Research Study Targets Rice Husks for Chemical Extraction

By Jayna Miller

luyi1Dr. Luyi Sun, an associate professor at UConn, is leading a research group in an EPA-sponsored project that is investigating the use of rice husks to produce two valuable chemicals, lignocellulose and silica.

“Rice husk biomass is a massive byproduct from rice milling. Applications of rice husks have been very limited, and they are often considered biowaste,” Dr. Sun says. Through  this study, he plans to extract both lignocellulose and silica from the rice husks to take full advantage of the rice husk biomass.

Previous studies in this area have focused on the extraction of silica from rice husks, while the lignocellulose was ordinarily burnt and thus wasted. Dr. Sun’s approach is unique two ways: (1) it involves a comprehensive use of rice husks, obtaining both lignocellulose and silica; (2) the mild treatment maintains the original microstructure of silica in rice husks, leading to the synthesis of high quality porous silica nanoparticles.luyi2

“The lignocellulose is extracted by dissolving the rice husks in ionic liquids, and then the chemical is separated and collected. The remaining residue after extraction, which contains a high concentration of silica, is thermally treated to synthesize amorphous porous silica nanoparticles with a high purity and surface area,” Dr. Sun explains. After extraction, lignocellulose can be used as an ingredient for biofuel and paper, while silica is a useful component in many products and the chemical industry. This research is expected to promote effective utilization of rice husk biomass globally in the near future. Some of the benefits of implementing this process include saving landfill space, minimizing pollution, and profits from the extracted lignocellulose and silica.

This project has been ongoing for two years under the sponsorship of the US EPA. Dr. Sun has published four research articles relating to this work. He will work with several graduate and undergraduate students on continuing this project, and the research opportunity will be available as a capstone class. For more information on Dr. Sun’s research, please visit: