利用煤矸石分步溶出硅铝连续化合成纯4A沸石

对煤矸石进行热活化(一次活化),再进行热活化与化学活化复合的二次活化,以活化后溶出的硅铝为原料连续化合成了纯4A沸石;并探讨了一次活化和二次活化的机理。实验结果表明,一次活化过程中,煤矸石的物相组成和微结构明显改变,煤矸石的潜在活性被激发,高岭石转变成偏高岭石、无定形SiO_2和活性γ-Al_2O_3;二次活化过程中,一次活化后的煤矸石与Na_2CO_3混合煅烧后生成了溶于水的Na_2SiO_3和溶于碱的NaAlSiO_4,其中铝以NaAlSiO_4的形式存在,用蒸馏水浸取可单独脱除部分硅,平衡煤矸石的硅铝比,有助于铝的溶出;用溶出的硅铝连续化合成的4A沸石没有杂晶,纯度很高,结晶度为82%,白度为98,钙交换值为310 mg/g,收率为310～350 g/kg。     

亚微米4A沸石的合成、结构与性能研究

介绍了以水玻璃、铝矾土和晶化导向剂为原料合成洗涤助剂用亚微米4A沸石的工艺过程,考察了各因素对合成的影响,并对亚微米4A沸石的结构和性能进行了研究。结果表明,最佳合成条件为n(SiO2):n(Al2O3)=1.9:1,晶化温度85℃,胶化时间20 min,晶化时间30 min,产物粒度<1 μm的占70％,钙交换能力为330 mg(CaCO3)／g(沸石)。     

宁夏矿区煤矸石中有价值元素提取初探

提取宁夏矿区煤矸石中有价值元素,是以煤矸石为原料合成4A分子筛的第一步。原料经过研磨、焙烧、酸浸、过滤、碱融、凝胶、干燥等预处理后,从煤矸石中提取有价值的铝、硅、铁。实验结果表明酸浸过程中最佳的条件是:酸液浓度20%、温度100℃、240 min和搅拌转速200 r/min。最佳条件下铝的提取率达到73.65%。     

亚微米级4A沸石的合成

研究了加入添加剂后碱度和晶化温度对水热合成4A沸石晶化时间和粒径的影响。通过X射线粉末衍射、扫描电子显微镜和激光衍射粒径分析等方法对合成的4A沸石进行测试。实验结果表明,在4A沸石合成体系中加入适量NaC l的同时,通过增加碱度、改变晶化温度,可以合成出亚微米级4A沸石。在n(Na2O)∶n(A l2O3)∶n(S iO2)∶n(H2O)∶n(NaC l)=6∶1∶2∶100∶2、晶化温度62℃、晶化时间100m in的条件下,可以合成出粒径0.5μm左右的4A沸石。     

由煤矸石制取NaX型沸石

以煤矿的废弃物煤矸石为原料 ,经Na2 CO3或NaOH碱熔活化和水热合成获得纯度、结晶度均较高的NaX型沸石。考察了碱量、水量、晶化时间、碱熔温度等因素对产物质量的影响 ,并与常规合成法反应体系进行对比。用XRD、IR、低温N2 吸附、常压流动法吸附、UV -VIS等手段对所得的NaX型沸石进行表征。利用XRD、TG -DTG等手段研究了碱熔物的结构。     

硅沸石、氟硅沸石的合成及晶化动力学

在Na_2O-C_4H_(11)-N-SiO_2-H_2O体系和NaF-Na_2O-C_4H_(11)N-H_2O体系中合成了硅沸石和氟硅沸石,讨论了合成过程诸因素对晶化的影响;用X-射线衍射法探讨了晶化动力学。气相和液相吸附数据证实了产品的憎水亲有机物特性。     

硅酸为硅源合成丝光沸石晶体

合成尺寸较大、形状均一的丝光沸石(MOR)晶体对于研究分子在MOR晶体中的吸附和扩散有重要意义.笔者采用硅酸作为硅源水热法合成了丝光沸石晶体,以XRD和SEM手段对所合成的丝光沸石进行表征,考察硅酸焙烧温度、硅酸粉末颗粒大小、体系Si/Al摩尔比(n(SiO2)/n(A12O3))以及碱度对合成丝光沸石晶体的影响.结果表明,减小硅酸粉末的颗粒大小、提高体系n(SiO2):n(A12O2)、适当降低体系碱度均可抑制杂晶相(ANA和PHI)的产生,同时得到尺寸较大、形状均一的纯相丝光沸石晶体.采用200～250目的硅酸粉末作为硅源,在n(Na2O)∶n(Al2O3)∶n(SiO2)∶n(H2O)＝5∶1∶25∶293.6的合成体系中,合成了晶体大小均一(约为23 μm×13 μm)的六方棱柱状MOR晶体,且不伴有杂晶产生.     

