|
Recycling Wastewater May Be One Simple Solution in the Production of Biofuels
The United States consumes and produces more ethanol fuel than any other country in the world. Across the nation ethanol fuel plants are being built everywhere, especially in Minnesota where there are currently 17 biofuel plants. This is, for the most part, a positive move, particularly as the U.S. tries to become less dependent on imported oil. America’s farmers, too, have reaped the benefits because of this growing demand for agricultural products. One significant negative associated with biofuel production, however, is the growing impact on our water supply because of the excessive amount of water required to produce biofuels.
On average, it takes four to six gallons of water to create one gallon of biofuel. It is estimated that the biofuel industry consumes two billion gallons of groundwater, and that number is expected to double within a year due to the soaring demand for alternative fuels. The water usage issue doesn’t stem from just the processing needs of biofuel plants; the irrigation process of the crops creates an additional need for more water. Without rain, it takes 6,000 gallons of water to produce one bushel of corn, and that one bushel of corn can only produce 2.8 gallons of ethanol.
|
Groundwater levels are difficult to measure due to the amount of water in underlying layers of porous rock. The concern is that with the increasing number of new biofuel plants springing up around the country, there is no accurate method to determine the actual water levels available over any given period of time to support these plants. If biofuel is going to be a solution to our dependency on fossil fuels, the industry needs to develop better, more efficient strategies for reusable water conservation.
Minnesota is leading the development of such solutions in the small town of Winnebago. The ethanol fuel plant uses approximately 350,000 gallons of water each day, while the city discharges approximately that same amount of treated wastewater into the river. The solution is a simple concept: the fuel plant would use this treated wastewater for production purposes. The city would have to divert the wastewater from the river to the ethanol plant. The company’s strategy is to get a state bill passed that would pay for the estimated cost of $275,000 to do this. The bill is currently under consideration. The company’s goal is to produce a maximum of 2 to 1 ratio between water and fuel. They know this process is a viable solution because Calpine Power Plant in Mankato is already operating efficiently with treated wastewater.
Ethanol fuels should not be considered the only solution to wean the U.S. off of “fossil fuel dependency” and for a number of very good reasons. Obviously, the main reason is that the U.S. does not want to be dealing with massive water shortages in the near future. Another reason is that ethanol fuel maybe cheaper than gas (per gallon) in many states across the U.S., but that does not always equate to better gas mileage efficiency. Other alternative fuel production options such as biodiesel, natural gas, propane, electric and hydrogen each offer positives and negatives and should be researched further. But until we can appropriately manage our treated wastewater recovery issues more effectively and utilize such methods in the production of biofuels, we may be cleaning up the environment in one area, while at the same time destroying our natural water supply.
|