【作者】 董小航；

【导师】 谭涓；

【作者基本信息】 大连理工大学 ， 化学工程与技术， 2017， 硕士

【摘要】 催化裂化(FCC)是重要的原油炼制工艺,FCC催化剂也是消耗量最大的催化剂。近年来石油资源重质化、劣质化趋势日益严重,制备对重油裂解能力更强的FCC催化剂变得尤为重要。高硅铝比的超细Y分子筛由于具有较大的外表面积,催化活性点相对增多,以及良好的结构稳定性等特点,能够适应于原油催化裂化苛刻的反应条件。而以高岭土为原料原位晶化合成的NaY分子筛具有晶粒尺寸小、活性稳定性高、丰富的中大孔结构、优秀的机械性能和较高的抗重金属污染能力等优点,在制备重油、渣油催化裂化催化剂方面具有较大优势。我们在前期工作中,已经实现了在无模板剂和添加剂的条件下采用廉价化工原料,直接合成高硅铝比(>6.0)、小晶粒(200~400 nm)NaY分子筛的工艺。在此基础上,本文探索了以高岭土为原料,采用直接合成法,原位晶化合成高硅铝比小晶粒NaY分子筛的工艺条件,为开发新一代FCC催化剂提供研究基础。主要研究成果有:(1)苏州和蒲城高岭土焙烧活化条件的研究结果表明,苏州高岭土经700℃~850℃焙烧后有96%的氧化铝具备反应活性,经950℃焙烧后有70%的氧化硅具备反应活性,能够作为合成NaY分子筛的硅源和铝源。经焙烧活化的蒲城高岭土中氧化硅和氧化铝的利用率分别在50%~60%和8%~12%之间,其活性组分利用率明显低于苏州高岭土。(2)以焙烧活化的苏州高岭土为原料合成了NaY分子筛,并考察了合成条件的影响。结果表明,合成样品的相对结晶度在70%~90%之间,骨架硅铝比在5.7~6.0之间、晶粒尺寸在300~600 nm之间;提高晶种胶添加量可以大大缩短NaY分子筛晶化诱导期;改变原料中高土/偏土比例可以调节产物中NaY分子筛含量;通过优化高硅铝比NaY分子筛的合成工艺,合成样品的骨架硅铝比可提高至6.2~6.3。(3)以焙烧活化的苏州高岭土微球为原料,采用原位晶化法合成了NaY分子筛,其骨架硅铝比为5.7~5.9,晶粒尺寸小于200 nm,相对结晶度为70%。随着陈化时间的增加,晶化速度加快,样品相对结晶度提高,但是晶化稳定期缩短。陈化时间为8 h~10 h时样品晶化效果最好。更多还原

【Abstract】 Fluid catalytic cracking（FCC）process is a core technology of crude oil cracking,while FCC catalyst is the most depletion among all kinds of catalyst.However,the crude oil quality is becoming more and more serious.It if urgent to prepare new FCC catalyst with higher ability of heavy oil cracking.The small size Y zeolites with high framework SiO₂/Al₂O₃ ratio can fulfil the rigour condition of the catalytic cracking because of the fact that small size Y zeolites have very huge surface areas,high catalytic activity.The in-situ synthesized NaY zeolites using Kaolin have the advantages of small particle size,high stability of catalysis activity,rich meso/macro porous structure,excellent mechanic properties of martrix and good performance of resistance to heavy metal pollution.In the preliminary work,we have prepared small size NaY zeolites with high framework SiO₂/Al₂O₃ ratio by directive synthesis proccess.The main goal of this paper is to prepare small size NaY zeolites with high framework SiO₂/Al₂O₃ ratio by in-situ synthesis using Kaolin as raw materials,aimming to provide reseach basis of synthesizing new FCC catalyst.The main research results of this paper are as followed:（1）The investigation of the optimal calcining condition of Kaolin show that,the availability of Al₂O₃ is about 96% in Suzhou Kaolin calcined among 700℃ to 850℃,and the availability of SiO2 is about 70% at 950℃.The availability of SiO2 and Al₂O₃ is about 50%⁶0% and 8%¹2% respectively in Pucheng Kaolin lower than Suzhou Kaolin.（2）Small size（300⁶00 nm）NaY zeolites with high framework SiO₂/Al₂O₃ ratio（5.7⁶.0）were synthesized by a one-step hydrothermal method using calcined Suzhou Kaolin.The results show that,with the raising of the addition of SDA,the synthesis induction period was shortened.The content of NaY zeolites in product can be changed by different Kaolin/meta-Kaolin ratio in raw materials.The framework SiO₂/Al₂O₃ ratio of NaY samples is increased to 6.2⁶.3 with the optimal synthesis proccess.（3）Small size NaY zeolites with high framework SiO₂/Al₂O₃ ratio on Suzhou Kaolin spheres were prepared by an in-situ synthesis proccess.The framework SiO₂/Al₂O₃ ratio of samples was 5.7⁵.9,the relative crystallinity was about 70%,the particle size was smaller than 200 nm.The influence of ageing time was investigated.The results show that,with the raising of ageing time from 6 h to 12 h,the synthesis speed is accelerated and the relative crystallinity is increased,but the stable period was shortened.The best ageing time is 8 h¹0 h.更多还原