The Capital Efficiency Challenge of Bioenergy Models: The Case of Flex Mills in Brazil

Bio-based energy sources have received increasing interest in recent years as petroleum prices have risen, geo-political instability has increased, and climate change has been in evidence. Extensive farming systems producing bio-based feedstocks, such as maize and sugarcane, are the models most widely used. Similar models are planned for dedicated cellulose crops such as miscanthus and eucalyptus. Bioenergy feedstock production that follows the current commercial agricultural model may inefficiently employ capital as the spatial density of the system, and the relative gravimetric density of the feedstock and volumetric density of the fuel products are low. The example of ethanol production in Mato Grosso, Brazil demonstrates the key concepts of density and capital intensity that are so critical to the efficient use of capital.