催化裂化低温接触/大剂油比技术的反应行为

采用微反活性、反应速度常数、热裂化因子、氢转移反应系数及原料硫到气体硫系数对催化裂化低温接触、大剂油比技术进行了系统评价。结果表明,低温接触、大剂油比技术能有效促进催化裂化反应、强化氢转移反应、抑制热裂化反应,从而使催化裂化装置干气产率降低、汽油硫和烯烃含量下降、烟气中SOx浓度减少。     

催化裂化汽油诱导期影响因素浅析

分析了热裂化反应、氢转移反应、操作条件等对催化裂化汽油诱导期的影响，指出催化裂化汽油诱导期低，主要是由于热裂化反应产物二烯烃造成的，针对此提出延长汽油诱导期应采取的措施。     

灵活多效催化裂化工艺及其工业应用

灵活多效催化裂化技术采用并联双提升管反应器及相应的工艺条件,选择性地控制裂化、氢转移等反应,实现了降低汽油烯烃和硫含量、增产丙烯的目的。工业应用结果表明,该工艺可使汽油烯烃体积分数降低至16%以下,硫质量分数降低22%~24%,研究法和马达法辛烷值分别提高1~2个单位,催化裂化装置的丙烯产率提高2~3个百分点。     

工业催化裂化汽油改质反应器的性能和行为

在工业重油催化裂化装置的辅助反应器上进行现场取样研究,详细考察了辅助反应器中催化裂化汽油改质的反应过程,分析了辅助反应器的性能和行为.结果表明,当烯烃含量要求不高时,最佳的反应条件为低反应温度、高进料负荷和没有床层藏量;当烯烃含量要求较高时,最佳的反应条件为低反应温度、高进料负荷和有床层藏量,其损失最小.催化裂化汽油改质过程中催化反应占主要地位,烯烃转化的损失主要是热裂化造成的,反应条件对烯烃转化的损失和热裂化的影响一致,其强弱顺序为:反应温度>床层藏量>进料负荷.增加床层催化剂藏量后,反应时间增加,氢转移系数HTC迅速增加.丙烯产率和HTC的变化规律相反,生成丙烯的最佳反应条件是高反应温度短反应时间.     

催化裂化轻汽油在ZSM-5分子筛催化剂上裂化反应的研究

以ZSM-5分子筛为催化剂，在小型固定床反应器上，进行了催化裂化轻汽油的裂化反应。考察了反应温度和空速对催化裂化轻汽油裂化反应气液相收率和产品分布的影响。实验结果表明，ZSM-5分子筛催化剂具有较强的裂化活性和氢转移活性。在保证裂化转化率的条件下，提高反应温度和空速可以抑制催化剂上氢转移反应的发生。以ZSM-5分子筛为催化剂上的催化裂化反应中，温度、空速是影响转化率和选择性的重要因素，因此可以通过改变温度、空速来提高目的产物的选择性。但是，单纯依靠改善反应条件，不能使目的产物的收率和选择性达到理想的程度，还必须对催化剂进行改性。ZSM-5分子筛催化剂上催化裂化反应的研究为ZSM-5分子筛催化剂的进一步改性，及ZSM-5分子筛催化剂在轻汽油催化裂解和汽油改质方面的进一步应用提供了试验依据。     

阿克苏-诺贝尔公司降烯烃催化剂在洛阳石化应用

阿克苏-诺贝尔公司的TOM OPAL 878L降汽油烯烃催化剂使用强抗金属能力的ADM-60基质及超稳定ADZ分子筛,改善了催化剂的物理性质,优化了原料分子向催化剂活性中心的扩散速度和催化裂化反应的速度。该催化剂同时采用了TOM技术,根据降低汽油烯烃的程度调整Y型和择形分子筛(K-2000)的种类和比例,通过裂化和氢转移反应     

催化裂化汽油降烯烃助剂的开发研究

基于催化裂化催化剂降烯烃方面的研究进展，在现有催化裂化金属钝化剂的基础上，围绕提高氢转移活性，提出制备降烯烃催化裂化助剂的技术路线，并研制开发了新型降烯烃催化裂化助剂。实验结果显示，降烯烃助剂不仅具有良好的抗重金属污染的特性，而且能有效地降低汽油中的烯烃含量，其具有较高的氢转移活性，可协调芳构化与氢转移反应，同时也改善了催化裂化产品分布。     

高硫FCC汽油加氢脱硫降烯烃DSRA技术开发

在分析催化裂化汽油硫和烯烃分布不均匀的基础上,对催化裂化汽油进行轻、重组分分馏,开发了活性高和稳定性好的重馏分辛烷值恢复催化剂及FCC汽油加氢脱硫降烯烃DSRA技术。采用DSRA技术对高硫格尔木催化裂化汽油进行轻馏分脱硫醇、重馏分加氢脱硫和辛烷值恢复等改质处理,总脱硫率为94.1%,烯烃降至20%,辛烷值不损失,汽油收率97.83%,化学氢耗0.88%,可生产符合欧Ⅲ规范的清洁汽油。     

