Microwave-Assisted Pretreatment of Sago Palm Bark

Abstract

Three types of microwave-assisted diluted solvents were employed using 0.1 N H2SO4 (MSA), 0.1 N NaOH (MSH), and 0.01 N NaHCO3 (MSB). These solvents were evaluated as possible pretreatment routes for sago palm bark (SPB) with their effects on the pretreated substrate. A variety of analyses, consisting of fiber analysis, energy dispersive X-ray spectroscopy (EDX), X-ray fluorescence spectrometer (XRF), X-ray powder diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscope (SEM), and high-performance liquid chromatography (HPLC), were performed to understand the pretreatment effects on the chemical and physical characteristics of SPB and pretreatment liquor. The thermal analysis has revealed that higher hemicellulose degradation was also found in MSA pretreatment. In the analyses of the pretreatment liquid for the extracted monomeric sugar, a higher amount of glucose was found (9 mg/g) using MSH pretreatment and the highest xylose level was found (4 mg/g) using MSA pretreatment. The analysis of the formation of inhibitors has shown that acetic acid was only found in the MSH pretreatment.

Effect of microwave‐assisted alkali pre‐treatment on fractionation of pistachio shell and enzymatic hydrolysis of cellulose‐rich residues

“…1(b),(c)). A similar trend was obtained by Ethaib et al 37 . and Vani et al ., 36 who performed microwave‐assisted pre‐treatment of sago palm bark and cotton plant residue, respectively.…”

“…and Vani et al ., 36 who performed microwave‐assisted pre‐treatment of sago palm bark and cotton plant residue, respectively. The increase in microwave power and pre‐treatment time also increases the temperature, which leads to high localized overheating and, consequently, cause the breakdown of hemicellulose into its monomeric sugars or by‐products 36,37 …”

“…In contrast to this, heat is generated internally by the direct interaction between the heated material and electromagnetic field in microwave heating, which provides volumetric and fast heating 22 . Besides the thermal effects of microwave application, the non‐thermal effects generate a physical explosion effect within the microfibers, which accelerate the destruction of the recalcitrant lignocellulosic structure 37 . These can be the reasons for increased hemicellulose recovery by the application of microwave in a shorter time.…”

Production of Valuable Materials from Sago Bark Using Subcritical Water Treatment

“…This degradation also implied that the increased of reaction temperature will enhance the competitive pathways of sugar degradation [59]. Basically, all of the resulted monosaccharides in this study are consistent with other researches done on SB using different methods [7], [32], [60]. More interestingly, SB inner layer treated in this study exhibited extremely better yield of monosaccharides in 5 min as compared when treated with the combination of microwave-acid and enzymatic hydrolysis that required ~72 h [7].…”

Microwave-Assisted Brine Extraction for Enhancement of the Quantity and Quality of Lipid Production from Microalgae Nannochloropsis sp.

“…Some factors that affect MAE efficiency include temperature, time, solid loading, solvent type, and its dielectric properties [31,32]. The microwave heating principles have been reported previously by many studies [33,34,35].…”