Sugarcane ethanol is an alcohol-based fuel produced by the fermentation of sugarcane juice and molasses. Because it is a clean, affordable and low-carbon biofuel, sugarcane ethanol has emerged as a leading renewable fuel for the transportation sector. Ethanol can be used two ways:
- Blended with gasoline at levels ranging from 5 to 25 percent to reduce petroleum use, boost octane ratings and cut tailpipe emissions
- Pure ethanol – a fuel made up of 85 to 100 percent ethanol depending on country specifications – can be used in specially designed engines
Benefits of Ethanol
- Cleaner Air. Ethanol adds oxygen to gasoline which helps reduce air pollution and harmful emissions in tailpipe exhaust.
- Reduced Greenhouse Gas Emissions. Compared to gasoline, sugarcane ethanol cuts carbon dioxide emissions by 90 percent on average. That’s better than any other liquid biofuel produced today at commercial scale.
- Better Performance. Ethanol is a high-octane fuel that helps prevent engine knocking and generates more power in higher compression engines.
- Lower Petroleum Usage. Ethanol reduces global dependence on oil. Sugarcane ethanol is one more good option for diversifying energy supplies.
Brazil: A Leader in Ethanol Production and Use
Brazil has achieved greater energy security thanks to its focused commitment to developing a competitive sugarcane industry and making ethanol a key part of its energy mix. In fact, Brazil has replaced more than half of its gasoline needs with sugarcane ethanol – making gasoline the alternative fuel in the country. Many observers point to Brazil’s experience as a case study for other nations seeking to expand use of renewable fuels and have identified two key factors for success:
- Sugarcane Ethanol. Brazil is the world’s largest sugarcane ethanol producer and a pioneer in using ethanol as a motor fuel. In 2010, Brazilian ethanol production reached 27.4 billion liters (7.2 billion gallons). Most of this production is absorbed by the domestic market where it is sold as either pure ethanol fuel or blended with gasoline. All gasoline sold in Brazil includes a blend of 18 to 25 percent ethanol.
- Flex Fuel Vehicles. The country first began using ethanol in vehicles as early as the 1920s, and the trend gained urgency during the oil shock of the 1970s. However, sugarcane ethanol’s popularity really took off in 2003 with the introduction of flex fuel vehicles that run on either gasoline or pure ethanol. More than 90 percent of new cars sold today in Brazil are flex fuel due to consumer demand, and these vehicles now make up about half of the country’s entire light vehicle fleet – a remarkable accomplishment in less than a decade. As a result, Brazilian consumers have a choice at the pump when they fuel their cars and most are choosing sugarcane ethanol for its price and environmental benefits. Since 2008, annual ethanol sales have surpassed that of gasoline in Brazil, making gasoline the alternative fuel in the country.
Since 2003, the combination of sugarcane ethanol and flex fuel vehicles has reduced Brazil’s emissions of carbon dioxide by 128 million tons. That’s as good for the environment as planting and maintaining 916 million trees for 20 years!
Sugarcane ethanol today is made from the sucrose found in sugarcane juice and molasses. This current process taps only one-third of the energy sugarcane can offer. The other two-thirds remains locked in leftover cane fiber (called bagasse) and straw. While some of this energy is converted to bioelectricity in Brazil, scientists have discovered new techniques to produce ethanol – known as cellulosic ethanol – from leftover plant material.
This complex process involves hydrolysis and gasification technologies to break down lignocellulose – the structural material found in plant matter – into sugar. While cellulosic ethanol can be manufactured from abundant and diverse raw materials, its production requires a greater amount of processing than traditional sugarcane ethanol and is therefore currently more expensive.
Once engineers and technical experts perfect commercial-scale manufacturing, production prices will come down, and cellulosic ethanol might double the volume of fuel coming from the same amount of land planted with sugarcane.