Comparative Evaluation of the Efficient Conversion of Corn Husk Filament and Corn Husk Powder to Valuable Materials via a Sustainable and Clean Biorefinery Process

Abstract

Corn husk is usually burned and discarded, resulting in environment pollution and a waste of resources. To make better use of corn husk, in this work, corn husk filament (CHF) and corn husk powder (CHP) were first separated and then the comparative evaluation of efficient conversion of CHF and CHP to valuable materials was carried out via a sustainable route [i.e., one-step formic acid (FA) hydrolysis]. After FA fractionation, over 90% hemicellulose could be removed (mainly converted to xylose), about 80% lignin with high purity could be isolated, and the fractionated cellulose solid residue was used to fabricate cellulose nanofibrils (CNFs) and functional cellulose nanopaper (CNP). Results showed that, compared to CHP, the CHF with lower density, longer fibers, and higher crystallinity could be easier to hydrolyze, and the resulting CNFs had a smaller diameter and higher crystallinity, leading the final CNP to have better mechanical properties. The maximum tensile strength and toughness of the resultant CNP reached up to 177.0 ± 6.1 MPa and 13.3 ± 1.7 MJ·m–3, respectively. Also, the CNP with high crystallinity and great thermal stability exhibited excellent water resistance and good barrier properties. Thus, the present work provides a sustainable and new route to make full use of corn husk through the production of xylose, high-purity lignin, and functional CNP.

Biomass Fractionation and Lignin Fractionation towards Lignin Valorization

“…[49] Similarly, after one-step FA hydrolysis (85°C, 5 h), about 80 % of lignin was removed from corn husk, and the obtained high-purity lignin (> 99 %) could have the potential for phenol-formaldehyde resin and concrete waterreducer applications. [50] To realize fractionation, harsh experimental conditions were needed such as increasing temperature and pressure. The β-O-4 linkages are broken during the FA-based fractionation, which resulted in an increased content of phenolic hydroxy, the formation of a CÀ C condensation structure, and the side-chain formylation of lignin.…”

“…obtained FAL with high guaiacyl content by using one‐step mild FA pretreatment, and the FAL fraction exhibited a loose structure suitable for its further catalytic conversion into chemicals and energy . Similarly, after one‐step FA hydrolysis (85 °C, 5 h), about 80 % of lignin was removed from corn husk, and the obtained high‐purity lignin (>99 %) could have the potential for phenol–formaldehyde resin and concrete water‐reducer applications …”

Performance Evaluation of Cellulose Nanofiber with Residual Hemicellulose as a Nanofiller in Polypropylene-Based Nanocomposite

“…Recently, nanocomposites made from polymeric matrix and CNF have been the subject of interest due to their versatility to be used for many purposes, ranging from household goods, such as for packaging, to premium products, such as for bioadsorbents [ 9 ], packaging [ 10 ], the military [ 11 ], paper [ 12 , 13 ], biomedical applications [ 14 , 15 , 16 ], automotive applications [ 17 ], and electronics [ 18 ]. More specifically, CNF, which was derived from plants by intensive mechanical action, has gained interest as a superb reinforcement material owing to its superior properties such as high mechanical strength [ 19 ], high thermal stability [ 20 ], high crystallinity [ 21 , 22 ], and high surface area [ 23 ].…”

Valorization of Enzymatic Hydrolysis Residues from Corncob into Lignin-Containing Cellulose Nanofibrils and Lignin Nanoparticles

“…Especially in the last few years, lignin-containing cellulose nanofibrils (LCNFs) have been gradually arousing people's interest. The preparation of LCNFs was confirmed by various approaches from different lignocellulose biomass including unbleached thermomechanical pulp, corn husk, and tobacco stalks, among others (Bian et al, 2017;Hu et al, 2018;Wang et al, 2018;Wen et al, 2019). In addition, lignin nanoparticles (LNPs) have gained significant interest among researchers in recent years, which will play a vital role in promoting lignin valorization (Chauhan, 2020;Dong et al, 2020a).…”