxic byproducts of conventional fossil fuel refining, and, ultimately, to replace fossil fuels with more environmentally friendly biofuels produced from plants. If microbes can be engineered to turn nearly every carbon atom they eat into recoverable fuel, they could help the world achieve a more carbon-neutral transportation fuel that would reduce the pollution now contributing to global climate change. Chang is a member of UC Berkeley’s year-old Center for Green Chemistry.

The basic steps evolved by Clostridium to make butanol involve five enzymes that convert a common molecule, acetyl-CoA, into n-butanol. Other researchers who have engineered yeast or E. coli to produce n-butanol have taken the entire enzyme pathway and transplanted it into these microbes. However, n-butanol is not produced rapidly in these systems because the native enzymes can work in reverse to convert butanol back into its starting precursors.

Chang avoided this problem by searching for organisms that have similar enzymes, but that work so slowly in reverse that little n-butanol is lost through a backward reaction.

“Depending on the specific way an enzyme catalyzes a reaction, you can force it in the forward direction by reducing the speed at which the back reaction occurs,” she said. “If the back reaction is slow enough, then the transformation becomes effectively irreversible, allowing us to accumulate more of the final product.”

Chang found two new enzyme versions in published sequences of microbial genomes, and based on her understanding of the enzyme pathway, substituted the new versions at critical points that would not interfere with the hundreds of other chemical reactions going on in a living E. coli cell. In all, she installed genes from three separate organisms – Clostridium acetobutylicumTreponema denticola and Ralstonia eutrophus — into the E. coli.

Chang is optimistic that by improving enzyme activity at a few other bottlenecks in the n-butanol synthesis pathway, and by optimizing the host microbe for production of n-butanol, she can boost production two to three times, enough to justify considering scaling up to an industrial process. She also is at work adapting the new synthetic pathway to work in yeast, a workhorse for industrial production of many chemicals and pharmaceuticals.

The work was supported by UC Berkeley, the Camille and Henry Dreyfus Foundation, the Arnold and Mabel Beckman Foundation and the Dow Sustainable Products and Solutions Program.




Landfills Can Free Us from Petrochemicals



GE and Genomatica collaborate to produce chemical products from landfill gasThe gigantic waste hauling company Waste Management has been transforming itself into something of a jolly green giant, given its recycling operations, landfill gas recovery and sewage-to-biofuel ventures. In its latest move, company signed an agreement with the research firm Genomatica to develop processes for converting municipal landfill gas to basic chemical products that are in turn used to manufacture plastics and many other chemical products. It’s an important step forward for the green chemistry movement, which seeks to use renewable or non-toxic feedstocks in chemical manufacturing.

Chemicals from Syngas

Petroleum, natural gas, and gassified coal are conventional feedstocks forsyngas (synthetic gas), which can be burned as fuel or used to manufacture other products. Since biomass and waste materials can also be used to make syngas, there is a potential to shift away from fossil feedstocks and focus more on renewables. However, until now the process for converting syngas to other chemicals has been energy intensive and not widely applicable.

Energy Efficient Syngas from Landfills

Genomatica’s solution is an energy efficient, microbe-based process. It has proven successful on various renewable feedstocks including plain sugar. The company’s first product is “green” 1,4-butanediol, a chemical which is used to manufacture plastics. It is also the foundation for other chemical products. Now the challenge is to develop a microbe that is hardy enough to chew through gas produced from municipal solid waste.

New Life for Waste Gas

Municipal landfills aren’t the only places where renewable gas feedstocks can be harvested from waste. Over in New Zealand, a company called LanzaTech has developed a microbe-based process for converting waste gas from steel mills into ethanol. It sure makes a lot more sense to harvest chemical feedstocks from steel mills and landfills, rather than blowing up mountains or putting our coastal communities at risk.







Surfactants not organic solvents: green pressurised liquid extraction of bioactive flavonoids 


Pressurised liquid extraction: an opportunity to go green

The knowledge that there are hundreds of thousands of natural products sequestered away in plants, many with bioactive properties, drives the search for better extraction procedures. The majority of plant extraction procedures are dependent on relatively large volumes of organic solvent, which is contrary to the contemporary notion of best practice.

In the interests of the environment and health and safety, organic solvents are now frowned upon by an increasing number of scientists. They can be toxic and inflammable, bringing risks into the lab. Their disposal can also be a problem, although recycling can overcome that to some extent.

A better solution, in both senses of the word, is to use water, the solvent of choice for green chemistry. However, it has limited compatibility with many compounds due to its high polarity, so often needs to be moderated to achieve acceptable yields of natural products.

