– By Joe LeMay
Many will attempt to blame fuel system issues on ethanol in their gasoline. The information below is not about the issue with ethanol, but how the ethanol got into the gasoline supply. Maybe with some background, it is easy to see the reason for the addition and see that it is time for a change due to technology.
The Clean Air Act of 1970 required vehicle emission reductions. Think back to the first vehicle you experienced that had emission controls. There was a lot of effort to make a basic carbureted engine operate with reduced emissions. There were add-on systems such as air injection and exhaust gas recirculation. The vehicles did not run that well because the combustion process was attempted to be mechanically altered. That system was inherently flawed from an emissions perspective.
In 1990, there were amendments to the Clean Air Act. The amendments included the requirement to use oxygenated gasoline (“reformulated” gasoline). An oxygenated gasoline mixture allows the fuel to burn more completely and therefore produce cleaner emissions. Its use in fuel has obvious benefits for improving air quality.
With the new revisions, petroleum companies had to come up with a new way to make a cleaner-burning fuel. One option that we had until recently is MTBE. It was added beginning in 1979 as an anti-knock agent, replacing lead that had a similar use as an anti-knock agent. MTBE also is an oxygenate for gasoline. In 2002-2007, MTBE was banned due to persistent groundwater contamination from leaking storage tanks.
Methanol was another effort. For a time in California, there were 5,000 Ford Taurus FFV that would operate on an 85% methanol fuel. There were also specific gas pumps for that fuel. Some of you may have remembered those vehicles if you lived in the region. That program did not last long.
Ethanol is used as an option as both an oxygenate and as an octane booster for anti-knock properties. There are however many issues with ethanol and with production of ethanol as a replacement for portions of gasoline.
At the time when an oxygenate became part of the fuel requirement, there were fewer choices of engine control systems, fuel injection systems, and performance enhancements available in engine technology. Ethanol provided a fuel option that was beneficial. However, technology has now surpassed the ethanol option. Ethanol as a oxygenate is no longer needed. Current emission control systems produce the required low emissions with lower levels of added ethanol.
The process of producing ethanol, transporting it, and the power that is produced from an ethanol fuel need to be considered when determining the overall efficiency of ethanol as a fuel additive. One can see there are detrimental effects on air quality, fuel energy or power, and cost.
Ethanol production emissions: There are significant air emissions to produce, transport, and use the ethanol. Ethanol is made from corn. There are a lot of steps from growing the corn to delivering it at the refinery. Think about the water that needs to be added to crops, water pumps run by fossil fuels that are used on a farm, and the fuel needed for the agricultural equipment. These are all sources of air emissions.
Creating ethanol for inclusion into gasoline requires more energy to make the ethanol than the energy the ethanol will produce. Adding up the energy costs of corn production and its conversion to ethanol, 131,000 BTU are needed to make 1 gallon of ethanol. One gallon of ethanol has an energy value of only 76,000 BTU. Put another way, about 70 percent more energy is required to produce ethanol than the energy that is in ethanol. Every time you make 1 gallon of ethanol for gasoline, there is a net energy loss of 54,000 BTU.
Then there is the fuel required to deliver the ethanol to refineries. I have seen rail cars of ethanol being delivered to our local refinery. The ethanol is then added to the gasoline the refinery produced.
Fuels are an energy source: The higher the fuel energy, the more efficient it is as a propulsion material. Fuels have different energy values that are measured by heat content of the fuel. Liquid fuels are measured by physical units such as gallons, and by heat content in BTUs. This becomes their energy content in BTU per gallon. Un-oxygenated gasoline (ethanol free) has a heat content of 125,000 BTU per gallon. Ethanol has a heat content of 76,000 BTU per gallon. A 10% ethanol gasoline therefore has a heat content of 120,000. As the amount of ethanol increases, the heat content of the fuel decreases and so does the power that is produced by it.
What happens with E10 gasoline? The power, and correspondingly, the gas mileage will decrease. There are studies that show this effect. That is only part of the issue with ethanol.
Cost: Since the creation of the domestic market for corn ethanol after the energy crisis of the 1970s, the federal government has nurtured and maintained the ethanol industry with a steady stream of subsidies. Federal subsidies include tax breaks for corn-based biofuels to dispense higher blends of ethanol such as E10 and the Renewable Fuel Standard mandate (RFS) for the use of corn ethanol. The RFS mandate requires oil and gas companies to blend increasing amounts of biofuels with gasoline each year through 2022, and corn ethanol comprises a majority (78 percent) of the mandate. Approximately $1 billion a year in current federal and state subsidies for ethanol production are costs to consumers. So, you lose gas mileage, lose power, have added air emissions, and have a subsidized fuel additive that does no one any good, unless you are growing the corn.
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