Energy Efficient Manufacturing of Nanocellulose by Chemo- and Bio-Mechanical Processes: A Review

Abstract

Nanocellulose is a new-age material derived from cellulosic biomass and has large specific surface area, high modulus and highly hydrophilic in nature. It comprises of two structural forms viz., nanofibrillated cellulose (NFC) and nanocrystalline cellulose (NCC). This review provides a critical overview of the recent methods of bio-and chemo-mechanical processes for production of nanocellulose, their energy requirements and their functional properties. More than a dozen of pilot plants/commercial plants are under operation mostly in the developed countries, trying to exploit the potential of nanocellulose as reinforcing agent in paper, films, concrete, rubber, polymer films and so on. The utilization of nanocellulose is restricted mainly due to initial investment involved, high production cost and lack of toxicological information. This review focuses on the current trend and exploration of energy efficient and environment-friendly mechanical methods using pretreatments (both chemical and biological), their feasibility in scaling up and the future scope for expansion of nanocellulose application in diverse fields without impacting the environment. In addition, a nanocellulose quality index is derived to act as a guide for application based screening of nanocellulose production protocols.

Aqueous morpholine pre-treatment in cellulose nanofibril (CNF) production: comparison with carboxymethylation and TEMPO oxidisation pre-treatment methods

“…Cellulose nanofibrils (CNF), alongside cellulose nanocrystals and bacterial nanocellulose, are the three types of nanocellulose that have been identified in literature (Abdul Khalil et al 2014;Bharimalla et al 2015;Jonoobi et al 2015;Klemm et al 2011;Lavoine et al 2012;Nechyporchuk et al 2016a;Siró and Plackett 2010). CNF can be derived from cellulose fibres by a combination of mechanical, enzymatic, and chemical pre-treatment steps prior to mechanical processing (Nechyporchuk et al 2016a).…”

“…There has been considerable industrial and research interest in the use of CNF in a wide range of applications, such as in biomedicine (Guise and Fangueiro 2016;Lin and Dufresne 2014), automotive exteriors and interiors (Faruk et al 2014), packaging materials (Ferrer et al 2017;Li et al 2015) and electronic devices (Du et al 2017;Shi et al 2013). This wide usage arises because of their renewability, biocompatibility and biodegradation potentials coupled with improved mechanical strength, lightweight properties, optical properties, barrier properties and structuring capabilities (Abdul Khalil et al 2014;Bharimalla et al 2015;Jonoobi et al 2015;Klemm et al 2011;Lavoine et al 2012;Siró and Plackett 2010). Moreover, the cellulose starting material, which is the most abundant polymer on earth, provides potential for sustainable low-cost products.…”

“…However, the inclusion of such recycling lines to the main production line may come at an extra cost and so striking the right balance between recycling of chemicals and use of fresh chemicals becomes imperative. Otherwise, the overall cost of the pre-treatment process could nullify any benefits accrued from a reduction in energy consumption (Bharimalla et al 2015).…”

Nanocellulose as a green and sustainable emerging material in energy applications: a review

“…The reinforcement of combined microcellulose and nanocellulose in reactive powder concrete was initiated to be effective in increasing toughness. Addition of 3% nanocellulose improved the fracture energy of concrete material by more than 50% …”

Update on bio-refining and nanocellulose composite materials manufacturing

“…This remained a “holy grail” until a discovery in 1977 by a research manager at the ITT Rayonier Eastern Research Division (ERD) Lab in Whippany, N.J. (Turbak, 2015). More recently, several reviews have been published on the preparation of nanocellulose (Lavoine et al, 2012, Girl and Adhikari, 2013, Reboullat and Pla, 2013, Duferesne, 2013, Klemm et al, 2011, Bharimalla et al, 2015, Postek et al, 2013b) describing various current methods for isolation such as: homogenization, grinding, cryo-crushing electrospinning, enzymatic pretreatments, TEMPO-mediated (2,2,6,6-tetramethylpiperidine-1-oxyl radical) oxidation, carbomethylation and acetylation. Yet, none have included the use of ionizing radiation in the manufacturing of these valuable materials.…”