Researchers potentially find a renewable path to fuel additives, rubber and solvents

The right balance of zinc and zirconium oxides in this catalyst (purple block) converts ethanol to isobutene with low amounts of unwanted byproducts such as acetone and ethylene.

RICHLAND, Wash. – Researchers in the Pacific Northwest have developed a new catalyst material that could replace chemicals currently derived from petroleum and be the basis for more environmentally friendly products including octane-boosting gas and fuel additives, bio-based rubber for tires and a safer solvent for the chemicals industry.

To make sustainable biofuels, producers want to ferment ethanol from nonfood plant matter such as cornstalks and weeds. Currently, so-called bio-ethanol’s main values are as a non-polluting replacement for octane-boosting fuel additives to prevent engine knocking and as a renewable replacement for a certain percentage of gasoline. To turn bio-ethanol into other useful products, researchers at the Department of Energy’s Pacific Northwest National Laboratory and at Washington State University have developed a new catalyst material that will convert it into a chemical called isobutene. And it can do so in one production step, which can reduce costs.

Reported by researchers in the Institute for Integrated Catalysis at PNNL and in the Gene and Linda Voiland School of Chemical Engineering and Bioengineering at WSU, the findings appeared July 21 in the Journal of the American Chemical Society.

“Isobutene is a versatile chemical that could expand the applications for sustainably produced bio-ethanol,” said chemical engineer Yong Wang, who has a joint appointment at PNNL in Richland, Wash. and at WSU in Pullman, Wash., and leads research efforts at both institutions.

In addition, this catalyst requires the presence of water, allowing producers to use dilute and cheaper bio-ethanol rather than having to purify it first, potentially keeping costs lower and production times faster.

No Z-Z-Z for the Weary

An important key to unlocking renewables to replace fossil fuel products is the catalyst. A catalyst is a substance that promotes chemical reactions of interest. The catalytic converter in a car, for example, speeds up chemical reactions that break down polluting gases, cleaning up a vehicle’s exhaust.

The PNNL and WSU researchers were trying to make hydrogen fuel from ethanol. To improve on a conventional catalyst, they had taken zinc oxide and zirconium oxide and combined both into a new material called a mixed oxide — the zinc and the zirconium atoms woven through a crystal of oxygen atoms. Testing the mixed oxide out, PNNL postdoctoral researcher Junming Sun saw not only hydrogen, but — unexpectedly — quite a bit of isobutene (EYE-SO-BEW-TEEN).

Hydrogen is great, but isobutene is better. Chemists can make tire rubber from it or a safer solvent that can replace toxic ones for cleaning or industrial uses. Isobutene can also be readily turned into jet fuel and gasoline additives that up the octane — that value listed on gas pumps that prevents an engine from knocking — such as ETBE.

Sun Shines

No one had ever seen a catalyst create isobutene from ethanol in a one-step chemical reaction before, so the researchers realized such a catalyst could be important in reducing the cost of biofuels and renewable chemicals.

Investigating the catalyst in greater depth, the researchers examined what happened when they used different amounts of zinc and zirconium. They showed that a catalyst made from just zinc oxide converted the ethanol mostly to acetone, an ingredient in nail polish remover. If the catalyst only contained zirconium oxide, it converted ethanol mostly to ethylene, a chemical made by plants that ripens fruit.

But the isobutene? That only arose in useful amounts when the catalyst contained both zinc and zirconium. And “useful amounts” means “a lot.” With a 1:10 ratio of zinc to zirconium, the mixed oxide catalyst could turn more than 83 percent of the ethanol into isobutene.

“We consistently got 83 percent yield with improved catalyst life,” said Wang. “We were happy to see that very high yield.”

Reactionary Insight

The researchers analyzed the chemistry to figure out what was happening. In the single metal oxides experiments, the zinc oxide created acetone while the zirconium oxide created ethylene. The easiest way to get to isobutene from there, theoretically speaking, is to convert acetone into isobutene, which zirconium oxide is normally capable of. And the road from ethanol to isobutene could only be as productive as Sun found if zirconium oxide didn’t get side-tracked turning ethanol into ethylene along the way.

Something about the mixed oxide, then, prevented zirconium oxide from turning ethanol into the undesired ethylene. The team reasoned the isobutene probably arose from zinc oxide turning ethanol into acetone, then zirconium oxide — influenced by the nearby zinc oxide — turning acetone into isobutene. At the same time, the zinc oxide’s influence prevented the ethanol-to-ethylene conversion by zirconium oxide. Although that’s two reaction steps for the catalyst, it’s only one for the chemists, since they only had to put the catalyst in with ethanol and water once.
More on New Catalyst For Ethanol Made From Biomass

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 Clostridium to 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 native Clostridium 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 acetobutylicum, Treponema 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.

UC Berkeley

The World’s Only Web-Based Biofuels Exchange Opens Today

Denver, CO (10/28/10). The US Biofuels Exchange, “the US-BX”, has opened today for live Ethanol and Biodiesel trading and will offer free trading on all listings posted before January 1, 2011. The US-BX’s web address is www.us-bx.com.

The US-BX’s proprietary “two-sided” trading platform was designed with direct input from Biofuels industry professionals, including Ethanol Producers, Biodiesel Producers, Biofuels Brokers and Petroleum Marketers. It is the most exciting, efficient and cost effective way to buy and sell Biofuels worldwide.

Allowing registered users to Post, Buy, Sell and Make Offers on and to both “Lot For Sale” and “Lot Wanted” listings, certifies that the US-BX is truly a disruptive innovation that will forever change the way Biofuels are bought and sold; the ultimate sales and procurement tool, bringing unmatched efficiency and cost effectiveness to a traditionally limited and outdated trading method.

And since the US-BX is web-based and utilizes “Cloud Computing” standards, no software needs to be purchased, downloaded or installed on the user’s computer. This allows accounts to be accessed and trades conducted from any computer on earth.

“We’re more than pleased to be the world’s only web-based Biofuels Exchange. We offer Biofuels Producers, Brokers, Blenders, Distributors, Importers, Exporters and Marketers the ability to anonymously buy and sell Ethanol and Biodiesel as well as the ability to make, receive and choose between multiple offers on listings,” said US-BX Vice President James Kaufman.

Kaufman added, “We believe the US-BX will create more consistent national pricing, increased price stability as well as expanded sales and purchasing opportunities, ultimately becoming a vital factor in the overall health and growth of the entire Biofuels Industry.”

Kind of jammed up here today trying to get out of town next week for vacation but got work of this initiative being done by Qatar Airways and thought I should get something up on it right now. I will come back and do an interview with them for you later but for now please read this info on alternative fuels in jets.

Taking Leadership in the Application of Cleaner Alternative Fuels Qatar Airways is a travel industry innovator in the study of the potential commercial use of jet fuel derived from natural gas as a means of reducing the impact of aviation on local and global air quality.

We have partnered with companies such as Qatar Petroleum, Shell, Airbus, Rolls Royce, Qatar Science & Technology Park and Woqod with the view to test the use of cleaner burning alternative fuels on commercial flights. Qatar Airways and its partners are striving to make a jet fuel blend including Gas to Liquids kerosene a cleaner-burning fuel of choice for the air transport industry in the future.

The world’s largest Gas to Liquids production plant is currently under construction in Qatar under a development and production sharing agreement between Qatar Petroleum and Shell, with production scheduled to start around the end of the decade. Qatar Airways aims to be the first airline in the world to operate a commercial flight using jet fuel containing Gas to Liquids kerosene.

In February 2008, an Airbus A380 conducted the first test flight of a commercial aircraft using GTL Jet Fuel, flying from Filton, UK, to Toulouse, France. The study partners are driving industry initiatives (CAAFI) to include GTL Jet Fuel in jet fuel specification (50% blend) (with ASTM approval expected mid 2009).

Under the study agreement Qatar Airways intends to operate a commercial flight using GTL Jet Fuel during 2009, becoming the first airline to do so. Qatar Airways also intends to be the first airline to operate regular commercial flights using GTL Jet Fuel, assuming commercial agreements can be reached. GTL Jet Fuel will be produced in Qatar from around 2012.

GTL Jet Fuel will likely be used in a semi-synthetic 50/50 blend with conventional jet fuel and can be used without any modifications to existing aircraft and engines. GTL Jet Fuel is virtually free of Sulphur and aromatics. As a result the aircraft engine will emit less Sulphur Oxide and fewer particulates during operation. The environmental benefits of this are being quantified and are likely to include improved air quality around airports.

GTL Jet Fuel has higher energy content by weight compared to conventional jet fuel – i.e. it has a lower density. It also offers improved thermal stability, meaning engines would be able to run hotter. Both of these characteristics may lead to potential fuel economy and improved payload/range performance which could result in a limited CO2 benefit for specific aircraft/route combinations. This is being studied.

These cleaner-burning fuels could become a major factor in future air quality improvement initiatives for the entire airline industry, further proving that Qatar Airways’ product leadership extends far beyond passenger comfort.

But we do not stop there. Currently Qatar Airways is working on its own roadmap towards alternative fuels which also includes biofuels.

March 2, 2009 – The New Fuels Alliance (NFA), one of the nation’s leading advocates for advanced biofuels, is warning that California’s efforts to reduce carbon emissions from gasoline may actually increase greenhouse gas emissions and worsen the state’s dependence on dirty fossil fuels.

Biofuels are being wrongly penalized by the California Air Resources Board’s (CARB) Low Carbon Fuel Standard (LCFS) which requires oil companies to reduce the carbon sold in their fuels by 10 percent by 2020. Under this proposal, all fuels are assigned a “carbon score” to reward the least carbon intensive fuels. But only biofuel is being singled out for so-called “indirect effects” thereby giving petroleum products a better carbon score and a competitive advantage. For drivers in California, it means they will be buying more dirty petroleum products and less of the cleaner renewable fuels.

“This proposal encourages oil companies to sell dirty fossil fuels like Canadian tar sands instead of renewable fuels including advanced biofuels like cellulosic ethanol,” said Brooke Coleman, head of the New Fuels Alliance. “Ironically, CARB’s proposal to reduce carbon will just result in more carbon in our environment.”

Even more alarming to the Alliance, CARB’s proposal puts up serious roadblocks to the development of more advanced biofuels from green sources like switchgrass. “These regulations will stifle advanced biofuels investment and derail the industry. California is moving the opposite direction of President Obama who stated in a recent speech it is critical to support advanced biofuels.”

Over 100 of the nation’s top scientists are also questioning CARB’s plan. In a letter sent to Governor Schwarzenegger, the scientists warned that: “this proposal creates an asymmetry or bias in a regulation designed to create a level playing field. It violates the fundamental presumption that all fuels in a performance-based standard should be judged the same way …Enforcing different compliance metrics against different fuels is the equivalent of picking winners and losers, which is in direct conflict with the ambition of the LCFS.” Click here to see the letter signed by 111 scientists from research labs such as the National Academy of Sciences, UC-Berkeley, Sandia National Labs, Lawrence Berkeley National Lab and MIT.

Go here to see the letter: http://www.arb.ca.gov/lists/lcfs-general-ws/28-phd_lcfs_mar09.pdf

CARB is scheduled to make their decision public in the next few days, and then there will be a public comment period before their decision is made final between April 23rd and 24th.