A novel heavy oil catalytic cracking catalyst RCC-1 was developed by using the ultra-stable zeolite, which was hydrothermally treated and modified through cleaning its pores to serve as the active component. The chemi...A novel heavy oil catalytic cracking catalyst RCC-1 was developed by using the ultra-stable zeolite, which was hydrothermally treated and modified through cleaning its pores to serve as the active component. The chemical composition and physicochemical properties of RCC-1 catalyst were studied by XRF, BET, pore volume analysis, attrition index analysis, and particle size distribution determination methods, and its catalytic cracking performance was also evaluated by a microreactor for light oil cracking and the ACE device. The test results showed that the new type of heavy oil catalytic cracking catalyst RCC-1 had good physicochemical properties and heavy oil cracking ability, strong anti-metallic contamination capability, good product distribution, good coke selectivity and gasoline selectivity, and excellent reduction of gasoline olefin content characteristics.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
The acidic modulations of a series of HZSM-5 catalysts were successfully made by calcination at different treatment temperatures, i.e. 500, 600, 650, 700 and 800 ℃, respectively. The results indicated that the total ...The acidic modulations of a series of HZSM-5 catalysts were successfully made by calcination at different treatment temperatures, i.e. 500, 600, 650, 700 and 800 ℃, respectively. The results indicated that the total acid amounts, their density and the amount of B-type acid of HZSM-5 catalysts rapidly decreased, while the amounts of L-type acid had almost no change and thus the ratio of L/B was obviously enhanced with the increase of calcination temperature (excluding 800 ℃). The catalytic performances of modified HZSM-5 catalysts for the cracking of n-butane were also investigated. The main properties of these catalysts were characterized by means of XRD, N2 adsorption at low temperature, NH3-TPD, FTIR of pyridine adsorption and BET surface area measurements. The results showed that HZSM-5 zeolite pretreated at 800 ℃ had very low catalytic activity for n-butane cracking. In the calcination temperature range of 500-700 ℃, the total selectivity to olefins, propylene and butene were increased with the increase of calcination temperature, while, the selectivity for arene decreased with the calcination temperature. The HZSM-5 zeolite calcined at 700 ℃ produced light olefins with high yield, at the reaction temperature of 650 ℃ the yields of total olefins and ethylene were 52.8% and 29.4%, respectively. Besides, the more important role is that high calcination temperature treatment improved the duration stability of HZSM-5 zeolites. The effect of calcination temperature on the physico-chemical properties and catalytic performance of HZSM-5 for cracking of n-butane was explored. It was found that the calcination temperature had large effects on the surface area, crystallinity and acid properties of HZSM-5 catalyst, which further affected the catalytic performance for n-butane cracking.展开更多
A new type of zeolite La-USL (ultra stable zeolite L (zeolite USL) modified by La), which has superior activity, stability and selectivity in catalytic cracking of hydrocarbons and thus can be used as an active ca...A new type of zeolite La-USL (ultra stable zeolite L (zeolite USL) modified by La), which has superior activity, stability and selectivity in catalytic cracking of hydrocarbons and thus can be used as an active catalyst component, is reported in this paper. The zeolite L with relative crystallinity of above 90% was synthesized by the hydrothermal crystallization method under optimum conditions and characterized by means of XRD, NH3-TPD and isotherm adsorption techniques. The in-situ synthesized zeolite L with a SiO2/Al2O3 mole ratio of 5-6 was modified by cation ion exchange, hydrothermal dealumination and chemical modifications with La in order to prepare La-containing USL with a higher framework SiO2/Al2O3 mole ratio of 15-30. The modified zeolite La-USL was used as an active additive component of fluid catalytic cracking (FCC) catalyst and the resulting catalysts were evaluated by microactivity test (MAT) and fixed-fluidized bed (FFB) experiments using heavy oil as feedstock. The influence of La content in La- USL on cracking product distribution, gasoline group composition and research octane number (RON) was investigated. The results showed that when La content in La-USL was 0.8 wt%, the addition of the corresponding La-USL could result in a FCC catalyst that produced significant improvement in product distribution and gasoline quality.展开更多
