Feeding Methanol in an FCC Unit

Abstract

The feasibility analysis of integrating methanol to olefins (MTO) with fluidized catalytic cracking (FCC) process is based on their similarities and compatibility. Feeding methanol in FCC is proposed to produce more light olefins. According to the characters of FCC, the effects of reaction temperature, water co-feed, and the coke content of catalyst in methanol conversion were studied systematically. It is concluded that high light olefins yields from methanol conversion were obtained on the FCC condition. Feeding methanol in FCC at the bottom of riser as the proper position was suggested on the ground of comparison with MGD process of FCC. The research proved the feasibility of feeding methanol in FCC and provided important reference for its commercial application in a certain degree.     

甲醇作为催化裂化部分进料反应过程的可行性分析

通过对甲醇制低碳烯烃(MTO)工艺与催化裂化(FCC)工艺的相似性分析,论述了二者结合的可能性。分析了FCC提升管反应器中的温度分布、催化剂活性变化和水存在的状况,以及这些因素对MTO反应的影响。同时对不同的甲醇加入方式进行了分析,并与FCC的多产液化气和柴油工艺(在提升管反应器底部注入汽油)进行比较,提出适宜的甲醇加入位置为FCC提升管反应器底部,先于原料油进料。此过程既可将甲醇转化为低碳烯烃,又有利于重油的催化裂化反应。初步论证了甲醇作为FCC部分进料的可行性,为甲醇作为FCC部分进料以多产低碳烯烃的进一步研究指出了方向。     

几种催化剂对甲醇转化制低碳烯烃催化反应的影响

本实验利用脉冲微型反应器-色谱装置，考察了甲醇在四种FCC工业平衡剂，LOSA-1助剂及SAPO-34上的转化反应过程。结果表明：在GOR-Ⅱ上纯甲醇的烃和低碳烯烃收率为19.91%和11.41%，在SAPO-34上为21.90%和16.52%，在LOSA-1助剂上为26.73%和12.01%，当GOR-Ⅱ中的LOSA-1比例为5.00%时，烃和低碳烯烃收率有最大值为27.52%和15.72%；在GOR-Ⅱ上40%甲醇水溶液的烃和低碳烯烃收率为9.09%和6.20%，在SAPO-34上为24.71%和20.08%；而甲醇在CHZ-4、DACS-GQ1及RAG-10上的烃和低碳烯烃收率均较低，RAG-10用量提高后烃和低碳烯烃收率可达到11.12%和6.04%。由实验结果可知:四种FCC工业平衡剂中，甲醇在GOR-Ⅱ上的烃和低碳烯烃收率较好，在GOR-Ⅱ中添加LOSA-1后烃和低碳烯烃收率有所提高，这为研究甲醇在FCC催化剂上制低碳烯烃的反应规律提供了初步的参考。     

催化裂化条件下甲醇与石脑油交互作用研究

为进一步研究甲醇作为催化裂化部分进料反应过程的特征,对催化裂化条件下甲醇与石脑油的交互作用规律进行了考察。利用小型固定流化床装置对甲醇与石脑油共同进料的反应过程进行研究。实验结果表明:随着石脑油中甲醇比例的增加,产物中气体烃产率、焦炭产率、二甲醚产率及低碳烯烃选择性增加;裂化汽油中烷烃含量、芳烃含量先增加后降低,烯烃含量增加;甲醇与石脑油的交互作用使得甲醇转化为低碳烯烃的反应程度加深,同时促进了石脑油的裂化反应。该研究初步探究了甲醇与石脑油的交互作用规律,为更深入的研究甲醇作为催化裂化部分进料的反应过程提供基础数据。     

轻汽油醚化负载型磷钨酸铯催化剂性能研究

制备了负载磷钨酸铯催化裂化的轻汽油醚化催化剂 ,在小型固定床反应装置上 ,考察了催化剂制备条件对催化剂性能的影响以及醚化反应温度、空速对醚化反应的影响。表明制备的负载型磷钨酸铯催化剂具有较好的醚化活性 ,叔碳烯烃转化率达 5 5 %以上。向反应器中通入氢气可以提高催化剂活性。经过 10 0 0h的稳定性试验 ,叔碳烯烃转化率基本保持不变 ,表明该催化剂活性稳定 ,具有工业应用价值     