富含高岭石结构的煤矸石活化及合成NaY分子筛

以煤矸石为原料,在无模板剂和无添加剂的条件下,采用“高温焙烧-碱熔-碱溶-晶化”过程水热合成NaY分子筛。采用XRF、TG、XRD、SEM、N₂吸附-脱附曲线、NH₃-TPD等手段对高温热处理的煤矸石及合成的NaY分子筛进行表征。结果表明：煤矸石中的高岭石相在600～800℃生成无定型偏高岭石相,随着碳酸钠与煤矸石质量比的增加或碱熔温度的升高,硅铝酸钠的晶相含量先增多后减少;加入质量分数0.1%～2.0%的NaY分子筛晶种提高了产物分子筛样品的相对结晶度和比表面积;增加NaOH浓度导致NaY分子筛硅/铝比下降;提高投料硅/铝摩尔比(n(SiO₂)/n(Al₂O₃)=6～30)使得NaY分子筛硅/铝比和相对结晶度先增大后减小。当晶种加入质量分数0.5%、投料n(SiO₂)/n(Al₂O₃)为20且NaOH浓度为3 mol/L时,合成的NaY分子筛n(SiO₂)/n(Al₂...     

以煤矸石为原料合成ZSM—35沸石

以天然矿物煤矸石为原料，在水热体系中合成了ＺＳＭ－３５沸石，利用ＸＲＤ、ＳＥ、ＩＲ及ＣＯ国合成低碳烃反应，对沸石产品的结构及性能进行了测试。结果表明，利用煤矸石合成的ＺＳＭ－３５沸石与化工原料合成的ＺＳＭ－３５沸石类似，均具有良好的结晶度和ＣＯ＋Ｈ２催化性能。     

碱酸联合处理H-ZSM-5沸石多级孔改性

采用水热合成和离子交换法制备H-ZSM-5沸石。以硅铝比为47的H-ZSM-5沸石为介孔改性原料,用水热碱预刻蚀—碱溶滤—酸洗处理法制备微孔-介孔材料。采用XRD、N2吸附-脱附、FTIR、SEM、TEM等技术,考察逐级碱酸处理过程和水热碱预刻蚀温度对改性沸石介孔形成、介孔尺度分布和织构性质的影响。实验结果表明,碱酸改性沸石具有较高的比表面积、介孔率和微孔-介孔结构性质,同时较好地保留了H-ZSM-5沸石的骨架结构。升高水热碱预刻蚀温度导致改性沸石的微孔体积、比表面积、相对结晶度和收率逐渐下降,总比表面积增幅由38%降至34%,附加介孔体积与总孔体积的比保持在70%以上。水热碱预刻蚀温度为358 K的HZ-2试样的介孔比表面积和介孔体积最大,分别为209.8 m2/g和0.295 cm3/g,微孔与介孔的体积之和可达0.364 cm3/g。     

NaY分子筛的改性及对FCC汽油选择吸附脱硫的研究

利用草酸对NaY分子筛进行脱铝改性制备了NH4Y分子筛,NH4Y分子筛经过焙烧制得HY分子筛,再用实验制得的NH4Y分子筛进行液相离子交换和焙烧制得Ce（Ⅳ）Y分子筛。对分子筛进行静态吸附脱硫对比实验,并利用微库仑综合分析仪对静态和动态处理过的FCC汽油样品进行硫含量测定。结果表明,在静态条件下,Ce（Ⅳ）Y比HY分子筛的吸附脱硫效果略好,二者吸附脱硫率分别为79.0%和77.8% 。在动态条件下,Ce(Ⅳ)Y分子筛能够脱掉HY分子筛较难脱除的二甲基噻吩类硫化物。再生后的成型Ce(Ⅳ)Y分子筛的吸附能力可达到新鲜Ce（Ⅳ）Y分子筛的95.5%。     

Synthesis of La-Modified Ultra Stable Zeolite L and Its Application to Catalytic Cracking Catalyst

A new type of zeolite La-USL (ultra stable zeolite L (zeolite USL) modified by La), which has superior activity, stability and selectivity in catalytic cracking of hydrocarbons and thus can be used as an active catalyst component, is reported in this paper. The zeolite L with relative crystallinity of above 90% was synthesized by the hydrothermal crystallization method under optimum conditions and characterized by means of XRD, NH3-TPD and isotherm adsorption techniques. The in-situ synthesized zeolite L with a SiO2/Al2O3 mole ratio of 5-6 was modified by cation ion exchange, hydrothermal dealumination and chemical modifications with La in order to prepare La-containing USL with a higher framework SiO2/Al2O3 mole ratio of 15-30. The modified zeolite La-USL was used as an active additive component of fluid catalytic cracking (FCC) catalyst and the resulting catalysts were evaluated by microactivity test (MAT) and fixed-fluidized bed (FFB) experiments using heavy oil as feedstock. The influence of La content in La-USL on cracking product distribution, gasoline group composition and research octane number (RON) was investigated. The results showed that when La content in La-USL was 0.8 wt%, the addition of the corresponding La-USL could result in a FCC catalyst that produced significant improvement in product distribution and gasoline quality.     

