Thermochemical conversion of lignocellulosic biomass to renewable fuels and chemicals occurs through high temperature decomposition of the main structural components in plants, including cellulose, hemicellulose, and lignin. Cellulose and hemicellulose comprise mostly carbohydrates. Two disaccharides, maltose and cellobiose, are used as model compounds to explore differences in thermal stability due to the orientation of the glycosidic bond. First principles molecular dynamics and density functional theory have been used to probe the decomposition of these disaccharides during pyrolysis at 700 K. The results suggest that maltose, the -disaccharide, is less thermally stable. Dynamic bond length analysis for maltose indicates that several CC bonds and the CO bonds on the pyranose ring demonstrate signs of weakening, whereas no such scissile bonds were identified for cellobiose. The higher stability of the cellobiose is believed to originate from the persistence of low-energy hydroxymethyl conformers throughout the simulation which enable strong inter-ring hydrogen bonding. Thermogravimetric and mass spectroscopic experiments corroborate the enhanced thermal stability of cellobiose, wherein the onset of decomposition was observed at higher temperatures for cellobiose than for maltose. (c) 2015 American Institute of Chemical Engineers AIChE J, 61: 2562-2570, 2015