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
A novel ultra-stable zeolite, NSZ, rich in secondary pores was developed through the combination of gas-phase andmild hydrothermal methods. This zeolite was successfully tested in an industrial setting for the first t...A novel ultra-stable zeolite, NSZ, rich in secondary pores was developed through the combination of gas-phase andmild hydrothermal methods. This zeolite was successfully tested in an industrial setting for the first time in the world. The porestructure characteristics of the NSZ zeolite prepared for industrial use were analyzed and characterized using BET. The resultsindicate a significant increase in the secondary pore volume of NSZ zeolite compared to the existing ultra-stable zeolite HSZ-5, which is produced through a conventional gas-phase method. The average secondary pore volume to total pore volume ratioin NSZ zeolite was found to be 58.96% higher. The catalytic cracking performance of NSZ zeolite was evaluated. The resultsshowed that the NSC-LTA catalyst, with NSZ as the active component, outperformed the HSC-LTA catalyst with HSZ-5 zeolitein terms of obtaining more high-value products (gasoline and liquefied petroleum gas) during the hydrogenated light cycle oilprocessing. Additionally, the NSC-LTA catalyst showed a significant improvement in coke selectivity.展开更多
The paper focuses on removing catalyst solids from oil slurry using 10 mm hydrocyclones, and aims to test the feasibility of the solution. An industrial sidetrack tester of residual oil separation by hydrocyclones was...The paper focuses on removing catalyst solids from oil slurry using 10 mm hydrocyclones, and aims to test the feasibility of the solution. An industrial sidetrack tester of residual oil separation by hydrocyclones was set up in 1.8 Mt/a resid fluid catalytic cracking (RFCC) unit, the effect of pressure drop, separation efficiency and inlet flowrate were studied. It was observed that an increase in feed flowrate will decrease the pressure drop ratio, and with an increase in feed flowrate, separation efficiency increases gradually. Under the condition that feed fiowrate was ranging from 250L/h to 270L/h, the separation efficiency was 45.77%-82.80%, the recovery rate of catalyst solid panicles was increased from 10 20% of electrostatic catalyst separator to 50 80%. Thus, it is feasible to separate the slurry by using the miniature hydrocyclones in RFCC unit.展开更多
This article elaborates on the research achievements of domestic and foreign researchers in exploring the conversion pathways and reaction mechanisms of cyclohexane catalytic cracking in recent years.It analyzes the e...This article elaborates on the research achievements of domestic and foreign researchers in exploring the conversion pathways and reaction mechanisms of cyclohexane catalytic cracking in recent years.It analyzes the effects of different catalysts and process conditions on the conversion laws of cyclohexane,summarizes the conversion pathways of cyclohexane,and discusses the chemical mechanisms of several main reactions of cyclohexane in catalytic cracking,such as cracking,isomerization,hydrogen transfer,dehydrogenation,and alkylation;Several advanced characterization methods and common research methods were listed,and prospects for future development in this field were proposed based on existing research.展开更多
The image processing and recognition technology is used in the micrographic diagnosis of the FCC catalyst. By quickly analyzing the image and quickly obtaining the analysis result of the catalyst property, the acciden...The image processing and recognition technology is used in the micrographic diagnosis of the FCC catalyst. By quickly analyzing the image and quickly obtaining the analysis result of the catalyst property, the accident of the FCC unit may be alerted. In this paper, the image recognition technology is used to better diagnose the catalytic cracking catalyst.展开更多
Supported KVO3 catalysts were prepared by impregnating different kinds of supporters (α-Al2O3, γ-Al2O3 and SiO2 powders) with a KVO3 solution. The activity of the bare supporters and supported catalysts were ev...Supported KVO3 catalysts were prepared by impregnating different kinds of supporters (α-Al2O3, γ-Al2O3 and SiO2 powders) with a KVO3 solution. The activity of the bare supporters and supported catalysts were evaluated in a continuous micro-reactivity test unit, with n-butane as a raw material. The results show that KVO3 has no catalytic activity, but it can increase the selectivity to light olefins. The supporter of α-Al2O3 has good catalytic performance for n-butane cracking when the reaction temperature is below 700℃.展开更多
