Seven-lump kinetic model for catalytic pyrolysis of heavy oil

A 7-lump kinetic model is proposed to describe the catalytic pyrolysis of heavy oil. The kinetic model contains 15 kinetic constants and one for catalyst deactivation. The experimental data were obtained in a confined fluidized bed reactor. The kinetic constants were estimated by a special program compiled based on the Marquardt’s algorithm. The apparent activation energies were calculated according to the Arrhenius equation. This model fits the experimental data well. The prediction shows that catalytic pyrolysis of Chinese Daqing atmospheric residue should be conducted at low space velocity to produce much ethene and at space velocity around 15 h⁻¹ to produce much propene and butene.     

多产丙烯助剂对LB-5催化剂催化裂解制低碳烯烃性能的影响

在固定流化床催化裂化试验装置上,以中国石油大庆炼化公司重油催化裂化装置所用原料油为原料,考察了多产丙烯助剂对LB-5催化剂催化裂解重油制低碳烯烃性能的影响。结果表明,LB-5催化剂中添加多产丙烯助剂后,氢转移反应得到了抑制,丙烯和丁烯收率增加较为显著。LB-5催化剂中添加5%的多产丙烯助剂LOP-A后,低碳烯烃总收率增加了4.17个百分点,达到24.17%;汽油中的烯烃含量降低了6.91个百分点,研究法和马达法辛烷值分别提高了3和2.5个单位。     

多产丙烯助剂对LB-5催化剂催化裂解制低碳烯烃性能的影响

在固定流化床催化裂化试验装置上,以中国石油大庆炼化公司重油催化裂化装置所用原料油为原料,考察了多产丙烯助剂对LB-5催化剂催化裂解重油制低碳烯烃性能的影响。结果表明,LB-5催化剂中添加多产丙烯助剂后,氢转移反应得到了抑制,丙烯和丁烯收率增加较为显著。LB-5催化剂中添加5%的多产丙烯助剂LOP-A后,低碳烯烃总收率增加了4.17个百分点,达到24.17%;汽油中的烯烃含量降低了6.91个百分点,研究法和马达法辛烷值分别提高了3和2.5个单位。     

重油催化裂化催化剂RCH的研究

RCH催化剂是继我国第一代超稳Y型催化裂化催化剂之后,开发研制的新型渣油裂化催化剂。该剂沸石含量低,而在裂化性能、产品收率、焦炭选择性等方面均与国内外同类型催化剂相当,可替代进口催化剂在重油催化裂化(RFCC)装置上使用;该剂更具有平衡活性和轻质油收率高、稳定性好、裂化重质油能力和抗重金属污染能力强等特点,同时制备工艺先进,流程简单,属国际先进水平。     

重油催化裂解集总动力学模型研究

建立了重油催化裂解七集总动力学模型,给出了模型的反应网络和数学表达式.利用小型固定流化床实验装置对大庆常压渣油进行了催化裂解实验,获得求取动力学参数的实验数据.提出了一个新的基于原料性质和操作条件的裂解催化剂失活模型.结合实验数据,编程求取了集总模型的动力学参数,催化裂解的反应活化能基本上都大于100kJ/mol,介于催化裂化活化能和热裂化活化能之间.根据所建立的集总动力学模型,预测了原料转化率、裂解产品产率和分布随操作条件的变化趋势,发现重油催化裂解宜采用高温、短油气停留时间的操作方式.     

面向过程控制的两段提升管重油催化裂解动态建模

两段提升管重油催化裂解多产丙烯技术具有原料适应性强、丙烯和高品质汽油产率高等优点,工业应用前景广阔。开展动态建模、非线性分析与控制等方面的研究对于揭示装置运行规律、提高能量/质量转化效率具有重要意义。从过程控制的角度出发,基于TMP工艺流程,通过合理假设,分别建立两段提升管、汽提段以及再生系统的数学模型并由循环催化剂连接形成一个整体动态数学模型。数值模拟结果表明,所建模型可以准确描述过程关键变量的动态变化趋势以及两段提升管-再生器之间的耦合关系,从而为后续非线性分析和控制系统设计创造有利条件。     

生物质热解催化剂失活的研究进展

生物质催化热解是实现生物质能源高效、高值化利用的有效手段。综述生物质催化热解过程中催化剂失活的过程及原因,从生物质热解催化剂的积炭失活、原料杂质的影响、催化剂的水热失活和负载型催化剂金属颗粒的烧结等进行阐述。对生物质热解催化剂的研究重点与方向进行展望。     

A molecular kinetic model for heavy gas oil catalytic pyrolysis to light olefins

Petroleum catalytic pyrolysis to light olefin technology has received wide-ranging research interest in the refining industry. This work built a molecular kinetic model for the catalytic pyrolysis of a heavy gas oil from bitumen synthetic crude oil (SCO) to light olefins. A feedstock compositional model was constructed containing 1311 molecules using bulk properties information. A variety of reaction rules was summarized and digitized, and from which, a reaction network involving 2631 substances and 6793 reactions was generated via a reaction network autogeneration algorithm. The reaction network for the catalytic pyrolysis was transformed into reaction rate equations. Systematical pilot-scale catalytic pyrolysis experiments were carried out, which were used to regress the molecular kinetic model parameters. The tuned model is able to predict the product yield and molecular distribution. Moreover, a range of sensitivity analysis was performed, revealing the dependence of light olefins yields on the reaction conditions.     

