Catalyst grading technology for promoting the diesel hydrocracking to naphtha

This paper reports the application of multi-component hydrocracking catalyst grading technology in diesel hydrocracking system to increase naphtha,and studies the influence of catalyst systems with different number of graded beds on the reaction process of diesel hydrocracking.Three hydrocracking catalysts with different physicochemical properties as gradation components,the diesel hydrocracking reaction on catalyst systems of one-component,two-component and three-component graded beds with different loading sequences are carried out and evaluated,respectively.The catalytic mechanism of the multi-component grading system is analyzed.The results show that,with the increase of the number of grading beds,the space velocity of reaction on each catalyst increases,which can effectively control the overreaction process;along the flow direction of feedstock,the loading sequences of catalysts with acidity decreasing and pore properties increasing can satisfy the demand of different catalytic activity for the conversion of reactant with changing composition to naphtha,which has a guiding role in the conversion of feedstock to target products.Therefore,the conversion of diesel,the selectivity and yield of naphtha all increase significantly on the multi-component catalyst system.The research on the grading technology of multi-component catalysts is of great significance to the promotion and application of catalyst systems in various catalytic fields.

Application of Acid Modified Catalysts with Different SiO_(2) Contents in the Hydrocracking of Light Cycle Oil for Light Aromatics Production

A series of functionalized USY/SiO_(2) zeolite composite supports were synthesized using the coating coprecipitation method,with tetraethyl orthosilicate(TEOS)as the silicon source and different ratios of USY to TEOS.Active metals nickel(Ni)and molybdenum(Mo)were loaded onto the supports using the impregnation method.Finally,a series of hydrogenation catalysts were synthesized.The characterization results showed that,compared with the USY catalyst,the addition of a certain quantity of SiO_(2) resulted in the disappearance of the strong acid sites on the catalyst,the number of weak acid and medium strong acid sites decreased,and a certain number of secondary mesoporous structures were formed.The addition of SiO_(2) reduced the secondary cracking of benzene,toluene,xylene,and ethylbenzene(BTXE)effectively,while excessive amounts of SiO_(2) reduced the hydrogenation activity of the catalyst,leading to a decline in the final yield of BTXE.At a maximum SiO_(2) content of 45%,the hydrogenation depth of light cycle oil(LCO)reached an optimum value.The hydrogenation performance of LCO was investigated in a fixed bed reactor at 380℃,4 MPa,and H2/oil volume ratio of 800:1,where the gasoline and diesel fractions reached 80.00%and 16.74%,respectively.NiMo-YS45 had the highest BTXE selectivity,and the final yield of BTXE reached 21.27%.

Development and Performance Evaluation of Catalyst for Productive Ethylene Cracking Feedstock in Selective Hydrocracking of Straight Run Diesel Oil

The upgrading of diesel oil to produce ethylene rich cracking feedstock is an important and promising technical route to reduce the ratio of diesel to gasoline. In the present work, a hydrocracking catalyst suitable for selective hydrocracking of straight run diesel oil to produce high-quality ethylene cracking feedstock at low cost was developed, by optimizing the composition of catalyst support materials, using amorphous silicon aluminum and aluminum oxide with high mesopore content as the main support, and modified Y zeolite with excellent aromatic ring opening selectivity as the acidic component. The catalyst has in-depth characterized by X-ray diffraction, transmission electron microscopy, scanning electron microscopy, N2-low temperature adsorption-desorption, NH3-temperature-programmed desorption, and IR techniques. And its catalytic cracking straight run diesel oil performance was evaluated. The results show that the prepared catalyst has high polycyclic aromatic hydrocarbon ring opening cracking selectivity. However, alkanes retained in diesel distillates can achieve the goal of producing more ethylene cracking feedstocks with low BMCI value under low and moderate pressure conditions. This work may shed significant technical insight for oil refining transformation.