Development of CDOS catalyst for bottoms cracking is based on DOSY zeolite,which is characterized by high metal tolerance.The results of DOSY tests have shown that the catalyst has better activity retention at high me...Development of CDOS catalyst for bottoms cracking is based on DOSY zeolite,which is characterized by high metal tolerance.The results of DOSY tests have shown that the catalyst has better activity retention at high metal content in the feed.The performance of catalyst tested in the bench scale was superior over that of the reference catalyst.The results of catalyst application have shown that the CDOS series catalysts have better bottoms cracking activity,high metal tolerance,excellent dry gas selectivity,and enhanced liquid yield.展开更多
Low-carbon light olefins are the basic feedstocks for the petrochemical industry. Catalytic cracking of crude bio-oil and its model compounds (including methanol, ethanol, acetic acid, acetone, and phenol) to light ...Low-carbon light olefins are the basic feedstocks for the petrochemical industry. Catalytic cracking of crude bio-oil and its model compounds (including methanol, ethanol, acetic acid, acetone, and phenol) to light olefins were performed by using the La/HZSM-5 catalyst. The highest olefins yield from crude bio-oil reached 0.19 kg/(kg crude bio-oil). The reaction conditions including temperature, weight hourly space velocity, and addition of La into the HZSM-5 zeolite can be used to control both olefins yield and selectivity. Moderate adjusting the acidity with a suitable ratio between the strong acid and weak acid sites through adding La to the zeolite effectively enhanced the olefins selectivity and improved the catalyst stability. The production of light olefins from crude bio-oil is closely associated with the chemical composition and hydrogen to carbon effective ratios of feedstock. The comparison between the catalytic cracking and pyrolysis of bio-oil was studied. The mechanism of the bio-oil conversion to light olefins was also discussed.展开更多
Catalysts, such as HZSM-5(Si/Al=50), HZSM-5(25), zeolite 5A, CaHZSM-5(50), ZnHZSM-5(50), and Kaolin were used in upgrading of crude biomass oil from pyrolysis in a fixed-bed reactor under atmospheric pressure, in orde...Catalysts, such as HZSM-5(Si/Al=50), HZSM-5(25), zeolite 5A, CaHZSM-5(50), ZnHZSM-5(50), and Kaolin were used in upgrading of crude biomass oil from pyrolysis in a fixed-bed reactor under atmospheric pressure, in order to investigate the effects of catalyst type on the yield of desired product. A blank test was carried out in a bed of inert packings to determine the extent of non-catalytical thermal cracking. The gas produced in the reaction was analyzed by the chemical absorption method. Among those catalysts, HZSM-5(50) gave the highest yield of the desired organic distillate while Kaolin gave the least formation of coke. Regeneration of deactivated HZSM-5(50) was studied. In terms of yield of organic distillate and formation rate of coke, the catalytic activity did not change much during the first 3 times of regeneration.展开更多
Driven by the increasing supply of heavy oils with deteriorating quality,a high nickel-resistant catalyst for catalytic cracking of inferior crude oils was developed by the Research Institute of Petroleum Processing(R...Driven by the increasing supply of heavy oils with deteriorating quality,a high nickel-resistant catalyst for catalytic cracking of inferior crude oils was developed by the Research Institute of Petroleum Processing(RIPP).Catalyst performance was evaluated in a laboratory fixed fluidized bed reactor.The test results showed that the high nickel resistance catalyst exhibited good bottoms crackability,good nickel resistance,and good adaptability to changes in operating parameters,which had no adverse effect on the product distribution,indicating to a most promising prospect for application of this catalyst in catalytic cracking of inferior crude oil.展开更多
The catalytic cracking of 1-hexene,1-heptene,1-octene,1-nonene,1-decene,and five olefins mixed with benzene,over USY catalysts was conducted in a small fixed fluidized bed reactor to study the conversion of benzene un...The catalytic cracking of 1-hexene,1-heptene,1-octene,1-nonene,1-decene,and five olefins mixed with benzene,over USY catalysts was conducted in a small fixed fluidized bed reactor to study the conversion of benzene under catalytic cracking conditions.Benzene mainly alkylated with C_(2)-C_(5)light olefins,generating monosubstituted alkylbenzenes,and the concentration of light olefins dramatically affected the alkylbenzene yield.Due to the limitation of thermodynamic equilibrium,the yield of benzene alkylation to alkylbenzene in catalytic cracking was in a relative low level.The equilibrium constant of benzene alkylation decreases with the increasing reaction temperature which resulted in reduction of alkyl benzene yield.展开更多
