Importance of Ethanol
High-level ethanol blends reduce nitrogen oxide emissions by up to 20%, and it can reduce net carbon dioxide emissions by up to 100% on a full life-cycle basis. High-level ethanol blends can reduce emissions of Volatile Organic Compounds (VOCs) by 30% or more (VOCs are major sources of ground-level ozone formation). As an octane enhancer, ethanol can cut emissions of cancer-causing benzene and butadiene by more than 50%. Sulphur dioxide and Particulate Matter (PM) emissions are significantly decreased with ethanol.
The US now uses more than 15 billion gallons of cleaner, ethanol-blended petrol a year, totalling 12% of fuel sales in the US. Most of it is a 10% blend, but 85% and even 95% blends are now being tested.
Ethanol blends are increasingly used in South Africa, while Brazil, the world leader, produces four billion gallons of ethanol a year: all Brazilian fuel contains at least 24% ethanol, and much of it is 100% ethanol (engines can be designed to run on 100% ethanol). Chrysler, Ford, and General Motors all recommend ethanol fuels, and nearly every car manufacturer in the world approves ethanol blends in their warranty coverage.