FCC汽油在ZSM-5分子筛上的芳构化反应

考察了全馏分催化裂化（FCC）汽油的芳构化改质反应，结果表明，在三种不同硅铝比的分子筛中，以硅铝比为50的分子筛为载体所制备的催化剂性能较好。对Ni、Mo、Zn、Co4种金属活性组分的选择考察，以Zn为活性组分的催化剂芳构化性能最好，以Ni为活性组分的催化剂液收最高。分析了FCC汽油中不同烃类的芳构化反应历程．得出金属组分应有适宜的含量。     

Cd-ZSM-5沸石催化剂的制备、表征和芳构化催化性能

采用离子交换、浸渍和混合三种方法制备镉改性ZSM-5沸石催化剂,考察了改性方法和镉含量对催化剂的表面酸性和Cd状态以及芳构化性能的影响。结果表明,加入镉降低了B酸性,Cd~(2+)与沸石结合形成了L_(1612)酸中心,其生成量取决于改性方法和Cd含量,并与芳构化活性提高有直接关系。     

A Study on the Selectivity of Methanol Aromatization

Abstract

The present study describes the performance of the HZSM-5 zeolite catalyst modified by Cu, Zn, Ga, La, P, Ag, and other ions for the conversion of methanol to aromatics in a fixed-bed reactor, and the influences of the system pressure and temperature on methanol aromatization are in discussion. The results show that the optimum single ion for the modification of catalyst was Zn or Cu. The optimum combined ions were Zn and Ga. The yield of aromatics could reach up to 66.6% on the catalyst modified with Ga2% and Zn10%.     

纳米HZSM-5沸石催化剂上催化裂化轻汽油的芳构化

利用小型固定床加压反应器在纳米 HZSM-5沸石催化剂上进行了流化催化裂化(FCC)轻汽油(馏出温度小于等于85℃的馏分)的芳构化反应。实验结果表明,在反应温度为360～400℃、反应压力为1.0～3.0 MPa、重时空速为1.0～4.0 h~(-1)、V(H_2)∶V(原料)为260、反应时间48 h 的条件下,FCC 轻汽油中的 C_5~+烯烃转化率为39.11%～97.92%,产物中芳烃净增量为2.59%～19.05%,说明 FCC 轻汽油可在纳米 HZSM-5沸石催化剂上有效进行芳构化反应。汽油收率低和催化剂失活快是 FCC轻汽油在纳米 HZSM-5沸石催化剂上进行芳构化反应需要解决的两个主要问题。对纳米 HZSM-5沸石催化剂进行必要的改性处理及脱除原料中的二烯烃杂质呵以改进 FCC 轻汽油芳构化催化剂的性能。     

在FX-02沸石催化剂上苯与乙烯烷基化反应的研究

采用固定床鼓泡反应器,在ＦＸ ０２沸石催化剂上进行苯与乙烯烷基化反应的研究。通过加速失活试验,考察了不同工艺条件对催化剂操作寿命的影响,得到了使苯转化率和乙苯选择性较高及反应产物中二甲苯含量极低的适宜的工艺条件。     

液化石油气在ZnNi/HZSM-5催化剂上的芳构化

用浸渍法制备ZnNi/HZSM -5催化剂 ,通过对液化石油气的芳构化试验表明 ,其活性明显高于HZSM -5催化剂。在常压、温度 540℃、质量空速 1h- 1条件下 ,芳烃和苯 -甲苯 -二甲苯 (BTX)混合物收率分别达到 4 8%和4 5%左右 ,液态产品中芳烃质量分数高达 98%。同时还考察再生活化温度、再生活化时间和反应温度对芳构化催化作用的影响。结果表明 ,再生活化温度对催化剂的恢复影响比较大 ,只有达到 575℃ ,活化时间至少 2h ,催化剂活性才能完全恢复 ;低温段 ( 550℃ )再生活化时 ,再生活化时间将影响催化剂活性 ;反应温度在 50 0～ 550℃时 ,随着反应温度增加 ,液体收率和芳烃收率随之增加 ,对芳烃选择性影响不大 ,BTX收率幅度波动较大。用金属改性的ZnNi/HZSM -5催化剂具有较强的芳构化能力。     

