吸附法脱除油品中有机氯研究进展

综述了近年来脱氯吸附剂的研究进展,分析了活性炭、分子筛、金属氧化物等吸附剂的优缺点。其中分子筛和金属氧化物吸附剂显示出了良好的脱氯性能,且可通过简单的空气热处理再生,是非常有前景的脱氯吸附剂。在升高温度的情况下,分子筛和金属氧化物对有机氯的吸附从物理吸附转为化学吸附,脱氯性能显著提升,因而分子筛和金属氧化物化学吸附脱氯将是未来研究的热点。     

改性Y型分子筛吸附脱除喹啉和吲哚过程的模拟计算

运用密度泛函理论（DFT）研究4种阳离子改性Y型分子筛(CeY,NiY,CuY,AgY)的吸附脱氮性能。采用GGA近似下BLYP交换的相关泛函和DNP基组，基于Fukui函数描述和布居分析法计算各个改性Y型分子筛的Lewis酸强度，结果显示Mulikun和Hirshfeld两种布居分析方法得到的4种改性Y型分子筛酸性强度由大到小的顺序均为：CeY>NiY>CuY>AgY；通过计算η1N和η5构型的吸附能，发现喹啉和吲哚在4种改性Y型分子筛的η5构型的吸附能要比η1N构型大，表明喹啉和吲哚的吸附构型以η5为主；计算了不同温度下CeY分子筛对喹啉和吲哚的吸附等温线，结果表明，吸附温度对吸附喹啉和吲哚影响不大，温度为298 K时CeY对吲哚的平衡吸附量大于喹啉。     

油品中有机氯脱除研究进展

综述了近年来国内外油品脱氯技术的研究进展,讨论了催化加氢法、亲核取代法、吸附法等脱氯技术的研究现状及优缺点。其中,吸附脱氯技术具有操作条件温和,工艺简单的优势,是极具应用前景的脱氯技术。并且,分子筛和金属氧化物吸附剂因性能优良,成本低,再生简单,将成为未来吸附脱氯研究的重点。     

分子筛吸附脱除烷基化油中微量氯化物的研究

对多种分子筛的脱氯效果进行了对比和筛选,结果表明NaY分子筛具有良好的脱氯性能.以NaY分子筛原粉为活性组分,采用混捏法制备NaY分子筛吸附剂,并以烷基化油为原料,详细考察了NaY分子筛吸附剂的制备条件对吸附剂脱氯性能的影响.试验结果表明,在NaY分子筛原粉/黏结剂质量比为2.0、焙烧温度为400℃、焙烧时间为3 h的...     

离子交换树脂应用于Y型分子筛离子交换过程的研究

Ion-exchange process of zeolite Y using ammonium-type resin as an exchange reagent was successfully carried out. The effect of temperature, space velocity and ion concentration on the breakthrough curves was carefully investigated. At the first exchange section, the maximum proportion of qualified zeolites(QR) was obtained at a temperature of 70 ℃, a weight hourly space velocity of 0.61 h-1, and an ion concentration of 197 mg/L. The minimum length of mass-transfer zone(MTZ) of the resin bed was achieved at a temperature of 70 ℃, a space velocity of 0.61 h-1, and an ion concentration of 423 mg/L. At the second exchange section, the length of MTZ of the resin bed was significantly increased, and the exchange of Na+ ions contained in zeolite Y was more difficult than that achieved at the first exchange section. In both the first and the second exchange sections, the zeolite Y subjected to ion exchange with the resin maintained the similar physical and chemical properties as compared to those exchanged by the conventional approaches, but the zeolite Y, which was obtained after ion exchange, contained a significantly lower content of Na2 O.     

