The Addition of ZSM-5 to a Fluid Catalytic Cracking Catalyst for Increasing Olefins in Fluid Catalytic Cracking Light Gas

Abstract

The second largest source of propylene supplied for petrochemical application is from fluid catalytic cracking (FCC) units. The primary function of the FCC unit has typically been to produce gasoline. However, refiners have been taking advantage of opportunity to produce and recover more propylene from their FCC unit by increasing reaction severity via riser temperature, adding shape selective catalyst, and installing a propylene recovery unit (PRU). At a conventional FCC process propylene exists in the off gas of FCC and it is about 6 wt% of off gas by changing the FCC process parameter quantity of propylene in off gas can be more than 20 wt% by using ZSM-5 additives and increasing temperature The effects of operating parameters, such as reaction temperature, and ZSM-5 as FCC catalyst additive, on the distribution of the product and the yield of propylene were investigated on a bench-scale fluidized bed reactor. It is the aim of this work to perform an overall analysis of the yields and selectivity of hydrocarbons obtained in the vacuum gas-oil conversion over FCC and ZSM-5 catalysts. The effectiveness of ZSM-5 additive in the FCC process was investigated by doing experimental work in a bench-scale setup. The experiment data of off gas analysis showed that vacuum gas oil cracking at high reaction temperatures of 450–550°C increases the yield of propylene. Similar behavior is observed with the addition of 10–25 wt% ZSM-5 additive. The combination of the two effects (high temperature and ZSM-5 addition) makes the FCC unit an excellent source of light olefins for downstream petrochemical units. Higher FCC reactor temperatures (600–650°C) would not have positive effects for increasing propylene yield.     

An upgraded bio-oil produced from sugarcane bagasse via the use of HZSM-5 zeolite catalyst

The pyrolysis upgrading of bio-oil from sugarcane bagasse (SB) using ZSM-5 zeolite catalyst was carried out in a fixed bed reactor to determine the effects of heating rate, temperature, and catalyst/biomass ratio on yield of bio-oil and their chemical compositions. Proximate analysis indicated that SB has 13.2% moisture content. The ultimate analysis carried out established that the percentage of carbon content is higher (48.2%) than oxygen content (44%) while the fibre content analysis showed 26.4% lignin, 33.3% cellulose, 30.1% hemicellulose. The heating rate, temperature and catalyst/biomass ratio were varied in the range of 10–50 °C/min, 400–600 °C and 0.05–0.25 respectively. The non-catalytic pyrolysis gave the maximum percentage yield (45.67 wt%) of bio-oil at a pyrolysis temperature of 600 °C, heating rate of 50 °C/min, sweeping gas flow rate of 40 mL/min and the catalytic pyrolysis gave 40.83 wt% of bio-oil at the same conditions. The FT-IR spectra showed that the non-catalytic bio-oil is dominated by oxygenated compounds (acids, ketones, aldehydes, alcohols), while the catalytic bio-oil had preponderances of desirable compounds (alkanes, alkenes, aromatics, phenols). The chemical composition of the bio-oils was analyzed using GC–MS, which revealed that the quality of the bio-oil has been improved using HZSM-5 catalyzed pyrolysis.     

Cyclohexane Dehydrogenation Using an Economical Iron Catalyst: Influence of Alumino-Silicate Structure on the Catalytic Activity

Abstract

The effect of mixing both local Egyptian hematitic ore and activated aluminosilicate material (bentonite clay) on the dehydrogenation activity of the former was studied.

Three mixtures were prepared in which bentonite percentages were 10, 20, and 40 wt%. Cyclohexane used as a model reactant for the catalytic dehydrogenation reaction carried out in catalytic flow system within reaction temperature ranged from 150 to 500°C in the presence of hydrogen stream (75 mL/min) and at constant space velocity 3.71 h^?1.

The results obtained indicated that in spite of the drop in the selectivity of the local material toward benzene formation by clay addition, a distinct increase in the benzene yield was observed. The maximum conversion attained ～28.14% at reaction temperature 500°C using a mixture containing 20 wt% activated bentonite.     

