In this study,the deactivation mechanism caused by high accessibility of strong acid sites for the waste FCC catalyst was proposed and verified for the first time.Based on the proposed deactivation mechanism,magnesium...In this study,the deactivation mechanism caused by high accessibility of strong acid sites for the waste FCC catalyst was proposed and verified for the first time.Based on the proposed deactivation mechanism,magnesium modification through magnesium chloride impregnation was employed for the regeneration of waste FCC catalyst.The regenerated waste FCC catalyst was characterized,with its heavy oil catalytic cracking performance tested.The characterization results indicated that,in comparison with the unmodified waste FCC catalyst,the acid sites strength of the regenerated waste FCC catalyst was weakened,with no prominent alterations of the total acid sites quantity and textural properties.The heavy oil catalytic cracking results suggested that the catalytic cracking performance of the regenerated waste FCC catalyst was greatly improved due to the suitable surface acidity of the sample.In contrast with the unmodified waste FCC catalyst,the gasoline yield over the regenerated waste FCC catalyst significantly increased by 3.04 percentage points,meanwhile the yield of dry gas,LPG,coke and bottoms obviously decreased by 0.36,0.81,1.28 and 0.87 percentage points,respectively,making the regenerated waste FCC catalyst serve as a partial substitute for the fresh FCC catalyst.Finally,the acid property change mechanism was discussed.展开更多
The cracking of polyolefins, especially polyethylene in the molten state was effectively catalyzed by the powdery spent FCC (Fluid Catalytic Cracking) catalyst which was dispersed in it. The activation energy of the...The cracking of polyolefins, especially polyethylene in the molten state was effectively catalyzed by the powdery spent FCC (Fluid Catalytic Cracking) catalyst which was dispersed in it. The activation energy of the catalytic cracking of polyethylene was about 74 kJ/mol. The cracked product was naphtha and middle distillate as the major product and gaseous hydrocarbon (C1-C4) as the minor product while little heavy oil was produced. The chemical compositions of the product were: aromatic hydrocarbons, isoparaffins and branched olefins, whereas that of the non-catalyzed products were: n-olefins and n-paraffins with minor amount of dienes with increasing the process time. Additionally, the product pattern shifted from naphtha rich product to kerosene and gas-oil rich product. However, any catalytic product showed low fluid point (〈 -10 ℃), while that of the non-catalyzed product was as high as 40 ℃. Catalyst could process, more than 100 times by weight of polyethylene with fairly small amount (- 30 wt%) of coke deposition. Spent catalyst gave higher hydrocarbons while fresh catalyst gave gaseous product as the major product. Other polyolefins such as polypropylene and polystyrene were tested on same catalyst to show that their reactivity is higher than that of polyethylene and gave the aliphatic products, alkyl benzenes and C6-C9 iso-paraffins as the major product. Product pattern of the cracked product suggested that the reaction proceeded via the primary reactions making paraffins and olefins which were followed by the isomerization, secondary cracking, aromatization and hydrogen transfer which based on the carbenium ion mechanism.展开更多
Catalytic cracking is the main method to lighten heavy crude oil,this process can produce high quality oil products such as gasoline and diesel,but also produces a large amount of fluid catalytic cracking slurry(FCCS)...Catalytic cracking is the main method to lighten heavy crude oil,this process can produce high quality oil products such as gasoline and diesel,but also produces a large amount of fluid catalytic cracking slurry(FCCS).The catalyst particles in FCCS seriously restrict the secondary processing of FCCS and need to be removed,and the properties of Fccs is an important factor that affects the removal efficiency of the catalyst particles.Based on the"effective contact point"model proposed by the research group,this study further proposed the"electrostatic separation efficiency calculation"model.In this model,since Fccs has a uniform distribution of catalyst particles,the ratio of the number of catalyst particles can be expressed as the ratio of area to achieve the calculation of separation efficiency.Then the catalyst removal efficiency under different viscosity was analyzed,thus verifying the feasibility of this model.The effects of temperature and mass ratio of four components on the viscosity of FccS were investigated respectively,then the effects of temperature and four components'mass ratio on the electrostatic sep-aration can be directly converted into the effect of viscosity on the electrostatic separation efficiency.All the results show the electrostatic separation efficiency decreases with increasing viscosity,and the best separationtemperatureis120℃.展开更多
