Influence of the pretreatment method on the hydrolysis of cassava starch factory residue

Abstract

Cassava starch factory residue (CSFR) is an attractive lignocellulosic material for bioethanol production because it is one of the most abundant renewable resources. The purpose of this work was to investigate the technical feasibility of converting CSFR into fermentable sugars using 12 different pretreatment methods. The yields of monosaccharides, oligosaccharides, and total sugars present in the hydrolysates obtained from the different pretreatment methods were examined by transferring the solid organic matter present to a liquid phase. We found that pretreatment with a dilute acid was superior to both alkaline and hot water pretreatment methods, while combined chemical‐enzymatic pretreatment was superior to single enzymatic pretreatment. More specifically, treatment with a dilute acid was conducive to the formation of monomeric sugars, whereas single enzyme pretreatment and high‐temperature alkaline pretreatment methods were conducive to the formation of oligomeric sugars. Pretreatment with 0.5% (w/v) HNO3 (160 °C, 10 min) gave the highest total monosaccharide concentration (i.e., 25,827 mg/L) with a yield of 30.99%, whereas hemicellulose (45 U/g CSFR) + cellulose (120 U/g CSFR) pretreatment gave the highest total oligosaccharide concentration (i.e., 22,152 mg/L) with a yield of 26.69%. Finally, pretreatment with 1% (w/v) H2SO4 (121 °C, 40 min) + hemicellulose (120 U/g CSFR) + cellulose (120 U/g CSFR) gave the highest total sugar concentration (i.e., 43,196 mg/L) with a yield of 51.84%. © 2018 American Institute of Chemical Engineers Environ Prog, 38: 624–629, 2019

Effect of pretreatment parameters and binder concentration on the densification of wood residue

“…Pretreatment regulated the thermochemical conversion of biomass and changed their structural properties and energy utilization efficiency 24,25 . Physical or chemical pretreatment methods are the most commonly used methods for wood residues which involve the use of organic or inorganic compounds to disrupt their structure 26 . It causes the lignin to split up for releasing the cellulose and hemicellulose from the lignocellulosic structure 20 .…”

“…24,25 Physical or chemical pretreatment methods are the most commonly used methods for wood residues which involve the use of organic or inorganic compounds to disrupt their structure. 26 It causes the lignin to split up for releasing the cellulose and hemicellulose from the lignocellulosic structure. 20 Success of pretreatment depends upon the reduction of hemicellulose and lignin.…”

High yield of glucose from cassava starch hydrolysis by poly(4‐vinylpyridine) hydrochloride

“…Starch conversion practices mainly involve two approaches. The first one, based on chemical process or thermal, pressure extrusion uses some surface modification and/or cross‐linking of the polysaccharides (Ayoub & Rizvi, 2009; Intaramas et al ., 2018; Yu et al ., 2019; Prasertsung et al ., 2019; Intaramas et al ., 2019). The second one, using acid or enzymatic hydrolysis (Ruiz et al ., 2011; Yu et al ., 2018; Ona et al ., 2019) transforms the high molecular weight into fermentable sugars.…”