十氢萘气相氧化裂解制低碳烯烃的研究

十氢萘气相氧化裂解（GOC）与传统的热裂解工艺相比,O2的存在降低了十氢萘GOC反应的活化能,使反应在较低温度下具有高的反应性能;O2同时起到消除积炭的作用,提高体系的抗积炭能力。十氢萘GOC反应在较低温度下即可获得较高的液体收率;高温下由于十氢萘裂解深度较高,低碳烯烃收率可高于液体收率,在所得的液体中,芳烃,尤其是BTX（苯、甲苯和二甲苯）占主要部分。十氢萘GOC反应制备低碳烯烃的适宜反应条件为,700℃~800℃,停留<0.4s,烷氧摩尔比0.3~0.5,空气可代替纯氧进料。800℃,烷氧摩尔比0.5,停留0.4s,可获得37％左右的低碳烯烃收率和50%左右的液体收率（BTX收率为29％）。     

C4/C5烃催化裂解制低碳烯烃的研究进展

从催化剂类型、裂解工艺、催化裂解的影响因素和裂解机理4个方面对国内外C4/C5烃催化裂解制低碳烯烃的研究进行了综述。催化裂解制低碳烯烃催化剂主要采用ZSM-5分子筛系列催化剂,在此基础上发展了酸改性或水热改性高硅ZSM系列分子筛及介孔MCM-41分子筛。总结了国内外C4/C5烃的裂解工艺,认为影响催化裂解的主要因素是裂解原料、催化剂类型及工艺条件。目前,裂解机理主要是自由基与碳正离子机理相结合的机理。并简述了本课题组目前有关C4烷烃催化裂解的主要研究进展。     

Fe/SiO_2纳米复合物上合成气制低碳烯烃催化性能研究

分别采用一步合成法和常规共沉淀法制备了Fe/SiO2催化剂,通过N2物理吸附、X射线衍射、透射电镜、傅里叶变换红外光谱和程序升温还原等方法对催化剂进行了表征,并在固定床反应器中对其费托合成制低碳烯烃的催化性能进行了评价。结果表明,与共沉淀铁基催化剂不同,采用一步合成法制备的纳米复合物主要由Fe3O4相构成,形貌呈规则球形,平均粒径为30 nm,尺寸分布窄,更容易还原。一步合成法制得的Fe/SiO2催化剂对费托合成反应具有较高的活性和低碳烯烃选择性、较低的甲烷选择性和良好的稳定性。     

Catalytic Cracking of Naphtha to Light Olefins

A catalytic process that produces light olefins from naphtha was developed to improve the yield of the conventional steam cracker. In laboratory-scale tests, a newly developed zeolite-based catalyst at a reaction temperature of 650°C produced an ethylene-plus-propylene yield of about 60%, which is about 10% higher than the conventional process operated at around 820°C. A feasibility study carried out for a catalytic cracking process using the developed catalyst, that cracks 3000 tons-naphtha/day, indicated an energy saving of about 20% compared with the conventional process.     

催化裂化过程中负氢离子转移反应和氢转移反应的不同特征

 基于重质油在酸性Y分子筛催化剂上的反应,区分了负氢离子转移反应和氢转移反应,认为负氢离子转移和氢转移是重质油催化反应过程中的两个不同过程. 确定了大庆减压蜡油在酸性Y分子筛催化剂上反应时,负氢离子转移反应主要发生在反应前期(转化率为5%～10%)至反应中后期(转化率为60%～70%)的转化深度区间,而氢转移反应主要发生在反应后期(转化率＞60%～70%). 负氢离子转移反应基本不产生焦炭,焦炭主要通过氢转移反应产生. Y分子筛上发生的主要是汽油烯烃和环烷烃之间的氢转移反应.     

C4/C5烃催化裂解制低碳烯烃的研究进展

从催化剂类型、裂解工艺、催化裂解的影响因素和裂解机理4个方面对国内外C4／C5烃催化裂解制低碳烯烃的研究进行了综述。催化裂解制低碳烯烃催化剂主要采用ZSM-5分子筛系列催化剂，在此基础上发展了酸改性或水热改性高硅ZSM系列分子筛及介孔MCM41分子筛。总结了国内外C4／C5烃的裂解工艺，认为影响催化裂解的主要因素是裂解原料、催化剂类型及工艺条件。目前，裂解机理主要是自由基与碳正离子机理相结合的机理。并简述了本课题组目前有关C4烷烃催化裂解的主要研究进展。     

托吡卡胺的平行催化氢波法测定

在005mol/LKCl11×10-2mol/LKIO3支持电解质中,托吡卡胺于-179V(vsSCE)处产生一平行催化氢波,其二阶导数峰峰电流与托吡卡胺的浓度在60×10-8～80×10-5mol/L范围内呈线性关系,检测限为3×10-8mol/L。该平行催化氢波比相应催化氢波提高分析灵敏度一个数量级。应用该方法不需要预处理,直接测定滴眼液中托吡卡胺的含量。并讨论了该平行催化氢波的产生机理。     

