Extraction of Lignocellulose and Synthesis of Porous Silica Nanoparticles from Rice Husks: A Comprehensive Utilization of Rice Husk Biomass

Abstract

Rice husk (RH) biomass is a massive byproduct from rice milling. Applications of RHs have been very limited. Therefore, RHs are often considered as a biowaste. RHs are mainly composed of lignocellulose (ca. 72–85 wt %) and silica (ca. 15–28 wt %). The majority of previous explorations focused on the preparation of silica or other silicon based materials from RHs, while the lignocellulose in RHs was usually burnt and thus wasted. Herein, an approach for comprehensive utilization of RHs has been developed to obtain both lignocellulose and high quality porous silica nanoparticles from RHs. Most of the lignocellulose in RHs was first extracted by dissolving in ionic liquids. The dissolved lignocellulose was subsequently separated and collected. The remaining RH residue after extraction that contains a high concentration of silica was thermally treated to synthesize amorphous porous silica nanoparticles with a high purity and surface area. It was also found that, during the extraction of lignocellulose using ionic liquids, some metal cations (e.g., K+) that generate negative effect for the synthesis of silica can be removed simultaneously, which generates a synergy for this comprehensive approach to make full use of RH biomass. The implication of the present findings is discussed.

Synthesis of Rice Husk Derived Activated Mesoporous Carbon Immobilized Palladium Hybrid Nano‐Catalyst for Ligand‐Free Mizoroki‐Heck/Suzuki/Sonogashira Cross‐Coupling Reactions

“…On the other hand, rice production associated with generation of huge amount of rice husks (RHs). RHs are tough in nature and have low nutritional value and were disposed by burning in the open field which results greenhouse gas emission and waste of huge amount of energy . Thus, search for sustainable applications of RHs are highly desirable in terms of economic and environmental concern.…”

Selective Primary Alcohol Oxidation of Lignin Streams from Butanol‐Pretreated Agricultural Waste Biomass

“…Rice husks make up around 20 wt % of the rice grain and are composed of approximately 22 % lignin, 38 % cellulose, 18 % hemicelluloses, 2 % extractives, and 20 % ashes with variations depending on geographical origin . As a result of high lignin and ash content, the husks are not a viable animal feed, but they can be burnt to yield large quantities of silica that can be used in a number of material applications . However, compared to the relatively well‐valorized polysaccharide fractions and processing of rice husk‐derived silica, little attention has been paid to the abundant lignin fraction from rice husks.…”

“…[25,26] As ar esult of high lignin and ashc ontent, the husks are not av iable animal feed, [27] but they can be burnt to yield large quantitieso fs ilica that can be used in an umber of materiala pplications. [25,[27][28][29][30][31][32][33] However,c ompared to the relatively well-valorized polysaccharide fractionsa nd processing of rice husk-derived silica, little attention hasb een paid to the abundant lignin fractionfrom rice husks.…”

Preliminary study for acetylation of cassava bagasse starch and microfibrillated cellulose of bamboo

“…MFC bamboo was homogenized in size by high energy milling. This preparation was conducted with slight modification of previous research [23][24]. Both acetylation was considered to follow Kumoro & Amalia (2015) procedure [25] and also degree of substitution (DS) for BS and bamboo MFC.…”