A novel catalytic cracking process named the MIP process was developed by the Research Institute of Petroleum Processing(RIPP),SINOPEC,to manufacture clean gasoline with lower olefin contents. The MIP pro-cess feature...A novel catalytic cracking process named the MIP process was developed by the Research Institute of Petroleum Processing(RIPP),SINOPEC,to manufacture clean gasoline with lower olefin contents. The MIP pro-cess features a unique riser consisting of two sequential reaction zones with different radii,in which different kinds of chemical reactions are intensified respectively to achieve better product slates and product properties. In order to fully implement the MIP potentials,a proprietary catalyst RMI tailored to the needs of the MIP process was devel-oped by adopting an AIRY zeolite having improved accessibility to active sites,which could result in better heavy oil cracking,coke selectivity and olefin reduction performance compared with the conventional REUSY zeolite. Its commercial application showed that the RMI catalyst could further reduce the olefin content in gasoline and raise the gasoline octane number while increasing the total liquid yield. On the basis of the MIP process,the MIP-CGP process was also developed to significantly reduce the olefin content in FCC naphtha and to enhance the propylene yield simultaneously. As far as the MIP-CGP process itself is concerned,both the MIP-CGP process and the MIP process have the similar reactor configuration but with different reactor size and operating parameters. The proprietary catalyst CGP-1 is also proposed to tailor for the MIP-CGP process. The specific features of the CGP-1 catalyst cover the new matrix,which possesses excellent capability to accommodate coke formation in the first reaction zone;the modified Y zeolite,which exhibits high hydrogen transfer activity in the second reaction zone;and the MFI zeolite,which has good gasoline olefin cracking activity. The commercial test results of MIP-CGP process applied along with the CGP-1 catalyst showed that the olefin content of gasoline was less than 18 v% and the propylene yield was more than 8 m%. Furthermore,as compared with the conventional FCC process,the gasoline properties were improved greatly and a higher total liquid yield was obtained. The advantages and characteristics of the MIP-CGP process were fully exploited by using the CGP-1 catalyst.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
This article is based on the experimental data on reaction of FCC naphtha in the presence of acid catalysts. The data published in the literature were reprocessed and compared with experimental data and the relationsh...This article is based on the experimental data on reaction of FCC naphtha in the presence of acid catalysts. The data published in the literature were reprocessed and compared with experimental data and the relationship of hydrogen and methane contained in the dry gas with the conversion rate was identified.The similarity between the route for cracking of olefin enriched FCC gasoline and the route for reaction of individual hydrocarbons was deduced, while the route for formation of ethylene in dry gas was also proposed to identify the relationship between the reaction path for formation of ethylene and the conversion rate.展开更多
文摘A novel heavy oil catalytic cracking catalyst RCC-1 was developed by using the ultra-stable zeolite, which was hydrothermally treated and modified through cleaning its pores to serve as the active component. The chemical composition and physicochemical properties of RCC-1 catalyst were studied by XRF, BET, pore volume analysis, attrition index analysis, and particle size distribution determination methods, and its catalytic cracking performance was also evaluated by a microreactor for light oil cracking and the ACE device. The test results showed that the new type of heavy oil catalytic cracking catalyst RCC-1 had good physicochemical properties and heavy oil cracking ability, strong anti-metallic contamination capability, good product distribution, good coke selectivity and gasoline selectivity, and excellent reduction of gasoline olefin content characteristics.