EFFECT OF ZSM-5 ADDITION ON PRODUCT DISTRIBUTION IN A HIGH SEVERITY FCC MODE

The high-severity fluid catalytic cracking (HS-FCC) process is a novel FCC process that enhances light olefins yield under high severity reaction conditions. The process has been investigated by using a small-scale FCC pilot plant (0.1 BPD) with a down-flow reactor. High severity reaction conditions are preferable for enhancing the production of light olefins by catalytic cracking of heavy oils. As another option for the light olefin production, adoption of ZSM-5 additive in conventional FCC units is well known. This presentation describes the effect of ZSM-5 additive on the catalytic cracking of vacuum gas oil under high severity reaction conditions, particularly focusing on the synergistic effect with the base catalyst. Three kinds of FCC catalysts with different activity were used as base catalysts. Although the employment of a ZSM-5 additive resulted in significant increase in the light olefins yield at the expense of gasoline in each catalyst system tested, the effectiveness was varied depending on the nature of the base catalysts. By choosing a suitable base cracking catalyst, more than 20 wt% of propylene yield was obtained at a one-pass conversion of fresh feed.     

EFFECT OF ZSM-5 ADDITION ON PRODUCT DISTRIBUTION IN A HIGH SEVERITY FCC MODE

The high-severity fluid catalytic cracking (HS-FCC) process is a novel FCC process that enhances light olefins yield under high severity reaction conditions. The process has been investigated by using a small-scale FCC pilot plant (0.1 BPD) with a down-flow reactor. High severity reaction conditions are preferable for enhancing the production of light olefins by catalytic cracking of heavy oils. As another option for the light olefin production, adoption of ZSM-5 additive in conventional FCC units is well known. This presentation describes the effect of ZSM-5 additive on the catalytic cracking of vacuum gas oil under high severity reaction conditions, particularly focusing on the synergistic effect with the base catalyst. Three kinds of FCC catalysts with different activity were used as base catalysts. Although the employment of a ZSM-5 additive resulted in significant increase in the light olefins yield at the expense of gasoline in each catalyst system tested, the effectiveness was varied depending on the nature of the base catalysts. By choosing a suitable base cracking catalyst, more than 20 wt% of propylene yield was obtained at a one-pass conversion of fresh feed.     

满足国Ⅵ标准的FCC汽油改质技术研究

介绍了3种基于汽油分子组成的催化裂化(FCC)汽油改质技术,以烯烃定向转化为基础,在降低FCC汽油烯烃含量的同时,最大限度减少辛烷值损失,使产品满足国Ⅵ汽油质量标准。其中,骨架异构技术以全馏分FCC汽油为原料,强化催化剂的异构化性能。中试结果表明,加氢条件下,在硫和烯烃含量达标的同时,RON损失仅0.7单位;异构-醚化组合技术以C_5烯烃为原料,经异构化过程将其中的直链烯烃转化为叔碳烯烃,再与甲醇醚化生成甲基叔戊基醚(TAME),相比于正构烯烃,RON可提高21.1单位;芳构化技术将正构烯烃定向转化为辛烷值很高的芳烃产品,同时实现降低烯烃含量和提高辛烷值的目标。     

催化裂化汽油的下行床催化转化

以循环下行床为反应器,催化裂化汽油为原料,在工业催化裂化(FCC)催化剂和催化裂解(DCC)催化剂作用下,研究了催化裂化汽油的催化转化过程。实验结果表明,在下行床反应器中,催化裂化汽油中的烯烃能显著降低,主要转化为低碳烯烃产品,同时得到富含芳烃的液体产品,副产干气和焦炭量很低。催化裂化汽油在FCC催化剂和DCC催化剂上表现出不同的反应机理。FCC催化剂孔道大,可以发生双分子裂化反应和单分子裂化反应,而DCC催化剂孔道小,以单分子裂化反应机理为主,同时DCC催化剂低碳烯烃选择性更高。     

