Efficient biomass value chains for heat production from energy crops in Ukraine
Keywords: energy crops, Miscanthus, willow, LCA, energy efficiency, GHG, Cumulative Energy Demand, Energy Yield Coefficient, bioenergy heat
AbstractThe purpose of the paper is to identify the most energy efficient value chains using solid biomass of specially grown energy crops and the most significant parameters affecting their energy efficiency and environmental sustainability. The methodology of Life Cycle Assessment (LCA) was used to determine the energy efficiency of value chains of heat production from energy crops. According to the methodology, the scope of the product system includes the raw material cycle of growing energy crops and the subsystem of transformation with production of thermal energy. Cumulative energy demand and energy yield coefficient were chosen as energy efficiency indicators. The product system was compared with a similar one using natural gas. The non-renewable energy yield coefficient was used to define how many times the energy output was bigger than the input of non-renewable energy. Assessment was conducted for two energy crops: Miscanthus as a typical representative of specially grown grassy energy crops and willow as a typical representative of specially grown woody energy crops. The growing of energy crops in Ukraine for the subsequent production of biofuel in the form of chips and their combustion in biofuel boilers are energetically effective with a maximum transportation distance of 400 km for Miscanthus chips and 180 km for willow chips.