重油催化裂解制低碳烯烃工艺条件研究

采用固定流化床催化裂化试验装置,以中国石油兰州石化公司3.0 Mt·a-1重油催化裂化装置所用原料油为原料,考察反应温度和剂油质量比对重油催化裂解制低碳烯烃性能的影响,在确定的适宜操作条件下研究中国石油兰州石化公司重催装置原料在不同催化剂上的催化裂解制低碳烯烃的反应性能。结果表明,较适宜的操作条件为:反应温度590℃,剂油质量比为7,与降烯烃催化剂和重油裂解催化剂相比,多产丙烯催化剂的低碳烯烃产率可达25.53%,更适合作为重油催化裂解制低碳烯烃时使用。     

基于多目标优化的两段提升管重油催化裂解自优化控制

针对两段提升管重油催化裂解过程经济运行要求和工艺特点,从多目标优化角度出发,提出一种自优化控制方法。首先,基于过程稳态模型,考虑操作约束条件,构造同时最大化丙烯产量和最小化干气产量的多目标操作优化问题,并采用标准化法向约束方法求解获得完整、均匀分布的Pareto最优解;然后,根据多目标优化结果所揭示的最优操作条件与积极约束之间的关系,提出了一种基于串级控制的自优化控制策略。仿真结果表明,与传统的提升管出口温度设定值跟踪控制相比,本文方法在干扰作用下能够及时调整操作条件,降低干扰对过程优化运行的不利影响。     

注蒸汽条件下供氢催化改质稠油及其沥青质热分解性质

利用CWYF-Ⅰ型高压反应釜模拟热采条件下,以甲酸作为供氢体.以自制的油溶性有机镍盐为催化剂进行的稠油水热裂解反应.考察了供氢体的加入对催化水热裂解反应前后稠油黏度、族组成及硫含量的影响,并采用TG-DTA分析法对供氢催化改质反应前后稠油中沥青质的热转化行为进行了分析.结果表明,随着加入供氢体质量分数增加,供氢催化水热裂解后稠油降黏率增大,饱和烃、芳香烃含量增加,胶质,沥青质含量降低,同时硫含量下降.供氢催化水热裂解反应后的稠油中沥青质TG-DTA曲线分析表明,供氢催化水热裂解反应后稠油中沥青质失重量高于催化水热裂解反应前稠油中含有的沥青质的失重量.经过供氢催化水热裂解反应,稠油中沥青质的稳定性下降.     

A new approach on catalytic cracking catalyst deactivation

The existence of acidic species other than those of vanadic acid is suggested to be responsible for the FCC catalyst deactivation. These species would come from SO _s adsorption on the catalytic surface which would react with the most acid sites of the zeolite, ultimately leading to loss of crystallinity.     

裂化催化剂失活动力学及平衡催化剂活性模型

基于催化剂全混流流动状态和呈指数形式的催化剂年龄概率密度函数,经催化剂失活动力学方程推导,确定了关联催化剂碳含量、金属沉积量、催化剂置换率、再生器温度和水蒸气分压的平衡催化剂活性或微反活性模型方程。对工业催化裂化装置操作数据进行模拟计算,确定了催化剂失活模型参数,建立了具有较高模拟计算精度的裂化催化剂失活动力学和平衡催化剂活性模型。比较模型参数大小可知,V沉积对催化剂活性的影响最大,其次是Ni和Fe,Na的影响最小。模型预测结果表明,随着平衡催化剂金属沉积量或碳含量减少,催化剂单耗增大,平衡催化剂活性或微反活性逐渐增大。适当降低再生器温度和催化剂藏量有利于提高平衡催化剂活性。     

DCR评价装置对重油催化裂化催化剂LDC-200的性能评价

采用DCR催化裂化评价装置,通过不同原料油及剂油比对重油催化裂化催化剂LDC-200的反应性能进行评价。结果表明,以中国石油天然气股份有限公司兰州石化公司3 Mt·a-1催化装置所用渣油为原料油,在剂油质量比大于8.4时,催化剂LDC-200裂化能力强,拥有良好的焦炭选择性,且异构化功能显著,明显提高汽油辛烷值。采用3 Mt·a-1催化装置所用渣油与蜡油质量分数各50%配成的原料油,在剂油质量比小于8.4时,能够在确保汽油收率的同时控制焦炭产率。     

Hydrotreating catalyst deactivation by coke from SRC-II oil

Samples of a CoMo/Al₂O₃ catalyst were partially deactivated with SRC-II feed in an autoclave reactor to give coked samples of 5 to 18 %C. The coked catalysts were analyzed for surface area, pore volume, coronene adsorption and diffusivity, and their catalytic activity determined for hydrodesulfurization (HDS), hydrodeoxygenation (HDO) and C-N hydrogenolysis (CNH) using model compounds. All of the above measurements decreased with increase in coke content. Property data indicate that some pores are blocked by coke and diffusivity results show narrowing of pore mouths with increasing coke content. Catalyst deactivation versus coke level was identical for HDS and HDO, but less for CNH. A simple model of coke deactivation was developed to relate activity to coke content. Coke is envisioned as forming wedge-like deposits in the catalyst pores.     

