Alkaline Fractionation and Subsequent Production of Nano-Structured Silica and Cellulose Nano-Fibrils for the Comprehensive Utilization of Rice Husk

Hyun Jin Jung, Hyun Kwak, Jinyoung Chun and Kyeong Keun Oh
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Hyun Jin Jung: Department of Chemical Engineering, Dankook University, Yongin, Gyeonggi-do 16890, Korea
Hyun Kwak: R&D Center, SugarEn Co., Ltd., Yongin, Gyeonggi-do 16890, Korea
Jinyoung Chun: Korea Institute of Ceramic Engineering and Technology (KICET), Jinju, Gyeongsangnam-do 52851, Korea
Kyeong Keun Oh: Department of Chemical Engineering, Dankook University, Yongin, Gyeonggi-do 16890, Korea

Sustainability, 2021, vol. 13, issue 4, 1-18

Abstract: The parameters of the alkaline fractionation process were investigated and optimized using a statistical analysis method to simultaneously remove hemicellulose and ash from rice husk (RH) concomitantly. After the alkaline fractionation process, the residual solid contained high cellulose, and the recovery yield of hemicellulose was enhanced in the fractionated liquid hydrolyzate. The hemicellulosic sugar recovery yield (71.6%), de-ashing yield (>99%), and lignin removal (>80%) were obtained at the reaction conditions of 150 °C of temperature, 40 min of reaction time, and 6% ( w / v ) of NaOH concentration. Subsequently, nano-structured silica was synthesized using black liquor obtained as a by-product of this fractionation process. For the production of nano-structured silica, it was observed that the pH of a black liquor and the heat treatment temperature significantly influenced the textural properties of silica product. In addition, the two-stage bleaching of solid residue followed by colloid milling for the production of high value-added CNF with was attempted. As a result, in addition to 119 g of fermentable sugar, 143 g of high-purity (>98%) silica with a surface area of 328 m 2 g −1 and 273.1 g of high-functional CNF with cellulose content of 80.1% were simultaneously obtained from 1000 g of RH.

Keywords: biorefinery; multi-objectives RSM; nano-silica; de-ashing; cellulose crystals (search for similar items in EconPapers)
JEL-codes: O13 Q Q0 Q2 Q3 Q5 Q56 (search for similar items in EconPapers)
Date: 2021
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (1)

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