QUESTIONING NF
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6 WWW.CEN-ONLINE.ORG JULY 14, 2008 I NCREASING DEMAND for electronic products, including flat-panel displays, has triggered concern among atmospheric scientists over emissions of ni- trogen trifluoride, a potent greenhouse gas. In electronics manufacturing, NF 3 is used to clean chambers used for chemical vapor deposition of key materials onto glass or a silicon wafer. Most, but not all, of the gas is destroyed in the process. In a new paper, Michael J. Prather and Juno Hsu of the University of California, Irvine, write that “it is urgent to document NF 3 emis- sions through atmospheric observations” because the gas has a life span of 550 years and its greenhouse effect is roughly 17,000 times as potent as CO 2 (J. Geophys. Res. Lett. 2008, 35, L12810). The gas is not monitored under the Kyoto protocol but is included in the 2001 Intergovernmental Panel on Climate Change assessment. Prather, an atmospheric chemistry re- searcher, was the lead author of the IPCC assessment. The gas was little used in 1996, when the Kyoto protocol was written, but demand for NF 3 began to increase in 1999, when the semiconductor industry vowed to cut greenhouse gas emissions 10% by 2010. The NF 3 process has been replacing older perfluorocar- bon systems, commonly based on C 2 F 6 . Although the greenhouse gas profiles of NF 3 and C 2 F 6 are similar, NF 3 is significantly more efficient as a cleaning agent. With the C 2 F 6 process, which is only 20–30% efficient, large quantities of the gas are re- leased to the atmosphere. Air Products & Chemicals, the leading manufacturer of NF 3 , is in the process of expanding global capacity to 3,000 metric tons per year to meet rising demand. Corning Painter, the firm’s vice president of global elec- tronics, agrees that atmospheric measurements should be taken but says “more than 20 years of research and work with our customers find that less than 2% of NF 3 is released to the atmosphere.” According to Painter, more than 98% of the gas is destroyed in the cleaning process and most of the rest by emission-control equipment. Prather and Hsu estimate that 2008 production of NF 3 will be about 4,000 metric tons. There are cur- rently no measurements of how much NF 3 is in the atmosphere.—MELODY VOITH L EADERS OF THE WORLD’S eight richest na- tions, who met last week in Japan, have pledged to cut global greenhouse gas emissions in half by 2050, but their declaration is short on details. Nonetheless, the statement from the leaders of Can- ada, France, Germany, Italy, Japan, Russia, the U.K., and the U.S. reflects a pivotal change in policy for President George W. Bush. Until this year’s G-8 meeting, Bush steadfastly resisted international calls for deadlines to curb greenhouse gas emissions. Japan pushed hard for the G-8 leaders to endorse a 50% reduction in greenhouse gas emissions by 2050. The leaders’ pledge, however, lacks a baseline year, such as 1990 or 2008, for those cuts. The earlier the year, the steeper would be the cutbacks required and presumably the greater the cost. The G-8’s goal to cut emissions “would not avoid dangerous climate change altogether” but “would greatly reduce the odds of catastrophic impacts,” says Eileen Claussen, president of the Pew Center on Global Climate Change. The center works with businesses and governments to address climate change. The G-8 declaration sets the U.S. on a path toward further international cooperation on climate change but leaves it up to the next U.S. president to work out details, says Michael A. Levi of the Council on Foreign Relations, a think tank. In addition, the G-8 leaders threw their support be- hind the development of technologies to capture and store carbon dioxide emitted by fossil-fuel-fired power plants, especially those that burn coal. They called for the launch of 20 large-scale capture-and-storage dem- onstration projects around the world by 2010. Meanwhile, leaders of five major developing coun- tries—Brazil, China, India, Mexico, and South Africa— met in parallel with the G-8 leaders in Japan and issued their own declaration on climate change. The so-called Group of Five said industrialized nations need to take the lead in addressing climate change and should reduce releases of greenhouse gases by 25–40% by 2020 and 80–95% by 2050, based on 1990 levels.—CHERYL HOGUE G-8 leaders pose for a photo in Toyako, Japan, on July 8. NEWS OF THE WEEK NEWSCOM G-8 ENDORSES EMISSIONS CUTS CLIMATE CHANGE: Declaration marks turning point for President Bush QUESTIONING NF 3 CONCERN: Scientists seek measurements of electronic chemical in atmosphere Air Products’ largest NF 3 plant is in Hometown, Pa. AIR PRODUCTS & CHEMICALS
Transcript of QUESTIONING NF
6WWW.CEN-ONLINE.ORG JULY 14, 2008
INCREASING DEMAND for electronic products, including flat-panel displays, has triggered concern among atmospheric scientists over emissions of ni-
trogen trifluoride, a potent greenhouse gas.In electronics manufacturing, NF3 is used
to clean chambers used for chemical vapor deposition of key materials onto glass or a silicon wafer. Most, but not all, of the gas is destroyed in the process.