Catalytic co-cracking of waste polypropylene and residual fuel oil

Abstract

Industrial waste polypropylene (PP) homopolymer and residual fuel oil (RFO) were pyrolyzed together in presence of catalyst ZSM-5 under the atmospheric pressure with different mixing ratios of the feedstocks. The experiments were carried out in a batch reactor at two different temperatures of 500?°C and 600?°C with the blended mixture (PP/RFO) to catalyst (ZSM-5) ratio of 4:1. The effects of blending ratios between the two feedstocks and temperature with respect to the yield of the products oil, gas, and residual coke were determined. The optimum blending ratio of PP and RFO with respect the higher quantity yield of liquid product was found to be 1:1 at 500?°C. The percentages of liquid fuel, gas, and coke were observed to be 74.8%, 10.2%, and 15% at 500?°C.     

催化裂化C_4烃催化转化增产丙烯

在小型固定流化床实验装置上,考察了4种有代表性的催化裂化C4烃在普通催化裂化催化剂上增产丙烯的反应规律,并对普通催化剂以及加入助剂时丙烯收率的变化进行了初步探索。实验结果表明,C4烃在反应温度为400~600℃内的催化转化,主要遵循正碳离子反应机理,C4烃部分催化转化生成丙烯;C4烃中的烷烃几乎不参加反应;低温对异丁烯和正丁烯转化有利,高温对2-丁烯转化有利;异丁烯的最佳反应温度为450℃左右;加入质量分数10%的LCC-A增产丙烯助剂,丙烯收率和芳烃收率分别提高到10%左右。     

C4烃类裂解制烯烃技术开发

介绍中石化洛阳工程有限公司C4馏分催化裂解生产烯烃的工艺技术开发情况。在中型试验装置上对C4馏分催化裂解生产烯烃的工艺条件进行了考察,结果表明,在600～650℃的反应温度下,丁烷的转化率为33%～52%,丙烯+乙烯的选择性为25%～45%,甲烷的选择性为8%～19%;在570℃的反应温度下,丁烯的转化率及乙烯、丙烯的选择性均较高,丙烯+乙烯的单程收率达到48.38%;如果将未反应的烯烃及生成液体产物中的烯烃进行循环裂解,乙烯+丙烯的收率可高达69%;在600℃的反应温度下,丁烯裂解生成的汽油中,芳烃的质量分数为87.6%,三苯(苯、甲苯、二甲苯)的质量分数为67.59%。     

Process Simulation and Modeling of Fluidized Catalytic Cracker Performance in Crude Refinery

The simulation of fluidized catalytic cracking (FCC) process was performed using Aspen HYSYS. The effect of crude flow rate on naphtha flow, coke yield, and catalyst to oil ratio in FCC were simulated. The interaction effects of riser height, inlet crude flow rate and operating temperature on naphtha mass flow, catalyst to oil ratio, and coke yield were studied by Box-Behnken design. The maximum yield of naphtha (100000 kg/h) was obtained for FCC operating temperature within 520–600°C and riser height greater than 30 m. The catalyst to oil ratio of above 12 was obtained for operating temperature beyond 590°C for the entire riser height variation of 10 to 60 m in FCC. The increase in riser height resulted in increase production of naphtha, but beyond 60 m of riser height secondary cracking occurs resulting in reduction in yield of naphtha.     

Different outlet for preparing nano-TiO2 catalysts for the photodegradation of Black B dye in water

Two nano-titania catalysts were prepared using two economically varying titanium precursors: titanium tetrachloride (A) and titanium isopropoxide (B). The catalysts were calcined at temperatures of 500 °C, 600 °C and 700 °C and characterized using X-ray diffraction (XRD), electron diffraction (ED), BET surface properties and high resolution transmission microscopy (HRTEM). The calcined catalysts were found to differ markedly in their physical characters and TiO₂ phases produced as well as their photocatalytic activities. The anatase titania phase diminished from 100% to 83% in TiO₂A but from 64% to zero in TiO₂B via temperature increase from 500 °C to 700 °C, due to transforming anatase to rutile. The brookite TiO₂ phase only appeared (17%) in catalyst B500. In general, the catalyst of choice is A600 by virtue of many compositional, economical and catalytic advantages.     