This is the case for the technique known as pressurised liquid extraction, an accelerated technique applied to solid matrices which employs a pressurised cell to reduce processing time and increase extraction yields. Water has been used as the solvent for PLE but scientists have shown that the addition of a very small percentage of surfactant can give yields as high as those using organic solvent.

Now, a team of researchers based in Singapore has applied surfactant-assisted PLE to the extraction of the principal flavonoids of an Asian medicinal plant, for subsequent analysis by micellar electrokinetic chromatography (MEKC), a combination that has not been reported to date.

Surfactant-assisted PLE matches Soxhlet extraction for ginger flavonoids

Swee Ngin Tan, Yong Qin Chang and Liya Ge from Nanyang Technological University and Jean Yong from the Singapore University of Technology and Design studied Costus speciosus, also known as crepe ginger, cultivated in some countries for medicinal uses and in others as an ornamental plant.

It is similar to other gingers in that it has been used to treat a range of ailments and illnesses, including dizziness, headache, fever, bronchitis, anaemia and diabetes, and surprisingly, both constipation and diarrhoea.

The researchers were interested in rutin, quercetin and quercitrin, which have been shown to be the beneficial bioactive components of the ginger species.

A small extraction cell measuring 25 cm long with an internal diameter of 10 mm was employed, providing a total volume of approximately 16-17 mL. Homogenised portions of dried flowers were mixed with sand and transferred to the cell to fill it completely.

The extraction was conducted with aqueous solutions of two surfactants, Triton X-100 or sodium dodecyl sulphate (SDS), which were forced through the material in the cell at a pressure of 20-30 bar. So long as the surfactants were above their critical micellar concentrations, micelles formed in solution which targeted hydrophobic and non-polar solutes in particular.

At the CMC, which are 0.2% by wt. and 0.03% by volume for SDS and Triton X-100, respectively, the extraction yields were the greatest. Higher concentrations of surfactant actually reduced the yields, due to the increased viscosity of the solutions.

After optimising each extraction, the efficiencies matched those obtained by Soxhlet extraction using organic solvent at elevated temperatures. SDS was found to be slightly more efficient than Triton X-100 for each of the three flavonoids.

Surfactant-assisted PLE extracts ideal for MEKC

The surfactant-based extracts were analysed directly by MEKC. The presence of SDS, borate and phosphate in the MEKC buffer helped to achieve baseline separation of the flavonoids from other extracted components and gave good resolution. The flavonoids were detected by UV absorption at 370 nm and their retention times were 10-15 minutes with an overall method precision of 7.5%.

The compatibility of the PLE extracts with the MEKC system disposed of a reconstitution step and eliminated completely the need for organic solvents. In addition, extraction was conducted at room temperature, which helps to reduce costs and prevents thermal degradation of any plant constituents.

The first combination of surfactant-assisted PLE with MEKC was effective for extracting flavonoids from the flowers of crepe ginger and should be applicable to other plant species, providing a rapid and green method for natural products studies.




A New Path For Waste Management: Trash-to-Chemicals




By Ucilia Wang Feb. 9, 2011, 1:21pm PST 


Trash king Waste Management will soon have new use for its waste: chemicals, courtesy of a new development partnership with green chemistry company Genomatica. The move is Waste Management’s latest, as it looks to expand the applications that can be made out of the municipal waste it collects, from biofuels to fertilizers to biogas.

Genomatica, based in San Diego, will engineer the organisms that will convert synthesis gas (syngas) produced from the trash into chemical compounds. The companies didn’t disclose the terms of the deal.

Genomatica’s researchers will make use of the patent secured last year to engineer organisms, such as E. coli, so that they can work with syngas, said Mark Burk, CTO of Genomatica. Burk declined to say what other organisms are under consideration by his team for the syngas conversion process.

Syngas can be made from a variety of sources, including natural gas, coal and biomass, and turned into electricity, fuels and other chemical compounds. Many companies are trying to produce ethanol using syngas made from renewable sources, such as wood chips, plants and trash. “Syngas is one of the most flexible and versatile feedstock from a wide range of materials – any organic matter can be gasified,” Burk said.

Genomatica, founded in 2000, already is using engineered E. coli to convert sugar into a chemical (1,4-butanediol, or BDO) that has been used to make spandex, running shoes and plastic auto parts. Genomatica has been running a pilot production of BDO in Michigan since last summer. The pilot facility can produce 3,000 liters of BDO, and the company plans to expand that to 10,000 liters this year, Burk said.

