Water resource constraints become biofuel's biggest bottleneck

According to foreign media reports, the bio-fuel and oil than has the advantage that a variety of sources. But not every corner of the world's oil or gas can be found, but most people can grow crops to produce biofuels. The only shortcoming is the need for crop irrigation, when it comes to water resources, the attractiveness of biofuels on the greatly reduced.
Soybean, for example, according to the University of Texas ? Kerry and Michael Weber, said the bio-fuel made from soybeans requires only a small amount of water. However, if soybean in the growth process can not rely on rain water, and rely on irrigation to grow, it will need a lot of water. In the U.S., an average of a traveling one kilometer road transport energy needs, biofuels, then if the need requires 28 liters of water used to irrigate soybeans. The production of ethanol from corn is almost as much water. An ordinary motor fuel vehicles required to travel one kilometer of wheat needs about 26 liters of water to irrigation.
Currently, about 20% of the U.S. Midwest corn millet growing areas require irrigation. Corn production is the relatively large number of local irrigation district. This is a problem, because the irrigation water of rivers and lakes have been accounted for in the United States 37% of available water. Again compare the use of water by the oil industry, Weber data provided by: either use petrol or diesel as a power, driving a kilometer is about 0.33 l water. This is a conservative estimate, because it does not include the oil in the mining process itself will be from the well water. Even the oil resources in oil shale, tar sands and does not need so much water to separate. In fact, we need to separate these high-temperature oil ancillary products. Gold and Weber said the average tar sands water separation 0.78L/km, the average water separation of oil shale 0.59L/km.