高硅铝比小晶粒NaY分子筛/高岭土复合物的合成及其催化裂化性能

以两种不同粒径的高岭土为原料,采用水热法合成了高硅铝比小晶粒NaY分子筛/高岭土复合物,通过XRD、SEM、晶粒度分析和N₂物理吸附等表征手段对复合物进行了结构和形貌表征。结果表明,与商品NaY相比,高岭土合成样品的结构稳定性和水热稳定性显著提高,以细化高岭土为原料合成样品的晶粒尺寸达310 nm,比表面积达807 m²·g^-1。以改性NaY分子筛/高岭土复合物为活性组分制备了催化裂化催化剂,采用NH₃程序升温脱附(NH₃-TPD)技术对其酸性特征进行了分析,并在小型微反装置上对其重油催化裂化性能进行了评价。研究结果发现,随着骨架硅铝比增大,催化剂表面酸中心强度增加,而酸量下降。采用细化高岭土合成的NaY分子筛/高岭土复合物的分子筛晶粒更小,催化剂酸中心数量以及催化裂化性能均大幅度提升。随着高温焙烧高岭土/偏高岭土质量比的增加,合成产物中的高岭土基质含量增加,催化剂表面酸中心强度下降。以原料高温焙烧高岭土/偏高岭土质量比为0.5,骨架硅铝比为6.1(摩尔比)的样品制备的催化剂,去柴重油转化率高达85.4%,同时有高达64.2%的汽油收率,表现出优异的重油催化裂化性能。     

一种催化新材料的孔结构与反应性能关联研究

在实验室研究了山西金洋土合成复合新型催化剂材料,并将其改性制成催化剂。在小型固定流化床装置上进行反应,采用XRD、静态N₂物理吸附法和热解吸色谱法等对催化剂进行表征。结果表明,山西金洋土在原位晶化体系中具有适度活性硅和较快活性铝的碱溶速率,有良好的晶化性能和裂化性能。经过水热处理和化学改性,形成了一定活性的中孔结构,设计的新型重油裂化催化剂具有较好的重油转化能力和良好的裂化产物选择性。     

Utilization of ZSM-5/MCM-41 composite as FCC catalyst additive for enhancing propylene yield from VGO cracking

A micro-mesoporous ZSM-5/MCM-41 composite molecular sieve (ZM13) was synthesized and tested as an FCC catalyst additive to enhance the yield of propylene from catalytic cracking of vacuum gas oil (VGO). The catalytic performance of the additive was assessed using a commercial equilibrium USY FCC catalyst (E-Cat) in a fixed-bed micro-activity test unit (MAT) at 520?°C and various catalyst/oil ratios. MCM-41, ZSM-5 and two ZSM-5/MCM-41 composites were systematically characterized by complementary techniques such as XRD, BET, FTIR and SEM. The characterization results showed that the composites contained secondary building unit with different textural properties compared to pure ZSM-5 and MCM-41. MAT results showed that the VGO cracking activity of E-Cat did not decrease by using these additives. The highest propylene yield of 12.2 wt% was achieved over steamed ZSM-5/MCM-41 composite additive (ZM13) compared with 8.6 wt% over conventional ZSM-5 additive at similar gasoline yield penalty. The enhanced production of propylene over composite additive was attributed to its mesopores that suppressed secondary and hydrogen transfer reactions and offered easier transport and accessibility to active sites. Gasoline quality was improved by the use of all additives except MCM-41, as octane rating increased by 6?C12 numbers.     

高岭土微球合成ZSM-5沸石及其催化裂化性能

在水热条件下,以正丁胺为模板剂,在高岭土微球中合成了晶粒直径约0.2～1μm的ZSM-5沸石粉体.采用X射线衍射、扫描电镜、N2吸附脱附方法对合成样品进行了表征.催化裂化选择性评价结果表明:在基础重油裂化催化剂LHO-1中,采用添加10%(质量分数,下同)所合成的高岭土微球(含27%ZSM-5)作为助剂,丙烯产率由2.96%提高到4.78%,焦炭和干气选择性不变;同时汽油质量明显提高,汽油芳烃减少近10%(体积分数),汽油辛烷值增加1.8.     

