Integration of energy and water consumption factors for biomass conversion pathways

Abstract

AbstractWater consumption is one of the critical factors for bioenergy production. In this study, six biofuel and six biopower production pathways are integrated with their water requirement to develop a new factor combining water consumption and energy efficiency for each pathway. This integrated factor is defined as water requirement for 1 MJ of net energy value (NEV) of biofuel or biopower. Agriculture‐residue‐based ethanol production pathways consume 51.2–63.6 liters of water per MJ of NEV. These pathways are both water and energy efficient. The biopower production pathways based on agriculture residues consume 27.2–50.6 liters of water per MJ of NEV. Although a switchgrass‐based ethanol production pathway is the most energy efficient, this pathway consumes an average of 130 liters of water per MJ of NEV due to poor water efficiency. Corn‐to‐ethanol and wheat‐to‐ethanol pathways are neither energy efficient nor water efficient and consume an average of 178 liters and 325 liters of water per MJ NEV, respectively. A rapeseed‐to‐biodiesel pathway is less energy intensive and lies between corn‐ and wheat‐grain‐based ethanol pathways and consumes an average of 211 liters of water per MJ of NEV. © 2011 Society of Chemical Industry and John Wiley & Sons, Ltd