ZSM-5分子筛晶粒尺寸对C4烯烃催化裂解制丙烯的影响

 采用水热法合成了晶粒尺寸分别为20～30,1～2和0.2～0.3 μm的三种ZSM-5分子筛样品,并用SEM,XRD,氮低温物理吸附,NH3-TPD和TGA等技术对ZSM-5分子筛进行了表征,以考察其晶粒尺寸对C4烯烃裂解生产丙烯过程中催化剂活性和稳定性的影响. 结果表明,在常压,WHSV=10 h-1和550 ℃的条件下,以ZSM-5分子筛为催化剂,通过C4烯烃的催化裂解可以获得高收率的丙烯,反应初期丙烯的单程收率可达38%; 尽管三种晶粒尺寸的分子筛具有相近的比表面积和总酸量,但小晶粒的ZSM-5分子筛(粒径0.2～0.3 μm)具有微孔短、外比表面积大和孔口多等特点,因而表现出较强的容积炭能力和较好的稳定性; 小晶粒的ZSM-5分子筛催化剂经过10次再生重复使用,其催化生成丙烯的收率没有明显降低.     

Production of Low-carbon Light Olefins from Catalytic Cracking of Crude Bio-oil

Low-carbon light olefins are the basic feedstocks for the petrochemical industry. Catalytic cracking of crude bio-oil and its model compounds (including methanol, ethanol, acetic acid, acetone, and phenol) to light olefins were performed by using the La/HZSM-5 catalyst. The highest olefins yield from crude bio-oil reached 0.19 kg/(kg crude bio-oil). The reaction conditions including temperature, weight hourly space velocity, and addition of La into the HZSM-5 zeolite can be used to control both olefins yield and selectivity. Moderate adjusting the acidity with a suitable ratio between the strong acid and weak acid sites through adding La to the zeolite effectively enhanced the olefins selectivity and improved the catalyst stability. The production of light olefins from crude bio-oil is closely associated with the chemical composition and hydrogen to carbon effective ratios of feedstock. The comparison between the catalytic cracking and pyrolysis of bio-oil was studied. The mechanism of the bio-oil conversion to light olefins was also discussed.     

Hexane Cracking over Steamed Phosphated Zeolite H‐ZSM‐5: Promotional Effect on Catalyst Performance and Stability

The nature behind the promotional effect of phosphorus on the catalytic performance and hydrothermal stability of zeolite H‐ZSM‐5 has been studied using a combination of ²⁷Al and ³¹P MAS NMR spectroscopy, soft X‐ray absorption tomography and n‐hexane catalytic cracking, complemented with NH₃ temperature‐programmed desorption and N₂ physisorption. Phosphated H‐ZSM‐5 retains more acid sites and catalytic cracking activity after steam treatment than its non‐phosphated counterpart, while the selectivity towards propylene is improved. It was established that the stabilization effect is twofold. First, the local framework silico‐aluminophosphate (SAPO) interfaces, which form after phosphatation, are not affected by steam and hold aluminum atoms fixed in the zeolite lattice, preserving the pore structure of zeolite H‐ZSM‐5. Second, the four‐coordinate framework aluminum can be forced into a reversible sixfold coordination by phosphate. These species remain stationary in the framework under hydrothermal conditions as well. Removal of physically coordinated phosphate after steam‐treatment leads to an increase in the number of strong acid sites and increased catalytic activity. We propose that the improved selectivity towards propylene during catalytic cracking can be attributed to local SAPO interfaces located at channel intersections, where they act as impediments in the formation of bulky carbenium ions and therefore suppress the bimolecular cracking mechanism.     

生物质催化热解制取轻质芳烃

以轻质芳烃苯、甲苯、二甲苯和萘(BTXN)为目的产物,采用双颗粒流化床反应器对3种木材生物质进行了热解实验. 结果表明,木材生物质的初次热解终止温度低,有利于低温催化转化. 生物质中92%的挥发分在673 K时已释放完全,且生物质在初期热解得到的焦油经过二次分解反应可以转化为其它产物,通过有效控制生物质热解二次气相反应,能够改变其产物的分布,从而获得不同的目的产物. 生物质的催化加氢热解实验结果表明,催化剂种类和热解温度对加氢热解产物收率及其分布均有影响, BTXN是热解或加氢热解过程中二次气相反应的中间产物. 为了获得高产率的BTXN, 必须选择加氢活性适度的催化剂. 当CoMo-S/Al2O3催化剂作为流化介质进行加氢热解时,在863 K时, BTXN的收率可达6 3%(干燥无灰质量基准), 而NiMo/Al2O3催化剂表现出了很强的加氢活性, CH4的收率高达99 5%.     

利用色谱-反应联合装置研究渣油及其胶质的反应性能

建立一套色谱－反应联合装置，实现了在微量进样条件下对胜利原油减渣中胶质组分的催化裂化反应性能的考察。结果表明，在特殊设计条件下，色谱－反应联合装置具有快速、简便、再现性能良好的特点，可完成对渣油中胶质组分的催化裂化反应性能考察。