活性碳纤维吸附法脱蜡降浊点的研究

Dewaxing and cloud point depression by activated carbon fiber adsorption

探讨了活性碳纤维对润滑油基础油脱蜡降浊点的工艺,考察两种不同比表面积的活性碳纤维在不同温度和不同空速条件下对浊点降低效果的影响和穿透量。结果表明,空速1 h-1,温度50℃,比表面积1 800 m2/g的活性碳纤维浊点降低效果最好,下降的总温度可达10℃。当吸附的基础油体积达到脱蜡塔体积的23倍时,活性碳纤维被穿透。SEM、BET等分析结果表明,比表面积1 800 m2/g的活性碳纤维的孔容、孔径比1 000 m2/g的活性碳纤维大,其表面具有更多的活性位点,更有利于蜡烃组分的吸附。通过尿素络合法分析吸附前后基础油的烃类组成情况,正构烷烃的质量分数由20%下降至10%。气相色谱仪分析吸附前后正十二烷与异构十六烷含量的变化证明,活性碳纤维对正构烷烃具有选择性吸附。

The research is dewaxing and depressing cloud point of lube base oils by using activated carbon fibers as adsorbent. When the space velocity is 1 h-1,determine the temperature is 50 ℃,the activated carbon fiber with a specific surface area of 1 800 m2/g has the best reduction effect,and the cloud point can drops 10 ℃. When the adsorptive base oil volume reaches about 23 times to the volume of the tower,the activated carbon fiber will be penetrated,and analyzed by SEM and BET. The result is the pore volume and pore diameter of activated carbon fibers with specific surface area of 1 800 m2/g are larger than those of 1 000 m2/g activated carbon fibers. Its surface has more active sites,which is more conducive to wax adsorption. The hydrocarbon composition of base oil before and after adsorption was analyzed by urea complexing method,the mass fraction of n-alkanes decreased from 20% to 10%,leading to a decrease in cloud point of base oils. The change of the content between positive twelve alkane and isomeric sixteen alkane before and after adsorption was analyzed by gas chromatograph. It is further proved that activated carbon fiber has selective adsorption on isoparaffin.