The Effects of Energy Contributions into Subsidiary Processes on Energetic Efficiency of Biomass Plantation Supplying Biofuel Production System

A number of technologies of biofuel production from various biomass crops are already in use, and many studies on new ones are carried out. Biomass production, like any other production processes, involves a number of necessary processes that facilitate subsequent production steps. Those subsidiary processes (e.g. tillage or logistic operations) are connected with consumption of energy. It is therefore important to assure that the sum of energy inputs into those technological steps does not exceed the energy output from the system. Obviously, large energy gain is desired. The paper is devoted to the estimation of energy inputs made into the subsidiary processes occurring in the agricultural subsystems in which various topological structures of plantations as well as for various technologies of tillage, and different requirements for transportation are allowed. Mathematical model describing above mentioned dependencies is derived, and appropriate algorithm elaborated for numerical computations, that have been performed for rapeseed plantations. The results demonstrate evident effects of the choices of technology, and organization of work onto efficiency of plantation as measured by EROEI - type indicator.