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■科學研究指出，海藻(圖)的脂肪豐富，能夠提煉出環保再生燃料。資料圖片
鑑於國際油價的波動與減緩氣候變化的誘因，專家正努力從一種新生物上取得燃料，這種物質就是池塘浮渣。
池塘浮渣即是黏稠、快速生長、富含油脂的海藻，現時很有潛力成為再生能源。
專家說，海藻可以吞下二氧化碳這種溫室氣體，但又生長在不會用來種植糧食的地方。
海藻喜歡住在蚊子大量滋生的沼澤，例如骯髒的池塘，甚至廢水之中。雖然至今還未有人能從海藻上大量生產廉價燃料，但競賽已開始。
全美的大學實驗室和新興公司都有參與。今年夏天，埃克森美孚石油公司成為第一個研究海藻的大型企業。該公司表示，將投資6億美元(約46.8億港元)與加州一間生物科技公司合作研究海藻。
科學家表示，如果研究成功，他們最終會找出合乎成本效益的方法，把海藻油脂轉化成燃料，然後注入汽車、貨車與噴射機的油缸。
邁阿密佛羅里達國際大學應用研究的化學工程師菲臘彼迪斯說：「研究並非不切實際，不用20年，幾年就可以有成果。」
菲臘彼迪斯說：「我們可以跟污染工業的排放點連接，收集排放氣體，拿去餵海藻，以防二氧化碳加劇氣候轉變。」
非牟利組織中西部研究中心佛州分組的分子基因專家斯威格表示：「海藻可愛之處是繁殖力強，隨處可見，你不用做甚麼，大自然有其安排。」
中西部研究中心3年前已就海藻燃料展開研究。斯威格警告，海藻燃料仍未能大派用場。雖然海藻無處不在，但現時將其轉化成燃料的成本每加侖高達100美元(約780港元)，並不划算。
最困難的地方是減成本、增產量，科學家必須找出便宜的方法，抽乾海藻和抽出其脂肪。
斯威格指出，利用5美元的電力來推動離心機，抽乾海藻，但最終只能製造出1美元燃料，這並不合理。如果一切順利，他相信5年內能將提煉成本降至每加侖40美元(約312港元)。
■綜合外電消息
■資深翻譯員 羅國偉
Algae May be Secret Weapon in Climate Change War
Driven by fluctuations in oil prices, and seduced by the prospect of easing climate change, experts are ramping up efforts to squeeze fuel out of a promising new organism: pond scum.
As it turns out, algae─slimy, fast-growing and full of fat─is gaining ground as a potential renewable energy source.
Experts say it is intriguing for its ability to gobble up carbon dioxide, a greenhouse gas, while living happily in places that aren't needed for food crops.
Algae likes mosquito-infested swamps, for example, filthy pools, and even waste water. And while no one has found a way to mass produce cheap fuel from algae yet, the race is on.
University labs and start-up companies across the country are getting involved. Over the summer, the first mega-corporation joined in, when ExxonMobil said it would sink 600 million dollars into algae research in a partnership with a California biotechnology company.
If the research pans out, scientists say they will eventually find a cost-effective way to convert lipids from algae ponds into fuel, then pump it into cars, trucks and jets.
"I think it's very realistic. I don't think it's going to take 20 years. It's going to take a few years," said chemical engineer George Philippidis, director of applied research at Florida International University in Miami.
"We could hook up to the exhaust of polluting industries," Philippidis said. "We could capture it and feed it to algae and prevent that CO2 from contributing to further climate change."
"Where algae is very nice, it's prolific. It's everywhere......and you don't have to do much. Mother Nature has kind of figured it out," said Roy Swiger, a molecular geneticist and director of the Florida division of the non-profit Midwest Research Institute.
MRI began studying algae as an energy source 3 years ago. Swiger warned that algal fuels are not ready for prime time yet. Even though algae grows like gangbusters, it currently costs up to 100 dollars to make a gallon of algal fuel─hardly a savings.
The rub is bringing cost down, and production up. To do this, scientists must find cheap ways to dry algae and extract the lipids.
Swiger noted that it would not make sense to spend 5 dollars of electricity to run a centrifuge to dry out algae, that in turn would only produce one dollar of fuel.
If research goes well, Swiger thinks it will take 5 years to bring down production costs to 40 dollars per gallon.
■AFP
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