In most western countries, corn is used for bio gas instead, whatever is the most abundant. Unfortunately, the process of making bio gas is very inefficient to produce, basically you use more energy producing a product that generates less energy that's the reason why bio gas hasn't been taking off as it should be... In theory, it take 1 unit of raw materials to produce half a unit of fuel, so in turn malaki rin ang wastage and usage of natural resources... Kinda like the same thing with H2 vehicles, it take much more fuel to power the machines to produce H2 gas than to create regular fuel... Electric cars din ganun...