Process scale up and characterization of wood cellulose nanocrystals hydrolysed using bioethanol pilot plant

- Acid hydrolysis of wood was integrated to pilot-scale bioethanol processing.
- Nanocrystals were isolated at point of use by mechanical processing with an yield of 600 g/day.
- Nanocrystals had negative surface charge and their films had high mechanical properties and cytocompatibility.

The paper discusses the isolation of cellulose nanocrystals (CNCBE) from wood resources by integrating the processing with pilot-scale bioethanol processing unit. The nanocrystals were isolated from cellulose obtained by acid pretreatment of wood chips in a bioethanol pilot-scale facility, followed by a series of chemical processes and subsequent homogenization using a lab-scale homogenizer. The isolated nanocrystals had diameters of 5-15 nm, cellulose I crystalline structure and formed a thick semi-transparent gel at low concentration (2 wt%). XPS data showed that these nanocrystals had predominantly OCO surface groups which also contributed to its high negative zeta potential. Casted CNCBE films showed excellent mechanical performance (200 MPa of strength, 16 GPa of modulus) and transparency and were also found to be cytocompatible. The developed process route resulted in high-quality nanocellulose crystals with a yield of 600 g/day.