Processing of Citrus Nanostructured Cellulose: A Rigorous Design‐of‐Experiment Study of the Hydrothermal Microwave‐Assisted Selective Scissoring Process

Abstract

A detailed design-of-experiment (DoE) study to investigate the cause-effect interactions of three process variables, that is, temperature (120-200 °C), holding time (0-30 min), and concentration (1.4-5.0 wt %), on the processing of citrus cellulosic matter using acid-free microwave-assisted selective scissoring (Hy-MASS) is reported. Analysis of variance (ANOVA) showed that post-microwave processing, the yield of cellulosic matter (25-72 %), decomposition temperature (345-373 °C), and crystallinity index (34-67 %) were strongly affected by temperature. SEM and TEM analyses showed that the isolated cellulosic matter was heterogeneous and consisted of a mixture of micro- and nanofibers more akin to microfibrillated cellulose (MFC) at low processing temperatures and tending towards aggregated cellulose nanofibrils (CNFs) and cellulose nanocrystals (CNCs) at higher processing temperatures. The water holding capacity of the processed cellulosic matter (15-27 gH2O g ) was higher than the original feedstock or previously reported values. The average molecular weight of the cellulosic matter (113.6-1095.9 kg mol ) decreased significantly by a factor of 10 at operating temperatures above 180 °C, invoking significant scissoring of the cellulosic chains. The process energy input and costs varied between 0.142-0.624 kWh and 13-373 € kg , respectively, and strongly depended on the reaction time.

Versatile Application of Nanocellulose: From Industry to Skin Tissue Engineering and Wound Healing

“…The trees include leaved trees, e.g., birch [33,57,58,59,60,61], and various coniferous trees [26,27,62,63,64], e.g., Pinus radiata [65]. Other trees are Acacia mangium [66], balsa [67], Syzygium cumini [68], banana pseudostem [5], palm [7,8,69], Khaya senegalensis [70], and citrus trees [71]. Nanocellulose from leaved trees is usually referred to as hardwood-derived, while nanocellulose from coniferous trees is softwood-derived.…”

Defibrillated Celluloses via Dual Twin-Screw Extrusion and Microwave Hydrothermal Treatment of Spent Pea Biomass

“…Matharu et al and de Melo et al reported a novel acid-free microwave hydrothermal treatment (MHT) method to obtain pseudonanocellulosic fibrils and/or nanocrystals without any additional chemicals. 20,44 Herein, the importance of this study is to explore the potential valorization of pea waste (rather than traditional wood pulp) as a source of defibrillated celluloses using twin screw extrusion as a 5 pretreatment prior to microwave hydrothermal treatment (MHT) ( Figure 1). Twin screw extrusion was selected as the pretreatment for being continuous, low cost, requiring no heat and the application of high shearing forces in the biomass 45 Pea (Pisum sativum) waste including leaves, vines, stems (haulm) was collected immediately after harvest from farmland nearby York (England, United Kingdom).…”

Decoding biomass recalcitrance: Dispersion of ionic liquid in aqueous solution and efficient extraction of lignans with microwave magnetic field

“…When lignocellulosic biomass is exposed to MAH heating, swelling and fragmentation occur within the biomass, resulting in the disruption of the lignocellulosic structure. This consequently results in an increase of surface area, decreases in the degree of polymerization and crystallinity of cellulose, and the depolymerization of lignin, which ultimately improves the accessibility of BCLs [43]. Therefore, IL-MAH was the best method to extract FBCL from S. chinensis fruit which extraction efficiency up to 4.12±0.37 mg g −1 (Fig 9).…”