磷改性ZSM-5/磷酸铝复合分子筛在甲醇制丙烯反应中的应用

以磷酸二氢铵对ZSM-5/磷酸铝 (ZSM-5/AlPO₄-m) 复合分子筛进行P改性,得到wP-ZSM-5/AlPO₄-m催化剂,采用XRD、N₂吸附-脱附、NH₃-TPD和FT-IR表征其物化性能,并系统地考察了在甲醇制丙烯(MTP)反应中,wP-ZSM-5/AlPO₄-m中P质量分数,反应温度、空速(MHSV)等反应条件对该复合分子筛催化性能的影响。结果表明,P改性可以有效地调节ZSM-5/AlPO₄-m的比表面积及酸性分布,3%P-ZSM-5/AlPO₄-m催化剂中B酸与L酸中心数的最大比达到3.03。当反应温度为500℃、MHSV为1 h-^-1时,3%P-ZSM-5/AlPO₄-m催化剂表现出最佳的MTP活性和稳定性;反应持续73 h,甲醇转化率保持100%,丙烯的单程选择性和产物中丙烯/乙烯摩尔比分别保持在50.0%和5。     

ZSM-5/磷酸铝复合分子筛在甲醇制烯烃反应中的应用

 水热体系中将 ZSM-5添加到磷酸铝分子筛的合成液中,制得了 ZSM-5/磷酸铝复合分子筛催化剂,采用 XRD、SEM、FT IR 和 NH₃-TPD 方法表征其物化性能,同时考察了该复合分子筛对甲醇制烯烃反应的催化活性。结果表明,制备的分子筛为 ZSM-5/磷酸铝复合分子筛,磷酸铝分子筛中含有 AlPO₄-5与 AlPO₄-18 2种晶相;与纯 ZSM-5分子筛相比,复合分子筛的酸性明显减弱且酸量减少。与 ZSM-5和 ZSM-5+磷酸铝分子筛机械混合样品相比,ZSM-5/磷酸铝复合分子筛表现出了良好的协同作用和优良的催化性能,在甲醇转化率为100%情况下,总低碳烯烃、乙烯和丙烯选择性分别为83.5%、 36.5%和36.0%,产物中 C₂~C₄烷烃以及 C₅₊选择性较低。     

Aromatization of FCC Gasoline Over Modified HZSM-5 Catalyst

Zinc and phosphorus incorporated HZSM-5 catalyst was prepared by adopting incipient wet co-impregnation (Zn-P/HZSM-5). Zn-P/HZSM-5 catalyst exhibited the lowest acidity but the highest aromatization activity with stable performance in the studied period of 16 hr. The process conditions on aromatization reaction and the coke deactivation mechanism of Zn-P/HZSM-5 catalyst were studied on a small-scale, fixed bed reactor using FCC naphtha (75-120°C). The weight contents of ZnO and P₂O₅ were 2% and 4%, respectively. Results showed that Zn-P/HZSM-5 catalyst under a temperature of 450°C, liquid hourly space velocity of 1.0 h^-1, and pressure of 0.1 MPa, the conversions of olefins and alkanes are 96.77% and 88.94%, respectively, the contents of olefins, aromatics in liquid product are 6.79% and 74.57%, respectively. Carbon deposition was the major reason for catalyst deactivation due to the catalyst's good performance as a fresh catalyst after regeneration. All of the blending products fitted the standards of Chinese gasoline.     

