Approaching zero cellulose loss in cellulose nanocrystal (CNC) production: recovery and characterization of cellulosic solid residues (CSR) and CNC

This study demonstrated the potential of simultaneously recovering cellulosic solid residues (CSR) and producing cellulose nanocrystals (CNCs) by strong sulfuric acid hydrolysis to minimize cellulose loss to near zero. A set of slightly milder acid hydrolysis conditions than that considered as "optimal" were used to significantly minimize the degradation of cellulose into soluble sugars that cannot be economically recovered, but resulted in CSR that is easily recoverable through conventional centrifuge. It was found that the window for simultaneous recoveries of CSR and producing high yield CNC in strong This work was conducted on official government time of Thu, Reiner, and Verrill. Wang was a visiting student at the USDA Forest Service, Forest Products Laboratory. Q. Q. Wang State Key Lab of Pulp and Paper Engineering, South China University of Technology, Guangzhou, China Q. Q. Wang • J. Y. Zhu ( ) • R. S. Reiner • S. P. Verrill USDA Forest Service, Forest Products Laboratory, Madison, WI, USA e-mail: [email protected] U. Baxa Electron Microscopy Laboratory, SAIC-Frederick, Inc., NCI-Frederick, Frederick, MD 21702, USA S. E. McNeil Nanotechnology Characterization Laboratory, Advanced Technology Program, SAIC-Frederick, Inc., NCI-Frederick, Frederick, MD 21702, USA 2tion Laboratory, Advanced Technology Program, SAIC-Frederick, acid hydrolysis was extremely narrow. However, we achieved significant CSR yield with near zero cellulose loss but without sacrificing CNC yield compared with that obtained at "optimal condition". The resultant CSR contains sulfate ester groups that facilitated subsequent mechanical nano-fibrillation to cellulose nanofibrils (CNFs), a potential high value nanocellulosic material for a variety of applications.