关于环境保护减少二氧化碳排放的英文资料要三个方案,简单一些,最好附上中文谢谢!
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关于环境保护减少二氧化碳排放的英文资料要三个方案,简单一些,最好附上中文谢谢!
关于环境保护减少二氧化碳排放的英文资料
要三个方案,简单一些,最好附上中文
谢谢!
关于环境保护减少二氧化碳排放的英文资料要三个方案,简单一些,最好附上中文谢谢!
OVERWHELMING SCIENTIFIC EVIDENCE SHOWS THAT CO2 EMISSIONS FROM FOSSIL FUELS HAVE
caused the climate to change, and a dramatic reduction of these emissions is essential to
reduce the risk of future devastating effects. On the other hand, access to energy is the basis
of much of the current and future prosperity of the world. Eighty percent of this energy is
derived from fossil fuel. The world has abundant fossil fuel reserves, particularly coal. The
United States possesses one-quarter of the known coal supply, and the United States, Russia,
China, and India account for two-thirds of the reserves. Coal accounts for roughly 25% of
the world energy supply and 40% of the carbon emissions.* It is highly unlikely that any of
these countries will turn their back on coal any time soon, and for this reason, the capture and
storage of CO2 emissions from fossil fuel power plants must be aggressively pursued.
This special issue of Science discusses the potential role of carbon capture and sequestration
(CCS) in reducing CO2 emissions. The scale of CCS needed to make a signifi cant
dent in worldwide carbon emissions is staggering. Roughly 6 billion
metric tons of coal are used each year, producing 18 billion tons
of CO2. In contrast, we now sequester a few million metric tons of
CO2 per year. At geological storage densities of CO2 (~0.6 kg/m3),
underground sequestration will require a storage volume of 30,000
km3/year. This may be suffi cient storage capacity, but more testing is
required to demonstrate such capacity and integrity.
We should pursue a range of options for new coal-fi red power plants
(such as coal gasifi cation, burning coal in an oxygen atmosphere, or
postcombustion capture) to determine the most cost-effective approach
to burn fuel and reduce the total amount of CO2 emitted. No matter
which technology ultimately proves best for new plants, we will still
need to retrofi t existing plants and new plants that will be built before
CCS is routinely deployed. Each new 1-gigawatt coal plant is a billiondollar
investment and, once built, will be used for decades.
Estimates of CCS costs vary considerably, but experience with other pollution control
technologies such as the scrubbing of SO2 and NOx show that costs can be considerably
lower than initial estimates. Furthermore, new ideas are now being explored, such as more
effi cient, lower-temperature catalytic conversion of coal to hydrogen and methane, CO2
capture based on phase separation, and polygeneration (production of variable mixtures of
electricity, methane, liquid fuel, and ammonia). In the natural world, sequestration of CO2
occurs through photosynthesis, calcifi cation of CO2 by phytoplankton, and mineralization
in ground root systems. Can we enhance natural processes (“reforestation plus”) or draw
inspiration from nature as a starting point for artifi cial capture? Similarly, nature provides
proof that the energy penalty for releasing adsorbed CO2 in postcombustion capture can be
decreased: Through carbonic anhydrases, our blood captures CO2 created by cell metabolism
and releases it in the lungs with no enthalpic energy penalty.
Public support of CCS R&D is essential, and for this reason, $3.4 billion of American
Recovery and Reinvestment Act money is being invested by the U.S. Department of Energy
(DOE) in CCS R&D. The DOE is also supporting the testing of CO2 sequestration in seven
different U.S. geologic formations. To accelerate global dissemination of CCS technology
and expertise, international collaborations are essential. The G-8 leaders called for at least
20 CCS projects by 2010. In July, I announced a new U.S.–China Clean Energy Research
Center that will facilitate joint research in several areas, including CCS. Intellectual property
developed jointly will be shared between our countries.
There are many hurdles to making CCS a reality, but none appear insurmountable. The
DOE goal is to support R&D, as well as pilot CCS projects so that widespread deployment of
CCS can begin in 8 to 10 years. This is an aggressive goal, but the climate problem compels us
to act with fi erce urgency.