It is useful for practical operation to study the rules of production of propylene by the catalytic conversion of heavy oil in FCC (fluid catalytic cracking). The effects of temperature and C/O ratio (catalyst to o...It is useful for practical operation to study the rules of production of propylene by the catalytic conversion of heavy oil in FCC (fluid catalytic cracking). The effects of temperature and C/O ratio (catalyst to oil weight ratio) on the distribution of the product and the yield of propylene were investigated on a micro reactor unit with two model catalysts, namely ZSM-5/Al2O3 and USY/Al2O3, and Fushun vacuum gas oil (VGO) was used as the feedstock. The conversion of heavy oil over ZSM-5 catalyst can be comparable to that of USY catalyst at high temperature and high C/O ratio. The rate of conversion of heavy oil using the ZSM-5 equilibrium catalyst is lower compared with the USY equilibrium catalyst under the general FCC conditions and this can be attributed to the poor steam ability of the ZSM-5 equilibrium catalyst. The difference in pore topologies of USY and ZSM-5 is the reason why the principal products for the above two catalysts is different, namely gasoline and liquid petroleum gas (LPG), repspectively. So the LPG selectivity, especially the propylene selectivity, may decline if USY is added into the FCC catalyst for maximizing the production of propylene. Increasing the C/O ratio is the most economical method for the increase of LPG yield than the increase of the temperature of the two model catalysts, because the loss of light oil is less in the former case. There is an inverse correlation between HTC (hydrogen transfer coefficient) and the yield of propylene, and restricting the hydrogen transfer reaction is the more important measure in increasing the yield of propylene of the ZSM-5 catalyst. The ethylene yield of ZSM-5/A1203 is higher, but the gaseous side products with low value are not enhanced when ZSM-5 catalyst is used. Moreover, for LPG and the end products, dry gas and coke, their ranges of reaction conditions to which their yields are dependent are different, and that of end products is more severe than that of LPG. So it is clear that maximizing LPG and propylene and restricting dry gas and coke can be both achieved via increasing the severity of reaction conditions among the range of reaction conditions which LPG yield is sensitive to.展开更多
In this work, Zr-M(M=Cu, Mn, Ce) type sulfur transfer agent was prepared by impregnation method. Under the condition similar to that in the regenerator of FCC units, the influence of different active metal components ...In this work, Zr-M(M=Cu, Mn, Ce) type sulfur transfer agent was prepared by impregnation method. Under the condition similar to that in the regenerator of FCC units, the influence of different active metal components and their contents on sulfur transfer agent were investigated. Moreover, the crystalline structure of sulfur transfer agent was characterized by X-ray diffraction(XRD) and Fourier transforms infrared spectroscopy(FT-IR). The result showed that the Zr-Mn sulfur transfer agent could effectively reduce the SO2 content in FCC regenerator flue gas, featuring high SO2 adsorption capacity. The sulfur transfer agent was inactivated in 40—60 min during the test. In the course of reduction reaction, after several reaction cycles, the formation of SO2 ceased and only H2 S was detected as the reduction product.展开更多
The sulfur-reducing functional component the Lewis acid-base pair compound and associated active zeolite component were developed to prepare the RFCC catalyst DOS for reducing sulfur content in gasoline. The results o...The sulfur-reducing functional component the Lewis acid-base pair compound and associated active zeolite component were developed to prepare the RFCC catalyst DOS for reducing sulfur content in gasoline. The results of catalyst evaluation have revealed that the Lewis acid-base pair compound developed hereby could enhance the conversion of macromolecular sulfur compounds by the catalyst to promote the proceeding of desulfurization reactions, and the synergetic action of the selected zeolite and the Lewis acid-base pair compound could definitely reduce the olefins and sulfur contents in gasoline. The heavy oil conversion capability of the catalyst DOS thus developed was higher coupled with an enhanced resistance to heavy metals contamination to reduce the sulfur content in gasoline by over 20%. The commercial application of this catalyst at the SINOPEC Jiujiang Branch Company has revealed that compared to the GRV-C catalyst the oil slurry yield obtained by the catalyst DOS was reduced along with an improved coke selectivity, an increased total liquid yield, and a decreased olefin content in gasoline. The ratio of sulfur in gasoline/sulfur in feed oil could be reduced by 20.3 m%.展开更多
SINOPEC Research Institute of Petroleum Processing has developed a FCC catalyst to crack heavy oil feedstock to improve high-value products yield, and its commercial application has been conducted successfully in RFCC...SINOPEC Research Institute of Petroleum Processing has developed a FCC catalyst to crack heavy oil feedstock to improve high-value products yield, and its commercial application has been conducted successfully in RFCCU at SINOPEC Jingmen Branch Company. This catalyst has revealed its excellent bottoms crackability and coke selectivity. Commercial application tests showed that the slurry yield decreased by 2.84%, and the coke make dropped by 0.64%, with the total yield of LPG, gasoline and diesel increased by 3.99%.展开更多
