A concrete idea to reduce CO2 emissions | Karen Scrivener

Transcriber: TED Translators Admin Reviewer: Mirjana Čutura

譯者: Zeddi Lee 審譯者: LoHsien Huang

混凝土的使用量在地球上僅次水。

Concrete is the second most used substance on earth after water,

and for this reason,

因此，

它對環境有顯著的影響。

it has a significant environmental impact.

If it were a country, it would rank third for emissions after China and USA.

如果混凝土是一個國家， 它的碳排放量是世界第三，

僅次於中國和美國。

But in fact, concrete is an intrinsically low-impact material

但事實上，混凝土是一種 對環境衝擊很低的材料，

每生產一噸所排放的 二氧化碳和消耗的能源

with much lower emissions of CO2 and energy per ton

than other materials like iron and steel, even things like bricks.

比鋼鐵等其它材料要低得多， 甚至也比磚塊低。

但由於使用的總量太大，

But because of the enormous volumes we use overall,

它的二氧化碳排放量 是所有人為排放的約 8%。

it contributes to about eight percent of man-made CO2 emissions.

混凝土是一種不可或缺的材料。

Concrete is an essential material.

我們需要它蓋房子

We need it to house people,

和修建道路、橋樑、水壩。

to build roads, bridges and dams.

因此，我們不能沒有它，

So we can't do without it,

但我們可以大量減少它的碳足跡。

but we can significantly reduce its carbon footprint.

混凝土是用水泥粘結而成。

Concrete is held together by cement.

我們今天使用的水泥稱為波特蘭水泥，

And cement we use today, called Portland cement,

是在攝氏 1450 度高溫下

is made by heating together a combination of limestone and clay

將石灰石和粘土一起加熱製成。

at a temperature of 1,450 degrees Celsius.

但事實上，大部分二氧化碳排放

But in fact, most of the CO2 emissions

不是來自加熱，

come not from the heating,

but from the breakdown of limestone, which is calcium carbonate,

而是來自石灰石，也就是碳酸鈣，

分解成氧化鈣和二氧化碳。

into calcium oxide and carbon dioxide, or CO2.

我們不能完全不用石灰石，

Now we can't do without this component altogether,

因為沒有別的東西能這麼有效地 將東西粘結在一起。

because nothing else is so efficient at holding stuff together.

但我們可以用其他碳足跡較小的材料

But we can replace a large proportion of it

來取代大部分石灰石。

with other materials with lighter carbon footprints.

許多同行都在找解決方案。

Many colleagues are looking for solutions.

在瑞士，

And here in Switzerland,

we have found that clays produce very reactive materials

我們發現粘土在煅燒時

會產生反應性很活躍的物質，

when they're calcined,

也就是加熱到攝氏 800 度，

that's to say heated to around 800 degrees Celsius,

比製造混凝土所需的 1450 度低很多。

significantly lower than the 1,450 needed to produce cement.

更重要的是，石灰石不會因分解

But more importantly, there's no CO2 emissions

而排放二氧化碳。

from the decomposition of limestone.

然後，我們用這種煅燒過的粘土，

We then take this calcined clay,

添加一點石灰石——

and we add a bit of limestone --

但不需要加熱， 所以不會排放二氧化碳——

but this time not heated, so no CO2 emissions --

再加一些水泥。

and some cement,

這種石灰石、煅燒粘土和水泥的組合，

and this combination of limestone, calcined clay and cement, we call LC3.

我們稱之為 LC3。

Now this LC3 here

LC3 和波特蘭水泥有相同的性質。

has the same properties as Portland cement.

它可以使用相同的設備和工法來生產，

It can be produced with the same equipment and processes

用途也相同，

and used in the same way,

但二氧化碳排放量少了 40%。

but has up to 40 percent lower CO2 emissions.

我們在印度占西（Jhansi）附近 建造的這所房子就證明了這一點，

And this was demonstrated in this house we built near Jhansi in India,

二氧化碳的排放 與現有材料相比，減少了 15 噸，

where we could save more than 15 tons of CO2,

相當於減少 30% 至 40%。

which was 30 to 40 percent compared to existing materials.

那為什麼很多人還不用 LC3 呢？

So why isn't everybody already using LC3?

每個地方用的水泥都是當地的材料，

Well, cement is a local material.

而波特蘭水泥之所以如此普遍，

The reason Portland cement is so pervasive

是因為它用的是地球上最豐富的材料。

is that it's produced from the most abundant materials on Earth

印度、美國、衣索比亞——

and can be produced in India,

in the United States, in Ethiopia, almost anywhere.

幾乎任何地方都可以生產。

我們必須與當地人合作，

And we have to work with people locally

找到製造 LC3 的最佳材料組合。

to find the best combination of materials to make LC3.

我們已經在印度和古巴 進行了全面的試驗。

We have already done full-scale trials in India and Cuba.

在哥倫比亞，用這種技術製造的產品

In Colombia, a product based on this technology

在幾個月前已經商業化。

was commercialized a few months ago,

在象牙海岸，

and in the Ivory Coast,

已經有全面生產煅燒粘土的工廠 接到訂單，開始生產。

the full-scale plant is being commissioned to calcine clays.

許多世界上最大的水泥公司

And many of the world's largest cement companies

都希望他們的工廠快點引進這項技術。

are looking to introduce this in some of their plants soon.

因此，用不同的材料

So the possibility to replace Portland cement

取代波特蘭水泥，

with a different material --

但具備相同特性、使用相同工法、

but with the same properties, produced in the same processes

具有相同用途，

and used in the same way,

碳足跡卻小很多。

but with much lighter carbon footprint --

這對因應氣候變遷來說確實非常重要，

is really crucial to confront climate change

因為我們可以快速、大規模地 完成這種轉型，

because it can be done fast and it can be done on a very large scale

而且每年可減少

with the possibility to eliminate

四億多噸二氧化碳的排放。

more than 400 million tons of CO2 every year.

我們不能沒有混凝土，

So we can't do without concrete,

但我們可以大量減少它的碳排放。

but we can do without a significant amount of the emissions it produces.

謝謝。

Thank you.