In a new paper, Michael J. Prather and Juno Hsu of the University of California, Irvine, write that “it is urgent to document NF3 emis-sions through atmospheric observations” because the gas has a life span of 550 years and its greenhouse effect is roughly 17,000 times as potent as CO2 (J. Geophys. Res. Lett. 2008, 35, L12810). The gas is not monitored under the Kyoto protocol but is included in the 2001 Intergovernmental Panel on Climate Change
assessment. Prather, an atmospheric chemistry re-searcher, was the lead author of the IPCC assessment.
The gas was little used in 1996, when the Kyoto protocol was written, but demand for NF3 began to increase in 1999, when the semiconductor industry vowed to cut greenhouse gas emissions 10% by 2010. The NF3 process has been replacing older perfluorocar-bon systems, commonly based on C2F6.
Although the greenhouse gas profiles of NF3 and C2F6 are similar, NF3 is significantly more efficient as a cleaning agent. With the C2F6 process, which is only 20–30% efficient, large quantities of the gas are re-leased to the atmosphere.
Air Products & Chemicals, the leading manufacturer of NF3, is in the process of expanding global capacity to 3,000 metric tons per year to meet rising demand. Corning Painter, the firm’s vice president of global elec-tronics, agrees that atmospheric measurements should be taken but says “more than 20 years of research and work with our customers find that less than 2% of NF3 is released to the atmosphere.” According to Painter, more than 98% of the gas is destroyed in the cleaning process and most of the rest by emission-control equipment.
Prather and Hsu estimate that 2008 production of NF3 will be about 4,000 metric tons. There are cur-rently no measurements of how much NF3 is in the atmosphere.—MELODY VOITH
LEADERS OF THE WORLD’S eight richest na-tions, who met last week in Japan, have pledged to cut global greenhouse gas emissions in half by
2050, but their declaration is short on details.Nonetheless, the statement from the leaders of Can-
ada, France, Germany, Italy, Japan, Russia, the U.K., and the U.S. reflects a pivotal change in policy for President George W. Bush. Until this year’s G-8 meeting, Bush steadfastly resisted international calls for deadlines to curb greenhouse gas emissions.
Japan pushed hard for the G-8 leaders to endorse a
50% reduction in greenhouse gas emissions by 2050. The leaders’ pledge, however, lacks a baseline year, such as 1990 or 2008, for those cuts. The earlier the year, the steeper would be the cutbacks required and presumably the greater the cost.
The G-8’s goal to cut emissions “would not avoid dangerous climate change altogether” but “would greatly reduce the odds of catastrophic impacts,” says Eileen Claussen, president of the Pew Center on Global Climate Change. The center works with businesses and governments to address climate change.
The G-8 declaration sets the U.S. on a path toward further international cooperation on climate change but leaves it up to the next U.S. president to work out details, says Michael A. Levi of the Council on Foreign Relations, a think tank.
In addition, the G-8 leaders threw their support be-hind the development of technologies to capture and store carbon dioxide emitted by fossil-fuel-fired power plants, especially those that burn coal. They called for the launch of 20 large-scale capture-and-storage dem-onstration projects around the world by 2010.
Meanwhile, leaders of five major developing coun-tries—Brazil, China, India, Mexico, and South Africa—met in parallel with the G-8 leaders in Japan and issued their own declaration on climate change. The so-called Group of Five said industrialized nations need to take the lead in addressing climate change and should reduce releases of greenhouse gases by 25–40% by 2020 and 80–95% by 2050, based on 1990 levels.—CHERYL HOGUE
G-8 leaders pose for a photo in Toyako, Japan, on July 8.
NEWS OF THE WEEKN
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G-8 ENDORSES EMISSIONS CUTS
CLIMATE CHANGE: Declaration marks turning point for President Bush
QUESTIONING NF3
CONCERN: Scientists seek measurements of electronic
chemical in atmosphere
Air Products’ largest NF3 plant is in Hometown, Pa.
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