XRF-based analytical methods for supporting sustainability in sugarcane biorefineries

There is a clear need for analytical methods able to evaluate impurities in sugarcane biorefineries. Impurities that may occur during sugar and ethanol production which involves a high content of starch, fructose, dextran and minerals. Another type of impurity comes from solid materials such as soil and the green or dry/brown leaves of the sugarcane plant. This study focused on the mineral content, which causes an increase in both cost and time, a loss of quality and a negative environmental impact, and may also hinder the crystallization process. The presently developed analytical methods demonstrate the possibility of using X-ray fluorescence-based techniques, even for complex samples like sugarcane juices. The exploratory analysis evidenced that X-ray fluorescence techniques can discriminate the sugarcane juices in different clarification stages. This report developed an analytical method by building up multivariate models based on partial least-squares regression. These models showed promising results in estimating the contents of Mg, P, S, K, Ca and Fe for all of the first seven clarification stages. For most elements, the relative prediction errors were <14%, with coefficients of determination >0.9083. The main achievement was the development of sustainable analytical methods to monitor mineral content in extracted juices from sugarcane during the clarification stages with reduced sample volume and fewer chemicals. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd.