Pham C.D., Le T.M., Nguyen C.T.X., Vo N., Do N.H.N., Le K.A., Mai T.P., Le P.T.K., 2022, Review of The Role of Pretreatment Step in Nanocellulose Production from Rice Straw, Chemical Engineering Transactions, 97, 67-72.
Nanocellulose is one of the most valuable biomass-derived materials, possesses outstanding properties, and is widely used in numerous applications for biomedical fields, packaging, and environmental waste treatment. Rice straw is an abundant by-product from the rice industry and among cellulose-rich feedstocks. The pristine structural network of this raw material is complicated composing cellulose, hemicellulose, and lignin. Therefore, the pretreatment step is necessary to facilitate further stages in the biomass conversion process. The effect of such methods on the characteristics of nanocellulose products from rice straw has not been widely investigated in comparison with other types of biomass. This review summarized the common methods for rice straw pretreatment and the effects of distinct methods on the obtained nanocellulose. Alkaline pretreatment is considered as one of the most effective method for the extraction of cellulose from lignocellulosic complex. Based on a comprehensive summary, this review also shows that cellulose nanocrystals (CNCs) which is usually isolated by acid hydrolysis, has a high crystallinity index due to the removal of amorphous region. Cellulose nanofibrils (CNFs) is obtained by employing mechanical methods to reduce the particle size of cellulose fibers.