VOA标准英语2010年-California Company's 'Green' Cement Ca

Cement is a major component¹ of concrete, the world's most widely used man-made material, an integral part of roads, bridges and buildings. But making cement requires heating limestone² and other materials to very high temperatures, a process that releases into the atmosphere large amount of carbon dioxide, or CO2, a leading cause of global warming.

Brent Constantz is working to fix that problem with an environmentally-friendly cement that actually captures CO2 and locks it away.

A clean approach to making a dirty product

 Calera
Calera's aggregate³ product is made in a variety of sizes

At his California company, Calera, scientists mix air and water to create the cement powder and aggregate pebbles⁴ that are the basic ingredients of concrete. But while traditional cement, called Portland cement, adds CO2 to the atmosphere, Calera's green cement takes the greenhouse gas out of the air - a lot of it. For every unit of carbon that Portland cement adds to the air, Brent Constantz says his green cement removes three units. "The more concrete you pour, the more CO2 you take out of the environment. So the way to mitigate⁵ the carbon problem is to pour more concrete!" But only, Constantz adds, if it's his concrete.

Conventional cement is the world's third-largest industrial contributor of CO2, mainly due to the high-temperature kilns⁶ required to make traditional cement pastes. Calera produces cement without high heat. Constantz explains the patented process mimics⁷ the way that nature grows the hard, durable⁸ materials in teeth, bone and sea shells. "It's a complicated, interesting, beautiful biologic process," he says, "that produces fantastic structures like a chambered nautilus shell or the human hip⁹ and the greater trochanter in the top of our femur, which are elaborate biologic structures made out of mineral."

 S. Schlender
Minerals in briny¹⁰ water attach to CO2 molecules¹¹ in the air to create a limestone-like material

Calera's technology targets the CO2 in the smoky air that's belched¹² from the smokestacks of large industrial sites, such as coal-fired power plants. To capture the gas, Calera mixes the air with briny, brackish¹³ seawater, oil field wastewater or other salty waters. This causes minerals in the water to bond with CO2 and then rain out as particles of synthetic¹⁴ limestone. As a bonus, the briny water becomes easier to turn into drinkable water.

Proving its process in the real world

Calera's been doing all this in its labs. Now, it's gearing up to do it on a grander scale, near California's largest power plant, at Moss¹⁵ Landing, on the Pacific coast near San Francisco. Giant turbines at the Dynegy company's gas-fired plant generate electric power for roughly 2 million people.

 S. Schlender
The first segment of the 3 meter wide pipe that will pull CO2-rich air from Dynegy's smokestack and deliver it 2.5 kilometers away to Calera's plant

In January, Calera began drawing one percent of the Dynegy stack gas through a massive pipe, across the street to its green cement plant. Calera hopes to capture 80 percent of the smokestack CO2, and sequester¹⁶ it in its patented cement mixture. If it works, says Moss Landing Power Plant manager Jim Dodson, the technology could be a game-changer for carbon sequestration efforts. He calls the Calera process "probably one of the best carbon-capture processes out there that we know of today."
 
Conventional carbon-capture technologies, such as chemical scrubbing, can capture as much as 90 percent of the CO2 from smokestack gas. However, they also use a lot of the energy generated by the plant, almost doubling the cost of the power for consumers.

The U.S. Department of Energy is looking for new carbon-capture technologies that can reduce this so-called parasitic¹⁷ load on power production below 30 percent. Calera's Brent Constantz says his company's relatively¹⁸ low-cost cement-making process can surpass that, cutting a plant's energy drain in half, to less than 15 percent. And he says adding in the potential profits from Calera's green cement would completely offset¹⁹ the financial loss of reduced power plant output. "Our costs of goods are lower than Portland cement because we don't have to burn coal or build a quarry²⁰ and quarry limestone," he explains, "so our capital costs are quite a bit lower." He estimates using Calera's technology would effectively cut the parasitic load to zero.