A mathematical model has been developed for the simulation of gas-particle flow and fluid catalytic cracking in downer reactors. The model takes into account both cracking reaction and flow behavior through a four-lum...A mathematical model has been developed for the simulation of gas-particle flow and fluid catalytic cracking in downer reactors. The model takes into account both cracking reaction and flow behavior through a four-lump reaction kinetics coupled with two-phase turbulent flow. The prediction results show that the relatively large change of gas velocity affects directly the axial distribution of solids velocity and void fraction, which significantly interact with the chemical reaction. Furthermore, model simulations are carried out to determine the effects of such parameters on product yields, as bed diameter, reaction temperature and the ratio of catalyst to oil, which are helpful for optimizing the yields of desired products. The model equations are coded and solved on CFX4.4.展开更多
基金supported by the Exploratory Research Program of Petrochemical Research Institute (16-yk-01-03),PetroChina
文摘In this study,the deactivation mechanism caused by high accessibility of strong acid sites for the waste FCC catalyst was proposed and verified for the first time.Based on the proposed deactivation mechanism,magnesium modification through magnesium chloride impregnation was employed for the regeneration of waste FCC catalyst.The regenerated waste FCC catalyst was characterized,with its heavy oil catalytic cracking performance tested.The characterization results indicated that,in comparison with the unmodified waste FCC catalyst,the acid sites strength of the regenerated waste FCC catalyst was weakened,with no prominent alterations of the total acid sites quantity and textural properties.The heavy oil catalytic cracking results suggested that the catalytic cracking performance of the regenerated waste FCC catalyst was greatly improved due to the suitable surface acidity of the sample.In contrast with the unmodified waste FCC catalyst,the gasoline yield over the regenerated waste FCC catalyst significantly increased by 3.04 percentage points,meanwhile the yield of dry gas,LPG,coke and bottoms obviously decreased by 0.36,0.81,1.28 and 0.87 percentage points,respectively,making the regenerated waste FCC catalyst serve as a partial substitute for the fresh FCC catalyst.Finally,the acid property change mechanism was discussed.
文摘The cracking of polyolefins, especially polyethylene in the molten state was effectively catalyzed by the powdery spent FCC (Fluid Catalytic Cracking) catalyst which was dispersed in it. The activation energy of the catalytic cracking of polyethylene was about 74 kJ/mol. The cracked product was naphtha and middle distillate as the major product and gaseous hydrocarbon (C1-C4) as the minor product while little heavy oil was produced. The chemical compositions of the product were: aromatic hydrocarbons, isoparaffins and branched olefins, whereas that of the non-catalyzed products were: n-olefins and n-paraffins with minor amount of dienes with increasing the process time. Additionally, the product pattern shifted from naphtha rich product to kerosene and gas-oil rich product. However, any catalytic product showed low fluid point (〈 -10 ℃), while that of the non-catalyzed product was as high as 40 ℃. Catalyst could process, more than 100 times by weight of polyethylene with fairly small amount (- 30 wt%) of coke deposition. Spent catalyst gave higher hydrocarbons while fresh catalyst gave gaseous product as the major product. Other polyolefins such as polypropylene and polystyrene were tested on same catalyst to show that their reactivity is higher than that of polyethylene and gave the aliphatic products, alkyl benzenes and C6-C9 iso-paraffins as the major product. Product pattern of the cracked product suggested that the reaction proceeded via the primary reactions making paraffins and olefins which were followed by the isomerization, secondary cracking, aromatization and hydrogen transfer which based on the carbenium ion mechanism.
基金supported by the[Natural Science Foundation Project of Shandong Province#1]under Grant[ZR2019MEE033][Fundamental Research Funds for the central Universities#2]under Grant[19CX02035A].
文摘Catalytic cracking is the main method to lighten heavy crude oil,this process can produce high quality oil products such as gasoline and diesel,but also produces a large amount of fluid catalytic cracking slurry(FCCS).The catalyst particles in FCCS seriously restrict the secondary processing of FCCS and need to be removed,and the properties of Fccs is an important factor that affects the removal efficiency of the catalyst particles.Based on the"effective contact point"model proposed by the research group,this study further proposed the"electrostatic separation efficiency calculation"model.In this model,since Fccs has a uniform distribution of catalyst particles,the ratio of the number of catalyst particles can be expressed as the ratio of area to achieve the calculation of separation efficiency.Then the catalyst removal efficiency under different viscosity was analyzed,thus verifying the feasibility of this model.The effects of temperature and mass ratio of four components on the viscosity of FccS were investigated respectively,then the effects of temperature and four components'mass ratio on the electrostatic sep-aration can be directly converted into the effect of viscosity on the electrostatic separation efficiency.All the results show the electrostatic separation efficiency decreases with increasing viscosity,and the best separationtemperatureis120℃.