A STUDY ON THE EFFECT OF PREPARATION PARAMETERS ON THE CATALYTIC PERFORMANCE AND ACTIVE COMPONENTS OF A NEW TYPE HYDRODESULFURIZATION CATALYST

ABSTRACT

The effects of the impregnating conditions on the contents of the active components of a new type hydrodesulfurization (HDS) catalyst have been studied by ICP technique in this paper. Meanwhile, the effects of the activation temperature, the activation time and the calcining temperature on the catalytic properties of the CoMo/(TiO₂ + Al₂O₃) catalyst have also been studied. The results show that at the given hygroscopicity of the support, the contents of the Co and the Mo, both of which are the active components of the catalyst, change linearly with the changes of the concentrations of the solvents in the impregnant. When the catalyst is impregnated at 40°C for 2 h, the contents of the active components reach the maximum values. The calcining temperature sharply affects the dispersed state of the active components on the surface of the support. When calcined at 500°C for 2 h, this HDS catalyst obtains the best catalytic activity. Even when the catalyst has been calcined at 600°C for 3 h, its activity is still good, which indicates that the heat resistance of this new type catalyst is satisfactory.     

SUPERCRITICAL AND CATALYTIC FLUID EXTRACTIONS OF TEA WASTES

Abstract

Air dried and ground tea waste was subjected to supercritical and catalytic fluid extraction by using water or acetone as solvent at different temperatures. The most important reactions variables were temperature and ratio of catalyst to the solid sample. The yields of the catalytic fluid reaction have been increased from 70.3 % to 92.4 % as the temperature increased from 230 °C to 340 °C by using water as solvent. The yield of extract was obtained from non catalytic supercritical water extraction was about 50.0 % at380°C.     

Stability of La-Zr-HZSM-5/Al2O3 zeolite catalysts in the conversion of dimethyl ether to lower olefins

The stability of the zeolite component and a La-Zr-HZSM-5/Al₂O₃ catalyst synthesized on its basis in the synthesis of lower olefins from dimethyl ether (DME) has been studied. It has been shown that both the zeolite component and the catalyst based on it exhibit highly stable catalytic properties. A high-temperature treatment of the zeolite component and the finished La-Zr-HZSM-5/Al₂O₃ catalyst with air and steam, respectively, leads to a significant increase in the catalyst selectivity for olefins, particularly propylene, while the activity in the DME conversion slightly decreases as the steaming temperature increases from 500 to 750°C.     

催化裂化C4烃组合回炼催化裂解增产丙烯研究

 在实验室小型提升管装置上研究了C4烃催化裂解增产丙烯的可行性以及C4烃与不同重质原料油组合进料时对干气收率的抑制。结果表明，反应温度和反应时间对C4烃裂解的影响较大，适宜的高温、短反应时间有利于C4烃催化裂解生产丙烯，降低干气、焦炭收率，降低氢转移反应，提高丙烯收率及选择性。当反应温度为600 ℃、反应时间为0.3 s时，C4烃单独反应的丙烯收率达到18.25％，干气收率在5.76％左右；在反应温度为600 ℃时，C4与重质油组合进料的丙烯收率可达13.05％~17.41％，干气收率下降至3.81％~5.28％。     

Comparative Evaluation of Catalysts Containing 0.35% Pt Supported on H-BEA Zeolite Dealuminated via EDTA,HCl Leaching,or Hydrothermally With Steam

