Although definitions vary, first-generation biofuels are generally regarded as those made from food crops like sugar cane, corn and palm oil, and are used commercially as ethanol.
Bio-esters on the other hand are produced by a chemical reaction between vegetable oil (e.g. rapeseed or soyabean oil) and an alcohol. The properties of bio-esters are very close to those of diesel fuel and the two can be mixed. This blend is known as biodiesel.Up to 10 percent of ethanol can be blended with standard fuel in the United States, and up to 5 percent in Europe, while bio-esters can be mixed with diesel.
As we have argued before, a lot of pertinent questions can be (and are) asked about the sustainability of first-generation biofuels.
Second-generation biofuels, on the other hand, are those made from nonfood feedstocks, like jatropha, wood chips, and cellulose. Using gasification technology, clean fuels can be produced for pure use, unblended with hydrocarbons. If used at 100 percent concentration, second-generation biofuels could reduce production-to-driving carbon dioxide production by up to 90 percent, according to Royal Dutch Shell.
It seems that the big oil companies are beginning to strategically diversify into alternative energy (not by definition sustainable by the way).
Also Singapore is reckonising the importance of second-generation biofuels.
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