Next step: convincing the concrete industry

But many experts in the traditional concrete industry - like Steve Regis of Cal-Portland Cement - are skeptical²¹ that Calera can make an affordable²² cement. "I simply don't believe it, and I've seen no evidence otherwise," he says.

 S. Schlender
Calera's cement product separates from the water in large holding tanks

While he doubts many of Calera's claims, Regis says he wants more carbon capture, and the concrete industry is eager to inspect Calera's products. "We can run tests that look at how hard it is, how durable it is, we can look at all that then run several tests out in less than 6 months." Brent Constantz says his products have already passed those tests, and he promises that the company will share that information when the time is right.

Constantz hopes that traditional concrete makers²³ will team up, first, by blending Calera's green cement product with traditional Portland cement. The goal will be to fight global warming by capturing carbon in concrete . . . so much that it would help reverse man-made climate change.

"We can actively²⁴ sequester about 16 billion tons of CO2 a year in a profitable, sustainable, ongoing²⁵ way for our children, our great grandchildren, for centuries to come and deal literally²⁶ with most of the carbon problem," he insists. The key, he says, is to start tackling that problem – right now.
 

1 component   

n.组成部分，成分，元件；adj.组成的，合成的

参考例句：

• Each component is carefully checked before assembly.每个零件在装配前都经过仔细检查。
• Blade and handle are the component parts of a knife.刀身和刀柄是一把刀的组成部分。

2 limestone   

n.石灰石

参考例句：

• Limestone is often used in building construction.石灰岩常用于建筑。
• Cement is made from limestone.水泥是由石灰石制成的。

3 aggregate   

adj.总计的，集合的；n.总数；v.合计；集合

参考例句：

• The football team had a low goal aggregate last season.这支足球队上个赛季的进球总数很少。
• The money collected will aggregate a thousand dollars.进帐总额将达一千美元。

4 pebbles   

[复数]鹅卵石； 沙砾； 卵石，小圆石( pebble的名词复数 )

参考例句：

• The pebbles of the drive crunched under his feet. 汽车道上的小石子在他脚底下喀嚓作响。
• Line the pots with pebbles to ensure good drainage. 在罐子里铺一层鹅卵石，以确保排水良好。

5 mitigate   

vt.（使）减轻，（使）缓和

参考例句：

• The government is trying to mitigate the effects of inflation.政府正试图缓和通货膨胀的影响。
• Governments should endeavour to mitigate distress.政府应努力缓解贫困问题。

6 kilns   

n.窑( kiln的名词复数 )；烧窑工人

参考例句：

• Bricks and earthware articles are baked in kilns. 砖和陶器都是在窑中烧成的。 来自辞典例句
• The bricks are baking in the kilns. ？里正在烧砖。 来自辞典例句

7 mimics   

n.模仿名人言行的娱乐演员，滑稽剧演员( mimic的名词复数 )；善于模仿的人或物v.（尤指为了逗乐而）模仿( mimic的第三人称单数 )；酷似

参考例句：

• Methods:Models were generate by CT scan,Mimics software and Abaqus software. 方法：采用CT扫描，Mimics软件和Abaqus软件的CAD进行三维有限元模型的创建。 来自互联网
• Relaxing the mind and body mimics the effect that some blood-pressure pills would have. 放松身心会产生某些降压药才能产生的效果。 来自辞典例句

8 durable   

adj.持久的，耐久的

参考例句：

• This raincoat is made of very durable material.这件雨衣是用非常耐用的料子做的。
• They frequently require more major durable purchases.他们经常需要购买耐用消费品。

9 hip   

n.臀部，髋；屋脊

参考例句：

• The thigh bone is connected to the hip bone.股骨连着髋骨。
• The new coats blouse gracefully above the hip line.新外套在臀围线上优美地打着褶皱。

10 briny   

adj.盐水的；很咸的；n.海洋

参考例句：

• The briny water is not good for the growth of the trees.海水不利于这种树木的生长。
• The briny air gave a foretaste of the nearby sea.咸空气是快近海的前兆。