NaY/β复合分子筛改性及对模拟柴油中氮化物的吸附性能

利用二次交换二次焙烧方法对NaY/β分子筛进行改性,制备CeY/β和BaY/β复合分子筛。采用XRD、ICP-MS表征方法对改性前后的分子筛结构进行分析;采用氮含量600 μg/g的模拟柴油,考察改性前后分子筛的吸附脱氮效果,并优化吸附脱氮条件。结果表明：改性前后分子筛的特征峰基本一致,说明改性没有改变分子筛的主体晶型;改性后分子筛的脱氮率明显增加,CeY/β分子筛的脱氮效果最佳;CeY/β分子筛的适宜吸附条件为：剂油质量比1:20,反应温度40 ℃,吸附时间3.0 h;BaY/β分子筛的适宜吸附条件为：剂油比质量1:40,反应温度40 ℃,吸附时间4.0 h。     

用改性Y型分子筛吸附剂从CO_2中选择吸附C_2H_4的研究

用不同金属阳离子如Ｃｕ２＋、Ｚｎ２＋、Ｃｄ２＋、Ｈｇ２＋、Ｎｉ２＋、Ａｇ＋、Ｌａ５＋、Ｃｅ３＋等对Ｙ型分子筛进行浸渍交换和改性，制备吸附剂，考察其活化温度及操作条件对Ｃ２Ｈ４／ＣＯ２分离性能的影响。结果表明，用ＩＢ族和ＩＢ族金属阳离子之一与镧系阳离子之一改性的Ｙ型分子筛吸附剂，可使Ｃ２Ｈ４／ＣＯ２的分离性能大大提高，稳定性良好。最佳操作条件为：活化温度４００～４５０℃，吸附温度５０℃，空速１５ｍｉｎ－１。     

Al-SBA-15吸附脱除油品中碱性氮化物的研究

对硅铝比为50的Al-SBA-15介孔分子筛开展吸附脱除喹啉的十二烷溶液中碱性氮化物的实验,研究其吸附脱氮工艺条件及性能。结果表明,碱性氮化物在Al-SBA-15(50)上的最佳吸附温度为140℃,适宜的剂油质量比是1∶30,适宜的吸附时间为20min。此时吸附量为30.6mg/g,脱氮率为68.02%,吸附动力学可用准二级动力学方程表示。     

Y型分子筛复合材料的改性及其裂化性能

采用两交一焙的工艺对Y型分子筛复合材料(NSY)进行改性处理,采用X射线衍射、X射线荧光光谱仪、氮气吸附法、差热分析仪等测试了改性后NSY的物化性能。将改性后稀土含量不同的NSY复合材料制备催化剂,采用小型固定流化床考察了催化剂的催化裂化性能。结果表明,稀土含量高的NSY复合材料具有好的重油转化能力和高的汽柴油收率;稀土含量低的NSY复合材料具有较好的焦炭选择性和高的液化气收率。     

Preparation of the Modified Y Zeolite for Removal of Organic Sulfur Compounds from FCC Gasoline

Abstract

Ce(IV)-loaded modified NaY (NH₄Y) zeolite was prepared for selective adsorptive desulfurization from fluid catalytic cracked (FCC) gasoline. Ce(β)Y was obtained from NH₄Y using a liquid-phase ion-exchange method. Ce(IV)Y was obtained from calcining Ce(β)Y at 550°C. The structures of the Ce(IV)Y and NaY samples, selective adsorption of organic sulfur compounds on Ce(IV)Y and NaY zeolite, sulfur content of FCC gasoline, and mechanism for adsorption of thiophene on Ce(IV)Y and NaY zeolite were investigated using X-ray diffraction (XRD), gas chromatography–sulfur chemiluminescence detection (GC-SCD), sulfur analysis, Fourier transform infrared (FTIR), frequency response (FR), and intelligent gravimetric analysis (IGA). The selective adsorption desulfurization from FCC gasoline containing organic sulfur compounds (S = 135 μg/g) was investigated with Ce(IV)Y adsorbent for removal.

The sulfur content was reduced to 20.14 μg/g. The thiophene adsorption mechanism showed that Ce(IV)Y can adsorb thiophene via π electronic interaction directly, and thiophene and Ce(IV) can form a stable sulfur–metal bond (S-M bond) that enhances the adsorption capacity of Ce(IV)Y for thiophene. This method for the modification of NaY zeolite provides a promising selective desulfurization process to prepare clean fuels.     

