善用科技 造紙業也可以很環保
摘錄自：天下雜誌 經濟學人電子報 2013/1/3
2013-12-05 Web only 作者：經濟學人
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| 圖片來源：flickr.com/photos/myhsu/ |
科技和環保似乎相處得不太好。部分環保者十分恐懼科技，多數環保政策將焦點放在價格、消費和太陽能及風力發電補助，但那並非是最先進的手段。突破性科技並不多，其中最具潛力的就是碳捕捉及儲存，此技術可以中和燃燒石化燃料所製造的二氧化碳。挪威的Mongstad先前推動了大型計畫──但挪威政府最近也決定放棄此計畫。
這給了我們更多理由，抱著帶有一定程度質疑的好奇眼光，看看試圖透過科技變革削減碳排的歐洲造紙企業是怎麼做的。本周，它們宣佈了一些想法，要是這些想法能獲得產業採用，那麼到了2050年，造紙產業的能源消耗將減低至少四分之一，二氧化碳排放量則會下滑一半以上。這些想法正好可以測試，看看企業所發展的科技，究竟可以減緩多少全球暖化。
造紙產業為全球排名第5的重大耗能產業。智庫世界資源研究中心預估，造紙產業2005年的二氧化碳排放量為5億噸。不過，歐洲企業亦相對環保：歐洲紙業聯合會（CEPI）表示，其會員在2011年的排放量為4,600萬噸。在規範不足的地區，紙漿廠還會製造大量汙物；例如一間位於俄羅斯貝加爾湖畔的紙漿廠，數年來就一直將漂白水排入全球最大的淡水水體之中。
CEPI在面臨大幅減低二氧化碳排放量的要求之際，決定測試科技變革是否可以帶來比微幅改善更好的成效。CEPI成立了兩個由科學家和商業人士組成的團隊；兩個團隊皆由造紙企業的前執行長帶領並共享知識，因為它們的目標是創意而非專利；此外，它們也會尋求其他減碳計畫的想法。兩個團隊各提出了4種解決方案，並於11月27日由評審委員會決定贏家。
造紙必須以機械碾磨木屑以分離纖維，或是以化學藥劑烹煮木屑以移除黏結纖維的木質素。接著利用大量水份軟化纖維，再將紙漿放進機器以擠出水份並烘乾紙張。
獲勝的提案放棄了碾磨和化學烹煮，改以深共熔溶劑軟化木頭並分離木質素。這類溶劑屬自然產物，植物在乾枯之時就會製造它們。這等同於將造紙轉變為生化產業，可減少主要能源消耗達40%，還能製造木質素等相當有用的副產品，例如純木質素就是許多化學品的原料，也是高價值化學品所使用的纖維素。此計畫的其中一項要求，就是新想法不但得減除成本，還要能增加價值。
造紙的大部分能源消耗出自烘乾紙張，因此，若造紙不需要水，自然可以減少耗能。團隊想出了兩種作法；第一種是使用蒸氣分離纖維（用水量較少），另一種則是讓纖維懸浮於黏性液體之中，並以改變纖維附近的黏性來排除液體。此想法源自企鵝；企鵝為了在水中逃離海豹，會釋放氣泡、在羽毛周圍形成空氣薄膜以減少磨擦力。
目前，這些想法只是試驗性計畫或是還留在實驗室內，並未真正商業化。因此，它們尚未通過最重要的可行性測試。
即使如此，它們還是帶來了幾個教訓。最主要的教訓就是，氣候變遷問題確實有科技解決方案；部分想法不但減少碳排，還讓能源密集企業跨入新領域──例如讓造紙廠跨足生化產業。其二，企業本身就能為氣候變遷有所貢獻，不必等待政府敦促；不過，CEPI還是希望歐盟可以提供資金並支持更基礎的研究。
最後，此計畫的不尋常之處在於企業攜手研究科技；通常，企業會在這方面相互競爭。造紙廠得以成功合作，是因為它們將範圍限縮於「競爭前的一般性概念」，亦即基礎性突破；希望接下來它們會搶著應用這些想法。（黃維德譯）
©The Economist Newspaper Limited 2013
The Economist
The paper industry and climate change
Roll on the
green revolution
By The Economist
From The Economist
Published: December 05, 2013
Nov 30th 2013 | From the print edition
A technological fix is proposed to combat global warming.