催化裂化生产低碳烯烃技术综述Ⅰ.生产低碳烯烃工艺

催化裂化增产低碳烯烃是催化裂化技术发展的一大趋势,介绍了催化裂化增产低碳烯烃的影响因素和目前国内外工业和实验室中具有代表性的多产低碳烯烃的催化裂化工艺、产品特点及工业应用情况,并指出催化裂化增产低碳烯烃具有很好的发展前景。     

催化裂化裂化气中甲醇生成的影响因素研究

鉴于丙烯市场需求的增长,催化裂化已成为丙烯生产的一条重要途径,但裂化气中生成的甲醇对下游产品聚丙烯的生产带来了不利影响。通过以甲醇中氧来源为切入点,研究了不同因素对甲醇生成的影响,结果表明：SOX、NOX和水是甲醇的氧来源;反应体系中存在SOX和NOX时,甲醇可通过烃分子与SOX、NOX和水参与反应生成;催化剂的活性影响甲醇的生成,当催化剂活性降低至热裂化反应占主导时,有利于促进甲醇的生成。甲醇的生成应遵循自由基反应机理;控制甲醇生成的主要措施是降低再生剂夹带烟气中SOX和NOX的含量,以及保持装置中催化剂活性在较高水平。     

加入甲醇对直馏汽油裂化反应的影响

采用小型固定流化床装置研究甲醇作为催化裂化部分进料的反应过程,考察了加入甲醇对直馏汽油裂化反应的影响,比较了不同进料方式的反应过程,分析加入甲醇后的催化裂化反应规律。结果表明,甲醇与直馏汽油同时进料相对于单独的直馏汽油裂化,气体产率增加,并可维持低碳烯烃的选择性;产物汽油的正构烷烃、异构烷烃、环烷烃含量降低,烯烃含量略有增加,芳烃含量增加。对甲醇作为催化裂化部分进料过程的反应机理进行了初步探讨。     

深度催化裂解(DCC)技术

深度催化裂解技术（ＤＣＣ技术）是一项选择性地催化裂解各种不同的重油原料，生产低分子烯烃的新技术。本文着重介绍ＤＣＣ工艺技术的特点以及在现有的炼厂或石油化工厂建一套ＤＣＣ装置可供实施的几个方案。其中包括把现有催化裂化（ＦＣＣ）装置改成ＤＣＣ装置的主要技术内容以及技术经济分析等。     

Comparison of Downer and Riser Based Fluid Catalytic Cracking Process at High Severity Condition: A Pilot Plant Study

Integration of refining and petrochemicals offers economic benefits to both the industries. Converting low value refinery products to high value petrochemicals require novel processes and extra investment. Though FCC is not a new process to the refining industry, it still has a potential for modification to enhance light olefins demanded by reformulated gasoline and the petrochemical industry. In this article a novel, High Severity FCC process based on the downer reactor is presented. Supported by the pilot plant study and comparison with riser, it is shown that the downer FCC reduces backmixing, which is the main cause of gasoline overcracking. Reduction of backmixing reduces coke and dry gas formation, resulting in increased yield of gasoline. Despite the operation at higher temperature, there is reduction in the thermal cracking. Though the light olefins yield is lower in case of downer, the total yield of useful products (gasoline + light olefins) is higher in downer as compared to the same from a riser. The increased yield of gasoline from downer can be converted to light olefins by using ZSM-5 based additives.     

Comparison of Downer and Riser Based Fluid Catalytic Cracking Process at High Severity Condition: A Pilot Plant Study

Abstract

Integration of refining and petrochemicals offers economic benefits to both the industries. Converting low value refinery products to high value petrochemicals require novel processes and extra investment. Though FCC is not a new process to the refining industry, it still has a potential for modification to enhance light olefins demanded by reformulated gasoline and the petrochemical industry. In this article a novel, High Severity FCC process based on the downer reactor is presented. Supported by the pilot plant study and comparison with riser, it is shown that the downer FCC reduces backmixing, which is the main cause of gasoline overcracking. Reduction of backmixing reduces coke and dry gas formation, resulting in increased yield of gasoline. Despite the operation at higher temperature, there is reduction in the thermal cracking. Though the light olefins yield is lower in case of downer, the total yield of useful products (gasoline + light olefins) is higher in downer as compared to the same from a riser. The increased yield of gasoline from downer can be converted to light olefins by using ZSM-5 based additives.     

