Energy Crops for the Production of Biofuels
Numerous options are available to supply biomass to biorefineries. Potential feedstocks include short rotation woody crops, herbaceous energy crops, and residues (forestry and agricultural). Each feedstock has unique chemical and physical properties that will influence the products and profitability from a biorefinery. For example, herbaceous feedstocks will have higher ash contents on average than woody products. Herbaceous feedstocks typically will have a lower lignin content and as a result a lower heating value than woody crops. Feedstock selection should consider the availability of equipment to establish, maintain, and harvest energy crops. In most cases, the equipment required is available to produce energy crops within the forestry and agricultural industries but is not optimized for energy crop production. Deciding which feedstock to produce will depend on site-specific considerations (soil type, temperature, and rainfall) that will influence the cost, yield, and composition of energy crops. Collection, storage, and transportation of energy crops is expensive relative to current fossil fuels, although biomass energy crops have lower greenhouse gas emissions than fossil fuels.