TECHNOLOGY and greenery don't mix well. Some greens are technophobes.
Most environmental policies focus on prices, consumption and subsidies to solar
and wind power, which are not at the cutting edge. The list of technological
breakthroughs is short. One of the most promising is carbon capture and
storage, which neutralises emissions of carbon dioxide from burning fossil
fuels. A big project was being built at Mongstad in Norway—but the Norwegian
government has just pulled the plug on it.
All the more reason, then, to look with interest—and a measure of
scepticism—at an effort by European pulp and paper companies to slash their
emissions through technological change. This week they announced some ideas
which, if adopted by the whole industry, would cut its energy use by at least a
quarter and its output of CO2 by more than half by 2050. The ideas will test
how far technology developed by companies can reduce global warming.
Pulp and paper is a big energy consumer—the world's fifth-largest
industrial user. The World Resources Institute, a think-tank, put the
industry's CO2 emissions at about 500m tonnes worldwide in 2005. However,
European companies are relatively green: the Confederation of European Paper
Industries (CEPI), a trade association, says its members' emissions were 46m
tonnes in 2011. Pulp mills in under-regulated places also produce disgusting
gunk. A mill on the pristine shores of Lake Baikal, in Russia, has been dumping
bleach into the world's biggest body of (once) freshwater for many years.
Facing demands for deep cuts in CO2 emissions, CEPI decided to see if
technological change could yield more than just marginal improvements. It set
up two teams of scientists and businesspeople, each under a former chief
executive (of Smurfit Kappa, the fourth-largest European papermaker, and Mondi,
the fifth). The teams set up a common knowledge base because the idea was to
test creativity, not proprietary information. They also sought ideas from
outsiders with carbon-reduction programmes, such as Tata Steel. Each team came
up with four ideas. On November 27th a jury chose a winner.
To make paper, you either grind woodchips mechanically to separate the fibres,
or cook them with chemicals to remove the lignin, which binds the fibres
together. You then dissolve the fibres in vast quantities of water and push
them through a slit into a machine that squeezes out the water and dries the
sheets.
The winning proposal would do away with all this grinding and chemical
cooking. Instead, it would use things called deep eutectic solvents to dissolve
wood and separate out the lignin. These solvents occur naturally: plants
produce them during droughts. They would essentially turn papermaking into a
biochemical business, cutting primary energy use by 40%. They would also
generate useful by-products, such as pure lignin, a raw material for bulk
chemicals, and a form of cellulose used in high-value chemicals. One of the requirements
of the project was that the ideas should add value, not just cut cost.
Most of the energy now used in making paper goes on drying the sheets.
So making it without water would also cut energy consumption. The teams came up
with two ways of doing that. One would separate the fibres with steam (using
less water). The other would suspend the fibres in a viscous fluid and then
expel the fluid by modifying the viscosity around the fibres. This idea has
been pinched from penguins. To escape from seals underwater, the birds release
trapped air bubbles which form a thin layer of air around their plumage,
reducing friction.
At the moment these ideas exist as pilot projects or in the laboratory,
but not commercially. The most important test of their usefulness is therefore
yet to be passed.
Even so, several lessons have emerged. The main one is that there are
technological solutions to climate change. "We were amazed at what we
found," says CEPI's Marco Mensink. Some of the ideas not only cut
emissions but take energy-intensive firms into new areas—biochemicals, in the
case of pulp and paper. Next, companies can do lot about climate change
themselves. They do not need to wait for a nudge from governments, although
CEPI also wants the European Union to put some money where its mouth is and support
more basic research.
Last, the project was unusual in that companies collaborated over
technology. Normally they compete. The pulp and paper firms managed to work
together by confining their efforts to "generic pre-competitive
concepts"—ie, basic breakthroughs. The hope is that they will now compete
to implement them.
From the print edition: Business
©The Economist Newspaper Limited 2013
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