Short rotation crops

Second-generation biofuel technologies make use of a much wider range of biomass feedstock (e.g., forest residues, biomass waste, wood, woodchips, grasses and short rotation crops, etc.) for the production of ethanol biofuels based on the fermentation of lignocellulosic material, while other routes include thermo-chemical processes such as biomass gasification followed by a transformation from gas to liquid (e.g., synthesis) to obtain synthetic fuels similar to diesel. The conversion processes for these routes have been available for decades, but none of them have yet reached a high scale commercial level. 

Energy crops. Energy crops are simply crops grown for this specific purpose and are continually replanted once harvested. Woody short-rotation crops are examples of these crops. Trees such as the poplar, the eucalyptus, the willow, and the conifers are expected to be useful [16-22], as are agricultural crops such as the sweet sorghum and the algae. 

Sawdust/chips Forest residues Wood residues Clearings thinnings Short rotation crops Agricultural residues Agricultural crops Straw Waste Peat... 

Wright, L., Christersson, L., (2000 1 Short Rotation Crops for Energy Purposes, IE A Bioenergy, Task 17, Short Rotation Crops for Energy Purposes, Proceedings Meeting Auburn, Alabama. 

Poplar tree (short rotation crop) was used as fuel in the combustion experiments. The biomass was air dried. The characterization analysis was made with a homogenous mixture of leaves and stems milled to a 2 mm size. 

Clearly there are commercial interests in developing clonal lines of trees that have modified or reduced amounts of lignin for fast-growing, short-rotation crops... 

Forest plantations are a remarkable source of wood on a global scale. Based on [26] one can estimate their potential wood supply to be some 1.75 billion m in 2005. In Western and Central Europe, however, wood supply from short rotation crops is marginal. In Sweden, Hungary, and Poland some 10000 hectares are stocked with willow and black locust whereas in other European countries short rotation crops are cultivated on a few hundred to thousand hectares. 

Regarding market prices for short rotation crops, there is the same situation as for wood. There are no global or national prices to report. 

The uptake of heavy metals from soils is also determined by their contents in soil and by plant species. If these crops are used for anaerobic digestion one has to consider that there is a remarkable risk of an accumulation of heavy metals in soil. In the case of combustion, most heavy metals can be removed by filtering the ash and it can be used safely as fertiliser. Thus cultivation and combustion of short rotation coppice is a smart scheme of removing heavy metals from contaminated soils. 

Energy crops Short-rotation woody crops, herbaceous woody crops, grasses, starch crops, sugar crops, forage crops, oilseed crops, switchgrass, miscanthus... 

Lignocellulosic perennial crops (e.g., short-rotation coppices and grasses) are a promising feedstock becanse of high yields, low costs, good snitability for low-quality land (which is more easily available for energy crops), and the low environmental impacts. 

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