In situ synthesis, characterization and catalytic activity of ZSM-5 zeolites on kaolin microspheres from amine-free system

ZSM-5 zeolites were synthesized by an in situ hydrothermal crystallization method on kaolin microspheres from an organic template-free solution. The as-synthesized samples were characterized by using X-ray diffraction, scanning electron microscopy, Fourier Transform Infrared spectrometry, N₂ adsorption and desorption, and Temperature Programmed Desorption. The results showed that small-sized ZSM-5 crystallites with less than 1 micron in diameter were effectively formed on kaolin microspheres. The synthesized products indicated high hydrothermal stability and strong acidity. By mixing the H-type ZSM-5/CMK composite with a Fluid Catalytic Cracking base catalyst, the performance of the catalyst is then evaluated. The results of catalytic performance evaluation showed that with the addition of ZSM-5/CKM, it favored the production of light olefins such as propylene and butylenes by catalytic cracking of vacuum gas oil.     

LOSA-1增产轻烯烃FCC助催化剂的开发及工业应用

在中国石化济南分公司800 kt·a^－1催化裂化装置上试应用了岳阳三生化工有限公司生产的LOSA-1增产轻烯烃FCC助催化剂，考察了该助催化剂催化裂化性能及其对汽油和柴油质量的影响。工业应用表明，增产轻烯烃助剂占系统催化剂总藏量4.0％时，丙烯（对催化进料）增加了1.19％，系统总液收及焦炭产率基本保持不变。     

Study of direct and indirect naphtha recycling to a resid FCC unit for maximum propylene production

To satisfy the increasing propylene demand, direct and indirect naphtha recycling schemes around an existing resid fluid catalytic cracking (FCC) unit were investigated. To this aim, light cracked naphtha (LCN), heavy cracked naphtha (HCN) and a PolyNaphtha (PN) oligomerisation product were cracked under a wide range of operating conditions over a commercial Y zeolite based equilibrium catalyst. Experimental data were acquired in three different units: a fixed bed bench scale unit, a fixed fluidised bed unit and an adiabatic circulating fluidised bed pilot plant. It was shown that FCC naphthas require high operating severities to crack, and that even then their conversion remains relatively moderate. Hence, direct recycling to the main riser does not seem a viable pathway to increase propylene product. Feeding FCC naphthas to a second reaction zone operating at high severity allows to increase the propylene yield in a significant manner. Increasing conversion, however, not only leads to higher LPG and propylene yields, but also results in very high dry gas yields. An alternative scheme was proposed, in which the olefinic C₄ and C₅ fractions are converted into a naphtha fraction through oligomerisation in a dedicated unit before being recracked in the secondary riser. As the highly olefinic oligomerised effluent mainly consist of dimerised and trimerised butenes and pentenes, this feed is more easily cracked and high conversions can be achieved. This indirect interconversion of butenes and pentenes into propylene therefore effectively allows to convert these butenes and pentenes into propylene, resulting in a significant increase in propylene yield. Each of the three main naphtha recycle options (directly to the main riser, directly to a secondary riser or indirectly via a light olefin oligomerisation unit) have been analysed and compared to a base case. In the evaluation of each of these schemes, all heat balance effects, both on the riser and the regenerator side, have been accounted for. The proposed process scheme with an indirect recycle via an oligomerisation unit enhances the already inherent flexibility of the FCC unit. The naphtha recycle can be turned on or off, the second reaction zone can be used to crack naphtha or to crack resid feed to maximise throughput, while the effluent of the oligomerisation unit can be recycled to the FCC unit for propylene production or hydrogenated and sent to gasoline and kerosene pool.     

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。     

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.     

草酸作为交换介质对FCC催化剂后处理制备工艺的影响

将NaY分子筛、拟薄水铝石、铝溶胶和高岭土打浆混合,喷雾干燥制得催化剂粉体NaY35。以NaY35为起始原料,研究探索催化剂焙烧和使用草酸替换铵离子进行洗涤的后处理制备工艺,最终制得Na2O质量分数小于0.3%,且基本性质能够满足工业要求的FCC催化剂。采用XRD、BET、NH3-TPD、IR和SEM等考察催化剂性质,结果表明,以草酸为交换介质制备的催化剂表面有完整的孔道结构,酸量大幅提高,磨损指数满足工业要求,同时重油转化率和微反活性高。     

轻汽油在HZSM-5分子筛上催化裂解制丙烯的研究

以催化裂化轻汽油（≤75 ℃）为原料,在小型固定床反应器上,考察了反应温度、反应空速、催化剂不同硅铝物质的量比及载体Al₂O₃含量对轻汽油的催化裂解性能及丙烯选择性的影响。实验结果表明,反应温度和空速对催化裂解的产物分布和丙烯收率有较大的影响,高硅铝比催化剂的丙烯选择性比低硅铝比催化剂好,适量Al₂O₃的添加有助于提高丙烯收率。选择合适的反应条件可以有效提高催化剂的裂化性能并能很好抑制氢转移反应的进行,从而提高丙烯的选择性。在550 ℃、0.2 MPa和空速4 h^－1条件下,高硅铝比n(SiO₂)∶n(Al₂O₃)=200］催化剂的丙烯收率为37.56％,当添加30%的Al₂O₃时,丙烯收率增至38.26%。     

酸改性高岭土基质FCC催化剂的反应性能

利用N^₂吸附法、IR酸性表征、微型和小型反应器等手段研究了改性高岭土基质催化剂的性能特点。结果表明，高岭土经过热和化学改性后形成了一定活性的中孔结构，添加这种新材料制成的FCC催化剂具有较强的抗重金属污染和重质油转化能力。     

Ce修饰Na Y分子筛负载PdO纳米晶催化剂用于苯的催化氧化反应

以CeO_2修饰多孔NaY分子筛作为载体,采用高温液相还原法制备纳米晶PdO催化剂,用于低浓度苯催化氧化反应。采用XRD、N2吸附-脱附、透射电镜-能谱(HRTEM-EDS)、H2程序升温还原(H_2-TPR)、O_2程序升温脱附(O_2-TPD)和程序升温表面反应(TPSR)等对载体和催化剂进行表征。结果表明,NaY分子筛结构稳定,比表面积651 m~2·g~(-1)和孔容0. 326 cm~3·g~(-1),纳米晶PdO能够较均匀地分散在NaY载体上,颗粒尺寸约(3～5) nm。加入一定量CeO_2后,Pd O以较小的纳米晶颗粒形式分散在CeO_2周围,活性组分与助剂协同作用促进了催化剂中晶格氧的流动性,明显改善了0. 2%Pd/NaY的氧化性能。0. 2%Pd/8%Ce/NaY表现出最佳催化活性和良好稳定性,250℃可完全催化降解1000×10~(-6)的苯,并且230℃连续反应100 h,催化剂转化率稳定在86%。     

Ca-Mg-Al复合氧化物催化尿素与1,2-丙二醇制碳酸丙烯酯

采用共沉淀法制备了系列Ca-Mg-Al复合氧化物催化剂,通过对沉淀剂配比、沉淀液pH值及焙烧温度等制备条件的考察,得到以Na₂CO₃为沉淀剂、pH=9.5、850℃下焙烧4h制备的Ca-Mg-Al催化活性最高。在 n(PG)∶n(urea)=1.5∶1、反应温度为145℃、绝压20kPa、反应时间4h、催化剂用量为尿素质量的5%时,碳酸丙烯酯收率达到84.6%。采用XRF、XRD、NH₃-TPD、SEM及BET对催化剂的组成、晶型及酸性进行了表征,发现随着沉淀剂中Na₂CO₃的含量增加,催化剂中CaO∶MgO的比例增大,碳酸丙烯酯的收率亦升高;经850℃焙烧后,催化剂中存在CaO和MgO两种活性中心,起协同催化作用;随着焙烧温度由700℃升高到850℃,NH₃-TPD脱附曲线向低温方向偏移,且强酸中心NH₃脱附峰面积比由81.14%明显下降为0,中强酸中心NH₃脱附峰面积比由0增加到78.07%,而碳酸丙烯酯收率由68%增加到84.6%,这表明催化剂强酸性位的减少是催化活性增加的主要原因。     

高抗磨NaY微球的制备与表征

在满足商用FCC催化剂粒度分布的基础上,通过向生高岭土喷雾浆液中添加功能助剂,利用原位晶化法制备了具有低磨损指数及高NaY分子筛含量的晶化微球。在不降低晶化微球机械强度的基础上,功能助剂能大幅度提高其结晶度及孔体积。因此,所制得的高结晶度、高机械强度及大孔体积的晶化微球是制备高性能FCC催化剂的优质前躯体。     

CGP-1催化剂的工业应用

介绍了CGP-1催化剂在重油催化裂化装置上的工业应用,结果表明,CGP-1催化剂能明显提高装置总液体收率,降低汽油烯烃含量,增加丙烯产量,实现装置效益最大化.     

