Page 69 - Biofuels for a More Sustainable Future

62 Biofuels for a More Sustainable Future

implications for human health (Gerbens-Leenes et al., 2009). Therefore, to
answer to the need of assessing the interplay between the different sectoral
demands and identifying win-win strategy of global resources management,
the nexus concept among food, energy, water, land use, and ecosystems has
been proposed (Ringler et al., 2013).
Karabulut et al. (2018) suggested a matrix for the operationalization of
nexus assessment toward the identification of the main interlinkages
between the different resources and proposed a theoretical framework for
integrating nexus and LCA.
Studies applying the nexus concept to biofuels are often focusing on
emerging economies, where the magnitude of impact will vary significantly
across regions and countries depending on the size of the biofuel targets
adopted, the identified technologies and feedstock, and especially the
water availability and scarcity level (see, e.g., Silalertruksa and Gheewala,
2019). Optimization of biofuels production systems may profit from a
nexus approach. For example, a biorefining system could be designed
ensuring that the interactions with the surrounding watershed are
taken into account, and the supply chain for the production and distri-
bution of feedstocks, grains, and biofuels is compatible with local water
and land requirements (Lo ´pez-Dı ´az et al., 2018). Recently, the assessment
of nexus has been coupled with input-output matrixes (Bellezoni et al.,
2018) for assessing possible consequences of future scenarios of biofuels
expansion.
From the modeling point of view, several challenges are in common to
food and biofuel assessment (Sala et al., 2017) whereas others are specific of
feedstocks for bio-based products (Mirabella et al., 2013).

4.5 Closing the loop: A circular bioeconomy to foster the use of
sustainable feedstocks
Both international and European policies are advocating a transition toward
“bioeconomy,” an economy aiming at reducing the dependence from
fossil-based resources, limiting greenhouse gas emissions, safeguarding food
security, and ensuring a sustainable economic growth. Besides, circular
economy policies are aiming at closing loop of resources as much as possible.
Increasingly, studies are performed to assess sustainability of bio-based
alternatives, starting from energy applications up to materials and products
(e.g., Mirabella et al., 2013). In fact, the application of circular economy
principles to bioeconomy could represent a valuable contribution to bio-
economy performance optimization (Corrado and Sala, 2018). However,