FCC催化剂基质组分直链烯烃反应研究

制备了一系列SiO2-Al2O3基质材料,采用吡啶吸附—红外光谱法对其酸性特征进行了表征。并且以n-C^=7-1为模型化合物考察了反应产物分布与基质材料酸中心特性的关联,提出了n-C^=7-1的裂化反应网络,对n-C^=7-1的异构化、氢转移、芳构化等二次反应进行了探讨。结果表明,异构化反应过程同时以单分子与双分子两种机理进行,但双分子反应选择性较低;氢转移反应不仅与基质的酸中心密度有关,对酸类型的影响更为敏感,在只有L酸的基质上,氢转移以Rideal机理进行,活性随酸密度呈线性增加;在既有B酸又有L酸的基质上,氢转移更倾向于L-H机理,活性随酸密度呈指数增加;烯烃二次反应之间选择性的竞争很大程度上取决于B酸与L酸在总酸量中的分配。     

催化裂化反应中催化剂重污染现象探讨

本文能冠军对催化裂化反应机理、催化剂性能、特点的介绍 ,着重分析了催化裂化反应中催化剂重金属污染的原因 ,并且针对污染善提出了解决办法 ,重点介绍了钝化剂的使用     

基于汽油烯烃转化的催化裂化动力学模型

以催化裂化反应机理为基础,把FCC原料及产品按馏程和化学组成进行集总划分.考虑氢转移、芳构化等二次反应,通过对反应网络的合理简化,提出了一种分子水平的动力学模型.通过参数估计求取18个动力学速度常数,建立集总动力学模型以预测汽油的化学结构组成.研究结果表明：该模型能较好预测不同条件下的产率分布,而且可以预测汽油组成分布,有助于降低汽油烯烃含量的研究.     

离子液体在烯烃复分解反应中的应用

离子液体作为一种环境友好的催化剂和溶剂，受到了人们日益的关注。本文从离子液体作为溶剂、催化剂溶解于离子液体、离子液体的负离子作为催化剂配体三个方面，详细地介绍了离子液体在烯烃复分解反应中的应用，很好地解决了催化剂难储存、难循环利用和底物范围狭窄等问题。     

用拓扑学方法研究正单烯烃的化学

本文提出了能反映正构单烯烃分子的大小、双健的位置以及顺反异构的拓扑指数。得到了从分子拓扑指数计算正烯烃化学的公式。其形式为：Ｅｘ°＝ｃｈ＝ａ．Ｒ＋ｂ＋Ｚｅ计算结果表明，总的绝对平均误差为０．３１％。     

催化裂化轻汽油中烯烃加氢反应宏观动力学

基于流化催化裂化(FCC)轻汽油(初馏点-358 K)中所含烯烃组分的性质,将其划分为4个集总,采用管式滴流床反应器,在压力0.5-2 MPa、反应温度353-413 K、液体空速2.5-7.5 h-1的条件下,对烯烃在镍加氢催化剂上的加氢反应进行宏观动力学研究.实验结果显示:n-C4＝,n-C5＝,i-C5＝,n-C...     

催化裂化汽油在加氢脱硫过程中烯烃饱和研究

对催化汽油进行了馏分切割及组成分析,以切割后的催化裂化重汽油为原料,在保证轻、重组分调和汽油硫含量≯10μg/g的前提下,考察了选择性加氢脱硫过程中,不同类型烯烃和不同碳数烯烃饱和变化规律,不同碳数的烯烃在选择性加氢脱硫过程中饱和率随着碳数呈先降低后增长的趋势;烯烃本身的结构是决定烯烃加氢饱和率的关键因素,相同反应条件下,加氢饱和率由高到低为:正构烯烃环烯烃异构烯烃。     

MTO与FCC汽油降烯烃组合反应催化剂的研究

以甲醇制烯烃（MTO）与催化裂化（FCC）汽油降烯烃组合反应工艺为研究目标,采用分子筛催化剂,在小型固定床微型反应装置,研究MTO反应、汽油降烯烃反应以及甲醇与汽油混合炼制反应,比较了典型酸性分子筛催化剂的催化性能。结果表明,组合反应过程呈现出非稳态特征,小分子烯烃具有自催化现象,导致产物组成分布随反应时间显著变化。NH₃-TPD分析表明,具有中强酸与强酸相结合分布特点的催化剂适合于反应过程的协同催化作用要求。适宜的反应条件为：以SAPO-34分子筛作催化剂,反应温度400 ℃,甲醇混炼比15%,反应时间30 min。该条件能同时较好满足MTO和FCC汽油改质要求,产物汽油中烯烃含量较FCC汽油中的含量下降50%,并可获得较高的小分子烯烃产率,实现MTO转化。     

