Bioeconomy and Biorefinery: Valorization of Hemicellulose from Lignocellulosic Biomass and Potential Use of Avocado Residues as a Promising Resource of Bioproducts

Abstract

Biorefineries of second generation (2G) are receiving more attention nowadays as an option for the development of bioeconomy all over the world. One of the main pretreatments utilized in this type of facilities for the conversion of lignocellulosic biomass is the use of hydrothermal processing using only water/steam as catalyst under different forms of heating (steam, electric heating jackets, or microwave radiation) at different temperatures. Currently, biorefineries are focused on obtaining feedstocks to produce biofuels, but the current position of these on the market shows that the new biorefineries must be integrated systems and so there is a need to focus on the valorization of the whole coproducts. One of them is hemicellulose, from which for instance oligomers could be derived and used in different areas as pharmaceutical products, food ingredients, fuels, chemicals, and bioplastics. In Mexico, avocado represents an important source for agro-industrial residues. These residues are in a process of valorization under the biorefinery concept, to obtain different types of bioproducts. This chapter describes the concepts usually utilized for the definition and understanding of biorefinery, especially the utilization of hydrothermal pretreatments. It focuses also on linking the concept of bioeconomy with biorefineries, and it introduces the utilization of avocado residues as an example of a Mexican residue with potential importance in the global market.