低温一步法活性炭基脱硫剂的制备与评价

以木屑为原料，在低温条件下一步法制得活性炭基吸附剂，考察了吸附剂制备条件和液-固、气-固吸附条件对吸附剂脱硫性能的影响。结果表明，吸附剂的最佳制备条件为，浸渍液与木屑质量比为1：1，浸渍液中硝酸质量分率为30%、吸附剂表面NiO负载量为5%，常温下浸渍24 h，400℃焙烧3 h。该吸附剂在0.2 g吸附剂/10 mL模拟油、温度为40℃及时间为5 h的液-固吸附脱硫的条件下，脱硫率为28.36%，吸附四次后饱和吸附硫容量可达2.34 mgS/g；在气-固吸附温度为250℃、空速为6.3 h^-1的条件下，饱和吸附硫容量为2.37 mgS/g；高温气-固吸附脱硫对吸附剂的影响表明，与脱硫前相比，吸附剂在比表面积、总孔体积、微孔体积均有明显提高，这说明气-固吸附脱硫过程同时实现了活性炭的扩孔活化。甲苯溶剂再生实验表明，经五次再生后吸附剂的再生性能均可达90%以上。

Preparation and evaluation of activated carbon-based desulfurization adsorbent by one-step method at low temperature

Activated carbon was prepared by one-step method at low temperature using sawdust as material. Effect of preparation and adsorption conditions among liquid-solid and gas-solid on desulfurization performance was discussed. The results show that the optimum preparation conditions are as follows:mass ratio of 1:1 for impregnation liquid (with HNO₃ mass fraction of 30%) and sawdust, NiO loading of 5% on surface of adsorbent, impregnation time of 24 h under room temperature and calcination time of 3 h under 400℃. Under adsorbent mass/DBT volume of 0.2 g/10 mL, liquid-solid adsorption temperature of 40℃ and adsorption time of 5 h, desulfurization efficiency can reach 28.36%. After continuous adsorption 4 times saturated adsorption sulfur capacity is up to 2.34 mgS/g. Under gas-solid adsorption temperature of 250℃ and adsorption velocity of 6.3 h^-1, adsorption sulfur capacity can reach 2.37 mgS/g. The effect of high temperature gas-solid adsorption desulfurization on adsorbent indicates that BET specific surface area, total pore volume and micropore volume of adsorbent have been improved obviously, which show that the gas-solid adsorption desulfurization process has realized the reaming activation of activated carbon simultaneously. The regeneration experiment of toluene solvent shows that the regeneration performance can reach more than 90% after 5 times cycle.