Improving mill efficiency through rapid analysis methodologies : final report 2014/051
Abstract
A rapid analysis system for measuring key constituents in sugarcane factory products has been
developed using diode array (DA) near infrared (NIR) spectroscopic technology. Analysis of key
constituents in prepared cane, bagasse, juice and syrup streams, magma, massecuite, molasses, raw
sugar and mill mud is feasible. The benchtop NIR spectroscopic systems are mill laboratory-based
and designed to augment the analysis already conducted by mill laboratories. More frequent
analyses of mill factory products will allow Mill Engineers to minimise losses, and consequently,
improve the factory’s coefficient of work. Additional benefits accrue through improved final product
quality and the ability to schedule maintenance based on impurity loading. The NIR spectroscopic analysis technique has been rigorously evaluated to demonstrate acceptable
performance under different conditions. Validation of systems in green-field sites has shown that
the global models provide suitable turn-key functionality. Standard error of prediction (SEP) values
show that mature and semi-mature models are accurate against the traditional wet chemistry
models and repeatability and reproducibility statistics for the NIR spectroscopic technique are better
than those published for equivalent wet chemistry methods in the Australian and International
method manuals. Characterisation of selected sugarcane factory products highlighted the chemical and spectral
variability in the samples, but molecularly-targeted calibration models did not improve the
predictive performance of the NIR spectroscopic technique. Despite this, NIR spectroscopic models
for the analysis of fresh raw sugar were developed and its demonstrated performance has been
equivalent or better than the standard model for evaluating pol and moisture in fresh raw sugar.