催化裂化汽油碱精制碱渣再生为碱的动态研究

KINETIC RESEARCH OF CAUSTIC REGENERATION IN FCC GASOLINE CAUSTIC REFINING

利用活性组分金属氧化物NO与催化裂化汽油碱精制碱渣中的无机硫化物及小分子硫醇钠反应生成 NaOH的特性,以氧化铝为担体,采用浸渍法制备了活性组分负载量不同的再生剂,通过固定床反应器对碱渣再生为碱的过程进行了动态研究。结果表明:该过程是一个化学反应与物理吸附共同作用的过程,在物理吸附段、反应吸附段和再生反应段各段中,化学反应与物理吸附所起作用大小不同。在40℃、再生剂装填量146．5 g、进料速度 1 mL／min时,再生180 min后游离碱浓度达95．41g/L,无机硫脱除率为99％,挥发酚保持率保持在为90％以上, COD脱除率达到25％以上。失活的再生剂经灼烧再生后,可再次利用。经5次失活-再生后,再生剂的活性比新鲜再生剂降低约10％。

The process of regenerating caustic sludge to produce caustic is kinetically investigated on a fixed-bed reactor using the catalysts of Al2O3 support impregnated with different amount of active components based upon the reaction in which the active components-the metal oxides （MO） in the catalyst react with inorganic sulfur compounds and small molecular sodium mercaptylate in FCC gasoline to form NaOH. The study shows that, the process is a combination of chemical reaction and physical absorption. The effects of physical absorption and chemical reaction are different in physical absorption stage, chemical reaction stage and regen- eration stage. At 146.5 g catalyst inventory, 1 mL/min feed flowrate and after 180 minutes＇ regeneration, the free caustics concentration is as high as 95.41g/L, the inorganic sulfur species removal is 99%, the volatile phenol retention is over 90% and COD removal rate is greater than 25%. The deactivated catalyst can be reused after regeneration by incineration. The activity of regenerated catalyst after 5 regeneration cycles is only 10% lower that than of fresh catalyst.