LBO-16H降烯烃催化剂在蜡油催化装置中的应用

在蜡油催化裂化装置使用了LBO—16H降低汽油烯烃含量裂化催化剂。工业试验表明,LBO—16H催化剂有较高的活性稳定性和良好的流化性能．抗碱氮能力强;在工艺操作条件相当的条件下,在不影响汽油辛烷值的前提下,产品分布较为理想,裂化汽油烯烃含量可以降低10个体积百分点以上。     

MIP-CGP清洁汽油生产工艺在催化裂化装置改造中的应用

催裂化技术是重油轻质化生产汽油、柴油的重要技术,随着社会对环境保护的要求越来越高,车用汽油的质量标准也越来越高,因此传统催裂化技术已不能适应生产清洁汽油的要求。MIP-CGP是一种可以有效降低催裂化汽油中烯烃含量,满足环境保护要求的新技术。本文就MIP-CGP技术在催化裂化装置改造中的应用进行分析。     

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.     

分子筛催化剂上催化裂化汽油掺混甲醇的改质研究

以实现甲醇制取低碳烯烃转化工艺和FCC汽油降烯烃工艺的有效组合为目的,在固定床微型反应装置上,使用SAPO-34、ZSM-5、DOCO以及分子筛组合催化剂,对FCC汽油掺混甲醇改质进行了研究。主要对反应温度、空速和混炼比等影响因素进行了考察。结果表明,SAPO-34分子筛上甲醇制取低碳烯烃效果较好,高烯烃含量汽油在SAPO-34分子筛上的氢转移和芳构化效果显著,ZSM-5分子筛上的芳构化反应效果和DOCO的异构化反应效果较显著,甲醇转化与汽油转化反应间的相互协同作用,既有利于甲醇转化成低碳烯烃又能提高汽油降烯烃转化深度。适宜的混炼条件:反应温度400℃,m(甲醇):m(汽油)=0.05,空速3h~(-1),组合催化剂上,产物汽油中烯烃含量较FCC粗汽油下降23%以上。     

Five-lump kinetic model with selective catalyst deactivation for the prediction of the product selectivity in the fluid catalytic cracking process

The effective simulation of the fluid catalytic cracking (FCC) operation requires a good understanding of many factors such as, reaction kinetics, fluid dynamics, and feed and catalyst effects. The different product slates that can be obtained are the consequence of a complex reaction scheme including cracking, isomerization, hydrogen transfer, oligomerization, etc. Furthermore, the catalyst deactivation may affect each one of the reactions in different ways, which creates an additional reason for different variation with time-on-stream of the yield to each product. On the basis of the experimental data of the FCC pilot plant operated in Chemical Process Engineering Research Institute (CPERI, Thessaloniki, Greece), a lumping model was developed for the prediction of the FCC product distribution. The lumped reaction network involved five general lumps (gas oil, gasoline, coke, liquefied product gas, and dry gas) to simulate the cracking reactions and to predict the gas oil conversion and the product distribution. The paths of catalyst deactivation were studied and a selective deactivation model was adopted that enhances the fundamentality and accuracy of the lumping scheme. The hypothesis of selective catalyst deactivation was found to improve the product slates prediction. Models with different assumptions were examined, regarding the behavior of the catalyst, as deactivated, and its effect on the reactions of the lumping scheme. A large database of experiments, performed in the FCC pilot plant of CPERI was used to verify the performance of the models in steady state unit operation. The simulation results depict the importance of incorporating selective catalyst deactivation functions in FCC lumping models.     

Recycling polystyrene into fuels by means of FCC: performance of various acidic catalysts

In accordance with the option of recycling plastics into fuels by dissolving them in standard feedstocks for the process of catalytic cracking of hydrocarbons, FCC, various acidic catalysts (zeolites ZSM-5, mordenite, Y, and a sulfur-promoted zirconia) were tested in the conversion of polystyrene dissolved into inert benzene at 550°C in a fluidized-bed batch reactor. Experiments were performed with very short contact times of up to 12 s. Main products were in the gasoline range, including benzene, toluene, ethylbenzene, styrene, and minor amounts of C_9–12 aromatics and light C₅₋ compounds. Coke was always produced in very significant amounts. All the products can be justified with basis on the properties of each catalyst and the various possible catalytic reaction pathways: cracking after protolytic attack on the polymer fragments, styrene oligomerization and subsequent cracking, or hydrogen transfer to styrene. Styrene would be mainly produced in this system from thermal cracking of the polymer as the initial step. If present, shape selectivity effects due to catalyst structure can influence significantly the prevalence of the various reactions, because they would interfere with those undergoing bulky transition states, like styrene oligomerization or hydrogen transfer. Even though sulfur-promoted zirconia is highly acidic, the low proportion of Brønsted-type acid sites does not allow the occurrence of secondary styrene reactions. It was shown that most favorable product distributions (higher yields of desirable products) are obtained on equilibrium commercial FCC catalysts.     