The company hasn’t announced customers yet for its BDO product and has taken 2.5 years to move from initial development to pilot. Genomatica has raised $40 million in venture capital from firm such as Alloy Ventures, Draper Fisher Jurvetson and Mohr Davidow Ventures.

There are basically two main ways to turn syngas into fuel or chemical additives: chemical catalysts, or organisms. Genomatica’s perspective is that chemical catalysts can lead to a more energy-intensive processes, and using organisms can be cheaper, less energy intensive, and can yield more chemical products. Other companies that are using organisms to convert syngas into products include Coskata and INEOS Bio, but Coskata and INEOS Bio are using naturally occurring organisms whereas Genomatica is developing engineered ones.

Waste Management has been actively lining up partners like Genomatica over the past year, and invested in trash to biofuel company Enerkem and will also provide trash to Fulcrum BioEnergy. Here’s a detailed look at Waste Management’s investment and innovation strategy.





14 Reasons Green Chemistry Works for Companies

Published February 10, 2011

14 Reasons Green Chemistry Works for Companies

WASHINGTON, DC — Fabric maker True Textiles saves some $300,000 a year by making its Terratex product out of recycled plastic and corn, which makes the material resistant to stains, odors and fire, meaning the company doesn't need to use harsh chemicals to impart those properties.

True Textiles is one of 14 companies covered in Environment America Research and Policy Center's new Safer by Design report, which lists companies' successes in adopting green chemistry practices in facilities, manufacturing processes and products.

True Textiles, though, started making Terratex in the '90s when it was still part of Interface, a company radically transformed by founder Ray Anderson. Not all companies have a Ray Anderson leading them, and they need more encouragement to move to greener chemical practices.

As the report points out, the companies and their efforts listed are exceptions in the business world, and Environment America adds its voice to the many who have been calling for policy reforms that would advance green chemistry efforts.

The example of True Textiles shows how green chemistry can lead to other positive impacts. By making material that is by itself stain-resistant and durable, the company doesn't need to use hazardous chemicals and also uses less water and energy during manufacturing.

The report also covers the different approaches BASF and Procter & Gamble took to reduce volatile organic compounds emissions from paint, various companies' screening programs to weed out unwanted chemicals, and what Apple, HP and Seagate are doing to take chemicals out of electronics.

Environment America concludes with calling for a number of policy measures: Require manufacturers to share more information on the potential hazards of the chemicals they use, require the phase-out of hazardous chemicals to ensure a market for safer alternatives, and make companies pay for the full health and environmental impacts of their pollution.

Read more: http://www.greenbiz.com/news/2011/02/10/14-reasons-green-chemistry-works-companies#ixzz1DfFpnoAc








Banking On Green Chemistry


Aiming for leadership in bio-based chemicals, PTT Chemical, Thailand's largest petrochemical producer, has invested $60 million in Myriant Technologies, a Quincy, Mass.-based firm that plans to build the world's largest bio-based succinic acid facility in Louisiana.

The investment is the second significant development in recent weeks for Myriant. Earlier this month, Louisiana Gov. Bobby Jindal announced the imminent start of construction on Myriant's succinic acid facility, in Port of Lake Providence. The $80 million plant will have annual capacity of 30 million lb of succinic acid made via fermentation of renewable raw materials.

What's more, the two firms have signed a letter of intent for a joint venture that will deploy Myriant's technology in Southeast Asia.

Today, most succinic acid is produced synthetically for small-volume uses in pigments, pharmaceuticals, and metal plating. Myriant and other proponents claim that biobased succinic acid can be made at a lower cost, opening big markets in plastics, fibers, and detergents.

PTT Chemical says the combination of its R&D capabilities and Myriant's technology will advance "the manufacturing of green chemicals using the abundant, high-quality biobased feedstock available in Thailand and the Asian region." The firm says the new venture is partly a response to a Thai government policy that encourages the private sector to set up bioplastics plants in the country. PTT Chemical's largest shareholder is PTT, Thailand's national oil company.

Several other companies are also developing bio-based succinic acid. Bioamber opened a demonstration-scale plant in France in 2009 and plans to ramp up production there to about 7 million lb per year by the end of 2011. BASF is working with Dutch firm CSM to isolate a new bacterium for succinic acid fermentation with an eye to starting production. And Reverdia, a joint venture between DSM and Roquette, plans to scale up from a demonstration plant in Lestrem, France.