Low-temperature catalytic combustion of trichloroethylene over cerium oxide and catalyst deactivation

Cerium oxide catalysts prepared by a thermal decomposition method using the salt nitrate as precursor were tested for the catalytic combustion of trichloroethlyene (TCE), as a model of chlorinated volatile organic compounds (CVOCs). CeO₂ catalysts calcined at different temperature were found to possess high catalytic activity for catalytic combustion of TCE, and CeO₂ calcined at 550 °C was the most active catalyst and the complete combustion temperature (T_90%) of TCE was 205 °C. Effects of systematic variation of reaction conditions, including space velocity, inlet TCE concentration and water concentration on TCE catalytic combustion were investigated. Additionally, the stability and deactivation of CeO₂ catalysts were studied by various characterization methods (such as TG/DTA, EDS, XRD, Raman and XPS) and other assistant experiments.     

碱改性HZSM-5催化热解木质素催化剂失活分析

对0.3 mol·L^-1 NaOH改性后的HZSM-5以及未改性HZSM-5催化剂进行循环和再生评价实验以考察催化剂的寿命。对反应后和再生的催化剂进行N₂吸脱附以及NH₃-TPD表征,并通过对反应后的催化剂进行SEM、TGA、FTIR、UV-Vis等表征分析催化剂积炭。两种催化剂的活性均随着循环实验次数的增加而逐渐降低,经4次循环实验的改性HZSM-5催化剂的催化活性远高于4次循环实验的未改性HZSM-5催化剂。反应过的催化剂经高温煅烧再生后其活性都有所恢复,再生后的改性HZSM-5的催化活性仍高于未改性催化剂。对两种不同催化剂积炭分析,改性后催化剂的积炭量少于未改性的催化剂,其积炭组分中高聚芳烃的含量相对较多。     

Two stages catalytic pyrolysis of olive oil waste

A study of the pyrolysis of a waste from the extraction of olive oil has been carried out. The work objective was to characterize the char, tar and gaseous phases generated in the process for their possible utilization in energy generation. On the other hand, the influence of a set of variables has been studied, including the efficacy of the dolomite as catalyst. Finally, as previous step to the design of industrial installations, a kinetic study of the process (catalyzed and uncatalyzed), based in the generation of the principal gases, has been carried out. In the uncatalyzed process only the influence of temperature (400–900 °C) was studied. In the catalytic process, the influence of temperature (500–800 °C) and mass of catalyst (0–100 g) was studied. Also, the dolomite effectiveness as catalyst was evaluated. For this motive, consecutive experiments, without reactivating dolomite, were carried out (0–6 runs), and the yields of solids, liquids and gases were determined. An increase in reaction temperature leads to a decrease in char and tar yield and to an increase in the gas phase yield. When the catalyst is present and when the mass of the same is increased, an important decrease in the tar yield and a high increase in the gas phase yield are produced. This increment in the yield of gases is very significant in the case of hydrogen. In addition, the catalyst is very stable. Your activity remains constant during six consecutive pyrolysis experiments, without need to carry out the reactivation of the same. In the kinetic study carried out, it has been considered that the gases are formed through parallel independent first-order reactions, with different activation energy. For uncatalyzed experiments, the experimental data, once adjusted to the model, provided activation energies of 77.8, 38.6, 70.5 and 16.9 kJ mol^− 1 and the Arrhenius pre-exponential factors of 210.1, 9.9, 775.3 and 0.43 min^− 1 for H₂, CO, CH₄, and CO₂, respectively. For catalyzed experiments (following the same sequence) the activation energies were 15.6, 16.5, 12.7 and 23.3 kJ mol^− 1 and the Arrhenius pre-exponential factors 3.8, 1.4, 4.3 and 3.5 min^− 1.     

重油催化裂解技术研究进展

重油催化裂解技术以增产乙烯、丙烯等低碳烯烃为主要目标,是重油轻质化的有效手段。对催化裂解技术的研究,催化剂和反应器是其核心。本文综述了重油催化裂解技术中采用的各种催化剂和反应器的研究进展,阐述了不同催化剂的适用条件和不同类型反应器的流体特性,并指出深入研究下行床反应器及开发与之匹配的催化剂将是今后开发重油催化裂解技术最具潜力的研究方向。