非临氢降凝ZSM-5分子筛催化剂的失活原因探讨

利用XRD、IR、TG—DTA、NH3-TPD、BET、N2吸附等技术,测试和表征新鲜的、失活的和再生后工业非临氢降凝ZSM-5分子筛催化剂的性能,并对上述几种催化剂进行活性评价,找出该催化剂失活的主要原因。经研究发现,非临氢降凝催化剂主要失活原因是积炭和原料杂质中毒,并由此引起催化剂比表面和孔隙率的变化;其中,积炭和有机硫、氮化合物的中毒使催化剂暂时失活,而重金属中毒使催化剂永久失活。探讨了在实验室利用马弗炉焙烧法对催化剂进行再生的过程,并由此提出了再生温度是影响催化剂烧炭、烧硫、烧氮过程以及再生后催化剂性能的主要因素。     

Aromatization of FCC Gasoline Over Modified HZSM-5 Catalyst

Abstract

Zinc and phosphorus incorporated HZSM-5 catalyst was prepared by adopting incipient wet co-impregnation (Zn-P/HZSM-5). Zn-P/HZSM-5 catalyst exhibited the lowest acidity but the highest aromatization activity with stable performance in the studied period of 16 hr. The process conditions on aromatization reaction and the coke deactivation mechanism of Zn-P/HZSM-5 catalyst were studied on a small-scale, fixed bed reactor using FCC naphtha (75–120°C). The weight contents of ZnO and P₂O₅ were 2% and 4%, respectively. Results showed that Zn-P/HZSM-5 catalyst under a temperature of 450°C, liquid hourly space velocity of 1.0 h^?1, and pressure of 0.1 MPa, the conversions of olefins and alkanes are 96.77% and 88.94%, respectively, the contents of olefins, aromatics in liquid product are 6.79% and 74.57%, respectively. Carbon deposition was the major reason for catalyst deactivation due to the catalyst's good performance as a fresh catalyst after regeneration. All of the blending products fitted the standards of Chinese gasoline.     

氧对丙烷在Ga／HZSM－5上催化芳构化影响的研究

利用连续和脉冲反应技术，考察了添加少量氧对丙烷在Ｇａ／ＨＺＳＭ－５上催化芳构化的影响。试验结果表明，氧的存在对丙烷转化为芳烃ＢＴＸ不利。通过进一步条件试验，对氧的作用进行了分析讨论，认为这与催化剂中活性组份镓的存在直接相关。     

ZSM－5沸石上合成甲胺的研究

在常压固定床反应器上研究以ＨＺＳＭ－５和ＺＳＭ－５为催化剂的甲胺合成反应。结果表明，ＺＳＭ－５催化剂有明显的择形催化作用，能有效的抑制三甲胺的生成，并有较高的活性。经Ｐ改性后的ＰＺＳＭ－５对三甲胺有更强的抑制作用。催化剂的吸附等温线给果表明，Ｐ的掺入使ＺＳＭ－５的孔道变窄，增加了吸附氨和一甲胺的酸性位，减少了吸附二甲胺和三甲胺的酸性位，从而有效的抑制了三甲胺的生成。     

Kinetic Modeling of MTO Process Applying ZSM-5 Zeolite Modified With Phosphorus as the Reaction Catalyst

In the present study, a number of phosphorus modified HZSM-5(Si/Al = 250) zeolite as MTO catalyst were prepared and characterized by various methods. A kinetic model for MTO process over PZSM-5 catalyst was developed based on data obtained from a differential fixed bed reactor within the temperature range of 360–425°C and 1 bar pressure applying the Langmuir-Hinshelwood formulation. The kinetic parameters were evaluated from the experimental data using genetic algorithm. It was found that the predicted data from the model were well correlated with the experimental results, indicating that ethylene and propylene are primary olefins.     

轻质烃在双功能ZnNi/HZSM-5催化剂上的芳构化

考察了混合碳四烃、石油液化气和正己烷在双功能ZnNi/HZSM -5催化剂上的芳构化 ,同时首次将微波辐射技术应用到芳构化中 ,并分别研究了混合碳四烃和正己烷在两种加热方式下的芳构化催化行为     

