Experiments were conducted with xylobiose in the microwave reactor and results are shown in Figure 9.8 for the decomposition of xylobiose and the formation of xylose at nominal temperatures of 125 and 145°C. As can be seen from these plots, the xylobiose is quickly converted to xylose at these temperatures, i. e., within 600 seconds for 125°C and within 120 seconds for 145°C. Furfural formation was less than that observed for decomposition of pure xylose, suggesting that the furfural arose from the decomposition of xylose and not xylobiose. The mass balances in these experiments were poor (80-85%), due probably to the poor calibration of xylobiose. Because of the expense of this compound, we were only able to use single-point calibrations. However, as Figure 9.9 shows, the chromatographs were clean and did not indicate the formation of other products. These results seem to confirm the

Time/min

results from our calculations that xylobiose will preferentially undergo hydrolysis relative to dehydration. We conclude that low DP xylo-oligomers will preferentially undergo hydrolysis to form smaller oligomers and xylose as opposed to dehydration to form furans in solution containing only catalytic acids.