2007年VOA标准英语-New Technology Opens Way for 'Clean Coal' Power

By Jeff Swicord
Terre Haute, Indiana
24 May 2007
 

As part of our continuing series on "Searching for Solutions", VOA traveled to Terre Haute, Indiana, to tour one of two so called "clean coal" electric generating plants in the United States.  Clean coal technology has been under development since the early 1990s in the U.S..  And in the next few years, 20 more plants will be built in different parts of the country.  Jeff Swicord reports.

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Toxic emission from coal

Coal is currently the most abundant energy resource in the U.S.  More than 600 coal-fired power plants produce more than half of the country's electricity.  But coal is also one of the most environmentally unfriendly energy sources, and emits pollution when it is mined, transported and burned.

For decades, coal-fired power plants across the country have emitted a variety of dangerous toxic substances that harm the environment. They include large amounts of carbon dioxide (CO2) that contribute to global warming.  But new "clean coal" technology is on the horizon that can dramatically reduce the toxic emissions³ from coal-fired plants.

"From DOE's perspective, I think clean coal is part of the future," says Jared Daniels, with the Office of Clean Coal Technology at the U.S. Department of Energy..  "There is no silver bullet in energy technologies.  If you look at all the various forecasts, some time around 2050, electricity demand in the U.S. is going to double."

The Wabash Valley Power plant in Terre Haute, Indiana, is one of two Integrated Gasification Combined Cycle, or IGCC, plants in the U.S.  IGCC technology converts coal into synthetic⁴ gas by heating it at very high temperature in this tall cylinder⁵. 

The pollutants⁶, sulfur⁷ and carbon dioxide (CO2), are removed and sold as products on the open market.  Another byproduct, slag⁸ (a non-toxic solid material left over from the gasification process) can be used in building materials and asphalt for roads.  There are two types of turbines that generate electricity in the IGCC system: one that runs on the natural gas, and another that runs on steam from the heat created from the heat of the gasification process.

"The advantage is that because you gasify the coal, you can clean up the contaminants as we discussed much more efficiently⁹ as they are more concentrated," adds Daniels, "and on the power side, because you have a gas turbine that is more efficient than a steam turbine in series with a steam turbine, the overall efficiency of the process is increased."

Not everyone thinks coal should be considered as a viable¹⁰ future energy source.  "Calling coal clean is just propaganda to keep this dirty energy source into the mix for the future" says Eric Pica, a representative of the environmental group Friends of the Earth.  

He acknowledges that the IGCC process produces far fewer pollutants than traditional coal-fired plants, but he says pollution is only part of the problem. "The problem is that these plants are getting their coal from somewhere.  They are getting their coal from the mountaintops of West Virginia, which are being blown apart and scraped out like a pumpkin¹¹ and filling thousands of miles of streambeds.  They are getting their coal from the mining of strip mines out west."

Pica adds that the power industry plans to build 150 coal-powered plants across the country in the next few years.  Only 20 of them will be IGCC plants. "The IGCC plants are being used to put a green spin on all these coal plants that are going to be built, that are going to use pulverized¹² coal with all the traditional pollution from the coal."

IGCC plants are expensive to build.  Jared Daniels acknowledges that until stringent¹³ emission standards are placed on coal-fired plants, there will be little economic incentive¹⁴ for power companies to build IGCC plants. 

He says IGCC technology is currently the best option for coal-generated electricity. "We will need to rely on coal for the a long time going out into the future.  Perhaps some of the renewable technologies [will] come of age and can gain a larger share of the market. 

"I think when you realize that fact, you develop technology and implement¹⁵ technology that uses coal in the most efficient and environmentally sound manner possible," adds Daniels.