催化裂化条件下甲醇和异辛烷相互作用的研究

基于甲醇作为催化裂化(FCC)部分进料的可行性分析,为研究甲醇加入对FCC过程的影响,考察了FCC条件下甲醇转化和烃裂化相互作用规律.采用小型固定流化床装置对不同甲醇比例与异辛烷共同进料的反应过程进行研究.试验结果表明:FCC条件下甲醇与异辛烷的相互作用降低了烃裂化产物中干气组分的选择性;提高了异丁烷和丁烯的选择性.随着甲醇加入比例的增加,汽油产物中高碳数组分(C7～C10)的选择性增加,而且芳烃选择性显著增加.论述了FCC条件下甲醇转化和异辛烷裂化的相互作用规律.     

催化裂化在当代炼油企业作用与地位的再认识

催化裂化装置具有原料适应性宽、重油转化率高、操作压力低与投资少的特点,是当代炼油企业的主要二次加工装置,产品方案可灵活调整,承担着车用燃料生产的主要任务,还兼顾生产低碳烯烃。随着原油重质化以及环保要求日益严格,催化裂化面临汽、柴油产品需要深度精制,柴油十六烷值偏低、烟气排放受限等一系列问题。催化裂化与各种加氢工艺之间的优化组合能够使催化裂化继续在原油炼制中发挥更大的作用,同时介绍了近年新建及改造催化裂化装置的特点与发展趋势。     

催化裂化轻汽油醚化新工艺研究

研究了催化裂化轻汽油预处理及深度醚化工艺。结果表明，经过预处理，碱性氮脱除率可达80％以上，二烯烃脱除率达90％以上，叔碳烯烃收率接近100％。原料经预处理后，醚化催化剂寿命大大延长。经过深度醚化，叔碳烯烃总转化率达70％以上，催化裂化全馏程汽油的研究法辛烷值提高2．1个单位，蒸气压下降10．8kPa，烯烃含量减少9．36个百分点，含氧量达2．0％。     

小型提升管反应器上甲醇与流化催化裂化汽油混炼改质的研究

在小型提升管流化催化裂化(FCC)装置上,使用FCC催化剂,进行了甲醇与FCC汽油的混炼实验,考察了反应温度、甲醇与FCC汽油的质量比(混炼比)及甲醇不同进料位置对精汽油族组成、裂化气组成和液体收率的影响。实验结果表明,甲醇与FCC汽油共混进料的反应效果优于甲醇提前或延后FCC汽油进料时的反应效果;甲醇与FCC汽油混炼在改善汽油质量的同时,有利于增产裂化气和提高液体收率。甲醇与FCC汽油混炼的适宜条件为:反应温度400~420℃、混炼比为5%~10%、剂油比10~12。在此条件下,FCC汽油烯烃含量下降50%以上,液体收率增加3%左右,裂化气中干气质量分数小于1.5%,精汽油与液化石油气收率之和达到98%以上。     

流化催化裂化汽油含硫化合物生成规律的考察

在小型固定流化床装置上采用流化催化裂化(FCC)催化剂、以FCC汽油轻馏分和H2S标准气为原料,考察了催化剂类型、原料组成和反应条件(反应温度、催化剂与原料油的质量比(剂油比)和重时空速)对硫化物生成的影响。实验结果表明,FCC汽油中的烯烃与H2S反应主要生成噻吩类硫化物和部分硫醇;在REUSY分子筛催化剂(催化剂A)上的硫化物收率比在ZRP型择形分子筛催化剂(催化剂B)上的高;且硫化物收率随H2S和烯烃含量的增加呈线性增长。受反应温度对烯烃转化程度的影响,较高的反应温度有利于抑制烯烃与H2S反应。因为反应机理及催化剂性质对噻吩类硫化物和硫醇的生成影响不同,两者收率随剂油比和重时空速的变化趋势不同,但变化幅度均不大,因而总硫化物收率随重时空速和剂油比的变化幅度也不大。