Carbon based materials for the decolorization in sugar production

Sugarcane is a main raw material for sugar production. In the production process, sugarcane bagasse is a by- product. Decolorization is a necessary process to reduce the color intensity of sugar syrup. This work aims to develop biomass– based activated carbon that can effectively remove colorants. Activated carbon was prepared from sugarcane bagasse by chemical activation with phosphoric acid at carbonization temperatures ranging from 600 to 900 °C. The porous textures, and functional groups of the as– prepared carbons were investigated by nitrogen adsorption- desorption measurements, X- ray photoelectron spectroscopy ( XPS) and Fourier– transform infrared spectroscopy (FTIR), respectively. This study investigated the color adsorption ability in a batch adsorption. The effects of adsorption parameters such as contact time, adsorption temperature, and adsorbent dosage, on the adsorption ability, were investigated. The adsorption performance was determined by UV–vis spectrophotometer at 420 nm. The best adsorption performance was observed with activated carbon that was activated at 700 °C (BAC700). Langmuir, Freundlich, and Redlich-Peterson isotherms were used to analyze the experimental adsorption data. BAC700 showed competitive color removal efficiency ( 93. 24%) with the commercially available activated carbon (95.49%) and ion exchange resin (43.60%). The estimated price of sugarcane bagasse-derived activated carbon was about 31.77 baht/ kg.甘蔗是制糖工业的核心原料。在制糖生产流程中，甘蔗渣（sugarcane bagasse）为主要副产物。脱色是降低糖液色度的必备工艺步骤。本研究旨在开发可高效脱除色素的生物质基活性炭（biomass-based activated carbon）。本研究以甘蔗渣为原料，通过磷酸化学活化法，在600~900℃的碳化温度区间内制备得到系列活性炭。分别采用氮气吸附-脱附测试、X射线光电子能谱（X-ray photoelectron spectroscopy, XPS）以及傅里叶变换红外光谱（Fourier-transform infrared spectroscopy, FTIR），对所制备活性炭的孔隙结构与表面官能团进行了表征分析。本研究通过静态间歇吸附实验考察目标活性炭的色素吸附性能，系统探究了接触时间、吸附温度、吸附剂投加量等吸附参数对吸附效果的影响。采用紫外-可见分光光度计在420 nm波长下测定吸附性能。在700℃活化条件下制备的活性炭（BAC700）展现出最优的吸附性能。采用朗缪尔（Langmuir）、弗伦德里希（Freundlich）以及雷德利希-彼得森（Redlich-Peterson）三种等温吸附模型对实验吸附数据进行拟合分析。BAC700的色素脱除率达93.24%，与商用活性炭（95.49%）及离子交换树脂（43.60%）相比，其脱除效率具备较强竞争力。甘蔗渣基活性炭的预估价格约为31.77泰铢/千克。