气相色谱法测定平衡催化裂化催化剂中碳元素含量

石油催化裂化反应中生成附着在催化剂表面的碳的单质或化合物会隔绝石油与催化剂的接触，从而使催化剂的选择性、活性降低．对平衡催化裂化催化剂中碳元素含量进行测定，可以有效地指导炼油厂的生产．通过对准确性、重复性的考察，表明燃烧和色谱测定法是平衡催化裂化催化剂中碳元素含量测定的有效方法之一．     

氢氟酸直接进样-电感耦合等离子体原子发射光谱法(ICP-AES)测定氧化锆中多种杂质元素

采用氢氟酸微波消解法前处理氧化锆材料,使用氢氟酸进样系统,不需要赶酸直接测定GBW06602氧化锆标准样品中的多元素含量,根据样品情况确定了最佳分析条件和最佳分析谱线。实验结果表明,测定元素线性关系及重复性良好,定量准确,可同时测定氧化锆中的多种金属元素,该方法检出限低,精密度高,分析结果与标准值相吻合,完全满足氧化锆中多元素杂质含量的工业分析要求。     

微波消解/湿法灰化-电感耦合等离子体原子发射光谱法测定原油重油中6种金属元素的含量

在石油炼制与加工过程中,原油重油中的微量金属元素容易引起管线设备结垢,反应器管线腐蚀,从而降低催化剂的使用寿命、影响产品的质量,因此对原油重油中微量金属元素的测定具有重要意义[1].目前油品中金属元素的测定方法主要有电感耦合等离子体原子发射光谱法(ICP-AES)[2]、原子吸收光谱法(AAS)[3]、电感耦合等离子体...     

原子吸收光谱法测定石油焦中铁和钠

石油焦是炼油厂原油炼制加工后剩余的最终产品。它分优质石油焦和普通石油焦 ,普通石油焦通常用于冶炼工业的燃料 ,优质石油焦用于制做冶炼铝和钢的工业电极、一般电极和绝缘材料。因此 ,在生产中对优质石油焦的质量要求很严格 ,优质石油焦中微量金属元素含量的多少直接影响到工业电极的性能 ,所以对其中金属元素含量的测定尤为重要。测定石油焦中微量金属元素含量的方法 ,目前国内还未见报道。类似的报道是测定原油和渣油中的微量金属元素[1,2 ] ,报道中采用干法灰化法处理样品 ,用盐酸溶解灰分后滤去不溶物进行测定。该法的缺点是样品灰分…     

标准加入法在激光剥蚀电感耦合等离子体质谱测定粉末样品中的应用

采用固体混合制样方法研究了标准加入法在激光剥蚀电感耦合等离子体质谱(LA-ICP-MS)测定粉末样品中的应用。以汽车尾气催化剂中贵金属元素为研究对象,选择具有2,4-二巯基-1,3,5-三嗪官能团的硅胶(DMT)定量吸附不同含量的贵金属元素,与汽车尾气催化剂混合均匀后,制备成薄片,使用LAICP-M S方法测定各元素强度,以强度为纵坐标,硅胶中待测元素为横坐标绘制工作曲线,通过标准加入法计算汽车尾气催化剂中贵金属元素含量。讨论了不同官能团硅胶的选择,pH对贵金属吸附的影响,制样方式对均匀性的影响。结果表明,使用DMT硅胶在pH 3.85时吸附贵金属,将硅胶与样品研磨均匀后制备的样品均匀性与重复性较好。将该方法用于汽车尾气催化剂分析用标准样品的测试,3种贵金属元素测定结果与标准样品认定值一致。     

电感耦合等离子体发射光谱法(ICP-AES)测定超基性岩中的微量金属元素

采用高压消解罐和硝酸、氢氟酸溶样前处理超基性岩样品,电感耦合等离子体发射光谱法(ICP-AES)测定了超基性岩GBW07101标准物质中的微量金属元素含量。实验结果表明,方法的线性相关性良好,可同时测定超基性岩中的微量元素。方法检出限低,精密度高,分析结果与标准值相吻合,完全满足地矿检测的需求。     

比值导数紫外吸收光谱法测定阿司匹林中的微量水杨酸

本文应用比值导数吸收光谱法于药物阿司匹林中微量水杨酸含量的测定,在０．０１￣０．１２％浓度范围内比值导数光谱峰高与水杨酸浓度成正比。线性相关系数为０．９９９４,检出限为０．００５％,样品测定回收率为９５．０％￣１０２．５％。将其用于阿司匹林原料中微量水杨酸杂质含量的测定,乙酰水杨酸含量在９０．０％￣９９．０％范围内,不干扰微量水杨酸的测定。     

原油中微量金属元素的测定及风化条件下元素的变化规律

建立了微波消解-电感耦舍等离子体质谱(ICP.MS)法同时测定原油及自然风化后原油中的V、Cr、Mn、Fe、Ni、zn、Mo、Ba等11种微量金属元素的方法.结果表明,11种微量金属元素的检出限为0.0056～0.8729μg/g,线性关系良好,相关系数r≥0.9995;相对标准偏差(RSD)<5.0%.经过30d风化...     