Effect of Catalyst Properties on Hydrocracking of Pyrolytic Lignin to Liquid Fuel in Supercritical Ethanol

The metal-acid bifunctional catalysts have been used for bio-oil upgrading and pyrolytic lignin hydrocracking. In this work, the effects of the metal-acid bifunctional catalyst prop- erties, including acidity, pore size and supported metal on hydrocracking of pyrolytic lignin in supercritical ethanol and hydrogen were investigated at 260 ℃. A series of catalysts were prepared and characterized by BET, XRD, and NHa-TPD techniques. The results showed that enhancing the acidity of the catalyst without metal can promote pyrolytic lignin poly- merization to form more solid and condensation to produce more water. The pore size of microporous catalyst was smaller than mesoporous catalyst. Together with strong acid- ity, it caused pyrolytic lignin further hydrocrack to numerous gas. Introducing Ru into acidic catalysts promoted pyrolytic lignin hydrocracking and inhibited the polymerization and condensation, which caused the yield of pyrolytic lignin liquefaction product to increase significantly. Therefore, bifunctional catalyst with high hydrocracking activity metal Ru supported on materials with acidic sites and mesopores was imperative to get satisfactory results for the conversion of pyrolytic lignin to liquid products under supercritical conditions and hydrogen atmosphere.

Selective hydrocracking of light cycle oil into high-octane gasoline over bi-functional catalysts

Light cycle oil(LCO) with high content of poly-aromatics was difficult to upgrade and convert,which had hindered upgrading fuel quality to meet with the standard of automotive diesel for the purpose of sustainable development.The hydrocracking behaviors of typical aromatics in LCO of naphthalene and tetralin were investigated over NiMo and CoMo catalysts.Several characterization methods including N2-adsoprtion and desorption,ammonia temperature-programmed desorption(NH3-TPD),Pyridine infrared spectroscopy(Py-IR),CO infrared spectroscopy(CO-IR),Raman and X-ray photoelectron spectroscopy(XPS) were applied to determine the properties of different catalysts.The results showed that CoMo catalyst with high concentration of S-edges could hydrosaturate more naphthalene to tetralin but exhibit lower yield of high-value light aromatics(carbon numbers less than 10) than NiMo catalyst.NiMo catalyst with high concentration of Mo-edges also presented a higher selectivity of converting naphthalene into cyclanes than CoMo catalyst.Subsequently,the naphthalene and LCO hydrocracking performances were also investigated over different catalysts systems.The activity evaluation and kinetic analysis results showed that the naphthalene hydrocracking conversion and the yield of light aromatics for CoMo-AY/NiMo-AY grading catalysts were higher than NiMo-AY/CoMo-AY grading catalysts at same condition.A stepwise reaction principle was proposed to explain the high efficiency of CoMo-AY/NiMoAY grading catalysts.Finally,the LCO hydrocracking evaluation results confirmed that CoMo-AY/NiMoAY catalysts grading system with low carbon deposition and high stability could remain high percentage of active phases,which was more efficient to convert LCO to high-octane gasoline.

Hydrocracking diversity in n-dodecane isomerization on Pt/ZSM-22 and Pt/ZSM-23 catalysts and their catalytic performance for hydrodewaxing of lube base oil

Nobel metallic Pt/ZSM-22 and Pt/ZSM-23 catalysts were prepared for hydroisomerization of normal dodecane and hydrodewaxing of heavy waxy lube base oil.The hydroisomerization performance of n-dodecane indicated that the Pt/ZSM-23 catalyst preferred to crack the C-C bond near the middle of n-dodecane chain,while the Pt/ZSM-22 catalyst was favorable for breaking the carbon chain near the end of n-dodecane.As a result,more than 2%of light products(gas plus naphtha)and3%more of heavy lube base oil with low-pour point and high viscosity index were produced on Pt/ZSM-22 than those on Pt/ZSM-23 while using the heavy waxy vacuum distillate oil as feedstock.