Investigation on Modification of NaY Zeolite and Its Behaviors in Selective Adsorptive Desulfurization of FCC gasoline

NaY zeolite was modified with oxalic acid, and Ce(IV)Y(1) zeolite was obtained via liquid phase ion exchange between the modified NaY zeolite and cerium nitrate. The Ce(IV)Y(2) zeolite was obtained via liquid phase ion exchange between NaY zeolite and cerium nitrate. The performance of two Y zeolites [Ce(IV)Y(1) and Ce(IV)Y(2)] was compared through static selective adsorptive desulfurization of FCC gasoline at room temperature and normal pressure. The sulfur compounds and contents of the FCC gasoline were a...     

Y分子筛催化异丁烷/丁烯烷基化反应中焦组分的吸附模拟

选取分子筛催化异丁烷/丁烯烷基化反应过程中不同结构类型和碳数的焦组分模型化合物,采用分子模拟方法计算模型化合物在Y分子筛孔道内B酸中心附近的稳定吸附构象,研究焦组分在Y分子筛孔道内的吸附能力差异性和堵孔效应。结果表明,不同结构类型焦组分的吸附能力由强到弱的顺序依次为烯烃类、烷基苯类、烷基萘类、烷烃类、烷基环己烷类、烷基萘烷类;焦组分碳数的增加对焦组分与B酸中心之间的相互作用并无影响;直链类焦组分对Y分子筛的孔道内呈二维空间占据,环状类焦组分对Y分子筛的孔道内呈三维空间占据,而双环类焦组分在X方向上对所在12元环孔道的径向空间占据更大,堵孔效应更明显。     

水热处理和硝酸处理对改性Y分子筛性能的影响

采用水热处理和硝酸处理相结合的方法对Y分子筛进行改性,并采用N2吸附-脱附、XRD、NH3-TPD、Py-FTIR、27Al MAS NMR、SEM等方法对改性前后的Y分子筛进行了表征。考察了不同改性方法对Y分子筛的孔结构、晶相结构、酸性以及Y分子筛催化剂加氢裂化性能的影响。实验结果表明,随水热处理温度的升高,Y分子筛的脱铝量增大,比表面积减小,总酸量降低;随硝酸浓度的增加,Y分子筛中的非骨架铝脱除,相对结晶度、比表面积和硅铝比增大。以改性后的Y分子筛制备的加氢裂化催化剂的活性和选择性得到改善,其中Y分子筛经680℃水热处理和0.6 mol/L硝酸处理后制备的加氢裂化催化剂,在保持较高正十二烷转化率的前提下,具有良好的中油(C4~8烃)选择性,中油收率为51.07%。     

改性Y型分子筛对石脑油脱硫效果的研究

NH4Y zeolite was prepared through ion-exchange of NaY zeolite with an ammonium salt. Then LaY zeolite was obtained through a secondary ion-exchange of NH4Y zeolite with a rare earth salt solution followed by calcination of the zeolite product. Dynamic adsorptive desulfurization of naphtha was conducted in the presence of the modified LaY zeolite, and the sulfur content of the treated naphtha samples was analyzed by microcoulometry. The test results showed that under dynamic conditions the LaY zeolite prepared through secondary ion-exchange of NH4Y zeolite, which was prepared using 1.0 mol/L ammonium salt, with the rare earth salt exhibited a better desulfurization efficiency. Furthermore, the LaY zeolite achieved a best desulfurization effect at an adsorption temperature of 45 ℃ and an adsorbent/oil ratio of 1:2.     