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The authors would like to thank the financial support from the National Basic Research Program of China fgrant No.2004CB 217806)the National Natural Science Foundation of China (Grant No.20373043) the Scientific Research Key Foundation for the Returned Overseas Chinese Scholars of State Education Ministry.
文摘The acidic modulations of a series of HZSM-5 catalysts were successfully made by calcination at different treatment temperatures, i.e. 500, 600, 650, 700 and 800 ℃, respectively. The results indicated that the total acid amounts, their density and the amount of B-type acid of HZSM-5 catalysts rapidly decreased, while the amounts of L-type acid had almost no change and thus the ratio of L/B was obviously enhanced with the increase of calcination temperature (excluding 800 ℃). The catalytic performances of modified HZSM-5 catalysts for the cracking of n-butane were also investigated. The main properties of these catalysts were characterized by means of XRD, N2 adsorption at low temperature, NH3-TPD, FTIR of pyridine adsorption and BET surface area measurements. The results showed that HZSM-5 zeolite pretreated at 800 ℃ had very low catalytic activity for n-butane cracking. In the calcination temperature range of 500-700 ℃, the total selectivity to olefins, propylene and butene were increased with the increase of calcination temperature, while, the selectivity for arene decreased with the calcination temperature. The HZSM-5 zeolite calcined at 700 ℃ produced light olefins with high yield, at the reaction temperature of 650 ℃ the yields of total olefins and ethylene were 52.8% and 29.4%, respectively. Besides, the more important role is that high calcination temperature treatment improved the duration stability of HZSM-5 zeolites. The effect of calcination temperature on the physico-chemical properties and catalytic performance of HZSM-5 for cracking of n-butane was explored. It was found that the calcination temperature had large effects on the surface area, crystallinity and acid properties of HZSM-5 catalyst, which further affected the catalytic performance for n-butane cracking.
文摘A new type of zeolite La-USL (ultra stable zeolite L (zeolite USL) modified by La), which has superior activity, stability and selectivity in catalytic cracking of hydrocarbons and thus can be used as an active catalyst component, is reported in this paper. The zeolite L with relative crystallinity of above 90% was synthesized by the hydrothermal crystallization method under optimum conditions and characterized by means of XRD, NH3-TPD and isotherm adsorption techniques. The in-situ synthesized zeolite L with a SiO2/Al2O3 mole ratio of 5-6 was modified by cation ion exchange, hydrothermal dealumination and chemical modifications with La in order to prepare La-containing USL with a higher framework SiO2/Al2O3 mole ratio of 15-30. The modified zeolite La-USL was used as an active additive component of fluid catalytic cracking (FCC) catalyst and the resulting catalysts were evaluated by microactivity test (MAT) and fixed-fluidized bed (FFB) experiments using heavy oil as feedstock. The influence of La content in La- USL on cracking product distribution, gasoline group composition and research octane number (RON) was investigated. The results showed that when La content in La-USL was 0.8 wt%, the addition of the corresponding La-USL could result in a FCC catalyst that produced significant improvement in product distribution and gasoline quality.
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.
基金the National Key R&D Program of China(2022YFA1504404)the SINOPEC Research Program(121036-5).
