The dilute acid (0.05 M H2SO4) hydrolysis at 175 oC of samples comprising varying fractions of crystalline (I?) and amorphous cellulose was studied. The amorphous content, based on XRD and NMR, and the product (glucose) yield, based on HPLC, increased by as much as a factor of three upon ball milling. These results are interpreted in terms of a model involving mechanical disruption of crystallinity by breaking hydrogen bonds in I??cellulose, opening up the structure and making more ?-1,4 glycosidic bonds readily accessible to the dilute acid. However, in parallel with hydrolysis to form liquid phase products, there are reactions of amorphous cellulose that form solid degradation products.
Revised: April 1, 2008 |
Published: February 1, 2006
Citation
Zhao H., J. Kwak, Y. Wang, J.A. Franz, J.M. White, and J.E. Holladay. 2006.Effects of crystallinity on dilute acid hydrolysis of cellulose by cellulose ball-milling study.Energy and Fuels.PNNL-SA-46829.