Chemical & Engineering News
ISSN 0009-2347
Copyright © 2011 American Chemical Society



Green chemistry digs in on pollution


RESEARCH TRIANGLE PARK -- Research into how pollutants cause disease has come a long way since an industrial dump in the Love Canal neighborhood of Niagara Falls, N.Y., brought about legislation to clean up or cap the worst toxic spills in the United States.

But with cancer and other pollution-linked diseases continuing to be lethal health problems, sizable gaps remain in environmental health research more than 40 years after Love Canal.

To fill some of the holes, about 80 doctors, epidemiologists, chemists, lawyers, statisticians and politicians gathered last week at the N.C. Biotechnology Center.


The substances we create are not measured by their health impact," said Paul Anastas, assistant administrator of the Environmental Protection Agency's Office of Research and Development in RTP. "We need to step back and redefine performance, so we make better designs and reduce the potential of harm."

Anastas, who was appointed by President Barack Obama, is also known as the father of green chemistry.

Supporters of green chemistry are no longer satisfied with reducing the amounts of environmental toxins. pesticides and pollutants in water, air and soil one at a time. They also want to look at how people's health is affected by where they live and work, what they eat, drink and breathe, and how they feel.

Spurred by some of the changes the health care overhaul holds in store - particularly expanded insurance coverage and electronic medical records - green chemistry supporters in the EPA, universities and public health agencies are pushing to bring together databases and expertise from a broad range of scientific disciplines, including the social sciences, urban planning, transportation, epidemiology and medical research.

"We have to get over the old turf battles," said Thomas Burke, associate chair of the Johns Hopkins Bloomberg School of Public Health. "If we do it right, we ask the right questions."

First steps toward this holistic approach already exist.

One is the environmental health tracking system the Centers for Disease Control and Prevention launched in partnership with the EPA in 2002. Among the data collected for 24 states are asthma hospitalizations, birth defects, cancers and measurements for air and drinking water quality.

North Carolina is not among the 24 states contributing to the CDC tracking system. But according to Dr. Wayne Cascio, associate vice chancellor of research at East Carolina University, researchers in the state followed a similar, holistic spirit with surprising results two years ago.

By combining health statistics with data from the EPA and the National Oceanic and Atmospheric Administration, researchers determined that a 2008 massive wildfire in Eastern North Carolina led to an increase in the number of heart failures in the exposed areas.

Read more: http://www.newsobserver.com/2010/10/04/718865/green-chemistry-digs-in-on-pollution.html#ixzz11ObsNj9d

Read more: http://www.newsobserver.com/2010/10/04/718865/green-chemistry-digs-in-on-pollution.html#ixzz11Obo0VI9





Working Towards Greener Chemistry

September 8, 2010

Working Towards Greener Chemistry

Phosphorus, a mineral element found in rocks and bone, is a critical ingredient in fertilizers, pesticides, detergents and other industrial and household chemicals. Once phosphorus is mined from rocks, getting it into these products is hazardous and expensive, and chemists have been trying to streamline the process for decades.

MIT chemistry professor Christopher Cummins and one of his graduate students, Daniel Tofan, have developed a new way to attach phosphorus to organic compounds by first splitting the phosphorus with ultraviolet light. Their method, described in the Aug. 26 online edition of Angewandte Chemie, eliminates the need for chlorine, which is usually required for such reactions and poses health risks to workers handling the chemicals.

Guy Bertrand, chemistry professor at the University of California at Riverside, says the beauty of the discovery is its simplicity. "It is amazing to realize that nobody thought earlier about such a simple approach to incorporate phosphorus into organic molecules," he says. "Such a synthetic approach to organophosphorus compounds is indeed urgent, since the old (chlorine)-based phosphorus chemistry has a lot of undesirable consequences on our environment."

While the new reaction cannot produce the quantities needed for large-scale production of phosphorus compounds, it opens the door to a new field of research that could lead to such industrial applications, says Bertrand, who was not involved in the research.

Extracting phosphorus
Most natural phosphorus deposits come from fossilized animal skeletons, which are especially abundant in dried-up seabeds. Those phosphorus deposits exist as phosphate rock, which usually includes impurities such as calcium and other metals that must be removed.

Purifying the rock produces white phosphorus, a molecule containing four phosphorus atoms. White phosphorous is tetrahedral, meaning it resembles a four-cornered pyramid in which each corner atom is bound to the other three. Known as P4, white phosphorus is the most stable form of molecular phosphorus. (There are also several polymeric forms, the most common of which are black and red phosphorus, which consist of long chains of broken phosphorus tetrahedrons.)