甲醇制烯烃反应工艺、反应机理及其动力学研究进展

甲醇制烯烃工艺近年来已成为煤化工领域的研究热点。不同的甲醇制烯烃催化剂将导致不同的反应过程,以SAPO-34为催化剂时,甲醇主要遵循烃池机理,通过快速的平行反应直接生产乙烯和丙烯(MTO)等低碳烯烃;以ZSM-5为催化剂时,甲醇主要遵循双循环机理中的烯烃循环机理,通过甲基化-裂解等多步反应间接生产丙烯(MTP)。这种反应特征的不同也决定着反应器类型和工艺条件的不同:SAPO-34催化剂易失活的特性决定了工业MTO过程通常采用易再生的流化床反应器从甲醇一步生成乙烯和丙烯,而具有良好抗结焦能力的ZSM-5催化剂使得工业MTP过程通常选择易放大的固定床反应器,通过大量烯烃循环与分离逐步获得丙烯。针对SAPO-34催化剂上MTO过程以及ZSM-5催化剂上MTP过程的不同反应情况,综述了近年来甲醇制烯烃代表性的反应工艺、反应机理以及反应动力学等方面的研究进展,并根据其存在的问题提出了相应的发展方向。     

碳四烷烃催化裂解制低碳烯烃的研究进展

论述了碳四烷烃催化裂解制低碳烯烃的催化剂体系、影响因素及催化裂解方式。该催化剂体系包括硅铝酸盐及锆硫酸盐,氧化铝与碱金属或碱土金属的混合物,负载型催化剂等3种类型。其中分子筛(晶体硅铝酸盐)及其改性催化剂是研究开发的主要方向。除操作条件外,稀释剂、引发和抑制剂和裂解反应方式对催化裂解反应均有影响。催化裂解反应机理与催化剂的种类和反应条件相关。对于酸性分子筛催化剂有2种比较公认的机理:正碳离子机理,自由基与正碳离子机理两种形式。研究表明碳四烷烃,特别是正丁烷催化裂解制低碳烯烃具有良好的低碳烯烃收率,收率可达50%以上。     

Modelling the kinetics of fast catalytic cracking reactions

Instantaneous kinetic constants and gasoline selectivities have been determined for catalytic cracking of n-hexadecane. The pulse technique was used in order to model the sequential build-up of coke which occurs on cracking catalyst within a riser transport-line reactor. The total amount of hydrocarbon injected per unit weight of catalyst was between 0 and 10. The mathematical model used to analyze the data was based on the unsteady state mass balance of the microcatalytic reactor with the assumption of plug flow. Results suggest a fast deactivation process during the run with fresh catalyst, while regenerated catalyst showed a slower deactivation. The catalyst regenerated three times evidenced a low apparent activation energy when temperature was increased from 500°C to 550°C.     

Study on reformulation of fluid catalytic cracking gasoline and increasing production of light olefins

The effects of reaction temperature, mass ratio of catalyst to oil, space velocity, and mass ratio of water to oil on the product distribution, the yields of light olefins (light olefins including ethylene, propylene and butylene) and the composition of the fluid catalytic cracking (FCC) gasoline upgraded over the self-made catalyst GL in a confined fluidized bed reactor were investigated. The experimental results showed that FCC gasoline was obviously reformulated under appropriate reaction conditions. The olefins (olefins with C atom number above 4) content of FCC gasoline was markedly reduced, and the aromatics content and octane number were increased. The upgraded gasoline met the new standard of gasoline, and meanwhile, higher yields of light olefins were obtained. Furthermore, higher reaction temperature, higher mass ratio of catalyst to oil, higher mass ratio of water to oil, and lower space velocity were found to be beneficial to FCC gasoline reformulation and light olefins production. __________ Translated from Chemical Reaction Engineering and Technology, 2006, 22(6): 532–538 [译自: 化学反应工程与工艺]     

