Rapid Evaluation of Biomass Properties Used for Energy Purposes Using Near-Infrared Spectroscopy

The parameters corresponding to combustion and pyrolysis such as proximate parameter (emissions), calorific value, elemental component, pyrolysis characteristics (temperature), and thermal properties are necessary to the thermal conversion process and the trading of biomass. Traditionally, these parameters of wood chips, milled wood, and biomass pellets are determined with chemicals, time-consuming, and required technical experts, such as thermogravimetry, bomb calorimetry, dry oven, muffle furnace, and so on. The near-infrared (NIR) spectroscopy is a rapid, noncontact no-chemical measurement. For NIR spectroscopy, only 2–3 seconds are used for evaluation, and it could be used for online measurement. The application of NIR spectroscopy in the estimation of the biomass characteristics of wood chips, milled wood, and biomass pellets is described in this chapter

Effects of Waxy Types of a Sugarcane Stalk Surface on the Spectral Characteristics of Visible-Shortwave Near Infrared Measurement

Precision of spectroscopic methods were frequently affected by the identity of the inhomogeneous materials, especially for direct scanning. This research aimed to investigated effects of waxy types, naturally founded on cane surface, on spectral characteristic. A portable Vis/SWNIR instrument with interactance mode across wavelength of 570-1031 nm were used for direct scanning on cane stalk. Principle component analysis (PCA) was applied to examine the differences of spectra scanned from 180 samples including 3 types of waxy type; white, black, and mixed black and white. Seven widespread pretreatments were employed to reduce the effect of waxy types. Results show that spectra of samples with each waxy type was separated in groups and SNV pretreatment gave the best results but was not able to eliminate the effect compared to the wax-removed samples.  Meanwhile, the standard deviation of absorbance values, at the wavelength of 760, 904 and 970 nm of 3 samples, was used for assessing the repeatability and reproducibility. The samples with removing waxy cover provided lower the standard deviation of absorbance values of spectra than the best pretreated spectra using standard normal variate (SNV) of the samples without removing waxy cover by one to six times. Thus, the waxy material on cane surface should be removed before collect spectra