文摘It is useful for practical operation to study the rules of production of propylene by the catalytic conversion of heavy oil in FCC (fluid catalytic cracking). The effects of temperature and C/O ratio (catalyst to oil weight ratio) on the distribution of the product and the yield of propylene were investigated on a micro reactor unit with two model catalysts, namely ZSM-5/Al2O3 and USY/Al2O3, and Fushun vacuum gas oil (VGO) was used as the feedstock. The conversion of heavy oil over ZSM-5 catalyst can be comparable to that of USY catalyst at high temperature and high C/O ratio. The rate of conversion of heavy oil using the ZSM-5 equilibrium catalyst is lower compared with the USY equilibrium catalyst under the general FCC conditions and this can be attributed to the poor steam ability of the ZSM-5 equilibrium catalyst. The difference in pore topologies of USY and ZSM-5 is the reason why the principal products for the above two catalysts is different, namely gasoline and liquid petroleum gas (LPG), repspectively. So the LPG selectivity, especially the propylene selectivity, may decline if USY is added into the FCC catalyst for maximizing the production of propylene. Increasing the C/O ratio is the most economical method for the increase of LPG yield than the increase of the temperature of the two model catalysts, because the loss of light oil is less in the former case. There is an inverse correlation between HTC (hydrogen transfer coefficient) and the yield of propylene, and restricting the hydrogen transfer reaction is the more important measure in increasing the yield of propylene of the ZSM-5 catalyst. The ethylene yield of ZSM-5/A1203 is higher, but the gaseous side products with low value are not enhanced when ZSM-5 catalyst is used. Moreover, for LPG and the end products, dry gas and coke, their ranges of reaction conditions to which their yields are dependent are different, and that of end products is more severe than that of LPG. So it is clear that maximizing LPG and propylene and restricting dry gas and coke can be both achieved via increasing the severity of reaction conditions among the range of reaction conditions which LPG yield is sensitive to.
基金supported by the research fund of the National Natural Science Foundation of China (21306162)the National Basic Research Program "973" Project of China (2010CB226903)Key Laboratory for Advanced Technology in Environmental Protection of Jiangsu Province (AE201309)
文摘In this work, Zr-M(M=Cu, Mn, Ce) type sulfur transfer agent was prepared by impregnation method. Under the condition similar to that in the regenerator of FCC units, the influence of different active metal components and their contents on sulfur transfer agent were investigated. Moreover, the crystalline structure of sulfur transfer agent was characterized by X-ray diffraction(XRD) and Fourier transforms infrared spectroscopy(FT-IR). The result showed that the Zr-Mn sulfur transfer agent could effectively reduce the SO2 content in FCC regenerator flue gas, featuring high SO2 adsorption capacity. The sulfur transfer agent was inactivated in 40—60 min during the test. In the course of reduction reaction, after several reaction cycles, the formation of SO2 ceased and only H2 S was detected as the reduction product.
文摘The sulfur-reducing functional component the Lewis acid-base pair compound and associated active zeolite component were developed to prepare the RFCC catalyst DOS for reducing sulfur content in gasoline. The results of catalyst evaluation have revealed that the Lewis acid-base pair compound developed hereby could enhance the conversion of macromolecular sulfur compounds by the catalyst to promote the proceeding of desulfurization reactions, and the synergetic action of the selected zeolite and the Lewis acid-base pair compound could definitely reduce the olefins and sulfur contents in gasoline. The heavy oil conversion capability of the catalyst DOS thus developed was higher coupled with an enhanced resistance to heavy metals contamination to reduce the sulfur content in gasoline by over 20%. The commercial application of this catalyst at the SINOPEC Jiujiang Branch Company has revealed that compared to the GRV-C catalyst the oil slurry yield obtained by the catalyst DOS was reduced along with an improved coke selectivity, an increased total liquid yield, and a decreased olefin content in gasoline. The ratio of sulfur in gasoline/sulfur in feed oil could be reduced by 20.3 m%.
文摘SINOPEC Research Institute of Petroleum Processing has developed a FCC catalyst to crack heavy oil feedstock to improve high-value products yield, and its commercial application has been conducted successfully in RFCCU at SINOPEC Jingmen Branch Company. This catalyst has revealed its excellent bottoms crackability and coke selectivity. Commercial application tests showed that the slurry yield decreased by 2.84%, and the coke make dropped by 0.64%, with the total yield of LPG, gasoline and diesel increased by 3.99%.
基金the Natura Science Foundation of China under contract number:20176024
文摘A mathematical model has been developed for the simulation of gas-particle flow and fluid catalytic cracking in downer reactors. The model takes into account both cracking reaction and flow behavior through a four-lump reaction kinetics coupled with two-phase turbulent flow. The prediction results show that the relatively large change of gas velocity affects directly the axial distribution of solids velocity and void fraction, which significantly interact with the chemical reaction. Furthermore, model simulations are carried out to determine the effects of such parameters on product yields, as bed diameter, reaction temperature and the ratio of catalyst to oil, which are helpful for optimizing the yields of desired products. The model equations are coded and solved on CFX4.4.