Is Ethanol Gasoline Really Environmentally Friendly?
A professor in the US pointed out that ethanol production costs fossil fuels and agricultural land.
For decades, humanity has been searching for new fuels. The dependence on fossil fuels has led to unstable gas prices, along with negative impacts on the environment.
Hydrogen is seen as a great alternative, but there are complex questions about safety. Some tech companies are betting on solar and wind, but the infrastructure will be expensive. For the energy industry, ethanol is a practical solution in the short term.
Ethanol has been a popular alternative fuel for a long time in the world. |
Ethanol is basically bio-alcohol. In the US, it is usually made from corn. In Brazil, it is made from sugarcane. Wheat, barley and potatoes are also among the many sources of ethanol in the world.
Ethanol is used as an additive to gasoline at certain percentages for a number of benefits. Ethanol contains a lot of oxygen in its chemical structure, which helps the fuel mixture burn efficiently. Adding a small amount of ethanol (usually one part ethanol to nine parts gasoline) to gasoline also helps reduce greenhouse gas emissions, such as carbon monoxide and nitrous oxide.
According to the Argonne National Laboratory in the US, greenhouse gas emissions decreased by about 10 tons in 2007 due to the use of ethanol fuel. Another study in 2006 in Wisconsin showed that the impact on the ozone layer decreased by 16% since the country used E10 gasoline in 1994.
Adding ethanol to the gasoline mix also reduces fuel consumption while driving, and any car can run on E10 biofuel. E85 blends burn cleaner, reducing more harmful emissions into the atmosphere. But only a small number of cars can use this fuel.
Ethanol has clear benefits, but there are two problems. First, there is not much energy in ethanol compared to gasoline (of the same volume), and producing ethanol from food crops will reduce the amount of land available to feed the population.
According to Cornell University professor David Pimentel, ethanol production creates a long-term energy loss. According to his calculations, growing corn and processing it into 1 gallon (3.7 liters) of ethanol requires 131,000 BTUs of energy, but 1 gallon of ethanol contains only 77,000 BTUs of energy.
Furthermore, people are using fossil fuel-powered equipment to grow, store, and harvest corn. And even processing corn into ethanol requires fossil fuel-powered machinery, and then transporting the ethanol to distribution points. The ethanol industry actually requires a large amount of fossil fuel to produce ethanol.
Ethanol gasoline is popular in the US, mainly E10 and E85. Photo:Howstuffworks. |
Not all scientists agree with Pimentel’s analysis of energy efficiency. The US Renewable Energy Laboratory says that it takes only 1 BTU of fossil fuel energy to produce 1.3 BTU of ethanol energy. This means that ethanol production increases energy by 30%, contrary to Pimentel’s conclusion.
Professor Pimentel says he doesn’t see a future for ethanol as a truly renewable energy source. He estimates that a car that uses ethanol for a year requires 44,515 square meters of corn, enough to feed at least seven people.
Not to mention that corn fields in the US need a period of time to recover after harvest. Therefore, there will be a period of time when the land is empty, and there is no corn to serve ethanol production. To maintain the ethanol industry, more and more agricultural land must be given over to corn cultivation. In the long run, it can lead to food shortages and push up the price of this commodity.
One alternative to ethanol is cellulosic ethanol, a biofuel made from non-food sources such as corn stalks or grasses. If scientists can develop this niche, cellulosic ethanol could solve the fuel and production cost problems.