萃取-紫外分光光度法测定微晶蜡中3, 4-苯并芘含量

要采用萃取-紫外吸收光谱法，测定微晶微量3，4-苯并芘的含量．选择二甲亚砜作为萃取溶剂，绘制工作曲线．结果表明，3，4-苯并芘含量在50-3000ng／g的范围内，成良好的线性关系，相关系数为0．9995．检出限为16ng／g．方法重复性好，相对标准偏差为6．2％，回收率在97．0％-99．4％之间．     

ICP-AES法同时测定精对苯二甲酸中微量金属元素

采用等离子体原子发射光谱法(ICP-AES)测定精对苯二甲酸(PTA)中微量金属元素。讨论了影响因素，优化了操作参数。钠、铁、钴、锰、镍、铬六种元素回收率在94．0％～104．0%之间。此法对其它有机体中的金属元素测定有参考价值。     

碱氮化合物喹啉催化裂化转化规律的研究

采用固定床微反活性实验装置，以甲苯、十六烷、四氢萘为溶剂，研究了碱性含氮化合物喹啉的催化裂化转化规律。反应温度、催化剂与原料油的质量比、空速、原料氮含量都影响待生催化剂的氮含量和氮在产物中的分布。催化剂的酸性、烃类溶剂的供氢能力对喹啉裂化有显著影响。催化裂化待生催化剂上的焦炭由烃生焦、吸附氮焦和缩合氮焦组成。提出了喹啉催化裂化的可能转化途径：喹啉通过物理或化学作用吸附于催化剂表面，或在催化剂上脱氢缩合生焦；喹啉烷基化；喹啉加氢生成四氢喹啉，四氢喹啉进一步裂化转化为吡啶、苯胺和氨。     

提高USY型FCC催化剂硫转移和催化裂化活性的研究

采用镁、铈、镧和磷对USY型FCC催化剂进行改性，采用FT IR分析方法对改性催化剂的表面酸性进行了表征，研究了硫转移活性组分对催化剂的硫转移和催化裂化活性的影响。结果表明，多次氧化 还原循环后，改性催化剂仍保持较好的硫转移活性，可以达到60%以上。镁的引入会减少基质和分子筛表面强酸的数量，少量镁的引入对催化裂化活性影响不大，铈和镧的引入会使分子筛和基质的表面酸量得到显著增加，提高催化裂化活性，但同时会引起焦炭的增加，磷改性可改善基质和分子筛表面酸性，抑制焦炭的产生，保持催化裂化活性的同时使汽油中的烯烃质量分数下降6%。     

Selectivity of catalytic methods of determination

By means of catalytic analytical methods, extremely low levels can be determined at low cost and with a high sensitivity that is equal to that of physical methods of trace analysis. The selectivity of the catalytic determinations, is, however, usually rather lower than that of other methods of trace analysis. The selectivity can sometimes be improved by modification of the indicator reaction through variation of the reagents and their concentrations, or by use of masking reagents or activators, or by combination with a separation method. Modification of the indicator reaction can be exemplified by the selective determination of osmium and ruthenium by their catalysis of the nitrate oxidation of 1-naphthylamine. By variation of the nitrate concentration and the use of 1,10-phenanthroline and 8-hydroxyquinoline as complexing agents it is possible to determine these two elements simultaneously. An especially significant increase in the selectivity is made possible by use of a preliminary separation step. If the ion to be determined is separated by solvent extraction and then catalytically determined directly in the extract, a very specific determination is possible; this technique has been called "extractive catalytic determination". This method has been used for determination of molybdenum (0.5 ng/ml) in sea-water, iron (5 ng/ml) in heavy metal salts, and copper (3 ng/ml) in the presence of numerous elements.     

Use of ZSM-5 catalyst in deoxygenation of waste cooking oil

This study investigated the potential use of waste cooking oil (WCO) in the production of engine fuels and valuable chemicals via catalytic cracking. WCO was processed in its pure form and in a mixture with hydrotreated vacuum gas oil (HVGO). Catalytic cracking experiments were performed using a microactivity test (MAT) (simulation of the fluid catalytic cracking environment). In cracking over the standard fluid catalytic cracking equilibrium catalyst (FCC-ECAT), the oxygen contained in the feed was consumed in the formation of CO and CO₂, water and into oxygenated organic compounds (phenolics, esters, carboxylic acids, etc.), which were found in the organic phase of the liquid product. In order to remove the unwanted organic oxygenates, the catalytic system based on pure FCC-ECAT was modified by addition of the ZSM-5-based FCC catalyst. By using the mixture containing FCC-ECAT and 10 mass % of FCC-ZSM-5, it was possible to reduce the amount of organic oxygenates to almost the feasible minimum when cracking pure WCO. The effect of the catalyst mixture on cracking the feed mixture of the vacuum gas oil with 10 vol. % of WCO was manifested in the practically zero formation of organic oxygenates and in a gasoline yield comparable with vacuum gas oil (VGO) cracking.     

