| Biorefineries aim at utilizing biomass efficiently to gain environmental and economic benefits. They have attracted broad attention due to recurring energy price swings and concerns about environmental impacts of fossil energy sources and national energy security. Biomass is an abundant and sustainable alternative to petroleum as a resource for the production of chemicals, materials and fuel. A major portion of biomass, lignocellulosic materials, has not been well utilized due to the structural complexity and difficult disassembly. One of the complexities of lignocellulosic materials is that the major component, cellulose, contains both crystalline domains and amorphous domains. The goal of this research is to develop a green process to usefully harness benefits from both domains. This research used four different pulps to produce nanofibrillated cellulose (NFC) and fermentable sugars by a combination of enzymatic hydrolysis and a mechanical treatment, sonification. The resulting NFC shows an entangled web structure. Both single nanofibers and the aggregation of NFC bundles were observed by transmission electron microscope (TEM). The effect of sonification time on the production of NFC has been shown by measuring water retention value (WRV) and observation in a scanning electron microscope (SEM). NFC was used to reinforce polyvinyl alcohol (PVA) and its reinforcement ability has been compared with CNC. A scale up of the process has been tested. Compared with the most commonly used process (involving a concentrated acid) to remove the amorphous domains (and produce cellulose nanocrystals, CNC), this process was carried out under mild conditions thus reducing both the expected capital expense and downstream costs (e.g. separation and recycling of acid). Furthermore, fermentable sugars, glucose and xylose, were available as co-products, which could increase the overall revenue of the process. |