ZSM-5分子筛催化下乙醇转化为液相烃

以ZSM-5,H-ZSM-5,Zn-ZSM-5为催化剂,在280～450℃范围内,乙醇在固定床反应器上转化为气相烃、液相烃和水。液相烃经GC-MS检测,主要成分是C5～9烯烃、C4～7烷烃和C6～11芳烃。实验结果表明,ZSM-5催化剂上,温度为425℃时,苯和甲苯选择性最大,分别为5.94%和24.81%;温度为450℃时,二甲苯选择性最大,为33.21%。Zn-ZSM-5催化剂上,温度为380℃时,苯和二甲苯选择性最大,分别为5.99%和37.89%;温度为450℃时,甲苯选择性最大,为24.45%。H-ZSM-5催化剂上,温度为380℃时,苯和甲苯选择性最大,分别为7.08%和27.60%;温度为450℃时,二甲苯选择性最大,为30.23%。硅铝比和反应温度对液相烃收率有显著影响,反应温度一定时,随硅铝比的增大,液相烃收率减小;硅铝比一定时,随反应温度的升高,液相烃收率先增大后减小。硅铝比为25时,ZSM-5和Zn-ZSM-5催化剂上,320℃下液相烃收率最大,分别为17.7%和13.8%;H-ZSM-5催化剂上,380℃下液相烃收率最大,为16.3%。     

催化裂化汽油馏分在P—Zn／HZSM-5催化剂上的芳构化

以50～100℃的FCC汽油馏分为原料,在连续固定床反应器上考察了工艺条件对P-Zn／HZSM-5催化剂在芳构化反应中性能的影响。结果表明,在反应温度410℃、反应压力0．5MPa、液时空速1．0h^-1的操作条件下,液相产物中的烯烃、异构烷烃和芳烃的含量分别为8．56％,13．07％,73．39％。催化剂P-Zn／HZSM-5具有较好的芳构化降烯烃效果。     

The Aromatization of Different FCC Naphtha Fractions over a P-Zn/HZSM-5 Catalyst

Abstract

The aromatization reaction performance of P-Zn/HZSM-5 catalyst was investigated on a fixed bed reactor using five fluid catalytic cracked (FCC) gasoline fractions (<100°C, 50°C–100°C, <120°C, 75°C–120°C, and full fraction) as feedstock, and the effect of feedstock on aromatization is discussed. The results showed that the activity and stability of P-Zn/HZSM-5 catalyst for the aromatization of the 50°C–100°C fraction were high in definite reaction conditions. After 16 hr, the content of olefin and aromatics in liquid product were 5.23 and 79.9%, respectively. The liquid product of low olefin and high aromatics was obtained. The distribution of benzene, toluene, and xylene in liquid product of 50°C–100°C fraction was investigated during aromatization, and the result showed that the toluene content was maximum among the three aromatics contents, the benzene content was minimum at the beginning of the reaction, xylene content became maximum, and benzene was still minimum after reacting for 20 hr. The content of C₉ ⁺ aromatics increased at the first stage of the reaction and then decreased with the increasing reaction time.     

载体及反应条件对Pt/BaKL沸石催化剂芳构化性能的影响

研究了γ-Al_2O_3或SiO_2载体,以及反应条件对Pt/BaKL沸石催化剂芳构化性能的影响。发现经过碱化或负载Sn的γ-Al_2O_3作为载体,能够较好地保持该催化剂在正己烷芳构化反应中的高活性和高选择性,并有益于改善Pt/BaKL沸石催化剂的抗硫性能。     

在ZSM－5分子筛上引入Zn、Ga物种对乙烷芳构化的影响

报道了在Ｚｎ、Ｇａ改性的ＺＳＭ－５分子筛上进行乙烷芳构化与乙烯芳构化反应的结果，并考察了反应温度对Ｚｎ－ＺＳＭ－５催化剂乙烷芳构化性能的影响和催化剂Ｇａ－ＺＳＭ－５的焙烧时间对其性能的影响等。试验结果表明：（１）乙烷脱氢活化步骤是乙烷芳构化反应的控制步骤，Ｚｎ、Ｇａ物种对乙烷脱氢活化起着至关重要的作用，并且ｚｎ物种的作用大于Ｇａ物种。Ｚｎ、Ｇａ物种还能促进聚合环化物脱氢向芳烃转化：（２）升高反应温度对乙烷脱氢活化和聚合环化物脱氢有利，同时会使聚合环化物的裂解反应速度增加，因而在乙烷芳构化反应中存在最佳温度；（３）延长焙烧时间，有利于乙烷的活化及乙烯、Ｃ＿３等芳构化中间产物向芳烃的转化。