NEWS OF THE WEEK
FUKUSHIMA PLANT REACHING STABILITY NUCLEAR ACCIDENT: Progress in containing damage means a cold shutdown could happen early next year OKYO ELECTRIC Power Co. (TEPCO) is steadi-
T
Amano (right) gears up to inspect the damaged Fukushima Daiichi nuclear plant.
T E P CO
ly making progress in its efforts to contain damage and stabilize the crippled Fukushima Daiichi nuclear power plant, the head of the United Nations’ nuclear monitoring agency said last week. Yukiya Amano, director general of the International Atomic Energy Agency (IAEA), said plant operator TEPCO has made notable headway in dealing with the crisis. On the basis of the progress made to date, he said, the utility’s plan to achieve a safe state by early next year, known as a cold shutdown, is possible. “IAEA welcomes the significant progress TEPCO has achieved overall in implementing its road map to contain and stabilize the situation,” Amano remarked before visiting the ac-
DETOUR TAKES CO2 TO METHANOL SUSTAINABLE CHEMISTRY: Alternative
syntheses open a door to more efficient industrial processes
C
O CH3O
OCH3
+
Dimethyl carbonate O + N OCH3 H Methyl carbamates R
R = phenyl or alkyl
ATALYTIC HYDROGENATION of carbon diox-
ide-derived carbonate, carbamate, and formate intermediates turns out to be a viable option to make methanol from CO2, according to a team of Israeli chemists. Their indirect approach could lead to more efficient industrial production of methanol and offers an opportunity to use CO2 generated from burning fossil fuels as a chemical feedstock. Methanol is typically Ru catalyst 3 CH3OH 3H2 produced by subjecting synthesis gas (CO and H2), derived from coal or natural gas, to high temperature and Ru catalyst 2 CH OH 3H2 3 high pressure in the presence of a heterogeNH2 R neous catalyst. Chemists would like to make methanol by direct hyWWW.CEN-ONLINE.ORG
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cident site on July 25 for the first time since the nuclear crisis began four months ago. Workers have been struggling to prevent radioactive contaminants from escaping the six-reactor facility since a massive earthquake and tsunami in March knocked out power and cooling systems at the Fukushima complex, eventually causing a series of explosions and partial core meltdowns. TEPCO said in mid-July that the first stage of a plan to cool and stably reduce radiation leaks from the damaged reactors had succeeded. The company is also sticking to a previously declared January 2012 timetable for a cold shutdown, which would prevent the evaporation of fluid used to cool reactor materials and prevent the escape of radiation. Once the plant is in a stable shutdown, the focus will shift to removing radioactive debris and getting spent fuel rods safely out of the damaged reactors. A full decommissioning of the reactors could take more than 10 years, officials have said. Amano also indicated that IAEA is prepared to assist Japan in dealing with the ongoing crisis. “IAEA can provide knowledge on various areas, including decontamination and extraction of spent nuclear fuel rods,” he said at a news conference after touring the stricken complex. “I would like to discuss specifics with the Japanese government.”—GLENN HESS
drogenation of cheap and readily available CO2 instead, but a practical process has not yet been developed. David Milstein and coworkers at the Weizmann Institute of Science reasoned that an alternative pathway would be to hydrogenate common CO2- or CO-derived intermediates under milder reaction conditions. The researchers expanded previous work in Milstein’s lab on homogeneous ruthenium phosphine-pyridine catalysts to develop versions that catalyze hydrogenation of the carbonyl intermediates. In what the researchers believe is a chemical first, they used the homogeneous process to convert methyl formate and dimethyl carbonate to methanol, and methyl carbamates into methanol and an amine (Nat. Chem., DOI: 10.1038/nchem.1089). These atom-economical reactions generate no byproducts or waste and proceed under neutral, homogeneous conditions at mild temperatures and hydrogen pressures without solvent, Milstein notes. They represent “the ultimate in green reactions,” he says. “Although many researchers have been trying to find a practical, fast, and economical way to make methanol from waste CO2, usually by heterogeneous catalysis, catalyst longevity and sensitivity to poisoning are serious limitations,” says Philip G. Jessop of Queen’s University, in Kingston, Ontario, whose research includes CO2 fixation. “Homogeneously catalyzed hydrogenation of CO2 to methanol is known, but the conditions are quite severe and the yields are low. Milstein’s group describes an exciting two-step work-around for the homogeneous hydrogenation.”—STEVE RITTER
AUGUST 1, 2011
