KL沸石的结晶状态对PtKL催化剂性能的影响  

EFFECT OF CRYSTALLINE STATE OF KL TYPE ZEOLITE ON PERFORMANCE OF PtKL CATALYST

作　　者：林洁[1] 赵佩琳 冯奇[1] 王斯文[1] 王君钰 

机构地区：[1]石油化工科学研究院

出　　处：《石油学报（石油加工）》1991年第1期39-47,共9页Acta Petrolei Sinica(Petroleum Processing Section)

摘　　要：对于正构烷烃的脱氢环化反应,载铂的L沸石(PtKL)具有比传统的双功能重整催化剂高得多的活性及选择性。研究表明,KL沸石的结晶度、晶粒大小及状态随合成所用的原料组成及晶化条件而变化,并影响到PtKL催化剂的活性、选择性和稳定性。本文用低硅、低碱原料合成了高纯度、高结晶度、圆柱体状的L沸石,晶粒直径1.5μm以上,长径比1.0左右。以这种沸石为载体的PtKL催化剂对正构烷烃的脱氢环化具有非常高的活性和选择性。通过对沸石合成条件及催化性质的关联,发现KL沸石的结晶度越高,PtKL催化剂的活性及稳定性越好;当沸石的平均晶粒直径小于1μm或圆柱体的长径比大于2时,催化剂的氢解活性较高,脱氢环化的初始选择性下降。实验结果还表明。合成L沸石时伴生的部分W沸石杂晶对催化剂性能没有显著的影响。Platinum-loading KL zeolite has much higher activity and selectivity for paraffin dehydrocyclization than the conventional platinum reforming catalysts, such as Pt-Re/Al_2O_3 or Pt-Sn/Al_2O_3. It has been found that the crystallinity, crystal size and shape of KL zeolite are dependent upon the starting gel composition and the conditions of crystallization, and affect the activity,selectivity and stability of P^KL catalysts. Larger cylindrical crystals of KL zeolite have been synthesized successfully by the authors from the material having lower Si/Al and OH/Al ratios(SiO_2/Al_2O_3<15, OH/Al<3.5). The PtKL catalyst based on this larger KL zeolite crystals (D>1.5 micron, L/D about 1) has excellent activity and selectivity for n-paraffin aromatization. Studies also show that the higher crystallinity of the L zeolite, the higher the activity and selectivity of the PtKL catalyat when the crystal size is less than 1 micron or the L/D ratio of the cylinders is larger than 2. The PtKL catalyst is more active in hydrogenolysis and less selective in dehydrocyclization. A small amount of W zeolite concomitantly formed during the synthesis of L zeolite has little effect on perrefinance of the PtKL catalyst.

关 键 词：KL PtKL 沸石 结晶 催化剂 

分 类 号：TE624.9[石油与天然气工程—油气加工工程]