固体超强酸S2O8^2-／ZrO2-NiO催化α-蒎烯合成龙脑

介绍了固体超强酸S2O8^2-／ZrO2-NiO催化剂制备方法,并将其用于催化α-蒎烯合成龙脑的酯化-皂化工艺。考察了催化剂焙烧温度、焙烧时间、催化剂用量及原料α-蒎烯与无水草酸摩尔比对龙脑产品收率和组成的影响。结果表明,当催化剂焙烧温度为600℃,焙烧时间为3h,催化剂用量为α-蒎烯质量的6％,原料α-蒎烯与无水草酸的摩尔比为1：0．2时,龙脑产品收率可达55．81％。产品中正龙脑含量可达77．01％,正、异龙脑的含量比高达4．44：1。     

φ沸石的合成

大孔(10.2)φ沸石已用水热法合成。以四甲基氢氧化铵(Me_4NOH)为模板剂,在特定条件下(H_2O/SiO_2+Al_2O_3+Na_2O=23.5,Me_4NOH/SiO2+Al_2O_3+Na_2O=0.21),SiO_2-Al_2O_3-Na_2O 三组份相图上给出的形成φ沸石的组成范围为:SiO_2/Al_2O_3=4.3-10.0,Na_2O/SiO_2=0.036-0.42。当 H_2O、SiO_2、Al_2O_3、Na_2O 恒定时,产生纯φ沸石的 Me_4NOH/SiO_2比为0.21-0.32。实验发现,在空气中焙烧,φ沸石的结晶度下降较快,在合适的保护气氛下焙烧是必要的。     

Fe-V共掺杂TiO_2高性能吸附剂的制备与表征

通过溶胶凝胶法、水热法和共沉淀法,分别以钛酸丁酯、异丙醇钛、硫酸钛、四氯化钛为钛源合成了一系列Fe-V共掺杂的纳米TiO_2吸附剂,研究了钛源、制备方法及煅烧温度对吸附剂吸附效果的影响,并采用XRD,SEM,EDX,TG-DTA,FTIR等手段分析了吸附剂的结构。实验结果表明,Fe-V共掺杂明显提高了TiO_2的吸附活性,其中以四氯化钛为钛源、通过共沉淀法制备、350℃焙烧处理的Fe-V共掺杂TiO_2具有最佳的吸附活性,30 min内对质量分数1.0×10~(-5)亚甲基蓝的脱色率可达97%以上;该吸附剂循环使用8次仍具有较高的吸附性能,且四氯化钛为较廉价的钛源,因此该高效吸附剂具有良好的工业应用前景。     

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.     

TS－1沸石晶化过程中的影响因素

用水热晶化法在ＳｉＯ＿２·ＴｉＯ＿２·ＴＰＡＯＨ－Ｈ＿２Ｏ反应体系中对影响ＴＳ－１沸石晶化过程的因素进行了考察。结果表明，ＳｉＯ＿２／ＴｉＯ＿２比、ＴＰＡＯＨ／ＳｉＯ＿２比，Ｈ＿２Ｏ／ＳｉＯ＿２比、晶化温度及晶化时间对、ＴＳ－１沸石分子筛的形成和结晶度均有很大影响。ＴＳ－１沸石的晶化速度较快，在１２－２４小时之间即可完成。延长时间，结晶度普遍有降低的趋势。晶化温度以４３３Ｋ－４４８Ｋ为佳，最佳配方为ＳｉＯ＿２·ｘＴｉＯ＿２·０．２５－０．４０ＴＰＡＯＨ．２５－４０Ｈ＿２Ｏ（ｘ＝０．００－０．１０）。从ＩＲ光谱数据Ｉ＿９６０／Ｉ＿５５０随时间变化来着，骨架钛含量最大值出现在３６－９６小时之间，所以实际晶化过程以２－４天为宜。从所绘的三元相区图来看，配方只能在小区间变化，这主要由于钛含量的限制。ＴＳ－１沸石热稳定性大于１４７３Ｋ。     

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.