1 toxic   

adj.有毒的，因中毒引起的

参考例句：

• The factory had accidentally released a quantity of toxic waste into the sea.这家工厂意外泄漏大量有毒废物到海中。
• There is a risk that toxic chemicals might be blasted into the atmosphere.爆炸后有毒化学物质可能会进入大气层。

2 emission   

n.发出物，散发物；发出，散发

参考例句：

• Rigorous measures will be taken to reduce the total pollutant emission.采取严格有力措施，降低污染物排放总量。
• Finally,the way to effectively control particulate emission is pointed out.最后，指出有效降低颗粒排放的方向。

3 emissions   

排放物( emission的名词复数 )； 散发物（尤指气体）

参考例句：

• Most scientists accept that climate change is linked to carbon emissions. 大多数科学家都相信气候变化与排放的含碳气体有关。
• Dangerous emissions radiate from plutonium. 危险的辐射物从钚放散出来。

4 synthetic   

adj.合成的，人工的；综合的；n.人工制品

参考例句：

• We felt the salesman's synthetic friendliness.我们感觉到那位销售员的虚情假意。
• It's a synthetic diamond.这是人造钻石。

5 cylinder   

n.圆筒，柱(面)，汽缸

参考例句：

• What's the volume of this cylinder?这个圆筒的体积有多少？
• The cylinder is getting too much gas and not enough air.汽缸里汽油太多而空气不足。

6 pollutants   

污染物质（尤指工业废物）( pollutant的名词复数 )

参考例句：

• Pollutants are constantly being released into the atmosphere. 污染物质正在不断地被排放到大气中去。
• The 1987 Amendments limit 301(g) discharges to a few well-studied nonconventional pollutants. 1987年的修正案把第301条（g）的普通排放限制施加在一些认真研究过的几种非常规污染物上。 来自英汉非文学 - 环境法 - 环境法

7 sulfur   

n.硫，硫磺（=sulphur）

参考例句：

• Sulfur emissions from steel mills become acid rain.炼钢厂排放出的硫形成了酸雨。
• Burning may produce sulfur oxides.燃烧可能会产生硫氧化物。

8 slag   

n.熔渣，铁屑，矿渣；v.使变成熔渣，变熔渣

参考例句：

• Millions of tons of slag now go into building roads each year.每年有数百万吨炉渣用于铺路。
• The slag powder had been widely used as the additive in the cement and concrete.矿渣微粉作为水泥混凝土的掺和料已得到广泛应用。

9 efficiently   

adv.高效率地，有能力地

参考例句：

• The worker oils the machine to operate it more efficiently.工人给机器上油以使机器运转更有效。
• Local authorities have to learn to allocate resources efficiently.地方政府必须学会有效地分配资源。

10 viable   

adj.可行的，切实可行的，能活下去的

参考例句：

• The scheme is economically viable.这个计划从经济效益来看是可行的。
• The economy of the country is not viable.这个国家经济是难以维持的。

11 pumpkin   

n.南瓜

参考例句：

• They ate turkey and pumpkin pie.他们吃了火鸡和南瓜馅饼。
• It looks like there is a person looking out of the pumpkin!看起来就像南瓜里有人在看着你！

12 pulverized   

adj.[医]雾化的，粉末状的v.将…弄碎( pulverize的过去式和过去分词 )；将…弄成粉末或尘埃；摧毁；粉碎

参考例句：

• We pulverized the opposition. 我们彻底击败了对手。
• He pulverized the opposition with the force of his oratory. 他能言善辩把对方驳得体无完肤。 来自辞典例句

13 stringent   

adj.严厉的；令人信服的；银根紧的

参考例句：

• Financiers are calling for a relaxation of these stringent measures.金融家呼吁对这些严厉的措施予以放宽。
• Some of the conditions in the contract are too stringent.合同中有几项条件太苛刻。

14 incentive   

n.刺激；动力；鼓励；诱因；动机

参考例句：

• Money is still a major incentive in most occupations.在许多职业中，钱仍是主要的鼓励因素。
• He hasn't much incentive to work hard.他没有努力工作的动机。

15 implement   

n.(pl.)工具，器具；vt.实行，实施，执行

参考例句：

• Don't undertake a project unless you can implement it.不要承担一项计划，除非你能完成这项计划。
• The best implement for digging a garden is a spade.在花园里挖土的最好工具是铁锹。