Study on Charcoal Materials Fabricated from Lignosulfonate

• Main Authors: Kei-Kei Chan, 陳旗旗
• Other Authors: Feng-Cheng Chang
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/52qx47

碩士 === 國立臺灣大學 === 森林環境暨資源學研究所 === 106 === In this study, the properties of lignin-based charcoal materials made by lignosulfonate (a technical lignin) through different process parameters were investigated, such as pyrolysis temperature, heating rate, holding time and washing treatment (Deionized water washing with ultrasonicator, acid washing by phosphoric acid). Analysis tests include surface morphology and pore properties, chemical properties and thermal properties. Surface morphology and pore properties include scanning electron microscope, surface area porosity and pore diameter analysis. Chemical properties include pyrolysis-gas chromatography/mass spectrometry, elemental analysis, fourier transform infrared spectroscope, X-ray diffraction, near edge X-ray absorption fine structure and zeta potential. Thermal properties include differential scanning calorimetry and thermogravimetric analysis. Results show that after pyrolysis processing, lignosulfonate particles would form porous charcoal spheres, caused by self-activation, cross-linking and gasification reaction caused by high temperature, gas emission during pyrolysis resulted in the porous structures for the lignin-based charcoals, producing the more porous structures for lignin-based charcoals. Furthermore, the carbon content of lignin-based charcoals has significantly increased with elevating pyrolysis temperatures. As the degreaser, deionized water and phosphoric acid can remove impurity of lignin-based charcoal increased the carbon content. In contrast to carbon content, the yields of lignin-based charcoals decreased with elevating pyrolysis temperatures and washing treatment. Acid washing charcoals have the highest carbon content, but deionized water washing charcoals have the best thermal stability and dispersibility. The results also show that the charcoal’s aromatic ring structure would increase and carboxylic carbon would decrease when pyrolysis temperature was increased. However, the graphitized structure could form only when the pyrolysis temperature was over 600°C. And the average pore diameter of the lignin-based charcoals washing by deionized water were decreased when the pyrolysis temperature was increased, but the surface area would first rise and then fall, the lignin-based charcoal has the highest surface area (688.5 m2 g-1) when the pyrolysis temperature was at 900°C. The porosity of the charcoals has no significance to pyrolysis temperature, the porosity of all lignin-based charcoals washing by deionized water was between 70–80%. The results of adsorption isotherms and pore size distribution both show that the pore structures of lignin-based charcoals are micro-pore.