Biochar Prepared from Sugarcane Bagasse for the Clarification of Brown Sugar Solutions

Abstract

The industry is actively seeking innovative technologies to eliminate color and other impurities in the production of refined sugar. This study evaluated the potential of biochar samples for sugar clarification using a brown sugar solution as a model. To this end, samples of biochar were produced from sugarcane bagasse under different pyrolysis temperatures (300 °C, 600 °C, 800 °C, and 1000 °C). In the clarification test, the samples were exposed to brown sugar solution (10 g.L⁻¹) for 1 h, and color reduction was monitored using UV‒Vis spectroscopy. As expected, varying the pyrolysis temperature caused changes in the physicochemical properties of the biochar. With increasing temperature, the carbon content, fixed carbon content, ash content, specific surface area, pH, and thermal stability increased, whereas the volatile material content, oxygen content, and gravimetric yield decreased. The pyrolysis temperature also influenced the color reduction ability of the brown sugar solution. When the pyrolysis temperature increased, the percentage color reduction also increased. Thus, the sample pyrolyzed at the highest temperature investigated (1000 °C) presented the greatest clarifying potential, reducing the color of a brown sugar solution (10 g.L⁻¹) by 87%. Furthermore, the UV‒Vis spectrum indicated the removal of dyes, including caramels, melanoidins, and hexose alkaline degradation products, from the brown sugar solution. Therefore, sugarcane biochar has the potential for sustainable application in sugar clarification processes.