Abstract

H-BEA was steamed at 500°C for 2 hr and then loaded with Pt to produce 0.35% Pt/St-H-BEA catalyst. Also, H-BEA was dealuminated with ethylenediamine tetraacetic acid (EDTA) and then loaded with Pt to produce 0.35% Pt/EDTA-H-BEA catalyst. Finally, H-BEA was dealuminated via HCl leaching followed by Pt loading to produce 0.35%Pt/HCl-H-BEA catalyst. These catalysts were reduced under H₂ flow at 500°C to give Pt metal. All catalysts were tested at 250°C–450°C for n-hexane hydroconversion. Maximum hydroisomerization of n-hexane was attained (75.1%) on 0.35% Pt/EDTA-H-BEA and 0.35% Pt/HCl-H-BEA catalysts but at 275°C on the former catalyst and at 300°C on the latter. At this temperature, n-hexane hydrocracking is only 1.2%. The hexane isomers selectivity on both catalysts was >99%. For the 0.35% Pt/St H-BEA catalyst, isohexanes yield and selectivity were lower than the above-mentioned catalysts. The catalyst of choice is 0.35% Pt/EDTA-H-BEA for its economic application at 275°C.     

Direct conversion of natural gas into COx-free hydrogen and MWCNTs over commercial Ni–Mo/Al2O3 catalyst: Effect of reaction parameters

A commercial hydrotreating nickel molybdate/alumina catalyst was used for the direct conversion of natural gas (NG) into CO_x-free hydrogen and a co-valuable product of multi-walled carbon nanotubes (MWCNTs). The catalytic runs were carried out atmospherically in a fixed-bed flow reactor. The effect of reaction temperature between 600 and 800 °C, and dilution of the NG feed with nitrogen as well as pretreatment of the catalyst with hydrogen were investigated. At a reaction temperature of 700 °C and dilution ratio of NG/N₂ = 20/30, the optimum yield of H₂ (～80%) was obtained with higher longevity. However, using the feed ratio of NG/N₂ = 30/20, the optimum yield of MWCNTs was obtained (669%). X-ray diffraction pattern for the catalyst after the reaction showed that the MWCNTs were grown on the catalyst at all reaction temperatures under study. TEM pictures revealed that the as-grown MWCNTs at 600, 650 and 800 °C are short and long with a low graphitization degree. At 700 °C a forest of condensed CNTs is formed, whereas both carbon nanofibers and CNTs were formed at 750 °C.     

LIQUEFACTION OF BEYPAZARI LIGNITE USING NiCl2-KCl-LiCl CATALYSTS. 1. DIFFERENCE IN SOLID AND MOLTEN SALT CATALYSIS

ABSTRACT

Liquefaction of Beypazan lignite in tetralin using NiCl₂-KCl-LiCl (14:36:50 molar percentages) as catalyst was investigated. Effects of the catalyst/lignite ratio and temperature were determined in experiments done at 275°C, 300°C and 360°C. Liquid products were separated into oils, asphaltenes and asphaltols by a solvent extraction method. Yield of liquefaction increased with temperature in all experiments, the highest yield was observed in experiments performed at the eutectic temperature of the catalyst mixture. The highest yields of oils were 20% and 30% with a catalyst/coal ratio of 0.5 at 275°C and 300°C, respectively. The activity of the catalyst increased in experiments in which the catalyst was molten. The yield of asphaltenes were not affected with increases in the catalyst/coal ratio in the experiments done at 275°C or 300°C in which the catalyst mixtures were in solid state. Asphaltene yields decreased from 25% to less than 5% with increasing values of catalyst/coal ratio and the asphaltol yields remained constant at 10% between catalyst/coal ratios of 0.25 and 1.00 and suddenly increased to 30% and 40% for catalyst/coal ratios of 1.50 and 2.00, respectively, at 360°C. The molecular weights of the oils decreased from 340 to a minimum value of 245 as the catalyst/coal ratio was increased from 0 to 1.00 in experiments done at 360°C where the catalyst was molten. As the catalyst/coal ratio was further increased from 1.00 to 2.00 the molecular weight increased to 310.It seemed that the N1Cl₂-KCl-LiCl catalyst mixture in all catalyst/coal ratios was more efficient in molten phase than it was used as a solid mixture.     

