Recently, the Root and Tuber Crops Food Science and Technology Innovation Team of IFST-CAAS conducted the systematic techno-economic analysis of cellulose nanocrystals derived from pilot production of sweet potato residue. This work was published in Sustainable Materials and Technologies (JCR Q1, IF=8.7). The GSCAAS-LGg program PhD student Shunshun Zhu is the first author, while Prof. Hongnan Sun and Prof. Taihua Mu are the corresponding authors. This study was funded by the Science and Technology Innovation Project of the Chinese Academy of Agricultural Sciences (CAAS-ASTIP-202X-IFST).

Bio-based materials, extracted from renewable biomass through physical, chemical, or biological methods, play a vital role in promoting sustainability globally due to their environmental friendliness, cost-effectiveness, and positive impact on sustainable development. Among these materials, nanocellulose stands out as a rising star, often hailed as the "star material of the 21st century." With its biodegradable, non-toxic, and eco-friendly properties, coupled with a high specific surface area and tunable surface chemistry, nanocellulose has demonstrated immense potential across various fields such as food, packaging, construction, and chemicals. As a significant branch of nanocellulose, cellulose nanocrystals (CNCs) have garnered significant attention due to their unique structure and physicochemical properties. Agricultural byproducts such as sweet potato residue, which are rich in cellulose, represent ideal raw materials for CNC production. Although a large number of studies have focused on the production methods, structural characterization, and application prospects of CNCs, the economics and environmental impacts of using agricultural by-products such as sweet potato residue for the production of CNCs compared to traditional commercial methods (e.g., sulfuric acid hydrolysis of wood for the production of CNCs) are still lacking in depth and further research is urgently needed to promote the sustainable development of green manufacturing.

This study successfully achieved the pilot production of CNCs from sweet potato residue and performed a systematic techno-economic analysis of the production process based on commercial wood CNCs manufacturing models. The results showed that sweet potato residue CNCs exhibit a rod-like structure with width ranging from 15.10 to 30.90 nm and lengths from 80.80 to 259.90 nm. The CNCs possess a highly crystalline cellulose I structure (crystallinity of 61.0%), highlighting the potential as reinforcement components in composite materials. Additionally, the maximum thermal degradation temperature of the CNCs was 347.88°C, with an initial thermal degradation temperature above 200°C, indicating excellent thermal stability, suitable for use as reinforcement materials in eco-friendly bio-composites. Furthermore, the zeta potential of sweet potato residue CNCs was measured at -40.07 mV, demonstrating good storage and colloidal stability. Based on a production model with a daily capacity of 200 tons, the total investment cost for producing sweet potato residue CNCs was reduced by $24.4 million compared to commercial wood CNCs, while annual operating costs were reduced by $5.5 million. Moreover, the net present value (NPV), a key indicator of project profitability, was significantly higher for the sweet potato residue CNC production process, further validating its high economic feasibility.

These findings clearly demonstrate the economic and environmental benefits of utilizing agricultural byproducts like sweet potato residue. The study also explores the potential to reduce fossil fuel usage and provides valuable data and theoretical guidance for the future production of CNCs and bio-based materials.

Link: https://doi.org/10.1016/j.susmat.2024.e012322

Preparation, characterization, and techno-economic analysis of sweet potato residue cellulose nanocrystals