The increased mass ratio of sodium aluminum oxide
(Al2O3$Na2O) to sodium aluminum oxide and cellulose indicated
a high ratio of Na2O/C [30]. The gasification results of
cellulose at the higher ratio of Na2O/C had been discussed in a
previous study. There were several important conclusions: i.
The concentration of Naþ and OH ions increases as the ratio
of Na2O/C increases, which could cause the corresponding
increase of the catalytic effect of ions. ii. The dehydrogenation
of cellulose at low temperatures could be caused by the catalytic
effect of ions. iii. Some of the CO was confirmed to come
mainly from the inner reaction of carbon with oxygen contained
in cellulose. iv. At high temperatures, hydrogen and
CO2 came mainly from the wateregas reaction and the
wateregas shift reaction. However, the mechanism of conversion
of C, H, and O elements was still not entirely clear
[29,30].
The formation rates of the product gases of S5 at
473e1073 K as a function of temperature were shown in Figs. 5
and 6, respectively. The methanation reaction that occurred
was exothermic. Therefore, hydrogen at a low temperature