What are the Pros and Cons of Ethanol Biofuel?

We use energy every day. We use it to turn on lights, to heat our homes, and to power cars. Most of the world’s energy comes from burning fossil fuels. But scientists and engineers are looking for more sustainable alternatives. 

Biofuels are becoming a popular alternative to traditional fossil fuel resources. But as with any new technology, it’s important to weigh the pros and the cons. Let’s consider some of these. 

What is Biofuel and How is it Used? 

Biofuels are derived from recently dead or living plant material and animal waste. This differs from fossil fuels, which are derived from long-dead plant and animal matter. The most commonly used biofuels are ethanol and biodiesel. They are produced from plants that are usually grown as crops. These plants make up the biomass that’s used as the feedstock in biofuel production. Feedstock is any material that is used to make biofuels. In North America, corn is the main type of feedstock used in ethanol production. 

To produce ethanol from corn, the first step is to break down starch. Starch is a complex carbohydrate. To produce ethanol, it must be broken down into simple sugars like dextrose and glucose. A process called fermentation then converts these sugars to ethanol. 

Did you know?

Yeast ferments sugar into ethanol in anaerobic conditions. This means that the process can occur without oxygen!

Biodiesel is made from vegetable oils or animal fats. A reaction called transesterification is responsible for the conversion of plant oils to biodiesel. Transesterification is the reaction of an alcohol with oil or fat to produce fatty acid alkyl esters, otherwise known as biodiesel.

Canadian biorefineries have the capacity to produce 1.7 billion litres of ethanol per year. Most of this is mixed into gasoline. The majority of gasoline-powered vehicles built since the 1980s can run on a mixture of up to 10% ethanol (E10) without any engine modifications. Some North American car companies make Flexible Fuel, or Flex-Fuel, vehicles with modified engines. These engines can use mixtures of up to 85% ethanol and 15% gasoline (E85). 

Did you know?

The United States and Brazil are the world leaders in biofuel production. Together, they produce 70% of the world’s biofuels!

Canada’s Renewable Fuel Regulations were enacted in 2010. They require that non-renewable fossil fuel contain an average of 5% renewable fuel content. That 5% level is currently being met with corn and wheat ethanol (E5). What about the E85 blend that can be used in Flex-Fuel vehicles? Some Canadian companies with large fleets of vehicles use E85. But it is not yet widely available. There are only a handful of gas stations in Canada that sell E85. In contrast, there are over 3 000 gas stations with E85 pumps in the U.S. That may sound like a lot. But it is still less than 2% of total fuel stations. 

What are the pros of biofuels?

Ethanol is considered a renewable energy resource. That’s because new crops can be grown to replenish the feedstock needed to make it. On the other hand, fossil fuels take millions of years to produce. They are considered a nonrenewable resource because once they’re used up, that’s it!

One of the main benefits of using biofuels is that it reduces greenhouse gas (GHG) emissions. In 2017, the oil and gas and transportation sectors accounted for over 50% of Canada’s total GHG emissions. Most of these were carbon dioxide (CO₂) released by burning fossil fuels, such as gasoline.

The CO₂ that is released into the atmosphere when fossil fuels are burned produces powerful GHGs. These GHGs contribute to climate change. Unfortunately, there is no way to turn CO₂ back into fossil fuels. 

CO₂ is produced when biofuels are burned, too. But some of the CO₂ released by burning biofuels is absorbed by the new crop of feedstock through the process of photosynthesis. The CO₂ is incorporated into the sugar molecules that the plants produce. These will eventually be converted back into biofuel. Because of this, ethanol is considered to be carbon neutral. 

Did you know?

It has been found that ethanol yields 25% more energy than is put into its production, and biodiesel yields a whopping 93%!

What are the cons of biofuels?

Biofuels come with concerns, too. Some concerns include energy balance, the food versus fuel debate, and the availability of biofuels.

Do biofuels have a negative energy balance or a positive energy balance?

Ethanol itself is considered carbon neutral. But the process of producing it is not. Fossil fuels are often used throughout the process of producing biofuels. For example, farmers’ tractors use diesel fuel. The trucks that transport the feedstock to biorefineries use diesel fuel. The biorefineries themselves sometimes use fossil fuels for power. If the input energy to make a fuel is greater than the output energy, that fuel has a negative energy balance. That’s not good. If the output energy is greater than the input energy, the fuel has a positive energy balance. That is good.

Scientists must do life cycle analyses to fully understand the GHG impact of biofuels compared to fossil fuels. In the early days of ethanol production, many studies found that it had a negative energy balance. However, recent Canadian and American life cycle analyses have found a modestly positive energy balance in the corn ethanol production industry. The improvement is largely due to newer, energy-efficient biorefineries. 

What is the “Food vs. Fuel Debate”?

Biofuels come with some economical and ethical concerns. Specifically, what happens if people use cropland to grow fuel biomass instead of food? This relates to food security. Critics of first generation biofuels argue that using food crops for fuel production increases food prices. This makes it more difficult for people to afford to eat healthily. 

A commodity is anything valuable that is bought, sold or traded. Let’s look at the example of one commodity: corn. 

Corn is a renewable feedstock. But some harvests are more successful than others. That means its supply can vary. When agricultural conditions are good, there may be plenty of corn. There may be enough for human food, animal feed, and biofuel production. But sometimes harvests suffer due to conditions like droughts, floods, and cold periods. At these times, the supply of corn may go down. And when the supply of a commodity goes down, the price goes up.

Of course, this ‘Food vs. Fuel’ debate has another side. Some studies show that global food wastage is a much bigger issue for food security than competition with biofuels is. Some scientists have even suggested that food that would normally go to waste should be diverted to the biofuel industry instead. 

Biofuels can affect food and resources for other organisms, too. It takes a lot of land to produce biofuels. Clearing land for agriculture can have big impacts on the environment, and the plant and animal life living there. 

Summing up

There are certainly no easy answers when it comes to the debate between fossil fuels and biofuels. The global food chain and the biofuel industry are interconnected in complicated ways. But people are more and more aware of the possible drawbacks of first generation food crop-based biofuels. There is also a push towards second generation biofuels instead. These use non-food feedstocks like agricultural, restaurant, and municipal waste.