SAPO-34分子筛上丁烯催化裂解制乙烯和丙烯

以SAPO-34分子筛为催化剂,在固定流化床装置上研究了丁烯裂解的反应规律和结焦规律。实验结果表明,反应温度对丁烯裂解产物分布影响较大,丁烯转化率、乙烯和丙烯收率均随反应温度的升高而增加,乙烯和丙烯总选择性(双烯选择性)随反应温度的升高先增加后降低,适宜的反应温度为580～600℃;延长停留时间可提高丁烯转化率及乙烯和丙烯总收率(双烯收率),但停留时间过长会增加二次反应,降低乙烯、丙烯的选择性,尤其是丙烯;水蒸气对丁烯裂解有一定的促进作用,可使丙烯收率明显增加。与ZSM-5分子筛相比,SAPO-34分子筛的稳定性较差,但双烯选择性较高,在运行初期可获得与ZSM-5分子筛相当的双烯收率。SAPO-34分子筛催化丁烯裂解时,在运行初期及高温下生焦速率快,积碳显著影响SAPO-34分子筛的酸性。     

碳四烯烃催化裂解制低碳烯烃反应性能的研究

以ZSM-5分子筛为催化剂,1-丁烯为碳四烯烃模型化合物,考察温度对烯烃催化裂解制丙烯、乙烯反应性能的影响。结果表明,空速0.8h-1时,丙烯收率在580℃附近出现最大值,乙烯收率随温度升高而呈线性增加。同时,碳四烯烃催化裂解机理分析指出,丁烯裂解过程主要经历异构化、聚合、裂解的反应历程,并通过数据演算对机理网络进行了验证,取得了较好的一致性。     

Quasi-solid state synthesis of EU-1 zeolite and its catalytic properties for the isomerization of C8 aromatics

In this study,EU-1 zeolite was successfully synthesized via a quasi-solid state approach and assembled to catalyst for the C 8 aromatics isomerization process.The catalytic properties were tuned through careful modification of the acidity of EU-1 zeolites and metal-doping of the catalyst.It was shown that EU-1 was an excellent candidate for the C 8 aromatics isomerization process due to its unique structure.In addition,steam treatment of EU-1 at 450-500 ℃ could optimize the acidic properties of the catalyst,hence enhance its catalytic performance.The effect of the amount of Pt on ethylbenzene conversion was studied and the optimum amount was determined to be about 0.3-0.4 wt%.It was confirmed that EU-1 zeolite prepared via a quasi-solid state approach and then dealuminated by steam treatment had better activity and selectivity than conventional mordenite(MOR) zeolite and could be an excellent candidate for C 8 aromatics isomerization.     

两段提升管催化裂解多产乙烯丙烯新工艺的实验室研究

在小型提升管催化裂化实验装置上模拟两段提升管催化裂解多产乙烯丙烯新工艺,进行反应条件的研究。实验结果表明,以大庆常压渣油为原料,使用专用MEP催化剂,在反应温度为600～610℃、两段总停留时间为2.8s、水油比为20%、剂油比为10～12的条件下,同时进行丁烯回炼的情况下,利用该工艺乙烯和丙烯的产率分别为13.01%和29.94%。     

Synthesis and investigation of ZSM-5 zeolite-based catalysts for benzene alkylation with ethylene

A catalyst for alkylation of benzene with ethylene to ethylbenzene has been prepared by mixing 70% H⁺-ZSM-5 zeolite having a silica ratio of 30 with 30% pseudoboehmite followed by shaping granules, their drying, and calcining for 6 h at 650°C in air. A part of the catalyst has been treated by steaming with 100% steam at 600°C for 3 h. The physicochemical and catalytic properties of catalyst samples have been studied. The catalysts have been tested in a laboratory setup in the temperature interval of 380–450°C at 2.5MPa, a benzene space velocity of 15 h^?1, and a benzene/ethylene molar ratio of 7: 1. The properties of EBEMAX-1, an imported analogue of the catalysts have been studied under the same conditions. It has been found that the synthesized catalysts are not inferior to the imported sample in the catalytic properties.