VOA科学技术2023--Are Biofuels a Clean Source of Energy?

Are Biofuels a Clean Source of Energy?

India has proposed an alliance to speed up the development of biofuels to support energy transition worldwide.

Biofuel is a kind of fuel produced from agricultural products or organic waste.

India plans to announce the alliance at the G-20 gathering¹ in New Delhi. It is expected that more than 15 countries will sign up to be part of the alliance. The United States, Canada, and Brazil are among a few of the countries expected to join India in such an alliance.

What are biofuels?

Humans have used biofuels since ancient times. For example, humans burn wood and animal waste for cooking, heating, and light. They have gained popularity in recent years for their possibility to deliver cleaner energy than some other sources.

Biofuels are grouped based on their source. Each group is known as a "generation." First-generation biofuels come from food crops like corn and sugar cane². Second generation come from non-food crops and agricultural waste. And third-generation come from small plants called algae³.

Ethanol, biodiesel, and biogas are popular kinds of biofuels. They can be produced from any of these sources and are grouped based on the source from which they are produced. For example, ethanol produced from farm-grown corn is grouped as first-generation ethanol.

Are biofuels always a source of clean energy?

Biofuels are not always a clean source of energy. But it depends on how it is produced. A biofuel made from waste, for example, with renewable energy to power the production, would have little or no greenhouse gas production, making it a clean fuel. But when crops are grown to just produce biofuels, the fertilizer and nonrenewable fuels needed to produce the fuel make it much less clean.

"If you look at the full life cycle of producing biofuels, it's many times not clean," said Lydia Powell. She is an energy policy researcher at the New Delhi-based Observer Research Foundation. She has followed developments related to biofuels for over 20 years.

Biofuels can also mean land that could have produced food is being used for energy. They can add to deforestation when land is cleared for their production.

Powell noted⁴ Europe's imports of plant-based palm oil from Indonesia and other East Asian countries to make biodiesel for cars and trucks. Those imports greatly fell after the European Union banned the sale of palm oil and other palm-based products when they could be linked to deforestation.

"They were destroying natural forests to plant palm trees so you produce oil to export to Europe. When you destroy forests, you destroy large chunks⁶ of carbon sinks," Powell said.

Those problems have led to debates about exactly how sustainable biofuels are.

What are biofuels used for?

Biofuels are often used for transportation of people and products.

Experts say once they are made, biofuels produce little to no greenhouse gases when used. The same cannot be said with the fossil fuels they are mixed with.

But there is a hope that biofuels might completely replace fossil fuels to power airplanes and ships.

"They are one option among a larger set of solutions," said Jane O'Malley of International Council on Clean Transportation, a Washington-based independent nonprofit.

O'Malley said it is important to use the right kind of biofuel for the right purpose. She said it is important for countries using biofuels to move as quickly as possible to produce them with little to no greenhouse gas production.

Words in This Story

transition – v. to make a change from one state, place, or condition to another

renewable – adj. restored or replaced by natural processes

greenhouse effect – n. the warming of the Earth's atmosphere that is caused by air pollution

cycle – n. a set of events or actions that happen again and again in the same order

chunk⁵ – n. a large amount or part of something

fossil fuels – n. a fuel (such as coal, oil, or natural gas) that is formed in the earth from dead plants or animals

option – n. the opportunity or ability to choose something or to choose between two or more things

1 gathering   

n.集会，聚会，聚集

参考例句：

• He called on Mr. White to speak at the gathering.他请怀特先生在集会上讲话。
• He is on the wing gathering material for his novels.他正忙于为他的小说收集资料。

2 cane   

n.手杖，细长的茎，藤条；v.以杖击，以藤编制的

参考例句：

• This sugar cane is quite a sweet and juicy.这甘蔗既甜又多汁。
• English schoolmasters used to cane the boys as a punishment.英国小学老师过去常用教鞭打男学生作为惩罚。

3 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。

4 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。

5 chunk   

n.厚片，大块，相当大的部分（数量）

参考例句：

• They had to be careful of floating chunks of ice.他们必须当心大块浮冰。
• The company owns a chunk of farmland near Gatwick Airport.该公司拥有盖特威克机场周边的大片农田。

6 chunks   

厚厚的一块( chunk的名词复数 )； （某物）相当大的数量或部分

参考例句：

• a tin of pineapple chunks 一罐菠萝块
• Those chunks of meat are rather large—could you chop them up a bIt'smaller? 这些肉块相当大，还能再切小一点吗？