Development and Application of Hydrocracking Catalysts RHC-1/RHC-5 for Maximizing High Quality Chemical Raw Materials Yield

To adapt to the change in the demand of the oil refining market,two hydrocracking catalysts,RHC-1 and RHC-5,were developed to improve the quality of tail oil.The catalysts were designed based on the theory of selective ring-opening.By selecting more acidic molecular sieves,the problem of poor selectivity of conventional materials can be solved to properly match up to the hydrogenation performance of catalysts.Compared with the performance of previous catalysts,the quality of the tail oil achieved by the said catalysts is better,and the BMCI is reduced by 1—2 units.In the long cycle operation of the petroleum industry,the good quality of the tail oil has been verified and the adaptability of the process conditions is good.When the RHC-1 catalyst is used to process heavy feed under medium pressure,a BMCI value of about12 can be obtained along with a nearly 60%yield of tail oil.The total yield of chemical raw material(steaming cracking feed+catalytic reforming feed)can exceed 80%,and the hydrogen consumption has dropped by nearly 50%as compared to the conventional hydrocracking conversion rate.When processing a mixed CGO and VGO feed with the full conversion mode under a hydrogen pressure of 13.0 MPa,the RHC-5 catalyst can yield about 68.4%of heavy naphtha with a potential aromatic content of up to 50.6,while the total yield of chemical raw materials can reach more than 98%.The results of industrial application of these catalysts show that more than 30%of high quality tail oil can be obtained via processing of inferior quality feed,and its BMCI value can reach 10.7.The total yield of chemical raw materials can reach more than65%.The industrial operation process has implemented two operating cycles totaling 8 years.

Effect of preparation methods on the hydrocracking performance of NiMo/Al_(2)O_(3) catalysts

In this work,NiMo catalysts with various contents of MoO_(3)were prepared through incipient wetness impregnation by a twostep method(NMxA)and onepot method(NMxB).The catalysts were then characterized by XRD,XPS,NH3TPD,H_(2)TPR,HRTEM,and N_(2)adsorptiondesorption technologies.The performance of the NiMo/Al_(2)O_(3) catalysts was investigated by hydrocracking lowtemperature coal tar.When the MoO3 content was 15 wt%,the interaction between Ni species and Al_(2)O_(3) on the NM15B catalyst was stronger than that on the NM15A catalyst,resulting in the poor performance of the former.When the MoO^(3) content was 20 wt%,MoO_(3) agglomerated on the surface of the NM20A catalyst,leading to decreased number of active sites and specific surface area and reduced catalytic performance.The increase in the number of MoS_(2) stack layers strengthened the interaction between Ni and Mo species of the NM20B catalyst and consequently improved its catalytic performance.When the MoO_(3) content reached 25 wt%,the active metals agglomerated on the surface of the NiMo catalysts,thereby directly decreasing the number of active sites.In conclusion,the twostep method is suitable for preparing catalysts with large pore diameter and low MoO_(3) content loading,and the onepot method is more appropriate for preparing catalysts with large specific surface area and high MoO_(3) content.Moreover,the NMxA catalysts had larger average pore diameter than the NMxB catalysts and exhibited improved desulfurization performance.

Development of Hydrocracking Catalyst to Produce High Quality Clean Middle Distillates

A novel hydrocracking Ni-W binary catalyst was tentatively designed and prepared by means ofimpregnation on mixed supports of modified Y zeolite and amorphous aluminosilicate . The structure andproperties of catalyst were extensively characterized by XRD, NH3-TPD, IR and XRF techniques. The perfor-mance of catalyst was evaluated by a 100-ml hydrogenation laboratory test unit with two single-stage fixed-bedreactors connected in series. The characterization results showed that the catalyst has a developed and con-centrated mesopores distribution, suitable acid sites and acid strength distribution, and uniform and highdispersion of metal sites. Under a high conversion rate of 73.8% with the >350℃ feedstock, a 98.1m% of C5+yield and 83.5% of middle distillates selectivity were obtained. The yield of middle distillates boiling between140℃and 370℃ was 68.70m% and its quality could meet the WWFC category III specification. It means thatthis catalyst could be used to produce more high quality clean middle distillates derived from heavy oilhydrocracking. The potential aromatic content of heavy naphtha from 65℃ to 140℃ was 37.5m%. The BMCIvalue of >370℃ tail oil was 6.6. The heavy naphtha and tail oil are premium feedstocks for catalytic reformingand steam cracker units.

