Near Infrared Spectroscopy as an Analytical Tool in the Biorefinery

Near infrared spectroscopy (NIR) is becoming a powerful technique for rapid quantitative biomass analysis, and its flexibility, ease of use, and small sample requirements make it an excellent tool for many applications within the biorefinery. Through the use of Partial Least Squares algorithms, robust and predictive chemometric models can be developed from calibration sets of known values. In our laboratory, NIR has been exploited for: 1) determining cellulose, hemicellulose, and lignin content of woody and herbaceous biomass, 2) observing lignocellulosic component changes before and after various pretreatment methods, 3) monitoring fermentation of glucose into ethanol, and 4) monitoring enzymatic hydrolysis of cellulose to glucose. These results demonstrate that NIR can be used for selecting optimal feedstocks for different process streams within the biorefinery based on composition, monitoring conversion of biomass to liquid fuels for optimization of reaction parameters, and tracking reaction completion. Because NIR can be utilized for solids or liquids and offers fast, nondestructive analysis, this technology has wide-ranging applications within the biorefinery.