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"Environmental Science Class" What is this lecture mainly about?
"Environmental Science Class" What is this lecture mainly about?
admin
2012-01-14
18
问题
"Environmental Science Class"
What is this lecture mainly about?
Narrator: Listen to part of a lecture in an environmental science class.
Professor:
Hydrogen is the most recent and, I’d say, one of the most promising, in a long list of alternatives to Q40
petroleum. Some of the possibilities include batteries, methanol, natural gas, and, well, you name it. But Q41
hydrogen fuel cells have a couple of advantages over some of the other options. First of all, they’re
really quiet, and they don’t pollute the atmosphere. Besides that, hydrogen is the most abundant
element in the universe, and it can be produced from a number of sources, including ammonia, or... or
even water. So, it’s renewable, and there’s an almost unlimited supply.
Okay. Now fuel cells represent a radical departure from the conventional internal combustion
engine and even a fairly fundamental change from electric battery power. Like batteries, fuel cells run on
electric motors; however, batteries use electricity from an external source and store it for use in the
battery while the fuel cells create their own electricity through a chemical process that uses hydrogen and
oxygen from the air. Are you with me? Look, by producing energy in a chemical reaction rather than
through combustion, a fuel cell can convert, say 40-60 percent of the energy from the hydrogen into
electricity. And when this ratio is compared with that of a combustion engine that runs at about half the
efficiency of a fuel cell, well, it’s obvious that fuel cell technology has the potential to revolutionize the
energy industry.
So, fuel cells have the potential to generate power for almost any kind of machinery or equipment
that fossil fuels run, but, the most important, urn, let’s say goal, the goal of fuel cell technology is the
introduction of fuel cell powered vehicles. Internationally, the competition is fierce to commercialize fuel
cell cars. I guess all of the leading automobile manufacturers worldwide have concept cars that use fuel
cells, and some of them can reach speeds of as high as 90 miles per hour. Even more impressive is the
per tank storage capacity. Can you believe this? Some of those cars can run for 220 miles between
refills. But many of those cars were designed decades ago, so... what’s the holdup?
Well, the problem in introducing fuel cell technology is really twofold. In the first place, industries will Q44
have to invest millions, maybe even billions of dollars to refine the technology—and here’s the real
cost’the infrastructure to, uh, support the fueling of the cars. And by infrastructure, I mean basic facili-
ties and services like hydrogen stations to refuel cars and mechanics who know how to repair them. I
think you get the picture. And then, consumers will have to accept and use the new products powered
by fuel cells. So, we’re going to need educational programs to inform the public about the safety and...
and convenience of fuel cells, if we’re going to achieve a successful transition to fuel cell products. But,
unfortunately, major funding efforts get interrupted. Here’s what I mean. When oil prices are high, then
there seems to be more funding and greater interest in basic research and development, and more
public awareness of fuel cells, and then the price of oil goes down a little and the funding dries up and
people just go back to using their fossil fueled products. And this has been going on for more than thirty
years.
Some government sponsored initiatives have created incentives for fuel cell powered vehicles but Q42
probably one of the most successful programs, at least in my opinion, is, uh, the STEP program, which
is an acronym for the Sustainable Transportation Energy Program. STEP is a demonstration project
sponsored by the government of Western Australia. Now, in this project, gasoline driven buses have
been replaced with fuel cell ’buses on regular transportation routes. I think that British Petroleum is the
supplier of the hydrogen fuel, which is produced at an oil refinery in Kwinana, south of Perth. So we
need to watch this carefully. Another collaborative research effort is being undertaken by the European
Union and the United States. Scientists and engineers are trying to develop a fuel cell that’s effectively
engineered and attractive to the commercial market. Now, under an agreement signed in about 2000, if Q43
memory serves, it was 2003, but anyway, the joint projects include the writing of codes and standards,
the design of fueling infrastructures, the refinement of fuel cell models, and the demonstration of fuel cell
vehicles. In Europe, the private sector will combine efforts with government agencies in the public
sector to, uh, to create a long-term plan for the introduction of fuel cells throughout the E.U. And the World
Bank is providing funding to promote the development and manufacture of fuel cell buses for public
transportation in China, Egypt, Mexico, and India, and we’re starting to see some really interesting
projects in these areas. So, uh, clearly, fuel cell technology is an international effort.
Okay, at the present time, Japan leads the way in addressing the issues of modifying the
infrastructure. Several fueling stations that dispense hydrogen by the cubic meter are already in place, with plans
for more. But even when a nationwide system is completed, decisions about how and where to produce
the hydrogen and how to transport it will still have to be figured out. Most countries share the view that
fleets of vehicles have significant advantages for the introduction of fuel cell powered transportation
because, well obviously they can be fueled at a limited number of central locations. And, uh, and other
benefits of a fleet are the opportunity to provide training for a maintenance crew and for the drivers. As
for consumer education, no one country seems to have made the advances there that... that would
serve as a model for the rest of us. But perhaps when the demonstration projects have concluded and Q45
a few model cars are available to the public, well, more attention will be directed to public information
programs.
选项
A、An overview of fuel cell technology
B、A process for producing fuel cells
C、A comparison of fuel cell models
D、Some problems in fuel cell distribution
答案
A
解析
An overview of fuel cell technology. The professor discusses the process for producing energy, the efficiency of the cells, the problems, and some model programs.
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