Mo supported on natural rectorite catalyst for slurry-phase hydrocracking of vacuum residue:An effect of calcination

In order to develop high-efficiency and low-cost catalyst for the slurry-phase hydrocracking of vacuum residue(VR),the catalyst supported on natural rectorite was prepared,and the effect of calcination modification of rectorite on the catalyst properties and performance was investigated.The support of rectorite and catalyst were characterized by XRD,FTIR,Py-FTIR,H_(2)-TPR and XPS to examine their structures and properties.The comparative reaction results show that VR conversions for the catalysts supported on calcined rectorite were similar with that on raw rectorite,possibly due to the VR cracking reaction controlled by the thermal cracking following free radical mechanism because of few acid sites observed on the catalysts surface.However,the yields of naphtha and middle distillates for the various catalysts were obviously different,and increased following as Rec-Mo(40.4 wt%)

Study on Performance of Hydrocracking Catalyst CHC-1

Evaluation of hydrocracking catalyst CHC-1 showed superior qualities ofcatalyst CMC-1. When it was used for hydrocracking reaction, the yield of middle distillates (jetfuel and diesel fuel) can reach more than 71 m%. When it was used for medium-pressurehydro-upgrading of Daqing FCC diesel fuel, diesel density was decreased by 0.0284―0.0365 g/cm^3(20℃). Cetane number increased by 7.8―10.5 and the contents of sulphur and nitrogen wereremarkably reduced. The storage stability of the upgraded diesel was improved.

Preparation of the Natural Zeolite Based Catalyst for Hydrocracking Process of Petroleum Derived Atmospheric Residue

This research focused on preparation catalysts by natural zeolite for hydrocracking and to compare their catalytic reactivity with commercial catalyst. Clinoptilolite type natural zeolite of Tsagaantsav and paraffinic atmospheric residue of Tamsagbulag crude oil were used in this research. The Ni or Fe ion was loaded into the zeolite sample which was enriched and calcined previously, by ion exchange method. It is determined by X-ray diffraction analysis that structure of natural zeolite was not broken down during metal loading. The conversion of feedstock in hydrocracking, in with modified zeolite was used, was 22.5% higher than none catalytic process and 8.9% higher than commercial catalyst. It is proved that both of modified zeolite catalysts worked effectively as a catalyst in hydrocracking of atmospheric residue. Even so the contents of sulfur in middle and heavy fraction were 490 - 615 ppm, after hydrocracking with Ni/zeolite, Fe/zeolite catalysts. This result showed that the Ni/zeolite, Fe/zeolite catalysts were inactive at hydrodesulfurization, because the contents of sulfur in middle and heavy fraction were 370 - 478 ppmafter hydrocracking without catalyst. Process for sulfur removal is needed after hydrocracking with Ni/zeolite orFe/zeolite catalyst.

Preparation and Commercial Application of ZHC-01 Hydrocracking Catalyst

The ZHC-01 hydrocracking catalyst, characterized by high hydrogenation activity, good selectivity for middle distillates, strong resistance to nitrogen poisoning, was prepared by co-gelling. The catalyst is not only suited to the single-stage hydrocracking process, but also to the first stage of serial hydrocracking process. In parallel with the fully loaded operation of the 1.4 Mt/a hydrocracking unit at the SINOPEC Qilu Petrochemical Company, a pilot test of the ZHC-01 catalyst was also carried out on the hydrocracking unit. The test results indicated that the activity, the yield of major target products and quality of the ZHC-01 catalyst could comply with the design requirements for the hydrocracking unit, and this catalyst could be applied in the hydrocracking unit. The commercial test results showed that the ZHC-01 catalyst, featuring good activity, stability, and flexibility in production, not only could meet the demand for producing environmentally friendly middle distillates, but could also increase the resource of optimized steam cracking feedstock.

