Sustainable development is the common goal of the current concepts of bioeconomy and circular economy. In this sense, the biorefineries platforms are a strategic factor to increase the bioeconomy in the economic balance. The incorporation of renewable sources to produce fuels, chemicals, and energy, includes sustainability, reduction of greenhouse gases (GHG), and creating more manufacturing jobs fostering the advancement of regional and social systems by implementing the comprehensive use of available biomass, due to its low costs and high availability. This paper describes the emerging biorefinery strategies to produce fuels (bio-ethanol and γ-valerolactone) and energy (pellets and steam), compared with the currently established biorefineries designed for fuels, pellets, and steam. The focus is on the state of the art of biofuels and energy production and environmental factors, as well as a discussion about the main conversion technologies, production strategies, and barriers. Through the implementation of biorefineries platforms and the evaluation of low environmental impact technologies and processes, new sustainable production strategies for biofuels and energy can be established, making these biobased industries into more competitive alternatives, and improving the economy of the current value chains.

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Bio-based ethylene produced by bioethanol dehydration is an environmentally friendly substitute for oil-based ethylene. It is a low-pollution raw material that can be used to produce high-value bio-based materials. Currently, some industrial plants use first-generation (1G) bioethanol to produce bio-ethylene. However, second-generation (2G) bioethanol is not currently used to produce bio-ethylene because the manufacturing processes are not optimized. The conversion of lignocellulosic biomass to bio-ethylene involves pretreatment, enzymatic hydrolysis of carbohydrates, the fermentation of sugars to ethanol, ethanol recovery by distillation, and ethanol dehydration to ethylene. This work presents a review of second-generation (2G) bio-ethylene production, analyzing the stages of the process, possible derivatives, uses, and applications. This review also contains technical, economic, and environmental considerations in the possible installation of a biorefinery in the northeast region of Argentina (NEA).

This work aims to evaluate second-generation bioethanol production from the soda-ethanol pulp of pine sawdust via two strategies: separate hydrolysis and fermentation and simultaneous saccharification and fermentation. A kinetics study of the enzymatic hydrolysis of separate hydrolysis and fermentation was included as a design tool. Three soda-ethanol pulps (with different chemical compositions), Cellic® Ctec2 cellulolytic enzymes, and Saccharomyces cerevisiae IMR 1181 (SC 1181) yeast were employed. The obtained kinetic parameters were as follows: an apparent constant (k) of 11.4 h-1, which represents the link frequency between cellulose and cellulase; a Michaelis-Menten apparent constant (KM) of 23.5 gL-1, that indicates the cellulose/cellulase affinity; and the apparent constant of inhibition between cellulose-glucose and cellulase (KI), which was 2.9 gL-1, 3.1 gL-1, and 6.6 gL-1 for pulps 1, 2, and 3, respectively. The kinetic model was applicable, since the calculated glucose values fit the experimental values. High bioethanol yields were obtained for pulp 3 in the separate hydrolysis and fermentation and simultaneous saccharification and fermentation processes (89.3% and 100% after 13 h and 72 h, respectively).

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