A Minireview of Cellulose Nanocrystals and Its Potential Integration as Co-Product in Bioethanol Production

Abstract

Cellulose nanocrystals appeared as important bio-based products and the collected information in term of production, characterization and application suggest that this nanomaterial could be easily extrapolated to bioethanol production. This review describes recent published syntheses using chemical and enzymatic hydrolyses and different preparations such as high pressure homogenization. Their industrial and medical applications, such as controled of delivery carriers, suggest a large projection of this nanomaterial. The most important aspect in this collected data is the potential to decrease significantly the final cost of the enzymes or the hydrolysis pre-treatment of lignocellulosic materials of all bioethanol processes in such a way that it could be economically feasible from materials such as bagasse, straw or wood resources.

Morphological evolution of curauá fibers under acid hydrolysis

“…Apart from this, cellulose nanometersized fillers have been shown to be effective to improve several polymer properties, such as mechanical, thermal and barrier, due to their high aspect ratio (Ayuk et al 2009;Capadona et al 2009;Durán et al 2011;Favier et al 1995;Goussé et al 2002;Lima and Borsali 2004;Lin et al 2009;Pandey et al 2010;Samir et al 2005; Sanchez-Garcia and Lagaron 2010).…”

“…Cellulose amorphous domains in microfibrils are randomly oriented and are susceptible to acid attack (Durán et al 2011;Lima and Borsali 2004;Samir et al 2005). Ranby (1952) was one of the first researchers to report this kind of cellulose acid hydrolysis.…”

“…However, this mixture could lead to the development of spherical nanocrystals (Wan et al 2008). Apart from this, cellulose whiskers can also be prepared by enzymatic hydrolysis (Durán et al 2011). It is reported that Cellulase hydrolysis of bacterial cellulose produces whiskers with higher mechanical and thermal properties than whiskers produced from sulfuric acid hydrolysis (George et al 2011).…”

Influence of Cryogenic Attrition Ball Milling on the Particle Size of Microcrystalline Cellulose at Different Moisture Contents

“…It is important to note that cellulose is a renewable natural material, and the most often occurring organic material on Earth. It also reveals its excellent properties in nature, since a significant part of the base material of plants is cellulose that provides good mechanical strength for those, withstands slightly acidic or basic effects and is biologically degradable [3][4][5].…”

“…Milling machines use the kinetic energy of grinding bodies, the shearing and compression forces, or sometimes the evolving turbulence in order to achieve size decrease. Although the mechanical method is much simpler than the chemical one, its significant disadvantage is that much smaller cellulose particles can be produced using the chemical method [4][5][6][7].…”