Hydrocracking of Goudron in the Presence of a Suspended Natural Catalyst

The main results of hydrocracking of goudron under reduced pressure in the presence of a suspended catalyst have beenanalyzed. It was investigate the influence of temperature to hydrocracking process of goudron. It was determined that with increasing of temperature from 400 ℃ to 440 ℃ （0.5 MPa pressure） the yield of light oil products increased from 31.39% to 61% mass.

Thoughts on the Development of High-pressure Hydrocracking Technology in China

The author makes a brief review of the history and the status quo of high pressure hydrocracking catalysts/processes development in China and gives out some thoughts and suggestions on the prospect of the said technology.

Application of Hydrocracking Process for Upgrading Tail Oil Quality in 1.0 Mt/a Hydrocracker Unit at SINOPEC Yangzi Petrochemical Company

This article focuses on the hydrocracking technology for upgrading the quality of tail oil and the first commercial application of the RN-32V/RHC- 1 catalysts in the 1.0 Mt/a hydrocracker at the Yangzi Petrochemical Company, which was started up successfully in September 2008. One month after start-up of the hydrocracking unit, an evaluation opera- tion has been conducted fbr assessing the catalysts performance. The technical calibration results showed that the RN- 32V/RHC-1 catalysts had high activity, and the product yield distribution was reasonable. The hydrocracker can provide abundant feedstocks for the downstream aromatic production unit and ethylene production unit.

Influence of Pressure to the Hydrocracking Process of Goudron in the Presence of a Modificated Suspended Halloysite

The main results of hydrocracking of goudron under reduced pressure in the presence of a suspended catalyst have been analyzed. It was investigated the influence of pressure to hydrocracking process of goudron. It was determined that with increasing from 0.5 to 4.0 MPa, the yield of light oil products increased from 47% to 58% mass.

NiW/介孔Y型分子筛催化剂上菲加氢裂化过程研究

为了实现对煤焦油中副产物多环芳烃菲的有效利用,采用等体积浸渍法制备了介孔Y型分子筛负载金属Ni、W催化剂,利用XRD、H2-TPR、BET、SEM-EDS对制备的催化剂进行表征分析,并在固定床反应器中考察催化剂上菲加氢裂化性能,探讨了反应过程中空速、气液比、温度、压力对催化剂积碳率、菲的转化率、液体收率及产物分布的影响.研究表明,增加空速和气液比会降低催化剂的积碳率,过高的反应温度会导致催化剂快速地积碳失活.通过定时采样对裂解产物分析得到菲在催化剂上的裂解率变化情况,同时也能反映出催化剂的稳定性.对反应过程条件优化得到的最优条件为:空速6 h^(-1),气液比750,温度400℃,压力6.5 MPa.此时,菲的裂解率可以稳定在99%以上,同时催化剂保持较高的稳定性,在4 h内未出现活性降低.

ZSM-5/USY/Beta分子筛催化剂对四氢萘加氢裂化制备BTEX的性能研究

分别采用ZSM-5、USY、Beta 3种分子筛通过等体积浸渍法制备了NiMo/ZSM-5、NiMo/USY、NiMo/Beta 3种催化剂,分别标记为cat-1、cat-2、cat-3。利用XRD、NH3-TPD、SEM对催化剂进行表征分析,在固定床反应器上以四氢萘作为模型化合物,研究其加氢裂化制备BTEX的催化性能,考察了四氢萘加氢裂化的工艺条件,并探讨了加氢裂化机理。结果表明,Beta分子筛制备的催化剂cat-3金属组分颗粒大小均匀,呈现出高度分散的状态,并且酸量适中。在反应温度为400℃、氢油比为600、反应压力为4MPa、2h-1空速的最佳反应条件下,与cat-1、cat-2相比,cat-3具有最佳的四氢萘转化率和BTEX选择性,分别高达95%和70%左右。