For most industrial uses, phosphorus has to be attached one atom at a time, so single atoms must be detached from the P4 molecule. This is usually done in two steps. First, three of the atoms in P4 are replaced with chlorine, resulting in PCl3 — a phosphorus atom bound to three chlorine atoms.

Those chlorine atoms are then displaced by organic (carbon-containing) molecules, creating a wide variety of organophosphorus compounds such as those found in pesticides. However, this procedure is both wasteful and dangerous — chlorine gas was used as a chemical weapon during World War I — so chemists have been trying to find new ways to bind phosphorus to organic compounds without using chlorine.

A new reaction
Cummins has long been fascinated with phosphorus, in part because of its unusual tetrahedral P4 formation. Phosphorus is in the same column of the periodic table as nitrogen, whose most stable form is N2, so chemists expected that phosphorus might form a stable P2 structure. However, that is not the case.

For the past few years, Cummins' research group has been looking for ways to break P4 into P2 in hopes of attaching the smaller phosphorus molecule to organic compounds. In the new study, Cummins drew inspiration from a long overlooked paper, published in 1937, which demonstrated that P4 could be broken into two molecules of P2 with ultraviolet light. In that older study, P2 then polymerized into red phosphorus.

Cummins decided to see what would happen if he broke apart P4 with UV light in the presence of organic molecules that have an unsaturated carbon-carbon bond (meaning those carbon atoms are able to grab onto other atoms and form new bonds). After 12 hours of UV exposure, he found that a compound called a tetra-organo diphosphane had formed, which includes two atoms of phosphorus attached to two molecules of the organic compound.

This suggests, but does not conclusively prove, that P2 forms and then immediately bonds to the organic molecule. In future studies, Cummins hopes to directly observe the P2 molecule, if it is indeed present.

Cummins also plans to investigate what other organophosphorus compounds can be synthesized with ultraviolet light, including metallic compounds. He has already created a nickel-containing organophosphorus molecule, which could have applications in electronics.

SOURCE: Massachusetts Institute of Technology

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Green chemistry saves millions for Intel


A one-of-a-kind green chemistry formula is helping Intel save millions and creating tiny microprocessors — smaller than 50 nanometers — more effectively than ever.

These miniature microprocessors serve as the brains for today’s personal computers. They are smaller than 50 nanometers, or about 20 times smaller than a typical germ. They are made from more than 10 layers of different materials, which must be selectively removed as they are formed.

Nabil Mistkawi, Intel

Nabil Mistkawi

Intel first challenged a number of outside chemical companies and academic labs to find a way to remove metal layers in 2004. After a year of research, however, all were unable to do it. But it only took Nabil Mitskawi, a process engineer at Intel’s Hillsboro campus since 1993, three days to demonstrate the feasibility of a green chemistry concept that could work.

Mistkawi was a doctoral student at Portland State University at the time. He continued to refine the idea in the labs at Intel while working closely with the university and the U.S. Department of Energy’s National Energy Technology Laboratory in Albany.

The resulting "wet etching" method was first implemented in 2006 and scaled up in 2007. It is now part of manufacturing for all current generations of Intel microprocessors.

"Our ability to make this formulation in house saved Intel a significant amount of money," said Mistkawi. "Additionally, the fact that it's environmentally friendly provides further considerable savings, since disposal and waste management costs do not apply to this chemistry."

Mistkawi’s concoction is 98 percent water and contains no more fluoride than toothpaste. It dissolves certain metals while preserving essential wiring components and insulators in processing chips, yet the process is cleaner and more effective than typical chemical polishing. The green formula replaced the use of toxic solvents in some of the wet etching processes used to manufacture microprocessors. It is also fast — complete in two minutes.

The experience served as the basis for Miskawi’s doctoral dissertation, which he successfully defended this winter at Portland State University. He received his doctorate in chemistry in June.

"I like to have students work on projects that actually amount to something tangible," said Shankar Rananavare, faculty adviser to Mistkawi and research associate professor of chemistry at Portland State. "It’s one thing to make it work in a test tube and beaker. It’s quite another to do so at 8,000 gallons each week."

Lee van der Voo, lvdvoo*at*gmail.com, is a freelance writer for Sustainable Business Oregon.

Tags: Green chemistryGreen technologyManufacturingUniversity research

Companies: IntelNational Energy Technology LaboratoryPortland State UniversityU.S. Department of Energy

People: Shankar RananavareNabil Mitskawi



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