Soybean Straw as a Feedstock for Value-Added Chemicals and Materials: Recent Trends and Emerging Prospects

Soybean straw is an agricultural residue of soybean whose yield is up to 1.5 kg per kg of soybean. The existing literature shows the vast potential of soybean straw as an environmentally friendly carbon source to produce value-added chemicals, materials, fuels, and energy in a similar way to oil refineries. However, the use of this biomass on a commercial scale in biorefineries still faces some challenges. This comprehensive review discusses the available literature in several topics related to the application of this agricultural residue, such as productive potential; quality of feedstock; feedstock delivery; challenges in the breakdown of the cell wall polymeric structure; conversion process into chemicals, heat, and power; and the production of advanced materials. Several examples of fiber treatment are presented to demonstrate the potential of taking advantage of the mechanical properties of soybean straw. Current knowledge gaps and challenges related to the conversion of soybean straw to fermentable sugars and the low performance of hydrolysate fermentation are discussed, besides other applications in the sugar platform. Thermochemical conversion is discussed as well because of the possibility of readily employing this biomass in co-processing plants. In the end, an outlook of potential directions for future research towards the next generation of integrated soybean/soybean straw biorefinery is presented to demonstrate the potential of further developing applications for this biomass. Graphical abstract Synopsis Potential applications of soybean straw are reviewed, with a focus on the sustainable production of biofuels, bioenergy, and advanced materials.