MnO2/NaY复合材料的制备及其对SO2脱除性能

以NaY分子筛为载体，MnO₂为活性组分，采用沉淀法制备MnO₂/NaY复合脱硫材料；通过X射线衍射（XRD）、扫描电子显微镜（SEM）、氮气吸附脱附法（N₂-吸附脱附）、X射线光电子能谱（XPS）、热重分析（TG）等手段进行材料的物理化学结构表征；使用容量法装置测试复合材料的脱硫性能；考察MnO₂不同负载量及不同反应温度对MnO₂/NaY复合材料脱硫性能的影响。结果表明：MnO₂/NaY复合材料的孔容越大，其脱硫性能越好；多孔珊瑚状MnO₂脱硫性能优于棒状MnO₂；随着MnO₂负载量及反应温度的增加，MnO₂/NaY的脱硫性能先增加后降低，MnO₂/NaY-41%在400℃时的脱硫性能最好，第1h脱硫量达到114.56mg {{}_{\mathrm{S}\mathrm{O}}}_{{}_2} /g_材料；500℃时复合材料脱硫性能下降，是由于脱硫反应过程中MnO₂分解生成Mn₃O₄；MnO₂/NaY比纯MnO₂拥有更好的脱硫性能，反应温度为300℃和400℃时，MnO₂/NaY-41%较纯MnO₂的第1h脱硫量分别提高28.3%和56.1%。MnO₂/NaY-41%复合材料在中低温下的高效脱硫性能有望应用于船舶尾气的深度脱硫。     

Natural rectorite mineral: A promising substitute of kaolin for in‐situ synthesis of fluid catalytic cracking catalysts

Fabrication of high‐performance fluid catalytic cracking (FCC) catalysts is suffering from the shortage of high‐quality kaolin that has long been used as matrix or starting material for synthesizing FCC catalysts. This work aimed at exploring the potential of rectorite, a natural aluminosilicate mineral, to substitute kaolin for preparing FCC catalysts through in‐situ synthesis technique. The physicochemical properties of a rectorite mineral, including its chemical composition, structure, thermal behavior, and chemical reactivity, were systemically investigated and compared with those of commercial kaolin. The results showed that the rectorite mineral suitably treated could substitute kaolin for synthesizing FCC catalysts. Moreover, we had shown that a hydrothermally stable ZSM‐5/rectorite composite in which ZSM‐5 crystals of ca. 2 μm in size were overgrown on preformed rectorite substrate could be synthesized using the rectorite mineral calcined at 800°C as raw material. When used as FCC additive, the obtained ZSM‐5/rectorite composite demonstrated enhanced light olefin (ethylene and propylene) yields. © 2010 American Institute of Chemical Engineers AIChE J, 2010     

催化裂化工艺掺炼焦化液化气的研究

采用在催化裂化工艺过程中掺炼焦化液化气(LPG)的方法来处理高含硫的焦化液化气,在提升管催化裂化中试装置上进行了增产丙烯的研究.考察了焦化液化气掺炼量、反应温度等工艺条件的影响,还考察了LPI-1增产丙烯助剂的效果.结果表明,当掺炼LPG的质量分数为9.41%,LPI-1助剂添加的质量分数为5%时,可使丙烯对原料的产率提高1.05%,即增产丙烯达18.83%,同时转化率提高,轻油收率基本不变.反应温度对丙烯产率和产品分布有一定的影响,提高温度有利于增产丙烯.     

Study of cracking FCC naphtha in a secondary riser of the FCC unit for maximum propylene production

To satisfy the increasing propylene demand, reprocessing FCC naphtha in a secondary riser of the FCC unit was investigated. To this aim, a full range FCC naphtha was cracked over a mixture of two kinds of commercial equilibrium FCC catalysts, which contained 95 t.% Y zeolite-based catalyst and 5 wt.% ZSM-5 zeolite-based additive. The effects of operating parameters such as reaction temperature (temperature of the riser outlet), catalyst-to-oil ratio and residence time on FCC naphtha cracking were studied in a continuous pilot plant. This work demonstrates that FCC naphtha requires high operating severities to crack, and approximately 12–19 wt.% FCC naphtha can be transformed into propylene. The conversion and yield of propylene showed a rapid increase with increasing reaction temperature, and the increase of catalyst-to-oil ratio also enhanced FCC naphtha cracking, even at high reaction temperature. However, at high catalyst-to-oil reactions, hydrogen-transfer reactions constrain further increases in light olefin yields. At these high operating severities, shortening residence time is an appropriate way to obtain high yields of propylene combined with (i) lower yields of dry gas and (ii) a lower apparent hydrogen-transfer coefficient.