离子注入改性NaY分子筛对汽油超深度吸附脱硫研究

Ultra deep desulfurization of gasoline and diesel fuels has got more attention in public nowadays. The adsorption desulfurization on modified zeolites has the characteristics of good selectivity, high precision and adsorbent regeneration etc. However, there are many problems in the existing modification methods, such as pores blockage and collapse. It is lack of high efficient adsorbent and it is necessary to study the mechanism of adsorption and desorption. The applicant proposes the latest application of ion implantation modified NaY molecular sieve in selective adsorption removal sulfide from gasoline. The research project demonstrates the ion implantation modified NaY zeolites preparation and desulfurization mechanism on it, through the ultra deep desulfurization adsorbent preparation and characterization, based on density functional theory calculations of molecular simulation, to solve the following key scientific problems:1) The project will study how to maintain the integrity of NaY molecular sieve framework and pore structure, achieve the high dispersion of transition metal ions on the surface of NaY molecular sieve, and prepare high performance deep desulfurization sorbent; 2) We will study the interaction between the highly dispersed metal nanoparticles on the surface of the zeolite as the active center with the sulfide, and sulfide compounds adsorption, desorption and migration of sulfur is studied from the molecular level; 3) The internal connection of surface characteristics, pore structure and adsorption properties of the ion implantation modified NaY molecular sieve, deep desulfurization mechanism is also discussed. The results are expected to guide the preparation of adsorbent and its desulfurization application.

汽油、柴油等燃料深度脱硫越来越受到重视。改性分子筛吸附脱硫具有选择性好、脱除精度高、吸附剂可再生等特点，但现有改性方法存在孔道堵塞、骨架坍塌等问题，缺乏高效吸附剂，吸附、脱附机理研究尚需完善。申请人最新提出将离子注入改性NaY分子筛用于汽油选择性吸附超深度脱硫。本项目拟通过超深度脱硫吸附剂制备与表征、密度泛函分子模拟理论计算等手段，研究离子注入改性NaY分子筛的制备及其深度脱硫机理，拟解决以下关键科学问题：1）研究如何保持NaY分子筛骨架和孔道结构完整性，实现过渡金属离子在NaY分子筛表面的高度分散，制备高性能超深度脱硫吸附剂；2）研究高度分散在分子筛表面上的纳米金属离子作为活性中心与硫化物的相互作用规律，从分子层面研究硫化物的吸附、脱附以及硫的迁移转化规律；3）研究离子注入改性NaY分子筛表面特性、孔道结构与吸附性能间的内在关联，探讨深度脱硫机理。研究结果可望指导吸附剂制备及其脱硫应用。

为满足环保和工业生产要求，油品中硫化物的超深度脱除问题亟待解决。吸附脱硫的关键在于开发高效吸附剂，现有方法制备的改性分子筛吸附剂尚存在孔道堵塞、骨架坍塌、吸附剂成型后吸附容量低等问题。缺乏高效吸附剂，吸附、脱附再生机理尚需完善等制约吸附脱硫发展。本项目很好的完成了既定的研究目标。通过联合浓缩粘粉体系制备纳米晶分子筛、分子筛原位晶化、离子交换、蒸汽诱导还原等策略制备了高性能脱硫吸附剂。还尝试制备了缺陷HKUST-1、ZSM-5纳米晶脱硫剂，并用于汽油选择性吸附超深度脱硫。通过吸附剂制备与表征、分子模拟理论计算等手段，研究改性ZSM-5分子筛的制备及其深度脱硫机理。主要研究成果包括：1）提出分子筛原位晶化策略，制备多级孔ZSM-5分子筛脱硫吸附剂，成功应用于燃油选择性吸附深度脱硫；2）通过混合模板策略制备了含多级孔的合理缺陷HKUST-1高效脱硫吸附剂；3）提出了一种混合连接缺陷策略来构建双峰微介孔HUKST-1，以增强对燃料中苯并噻吩（BT）的吸附去除；4）基于Metropolis Monte Carlo方法，运用COMPASSⅡ力场模拟DMDS与2-丁烯在Cu(I)Y分子筛上的纯组份吸附和竞争吸附，采用密度分布和局部吸附构型对吸附位点进行直观描述；5)提出以聚氧乙烯-聚氧丙烯-聚氧乙烯（PEO-PPO-PEO）三嵌段共聚物作为表面活性剂，制备的超微孔二氧化硅具有比表面积高、孔容高、合成工艺简单等特点，用于苯并噻吩脱除，净化效果良好；6)开展了浓缩粘粉体系制备纳米晶ZSM-5脱硫剂制备及其在吸附脱除模拟燃料油中噻吩的研究。探究了脱硫吸附剂表面特性、孔道结构与吸附性能间的内在关联，探讨深度脱硫机理。通过负载Ag+制备的Ag/ZSM-5纳米晶，其穿透硫容达到16.20mgS/g 吸附剂，远超过研究任务书中的指标2.0mgS/g 吸附剂。本项目为多孔材料选择性吸附深度脱硫研究提供新方法和理论基础。研究结果可望指导吸附剂制备及其脱硫应用，具有重要的理论和现实意义。相关成果在J. Hazard. Mater., Sep. Purif. Technol.，Ind. Eng. Chem. Res. 等本领域高水平国际期刊上发表SCI收录论文13篇，申请中国发明专利11项。