VOA标准英语2010年-Getting Mileage Out of Manure
时间：2019-01-13 作者：英语课 分类：VOA标准英语2010年(二月)
Dairy farmer, researchers look for ways to power cars with bio-gas from cattle
Tom Banse | Bellingham, Washington 23 February 2010
Dairy owner Darryl Vander Haak turns cow manure 1 into 'bio-gas' which burns like natural gas in a small electric power plant right on his farm.
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Western Washington University's Vehicle Research Institute
Five years ago, dairy farmer Darryl Vander Haak flipped 2 the switch on the first electric generator 3 in Washington State powered by manure. The facility is officially known as a methane 4 digester.
Manure from about 1,000 cows goes in one end and then, controlled decomposition 5 yields methane gas at the other.
The raw material for the digester comes from livestock 6 waste that might otherwise end up in a smelly manure lagoon 7 on the farm. This so-called 'bio-gas' is burned like natural gas in a small electric power plant right on Vander Haak's farm. The dairyman sells his excess power to the local electric utility.
Methane digesters are increasing in number, especially in Europe. But there's an important difference between Europe and America: electricity in the U.S. is relatively 8 cheap. Dairyman Vander Haak says his energy sales have not been profitable. "The Northwest has too much [cheap] hydropower to compete with," he points out, adding that he's been looking for alternative markets. "It would be easier to compete with the gas companies, I guess."
Cow power to horsepower
That's why Vander Haak was open-minded when the Vehicle Research Institute at Western Washington University, just down the road from his dairy, called with an offer to truck away some of his methane.
One researcher calculates that cows from two large dairies could fuel all public buses in a medium-sized American city.
Institute director Eric Leonhardt says he's had his eye on the dairy herd 9 as a source of transportation fuel for a long time. He calls it "cow power to horsepower."
Leonhardt says the challenge is to cost-effectively remove impurities 10 from the manure-derived methane. "When the gas comes off the digester, it has not only methane in it - 60 percent -- it also has carbon dioxide -- 40 percent, roughly. And it has a trace of hydrogen sulfide," says Leonhardt. Those impurities rapidly corrode 11 engine parts.
Powering vehicles with clean natural gas is not new. Nor is generating fuel from renewable sources. But cars and trucks that run on methane are still a novelty in the U.S.
However, since last year, biogas has gotten renewed attention from the Obama Administration as part of a larger push to promote domestic renewable energy.
The Viking 32, built by students and faculty 12 at Western Washington University, runs on biofuel.
The economics of methane-powered cars
The U.S. Department of Energy gave the Vehicle Research Institute a $500,000 grant to improve the biogas refining process and then demonstrate whether the fuel can be cost-competitive in cars. Leonhardt says a lot depends on the price of traditional fossil fuel.
It would have to climb higher to give consumers a financial incentive 13 to switch. At present, the average price of gasoline in the United States is well below Leonhardt's barely-competitive threshold of about 75-cents per liter.
This spring, the Vehicle Research Institute plans to retrofit a donated shuttle bus to run on methane. It will take a few months of road testing to confirm Leonhardt's cost estimates. The researcher has already calculated that the cows from just two large dairies could fuel all the public buses in a medium-sized American city.
- The farmers were distributing manure over the field.农民们正在田间施肥。
- The farmers used manure to keep up the fertility of their land.农夫们用粪保持其土质的肥沃。
- The plane flipped and crashed. 飞机猛地翻转，撞毁了。
- The carter flipped at the horse with his whip. 赶大车的人扬鞭朝着马轻轻地抽打。
- All the while the giant generator poured out its power.巨大的发电机一刻不停地发出电力。
- This is an alternating current generator.这是一台交流发电机。
- The blast was caused by pockets of methane gas that ignited.爆炸是由数袋甲烷气体着火引起的。
- Methane may have extraterrestrial significance.甲烷具有星际意义。
- It is said that the magnetite was formed by a chemical process called thermal decomposition. 据说这枚陨星是在热分解的化学过程中形成的。
- The dehydration process leads to fairly extensive decomposition of the product. 脱水过程会导致产物相当程度的分解。
- Both men and livestock are flourishing.人畜两旺。
- The heavy rains and flooding killed scores of livestock.暴雨和大水淹死了许多牲口。
- The lagoon was pullulated with tropical fish.那个咸水湖聚满了热带鱼。
- This area isolates a restricted lagoon environment.将这一地区隔离起来使形成一个封闭的泻湖环境。
- The rabbit is a relatively recent introduction in Australia.兔子是相对较新引入澳大利亚的物种。
- The operation was relatively painless.手术相对来说不痛。
- She drove the herd of cattle through the wilderness.她赶着牛群穿过荒野。
- He had no opinions of his own but simply follow the herd.他从无主见，只是人云亦云。
- A filter will remove most impurities found in water. 过滤器会滤掉水中的大部分杂质。
- Oil is refined to remove naturally occurring impurities. 油经过提炼去除天然存在的杂质。
- The tools will corrode with rust if never used.这些工具如长期不用会长铁锈而损坏。
- It will pollute people's aesthetic taste and corrode social spirit.它污染人们的审美趣味，腐蚀社会精神。
- He has a great faculty for learning foreign languages.他有学习外语的天赋。
- He has the faculty of saying the right thing at the right time.他有在恰当的时候说恰当的话的才智。