Enhancing propylene production from catalytic cracking of Arabian Light VGO over novel zeolites as FCC catalyst additives

The catalytic cracking of vacuum gas oil over fluid catalytic cracking (FCC) catalyst containing novel additives was investigated to enhance propylene yield. A conventional ZSM-5, mesoporous ZSM-5 (Meso-Z), TNU-9 and SSZ-33 zeolite were tested as additives to a commercial equilibrium USY FCC catalyst (E-Cat). Their catalytic performance was assessed in a fixed-bed micro-activity test unit (MAT) at 520 °C and various catalyst/oil ratios. The cracking activity of all E-Cat/additives did not decrease by using these additives. The highest propylene yield of 12.2 wt.% was achieved over E-Cat/Meso-Z compared with 9.0 wt.% each over E-Cat/ZSM-5 and E-Cat/TNU-9, at similar gasoline yield penalty. The enhanced production of propylene over Meso-Z is attributed to its mesopores that suppressed secondary and hydrogen transfer reactions and offered easier transport and accessibility to active sites. The lower enhancement of propylene over the large-pore SSZ-33 additive was due to its high-hydrogen transfer activity. Gasoline quality was improved by the use of all additives, as octane rating increased by 7-12 numbers for all E-Cat/additives.     

从ACE评价数据看高液收低焦炭型FCC催化剂的设计

从大量ACE评价数据入手,研究了重油转化率、油浆收率和焦炭之间的相互关系,反应产物柴油、干气与焦炭的关系,热裂化与催化裂化比值、氢转移指数与焦炭的关系。结果表明,在低焦炭产率的同时要获得高的总液收(汽油+柴油+液化气),应结合装置特点合理控制重油转化率,并以碳氢比低的柴油作为催化裂化的主要目标产品,同时降低反应过程中的热裂化反应和氢转移反应。对这些规律进行了深入分析,并提出了具体的高液收低焦炭催化裂化催化剂的设计思路。     

劣质原料催化裂化脱硫降烯烃生产清洁汽油技术

介绍了劣质催化裂化原料的特点,分析了催化裂化汽油清洁化对策,应从提高FCC汽油质量关键应从FCC进料预处理、优化FCC加工过程以及FCC汽油精制等3方面出发．采用有效的降烯烃技术以及选择性加氢和氧化一萃取等脱硫技术对催化裂化汽油进行清洁化处理。认为应注重发展加氢技术,增强加氢在清洁油品生产中的作用;适当减少FCC汽油所占比例,增加异构化油、烷基化油、重整汽油比例,缩小与国外成品油结构组成的差距。     

The effect of heavy aromatic sulfur compounds on sulfur in cracked naphtha

The scope of the present study was to elucidate the effect of heavy sulfur compounds, commonly found in the gas oils, on the percentage of sulfur in gasoline range during the Fluid Catalytic Cracking (FCC) process. Five model sulfur compounds commonly found in the gas oils were studied: benzothiophene, 2-methyl-benzothiophene, 3-decyl-thiophene, dibenzothiophene and 4,6-dimethyl-dibenzothiophene. In order to maintain a realistic hydrocarbon environment each one of the heavy sulfur model compounds were diluted in conventional gas oil. Their cracking behaviour were studied using a steamed deactivated FCC catalyst, while the run tests were performed in an automated Short Contact Time Microactivity Test Unit (SCT-MAT) operated at 560 °C and 12 s run time. The experimental results indicated that the long chain alkyl-thiophene (3-decyl-thiophene) is mainly responsible for the increase of sulfur amount in the gasoline range during cracking, through dealkylation and side cracking reactions for the production of thiophene and shorter chain alkyl-thiophenes, respectively. That sulfur compound was also the most reactive one with respect to desulfurization, since it was highly cracked to H₂S and decomposed to S in coke. On contrary, the polycyclic sulfur compounds did not affect the sulfur amount in gasoline, while their reactions were strongly related to their chemical structure. Thus, the main reaction pathway of the alkylated 2-methyl-benzothiophene and 4,6-dibenzothiophene during the FCC process was isomerization, while for benzothiophene and dibenzothiophene alkylation reactions were dominated.