11 molecules   

分子( molecule的名词复数 )

参考例句：

• The structure of molecules can be seen under an electron microscope. 分子的结构可在电子显微镜下观察到。
• Inside the reactor the large molecules are cracked into smaller molecules. 在反应堆里，大分子裂变为小分子。

12 belched   

v.打嗝( belch的过去式和过去分词 )；喷出，吐出；打（嗝）；嗳（气）

参考例句：

• He wiped his hand across his mouth, then belched loudly. 他用手抹了抹嘴，然后打了个响亮的饱嗝。
• Artillery growled and belched on the horizon. 大炮轰鸣在地平面上猛烈地爆炸。 来自《现代英汉综合大词典》

13 brackish   

adj.混有盐的；咸的

参考例句：

• Brackish waters generally support only a small range of faunas.咸水水域通常只能存活为数不多的几种动物。
• The factory has several shallow pools of brackish water.工厂有几个浅的咸水池。

14 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。

15 moss   

n.苔，藓，地衣

参考例句：

• Moss grows on a rock.苔藓生在石头上。
• He was found asleep on a pillow of leaves and moss.有人看见他枕着树叶和苔藓睡着了。

16 sequester   

vt.使退隐，使隔绝

参考例句：

• Everything he owned was sequestered.他的所有财产都被扣押了。
• This jury is expected to be sequestered for at least two months.预计这个陪审团将至少被隔离两个月。

17 parasitic   

adj.寄生的

参考例句：

• Will global warming mean the spread of tropical parasitic diseases?全球变暖是否意味着热带寄生虫病会蔓延呢？
• By definition,this way of life is parasitic.从其含义来说，这是种寄生虫的生活方式。

18 relatively   

adv.比较...地，相对地

参考例句：

• 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。

19 offset   

n.分支，补偿；v.抵消，补偿

参考例句：

• Their wage increases would be offset by higher prices.他们增加的工资会被物价上涨所抵消。
• He put up his prices to offset the increased cost of materials.他提高了售价以补偿材料成本的增加。

20 quarry   

n.采石场；v.采石；费力地找

参考例句：

• Michelangelo obtained his marble from a quarry.米开朗基罗从采石场获得他的大理石。
• This mountain was the site for a quarry.这座山曾经有一个采石场。

21 skeptical   

adj.怀疑的，多疑的

参考例句：

• Others here are more skeptical about the chances for justice being done.这里的其他人更为怀疑正义能否得到伸张。
• Her look was skeptical and resigned.她的表情是将信将疑而又无可奈何。

22 affordable   

adj.支付得起的，不太昂贵的

参考例句：

• The rent for the four-roomed house is affordable.四居室房屋的房租付得起。
• There are few affordable apartments in big cities.在大城市中没有几所公寓是便宜的。

23 makers   

n.制造者，制造商（maker的复数形式）

参考例句：

• The makers of the product assured us that there had been no sacrifice of quality. 这一产品的制造商向我们保证说他们没有牺牲质量。
• The makers are about to launch out a new product. 制造商们马上要生产一种新产品。 来自《简明英汉词典》

24 actively   

adv.积极地，勤奋地

参考例句：

• During this period all the students were actively participating.在这节课中所有的学生都积极参加。
• We are actively intervening to settle a quarrel.我们正在积极调解争执。

25 ongoing   

adj.进行中的，前进的

参考例句：

• The problem is ongoing.这个问题尚未解决。
• The issues raised in the report relate directly to Age Concern's ongoing work in this area.报告中提出的问题与“关心老人”组织在这方面正在做的工作有直接的关系。

26 literally   

adv.照字面意义，逐字地；确实

参考例句：

• He translated the passage literally.他逐字逐句地翻译这段文字。
• Sometimes she would not sit down till she was literally faint.有时候，她不走到真正要昏厥了，决不肯坐下来。