The perfectly normal grain harvest produces up to 80% waste products, mainly in the shape of straw. Thereby, the further processing, e.g., threshing and milling haven't even been taken into consideration. The second generation of biomass distinguishes itself by no longer being in competition to the production of foodstuffs, thus pushing the price up.
Particularly after the large-scale forest clearing (very often the tropical forests) became common knowledge for the production of bio-fuel, like e.g., Ethanol, there was a lot of commotion. What's the point of avoiding CO2 by using renewable raw materials, when one of the biggest natural converters of CO2 is being decimated at the same time?
At least the EU has reacted and limited this amount of biomass. Starting in 2020, the manufacturers will have to look for more complicated processes. Indeed, should they succeed, then there will be no lack of raw materials. After all, during the processing of almost all natural products, residual products spin off, which are then sold for a low price, as long as the demand for them is still limited.
Actually, the production-plants shouldn't be too large, because the more they can process, the longer the delivery distances are. Unfortunately, the basic approach to a production of this nature, always tends to be somewhat oversized. Perhaps, e.g., the manpower-costs can be better calculated if the facility is umpteen times bigger.
At least there is already a movement to lower the cost of transporting to the large plants. Thereby, smaller plants, which extract only the desired portion of the residual materials are being developed. Through this, the biomass is very much reduced and the transporting can be carried out much more cheaply with trucks instead of with tractor/trailer combinations. After all, at the end of the day everyone wants to make a profit.
To explain it quite simply, the sugar, wood and other residual materials, contain portions which can be well burnt. The latter is used for generating the internal power in the production-plant. Similar to the purifying of waste water, the main work is done by micro-organisms. The conditions are: Chopping the material into the smallest possible parts, a certain amount of warmth and other things, which speed up the pre-treatment process. 10/13
In the video shown here you can see the possible advantages of Ethanol.
You can read here, about how the composition of fuels can help in the development of engines.