Kinetic study of crude oil-to-chemicals via steam-enhanced catalytic cracking in a fixed-bed reactor

This study presents new experimental results on the direct conversion of crude oil to chemicals via steam-enhanced catalytic cracking. We have organized the experimental results with a kinetics model using crude oil and steam co-feed in a fixed-bed flow reactor at reaction temperatures of 625, 650, and 675°C over the Ce-Fe/ZSM-5 catalyst. The model let us find optimum conditions for crude oil conversion, and the order of the steam cracking reaction was 2.0 for heavy oil fractions and 1.0 for light oil fractions. The estimated activation energies for the steam cracking reactions ranged between 20 and 200 kJ/mol. Interestingly, the results from kinetic modelling helped in identifying a maximum yield of light olefins at an optimized residence time in the reactor at each temperature level. An equal propylene and ethylene yield was observed between 650 and 670°C, indicating a transition from dominating catalytic cracking at a lower temperature to a dominating thermal cracking at a higher temperature. The results illustrate that steam-enhanced catalytic cracking can be utilized to effectively convert crude oil into basic chemicals (52.1% C2-C4 light olefins and naphtha) at a moderate severity (650°C) as compared to the conventional high-temperature steam cracking process.     

高岭土附晶ZSM-5分子筛的合成及对正丁烷催化裂解性能

以高岭土微球为基体,在水热体系中成功地附晶生长了ZSM-5分子筛,并采用XRD、SEM、NH3-TPD和BET等测试手段对催化剂进行表征,考察高岭土附晶ZSM-5分子筛和对比催化剂在固定床微反装置上催化裂解正丁烷性能.结果表明,实验合成的高岭土附晶ZSM-5分子筛催化剂在正丁烷的催化裂解中具有更高的乙烯选择性,乙烯选择...     

PZSM-5分子筛催化剂用于烯烃催化裂解的研究

以固定流化床研究了不同磷含量改性的ZSM-5分子筛对混合₄烯烃催化裂解性能的影响,并以适当磷含量的催化剂进行了工艺条件试验。试验表明,磷与ZSM-5分子筛骨架中的羟基发生了化学作用,改善了催化剂的催化性能及水热稳定性;高负荷、高水比及适当增加磷的负载量,可以抑制烯烃裂解的氢转移反应,有利于提高丙烯选择性。     

Relative reactivities of alkanes in multi-component catalytic cracking reactions

An experimental technique is discussed for measuring relative reactivities of alkanes in the catalytic cracking of multi-component hydrocarbon mixtures over a heterogeneous, Y-zeolitebased catalyst at 250–350 °C. With the technique, ca. 0.1 l of an alkane mixture is evaporated and contacted with a catalyst, after which the mixture of reaction products and the unreacted feed enters the chromatographic column and is immediately analyzed. The technique is used to measure relative reactivities of 21 alkanes in a single experiment. The principal results of these experiments are similar to the results of single-component cracking: alkane reactivity rapidly increases with the increase of the carbon number, and methyl-branched alkanes are more reactive than linear alkanes. However, the variations in alkane reactivities as a function of their molecular weight and skeleton structure differ very significantly between single- and multicomponent experiments.     

催化汽油氧气氧化脱硫的反应动力学

以氧气作为氧化剂,开展催化汽油氧化萃取脱硫实验及氧化动力学研究。实验结果表明,氧气氧化萃取脱硫对催化汽油具有较好的脱硫效果;随着相转移催化剂用量增加、温度提高、氧气分压增大、时间延长、水与汽油体积比增大,汽油脱硫率持续提高,而汽油收率呈现降低的变化趋势。根据反应动力学方程和萃取相平衡原理,确定了脱硫率和汽油收率模型,并开展模型参数估值、统计检验和预测分析。研究结果显示,所建模型具有较高的模拟精度,预测结果与脱硫实验结果的变化趋势相同。     

烯烃催化裂化制丙烯的技术进展

综述了国内外烯烃催化裂化制丙烯主要工艺发展现状以及有关催化剂的研究。指出在丙烯工业的原料和工艺方面的发展方向是原料多元化和开发新技术。烯烃催化裂化技术具有操作简单和成本低廉等优势，应加快研究开发。