密歇根新闻广播 抑制藻类生物燃料

 

For years, scientists have been developing ways to put algae¹ in your gas tank. It works, but we're still a long way from buying algal biofuel at the pump.

Researchers at the University of Michigan have been experimenting with methods that could improve the fuel's long-term prospects².

In 2016, the team set up 80 large containers at a site near Pinckney, northwest of Ann Arbor³, to serve as small ponds where they could grow different species of algae together. Picture a field surrounded by trees with row after row of round, black tubs filled with bright green liquids, like witches cauldrons. U of M recently released their findings.

Bradley Cardinale is a professor in U of M's School for Environment and Sustainability. He oversaw⁴ the research team. Cardinale says algae have molecules⁵ that are highly combustible⁶.

"Things like fatty acids, polysaccharides and carbohydrates⁷ are things that we can burn easily and get a lot of energy out," he said in an interview with Michigan Radio Morning Edition host Doug Tribou. "The second thing that makes them viable⁸ is that they don't require a lot of area. We can grow a lot of algae in a relatively⁹ small area of pond that would not require a huge ecological¹⁰ footprint in the way that something like corn ethanol might."

Grow, grow, grow

The challenge is to grow algae at a large enough scale to generate a steady output that can be sent to a refinery¹².

"You need to get high yields out of the algae, so we need to have a high mass of the crop that needs to [have] good molecules for combustion¹³ like these fatty acids," Cardinale said. "It needs to be resistant¹⁴ to pests and disease. It needs to be stable in the face of weather fronts that Mother Nature is going to throw at you."

The U of M researchers tried to grow different species together, using an approach called ecological engineering, or biomimicry.

"One of the very first principles of ecological engineering is that no single species can be good at everything, but you can potentially take several different species, each of which is good at a different thing, and grow them in combinations and have them collectively accomplish all of the things you need," Cardinale said.

Commercial interests

Exxon Mobil has taken a different approach in its work on algal biofuel. According a recent report by Fast Company, the oil company and its partner, Synthetic¹⁵ Genomics, believe they will be able to produce 10,000 barrels of algal biofuel a day by the year 2025.

As Fast Company noted¹⁶, "by tweaking a particular gene¹¹ in a certain species of algae, they were able to make the algae produce twice as much fat as it would in the wild, but still grow as quickly as usual. That fat can be made into fuel."

But Cardinale says he's skeptical¹⁷ of their technique.

"We can, in fact, genetically¹⁸ engineer species in the lab that produce high yields that also give us these great biomolecules like fatty acids, but those fatty acids are very yummy to things that like to eat algae in nature," he said.

Growing massive amounts of algae requires space and that means outdoor ponds that are up to an acre in size. Outside the safety of the lab, Cardinale believes Exxon Mobil will see different results.

"In an open cultivation¹⁹ pond, they're going to have population crashes and it's going to be very difficult to sustain those genetically engineered species at the scale of open commercial ponds."

Cardinale says U of M might partner with energy companies to develop its own commercially viable outdoor ponds. He and his fellow researchers also hope to discover more kinds of algae that can be paired up.

"Our analyses suggest there are probably hundreds of thousands of combinations of species that occur naturally that are even better than the ones that we've identified and worked with so far."

Environmental upsides ... and downsides

Algal biofuel is carbon neutral. When burned, it releases the same amount of carbon the plants took up while they grew.

However, Cardinale notes that it would take massive amounts of fertilizer to grow algae at commercial scale. Fertilizers are the biggest source of water pollution worldwide.

A long way to go

Don't expect to see "algal biofuel" next to unleaded regular and diesel²⁰ at your local filling station anytime soon.

Cardinale said. "If the oil prices remain low, or we have an administration that does not prioritize renewable fuels, we're on the timescale of probably several decades."

1 algae   

n.水藻，海藻

参考例句：

• Most algae live in water.多数藻类生长在水中。
• Algae grow and spread quickly in the lake.湖中水藻滋蔓。

2 prospects   

n.希望，前途(恒为复数)

参考例句：

• There is a mood of pessimism in the company about future job prospects. 公司中有一种对工作前景悲观的情绪。
• They are less sanguine about the company's long-term prospects. 他们对公司的远景不那么乐观。

3 arbor   

n.凉亭；树木

参考例句：

• They sat in the arbor and chatted over tea.他们坐在凉亭里，边喝茶边聊天。
• You may have heard of Arbor Day at school.你可能在学校里听过植树节。

4 oversaw   

v.监督，监视( oversee的过去式 )

参考例句：

• He will go down as the president who oversaw two historic transitions. 他将作为见证了巴西两次历史性转变的总统，安然引退。 来自互联网
• Dixon oversaw the project as creative director of Design Research Studio. 狄克逊监督项目的创意总监设计研究工作室。 来自互联网

5 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。

6 combustible   

a. 易燃的,可燃的; n. 易燃物,可燃物

参考例句：

• Don't smoke near combustible materials. 别在易燃的材料附近吸烟。
• We mustn't take combustible goods aboard. 我们不可带易燃品上车。

7 carbohydrates   

n.碳水化合物，糖类( carbohydrate的名词复数 )；淀粉质或糖类食物

参考例句：

• The plant uses the carbohydrates to make cellulose. 植物用碳水化合物制造纤维素。 来自《简明英汉词典》
• All carbohydrates originate from plants. 所有的碳水化合物均来自植物。 来自辞典例句

8 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。

9 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。

10 ecological   

adj.生态的，生态学的

参考例句：

• The region has been declared an ecological disaster zone.这个地区已经宣布为生态灾难区。
• Each animal has its ecological niche.每种动物都有自己的生态位.

11 gene   

n.遗传因子，基因

参考例句：

• A single gene may have many effects.单一基因可能具有很多种效应。
• The targeting of gene therapy has been paid close attention.其中基因治疗的靶向性是值得密切关注的问题之一。

12 refinery   

n.精炼厂，提炼厂

参考例句：

• They built a sugar refinery.他们建起了一座榨糖厂。
• The purpose of oil refinery is to refine crude petroleum.炼油厂的主要工作是提炼原油。

13 combustion   

n.燃烧；氧化；骚动

参考例句：

• We might be tempted to think of combustion.我们也许会联想到氧化。
• The smoke formed by their combustion is negligible.由它燃烧所生成的烟是可忽略的。

14 resistant   

adj.(to)抵抗的，有抵抗力的

参考例句：

• Many pests are resistant to the insecticide.许多害虫对这种杀虫剂有抵抗力。
• They imposed their government by force on the resistant population.他们以武力把自己的统治强加在持反抗态度的人民头上。

15 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。

16 noted   

adj.著名的，知名的

参考例句：

• The local hotel is noted for its good table.当地的那家酒店以餐食精美而著称。
• Jim is noted for arriving late for work.吉姆上班迟到出了名。

17 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。

18 genetically   

adv.遗传上

参考例句：

• All the bees in the colony are genetically related. 同一群体的蜜蜂都有亲缘关系。
• Genetically modified foods have already arrived on American dinner tables. 经基因改造加工过的食物已端上了美国人的餐桌。 来自英汉非文学 - 生命科学 - 基因与食物

19 cultivation   

n.耕作，培养，栽培（法），养成

参考例句：

• The cultivation in good taste is our main objective.培养高雅情趣是我们的主要目标。
• The land is not fertile enough to repay cultivation.这块土地不够肥沃，不值得耕种。

20 diesel   

n.柴油发动机，内燃机

参考例句：

• We experimented with diesel engines to drive the pumps.我们试着用柴油机来带动水泵。
• My tractor operates on diesel oil.我的那台拖拉机用柴油开动。