NEWS OF THE WEEK
OSMIUM IS ANCIENT MARKER
ANTONIO MARTINEZ CORTIZAS
A sample of peat bog from northwestern Spain contains evidence of ancient mining.
GEOCHEMISTRY: Rare element can be
used to detect past human activities
E
VIDENCE OF ANCIENT human activity can be
gleaned from the concentrations of the rare element osmium in peat core samples, a new report shows. The finding suggests that osmium could be used to discover and date past human industrial activities. An international team led by Sébastien Rauch at Chalmers University of Technology, in Sweden, shows that 4,700 years ago technologies such as mining and smelting affected the distribution and concentration of osmium in peat bogs in the Xistral Mountains of northwest Spain (Environ. Sci. Tech., DOI: 10.1021/es901887f). Next to iridium, osmium is the least abundant element in Earth’s crust. But it can be emitted as a by-product of processes such as mining or smelting. Scientists have already discovered that some modern human technologies, including the use of automobile catalytic converters, have concentrated osmium in some areas.
BIOREFINERS WIN GOVERNMENT FUNDS GREEN GOAL: Grants will advance
fuels and chemicals from renewable raw materials
ceiving a half-billion-dollar injection from the Department of Energy. The money will go to 19 projects, most of which seek an as-yet-unattained goal: the large-scale production of fuels and chemicals from cellulosic and other nonfood agricultural sources. The $564 million in grants, from the American Recovery & Reinvestment Act, will be matched with funds from private sources for a total investment of almost $1.3 billion, DOE says. “These projects will help establish a domestic industry that will create jobs here at home and open new markets across rural America,” Energy Secretary Steven Chu said in announcing the grants. U.S. companies alZEACH EM
ZeaChem will use its $25 million to expand this semiworks plant making ethanol and ethyl acetate.
T
HE NASCENT U.S. biorefining industry is re-
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“In a period when we are focusing on major emissions—greenhouse gases—this study shows that human activities also affect the cycle of trace elements,” Rauch notes. Now, Rauch and colleagues have found that osmium concentrations in their Spanish peat bog samples increased around 4,700 years ago, corresponding with the start of early mining. A second increase occurred about 2,000 years ago, during the Roman occupation of the Iberian Peninsula in southern Spain, possibly due to production of copper from sulfide deposits. A third increase occurred around 1750, during the start of the industrial age. Ilia Rodushkin, a geochemist at Luleå University of Technology, in Sweden, says the paper “is a great example of the potential of this radiogenic system for reconstructing ancient industrial activities.” The work also bears on modern human activities, notes Mukul Sharma, a professor at Dartmouth College, whose lab has suggested that refinement of osmium-containing platinum ores releases osmium as volatile OsO4. Production of platinum has been increasing exponentially over the past 30 years, Sharma says, and may continue to rise as consumption of other platinum group metals, in products such as automobile catalytic converters and fuel cells, increases. That rise, it follows, may be reflected in osmium soil profiles.—ELIZABETH WILSON
ready produce billions of gallons of fuel ethanol from corn, but the government’s goal is for future biofuels to be based on nonedible feedstocks. In 2010, fuel blenders will be required to use 100 million gal of cellulosic biofuels, and the requirement rises annually from there. The winning projects span 15 states, numerous technologies, and multiple products. Algenol Biofuels, for example, won $25 million to produce ethanol from algae at Dow Chemical’s plant in Freeport, Texas. ClearFuels Technology will get $23 million to produce diesel and jet fuel in Commerce City, Colo., from woody biomass. Several of the projects will produce industrial chemicals. Archer Daniels Midland is getting $24.8 million for a plant in Decatur, Ill., that will produce ethanol and ethyl acrylate by acidifying biomass. Myriant Technologies is receiving $50 million to help build a plant in Lake Providence, La., that makes succinic acid from sorghum (see page 23). Although many of the companies need more money before they can start construction, Dallas Kachan, managing director of Cleantech Group, a research, events, and advisory company, says private investors generally have confidence in projects that win the government funding. Projects that don’t, in contrast, have a harder time attracting investors. “DOE is picking winners and, by definition, losers,” Kachan says. According to Kachan, investors’ long-term transportation bet is on electric vehicles. But the opportunity for transitional biofuels is still real. “Liquid-fuel cars aren’t going away within any of our lifetimes,” he says.—MICHAEL MCCOY
DECEMBER 14, 2009