稀土改性L沸石在烃类催化裂化催化剂中的应用

采用离子交换的方法制备了一系列复合稀土（含La及Ce）质量分数不同的稀土改性超稳L沸石（RE-USL）,以RE USL沸石替代质量分数为5%的REUSY作为催化裂化催化剂的活性组分,用标准轻油微反活性试验（MAT）评价了其催化性能,并同单一稀土元素改性USL沸石进行了对比。结果表明,一定量的复合稀土改性USL沸石的催化性能优于单一稀土（La或Ce）改性的USL沸石,在催化裂化催化剂中加入稀土改性USL沸石,可以降低汽油产品的烯烃质量分数;可以提高汽油的辛烷值。当复合稀土在RE USL沸石中的质量分数为0.4%左右时, 与不加稀土改性USL沸石催化剂相比较,催化剂的活性指数MAT提高3.6个单位,烯烃质量分数降低1.57个单位,研究法辛烷值（RON）提高2.08个单位,产品分布更合理。     

俄罗斯含硫原油常压渣油催化裂化反应性能及硫分布规律的研究

利用小型固定流化床对俄罗斯含硫原油常压渣油的催化裂化反应性能进行了考察,并研究了原料油中硫在催化裂化产品中的分布；结果表明,较高的反应温度和较低的剂油比有利于提高产品的轻油收率,降低焦炭产率；而较高的反应温度和较高的剂油比有利于降低汽油中的硫含量,但会导致柴油中的硫含量迅速增加；催化裂化过程中,原料中约40%以上的硫会转化成为分子量很低的硫化物,其次是柴油和焦炭中,分别占25%和10%左右。     

大庆蜡油催化裂化过程中的质子化裂化反应

在小型固定流化床装置上采用酸性催化剂进行了多系列不同反应深度的催化裂化实验,对大庆VGO催化裂化过程中发生的质子化裂化反应进行了初步的研究。在重质油的催化裂化过程中会出现二次质子化裂化反应。二次质子化裂化反应主要是由于汽油中烷烃重新在酸性催化剂上形成五配位正碳离子随后分解所造成,其产生的原因主要是由于反应后期催化剂对反应中间产物的选择性吸附改变所致。二次质子化裂化反应对温度不敏感。大庆VGO在500℃下反应时二次质子化裂化反应约占整个质子化裂化反应的60%。     

Production and characterization of the biofuels obtained by thermal cracking and thermal catalytic cracking of vegetable oils

The thermal cracking and the thermal catalytic cracking of soybean oil were evaluated for the production of biofuels as an alternative to fossil fuels. The catalyst proposed for the cracking reaction was bauxite, a high-acidity and low-cost catalyst. The chromatographic profile of the biofuels obtained by cracking showed hydrocarbon compounds such as alkanes, alkenes and aromatics, as well as some oxygenated compounds such as carboxylic acids, ketones and alcohols. The products generated by the thermal catalytic cracking process showed better results than the thermal cracking products because of the low quantity of acids present. The catalyst used was thus shown to act in the secondary cracking process, in which the fatty acids decompose and generate hydrocarbons.     

Single Particle Assays to Determine Heterogeneities within Fluid Catalytic Cracking Catalysts

Fluid catalytic cracking (FCC) is an important process in oil refinery industry to produce gasoline and propylene. Due to harsh reaction conditions, FCC catalysts are subject to deactivation through for example, metal accumulation and zeolite framework collapse. Here, we perform a screening of the influence of metal poisons on the acidity and accessibility of an industrial FCC catalyst material using laboratory-based single particle characterization that is, μ-XRF and fluorescence microscopy in combination with probe molecules. These methods have been performed on density-separated FCC catalyst fractions, allowing to determine interparticle heterogeneities in the catalyst under study. It was found that with increasing catalyst density and metal content, the acidity and accessibility of the catalyst particles decreased, while their distribution narrowed with catalyst age. For example, particles containing high Ni level possessed very low acidity and were hardly accessible by a Nile Blue dye. Single catalyst particle mapping identifies minority species like the presence of a phosphated zeolite ZSM-5-containing FCC additive for selective propylene formation, catalyst particles without any zeolite phase and catalyst particles, which act as a trap for SO_x.