Optimization of Microwave-Hydrogen Peroxide Pretreatment of Cellulose

Abstract

A hydrogen peroxide (H2O2) solution was adapted for microwave pretreatment of microcrystalline cellulose, which can be further used for heavy metal adsorption. The H2O2 concentration, temperature, and retention time were the key factors affecting the microwave/hydrogen peroxide pretreatment process. A Box-Benhken design (BBD) with response surface methodology (RSM) was employed to design and optimize the microwave-hydrogen peroxide pretreatment process (H2O2 pretreatment) of cellulose. After the H2O2 pretreatment, the crystallinity of cellulose decreased by 20% and the degree of polymerization (DP) decreased by up to 30%. The optimal conditions obtained by BBD were a H2O2 concentration of 8.37%, a temperature of 90 °C, and a retention time 5.33 min. Under these conditions, a minimum DP of 91.74 was achieved. The results indicated that all three of the factors notably affected the reduction of cellulose polymerization degree and pronounced interactions existed among the response variables. The predictive model developed was able to optimize the pretreatment process for the reduction of cellulose polymerization degree, which could improve the cellulose modification reactivity.

The removal of heavy metal ions from aqueous solutions by amine functionalized cellulose pretreated with microwave-H2O2

“…At full power, the microwave reactor delivered approximately 1800 W of microwave energy at a frequency of 2450 MHz and was controlled by a microcomputer that monitored the operation. 12 Pre-processing was performed in a digestion tank with H 2 O 2 solution (9%) and MCC (solid-liquid ratio 1 : 20) at 90 C for 5 min. The microwave reactor was digitally programmed to control the experimental conditions, which included a detection system to measure the real-time temperature and power.…”

A Comparison of Cooking Conditions of Rhizoclonium Pulp as a Substitute for Wood Pulp

“…We found that the polymerization decreased with higher solvent concentrations of between 1451 and 1878 ( Figure 2 d), and the Rhizoclonium pulp became cotton-like. The decrease in polymerization is primarily the result of the oxidation of hydroxyl-free radicals by the high solvent concentration [ 40 ]. From these results, the solvent type and concentration primarily affect the width of the fibers.…”

Isolation of Cellulose Nanocrystals from Banana Peel Using One-Pot Microwave and Mild Oxidative Hydrolysis System

“…Dielectric polarization by microwave energy facilitates rapid loosening and swelling of the lignocellulosic structure by penetration of water molecules in the space between the cellulose microfibers [8,40]. Further pre-treatment using H 2 O 2 facilitates the removal of hemicellulose and the delignification process, enabling the implementation of the one-pot process as the decomposition of hydrogen peroxide produced water and oxygen [41,42]. Thus, successive washing after pre-treatment is unnecessary, and hydrolysis can be carried out directly in the same pot.…”