分子筛脱硫剂的制备及其吸附脱硫性能研究

利用铵盐离子交换的方法对NaY分子筛进行改性制备了HY型分子筛,HY型分子筛分别采用与硝酸铜溶液进行二次离子交换和浸渍法制得两种CuY型分子筛脱硫剂A和脱硫剂B。利用改性的Y型分子筛脱硫剂进行直馏柴油静态吸附脱硫实验,结果表明,HY型分子筛经过浸渍法和离子交换法两种改性方法制备的脱硫剂其脱硫效果又进一步增强,其中以硝酸铜溶液离子交换法制备的脱硫剂A脱硫效果最好,其脱硫率接近70％。     

Cu(Ⅰ)Y分子筛吸附剂的制备及其脱硫性能

采用水热离子交换法制备了Cu(Ⅱ)Y分子筛,对Cu(Ⅱ)Y分子筛进行活化处理制得Cu(Ⅰ)Y分子筛吸附剂,在固定床中考察了吸附温度、操作压力和液态空速对Cu(Ⅰ)Y分子筛吸附剂脱硫性能的影响。实验结果表明,Cu(Ⅱ)Y分子筛适宜的离子交换条件为:Cu(NO3)2溶液浓度0.5 mol/L、固液比(离子交换过程中NaY分子筛与Cu(NO3)2溶液的质量比)0.05、交换温度135℃、交换时间12 h;在低于600℃时,活化温度越高,活化时间越长,Cu(Ⅰ)Y分子筛吸附剂的脱硫性能越好,适宜的活化条件为在N2中500℃下活化6 h;在固定床中,Cu(Ⅰ)Y分子筛吸附剂适宜的脱硫条件是常温、常压、液态空速10 h-1,在此条件下,Cu(Ⅰ)Y分子筛吸附剂对模型汽油的饱和硫容量为8.61%。     

不同浓度草酸改性对Y分子筛性能的影响

采用水热处理和草酸处理相结合的方法对Y分子筛进行改性,采用N2吸附-脱附、XRD、吡啶吸附FTIR、27Al MAS NMR和SEM等方法对Y分子筛进行了表征,并在微型反应装置上评价了改性Y分子筛制备的催化剂的加氢裂化活性,考察了不同浓度草酸改性对Y分子筛性能的影响。表征结果显示,随草酸浓度的提高,Y分子筛的比表面积、孔体积和孔径逐渐增大;硅铝比均明显提高,相对结晶度增大,晶胞常数减小;总酸量、弱酸酸量、中强酸酸量及B酸酸量均出现不同程度的减小。催化剂的加氢裂化活性评价结果表明,较为适宜的草酸处理浓度为0.20 mol/L。     

磷改性Y型分子筛的合成与表征

 采用母液合成法制备了含磷的Y型分子筛PY。利用X射线粉末衍射(XRD)、傅里叶变换红外光谱(FT-IR)、固体魔角自旋核磁共振波谱(MAS-NMR)、吡啶吸附红外光谱等方法对PY分子筛进行表征。结果表明,制备过程中有部分磷原子进入了Y型分子筛的骨架中,磷的引入使PY分子筛的强B酸中心与总酸中心数量均下降。     

Theoretical Study on Adsorption of Methanol on Zeolite and Phosphorus Modified Zeolite

Methanol adsorption in zeolite and phosphorus modified zeolite has been investigated within the cluster model framework of quantum chemical calculation. Full optimization and frequency analysis of all cluster model have been carried out using Gaussian 94 soft package with Hartree-Fock method and B3LYP, B3P86 hybrid methods of density functional theory at 3-21G, 6-31G basis set level for hydrogen atoms and 6-31G (d) basis set level for the other atoms performed on small cluster model for CH3OH, H3Al(OH)SiH2(H2PO4), H3Al(OH)SiH2(H3SiO4), H3Al(OH-CH3OH)SiH2(H2PO4) and H3Al(OHCH3OH)SiH2(H3SiO4). The results show that phosphorus grafting in the zeolite framework has modified the chemical environment in the vicinity of the zeolite bridging hydroxyl. Phosphorus modification can enhance the acid strength of zeolite bridging hydroxyl, which was suggested by the lengthening of zeolite bridging hydroxyl O-H bond and the increasing methanol adsorption energy. This may be favorable to the initial CH3OCH3 formation in the methanol to gasoline (MTG) process.