Bioenergy in Portugal

The utilization of biomass from different sources for obtaining valuable products in the form of chemical compounds or energy has led to the development of a new field. Its aim is to promote the technological development and industrial application of new refinery processes and the development of specific valorization routes for biomass research. In Portugal, several biomasses have started to be studied for valorization, such as forest cuttings and agricultural waste, with the added value of developing a biomass-based energy system. Also, the use of by-products (e.g., insect exuviate) has started with promising results. Therefore, in this chapter, we propose a review of the status of those complementary approaches in Portugal and an important comparison with the most developed Mediterranean country, Italy. One approach is the revision of the literature concerning the valorization of selected biomasses which have been investigated or are under investigation in the country. In particular, spent coffee grounds, spent tea, eucalyptus leaves and insects exuviae are taken into consideration. As for coffee, tea and eucalyptus biomasses, their valorization involves: extraction with solvents (in particular, ethanol) to identify organic compounds of industrial interest; thermal treatment of solid residues to prepare biochar for applications in agriculture or activated carbon depending on the reaction conditions: an overview of the analytical techniques used to characterize these carbonaceous materials is presented. The second approach is the utilization of green metrics to deepen our understanding of greener treatment methods and how sustainable they really are. Concepts such as the E-factor (one of the most adopted metrics by the chemical industry worldwide) or the Eco-Footprint, EATOS and Eco-Scale are still not available. The use of sustainable metrics, such as value-added, employment, the impact of biomass supply chains, and environmental impacts are parameters already used by EU countries, such as Italy, to identify key points in biomass research. In this chapter, we aim to summarize the current state of knowledge and its application to the field of the developmental implementation of biomass-related industries in Portugal.