Thermal super-insulating aerogels from rice hulls

Overview

Agricultural waste, such as rice hulls, often presents a disposal challenge yet holds untapped potential. At the University of Arkansas System Division of Agriculture, our research focuses on upcycling rice hulls to create thermal super-insulating aerogels. These aerogels are characterized by their ultra-low density and outstanding insulating properties, offering a sustainable solution to waste management and material innovation.

Technical specifications

Aerogels developed from rice hulls leverage their composition of cellulose, hemicellulose, lignin, silica, and phytochemicals. The process involves extracting biopolymers through a combination of alkali and hydrogen peroxide treatments. Hemicelluloses and silica are extracted using an alkaline solution, followed by lignin extraction. The resulting cellulose residue is used to form gels, which are then dried and silanized to enhance moisture-repellent and fire-resistant properties. These aerogels possess extremely low thermal conductivity, making them suitable for diverse applications needing superior insulation.

Technology readiness level

Currently at Technology Readiness Level 3, the aerogels have undergone initial validation through established extraction and processing methods. Further experimental validation and scaling are planned to advance their readiness for commercial applications.