Second-Generation Bioplastics from Lignocellulosic Materials

Second-generation (2G) bioplastics are emerging as a new potential source to supply the global plastics market. Differently to the first generation, 2G bioplastics are produced from non-edible, bio-based sources. Lignocellulosic biomass and non-edible vegetable oils are the main carbon sources for the production of 2G bioplastics, avoiding competition with the food industry for the same raw material source. Lignocellulosic biomass is the most promising and widely distributed source for the sustainable production of 2G bioplastics. However, the rich composition in polymers (carbohydrates and lignin) make the lignocellulosic biomass recalcitrant. For this reason, it is necessary to apply pretreatment methods for the destructuring of lignocellulosic biomass and to improve the release of fermentable sugars and phenolic monomers. Then, these monomers are used through biotechnological and chemical processes to produce 2G bioplastics. Depending on the applied chemical or fermentative route, biodegradable or non-biodegradable 2G bioplastics can be obtained with the same properties as traditional plastic. The use of lignocellulosic biomass generates great prospects for sustainable production of 2G bioplastic. In addition, the application of circular bioeconomy concepts and the implementation of lignocellulosic biorefineries would make industrial-scale production viable, increasing the reuse and valorization of agro-industrial by-products.