The resource footprint of biobased products: A key issue in the sustainable development of biorefineries

Abstract

The multifunctionality of bioresources is a major opportunity for the future; it offers the ability to replace fossil-related market demands in a carbon neutral way. However, the switchover to a biobased economy faces two main challenges in comparison with the current fossil-based situation: biofeedstock requires an intensive cultivation step and furthermore there is a certain competition with the food chain which limits the amount of land available for new markets. So whilst biomass is seen as a 'renewable' resource, it is definitely not 'gratuite', inducing the need of an efficient cultivation and valorization. In this paper, a case study is executed to highlight that biorefining feedstock into a wide range of products is a thermodynamically efficient (81.1%) way of processing all molecules of the bioresources for specific purposes in different segments of the market demand. On the other hand, it is demonstrated in the second part of the paper that replacing fossils requires a certain amount of inputs from the Earth's crust causing additional thermodynamic losses in the production chain (15.3% efficient), which are quantified based on the resource footprint of the Cumulative Exergy Extracted from the Natural Environment (CEENE) methodology. A scenario assessment demonstrates the resulting tradeoff between the carbon footprint of bioproducts and the land, water, and minerals footprint; in the case study executed, 27% fossil resources are saved at the cost of 93% extra land, water and mineral input from the natural environment.© 2011 Society of Chemical Industry and John Wiley & Sons, Ltd.