Influence of Particles Size on NIR Spectroscopic Estimations of Charcoal Properties

Abstract

The objective of this study was to evaluate the influence of particle size of charcoal samples on the predictive model statistics of charcoal chemical composition based on the NIR spectroscopy. Spectra of Acacia and of Eucalyptus charcoal were collected in the 100, 60 and 40 mesh granulometry, besides the powder remaining at the bottom of the sieves sets. They were subjected to principal component analysis and partial least square regression in order to estimate of volatile material (VMC), ash (AC) and fixed carbon content (FCC) values. The estimation of the FCC, VMC and AC of Eucalyptus based on NIR was more accurate using spectra of lower-particle-size powder. The models for Acacia charcoal were better using spectra measured at 40 mesh to predict FCC, 100 mesh for AC, and smaller size for VMC. NIR spectroscopy was efficient in estimating the immediate chemical composition of charcoal, except for AC.

Before reliable near infrared spectroscopic analysis - the critical sampling proviso. Part 2: Particular requirements for near infrared spectroscopy

“…Caution should always be observed regarding vial wall thickness. [20][21] A critical issue is the need to consider a distinction between a sample cell (containing a sample already extractedwith or without managed sampling errors) and a sampling cell, which is actively delineating the effective sample volume from which spectral acquisition takes place for a moving material stream (conveyor belt, pipeline, bypass stream, PAT). The sampling cell interface actually determines the very possibility for representative PAT process analysis or not; full treatment of these issues can be found in 3,[5][6][7]12 ; this topic was recently treated in depth at the 10 th World Conference on Sampling and Blending (WCSB10).…”