Abstract:

In this study, fiber cells and parenchyma cells of poplar were prepared from poplar by glacial acetic acid-hydrogen peroxide treatment. On this basis, the differences of enzymatic hydrolysis between fiber cells and parenchyma cells were investigated, and the influencing factors, water distribution and mechanical properties of the enzymatic hydrolysis process were analyzed. The results showed that parenchyma cells had higher accessibility of enzymatic reaction and the fermentable sugar content of parenchyma cells reached 208.6 g/L after 72 h of enzymatic hydrolysis, which was 8.5% higher than that of fibrous cells. With the same enzymatic hydrolysis efficiency of xylose(59%), the enzyme loading of parenchyma cells decreased by 50% compared to fibrous cells. The enzymatic hydrolysis rate of parenchyma cells increased by 15.4%-33.3% with the high solid system(the solid loading was more than 15 g/mL). The state of water distribution showed that parenchyma cells had weaker water binding effect during enzymatic hydrolysis process and had better liquefaction performance. The mechanical properties showed that the key stage determining the difference of enzymatic hydrolysis performance between fiber cells and parenchyma cells was the first 24 h. In addition, parenchyma cells had weak mechanical properties during enzymatic hydrolysis, which helped to save energy and shorten cycle time.

Key words: fiber cells, parenchymal cells, enzymatic hydrolysis, water distribution, mechanical property