THERMOGRAVIMETRIC AND FTIR ANALYZES OF CORN COB PYROLYSIS

Charcoal has a large share in the Brazilian market. The production is carried out by pyrolysis of biomass at different temperatures, between 300 and 500 °C. In this study, the corn cob pyrolysis was investigated using thermogravimetric analysis (TGA) and Fourier Transform Infrared Spectroscopy (FTIR). Samples after pyrolysis were compared with raw biomass to evaluate changes in fuel characteristics. In DTG curves a reduction in the number of degradation peaks in the carbonized material was observed. The FTIR spectra allowed to identify the aromatic ring of the lignin in the charcoals structure, indicating the presence of this compound even in charcoals produced with a temperature of 500 °C. It can be concluded that the temperature of 400 °C was enough to completely degrade the hemicellulose and cellulose of the biomass, resulting the final product (charcoal) less reactive or thermally more resistant than the in natura corn cob.

木炭在巴西市场占据较大份额。其生产通过在300至500℃的不同温度下对生物质进行热解实现。本研究采用热重分析（Thermogravimetric Analysis, TGA）与傅里叶变换红外光谱（Fourier Transform Infrared Spectroscopy, FTIR）对玉米芯热解过程展开研究。将热解后的样品与原始生物质进行对比，以评估其燃料特性的变化。在微商热重（Derivative Thermogravimetry, DTG）曲线中，观察到炭化材料的降解峰数量有所减少。通过FTIR光谱可识别木炭结构中木质素的芳香环，表明即便在500℃下制备的木炭中仍存在该组分。由此可得出结论：400℃的热解温度足以使生物质中的半纤维素与纤维素完全降解，最终产物（木炭）的反应活性较天然玉米芯更低，或热稳定性更强。