木屑制备高孔隙成型活性炭及Doehlert设计法优化

以木屑为原料，不添加任何黏结剂，使用H₃PO₄作为活化剂，制备高孔隙的成型活性炭。利用N₂吸附-脱附、XRD及万能试验机，考察了不同活化时间（1~3 h）、活化温度（500~700 ℃）对成型活性炭性能的影响。结果表明：制备的成型活性炭具有较高的比表面积、孔隙率、得率、表观密度、耐压强度和总孔容积。在活化温度为600 ℃，活化时间为1 h的条件下，其比表面积达1 022.6 m²/g，得率为32.2 %，表观密度为0.62 g/cm³，耐压强度为5.23 MPa，总孔容积为0.49 cm³/g，微孔比例达到91.8 %。通过Doehlert设计法对反应条件进行优化，结果表明优化的制备条件为活化温度590 ℃，活化时间2.1 h，此时成型活性炭得率、耐压强度和表观密度分别为31.8 %、5.54 MPa、0.87 g/cm³。理论值和实验值存在很好的一致性，表明该理论模型是可靠的。

Preparation of High Porosities Active Carbon Monoliths from Sawdust and Doehlert Matrix Method Optimization

Sawdust was used as precursor to prepare binderless high porosities active carbon monoliths(ACMs) with H₃PO₄ as activator and without binder. The influences of temperature(500-700 ℃) and activation time(1-3 h) on the properties of ACMs were analyzed by N₂ adsorption-desorption, X-ray diffraction(XRD) and compression test. The results showed that the ACMs had high specific surface area, porosity, yield, apparent density, compressive strength and total pore volume and they could reach 1 022.6 m²/g, 32.2 %, 0.62 g/cm³, 5.23 MPa, 0.49 cm³/g and 91.8 % when the activation temperature was 600 ℃ and the activation time was 1 h. The Doehlert matrix method was used to optimize the reaction conditions and the optimal temperature and time were 590 ℃ and 2.1 h. Under these conditions the yield, compressive strength and density of ACMs were 31.8%, 5.54 MPa and 0.87 g/cm³. It was found that the theoretical value was consistent with experimental value and the theoretical model was reliable.