文摘A novel ultra-stable zeolite, NSZ, rich in secondary pores was developed through the combination of gas-phase andmild hydrothermal methods. This zeolite was successfully tested in an industrial setting for the first time in the world. The porestructure characteristics of the NSZ zeolite prepared for industrial use were analyzed and characterized using BET. The resultsindicate a significant increase in the secondary pore volume of NSZ zeolite compared to the existing ultra-stable zeolite HSZ-5, which is produced through a conventional gas-phase method. The average secondary pore volume to total pore volume ratioin NSZ zeolite was found to be 58.96% higher. The catalytic cracking performance of NSZ zeolite was evaluated. The resultsshowed that the NSC-LTA catalyst, with NSZ as the active component, outperformed the HSC-LTA catalyst with HSZ-5 zeolitein terms of obtaining more high-value products (gasoline and liquefied petroleum gas) during the hydrogenated light cycle oilprocessing. Additionally, the NSC-LTA catalyst showed a significant improvement in coke selectivity.
文摘The paper focuses on removing catalyst solids from oil slurry using 10 mm hydrocyclones, and aims to test the feasibility of the solution. An industrial sidetrack tester of residual oil separation by hydrocyclones was set up in 1.8 Mt/a resid fluid catalytic cracking (RFCC) unit, the effect of pressure drop, separation efficiency and inlet flowrate were studied. It was observed that an increase in feed flowrate will decrease the pressure drop ratio, and with an increase in feed flowrate, separation efficiency increases gradually. Under the condition that feed fiowrate was ranging from 250L/h to 270L/h, the separation efficiency was 45.77%-82.80%, the recovery rate of catalyst solid panicles was increased from 10 20% of electrostatic catalyst separator to 50 80%. Thus, it is feasible to separate the slurry by using the miniature hydrocyclones in RFCC unit.
文摘This article elaborates on the research achievements of domestic and foreign researchers in exploring the conversion pathways and reaction mechanisms of cyclohexane catalytic cracking in recent years.It analyzes the effects of different catalysts and process conditions on the conversion laws of cyclohexane,summarizes the conversion pathways of cyclohexane,and discusses the chemical mechanisms of several main reactions of cyclohexane in catalytic cracking,such as cracking,isomerization,hydrogen transfer,dehydrogenation,and alkylation;Several advanced characterization methods and common research methods were listed,and prospects for future development in this field were proposed based on existing research.
文摘The image processing and recognition technology is used in the micrographic diagnosis of the FCC catalyst. By quickly analyzing the image and quickly obtaining the analysis result of the catalyst property, the accident of the FCC unit may be alerted. In this paper, the image recognition technology is used to better diagnose the catalytic cracking catalyst.
文摘Supported KVO3 catalysts were prepared by impregnating different kinds of supporters (α-Al2O3, γ-Al2O3 and SiO2 powders) with a KVO3 solution. The activity of the bare supporters and supported catalysts were evaluated in a continuous micro-reactivity test unit, with n-butane as a raw material. The results show that KVO3 has no catalytic activity, but it can increase the selectivity to light olefins. The supporter of α-Al2O3 has good catalytic performance for n-butane cracking when the reaction temperature is below 700℃.
基金support provided by the Sinopec Corporation (Contact number: 105111)
文摘Development of CDOS catalyst for bottoms cracking is based on DOSY zeolite,which is characterized by high metal tolerance.The results of DOSY tests have shown that the catalyst has better activity retention at high metal content in the feed.The performance of catalyst tested in the bench scale was superior over that of the reference catalyst.The results of catalyst application have shown that the CDOS series catalysts have better bottoms cracking activity,high metal tolerance,excellent dry gas selectivity,and enhanced liquid yield.
基金This work is supported by the National Key Basic Program of China (No.2013CB228105) and the National Natural Science Foundation of China (No.51161140331).
文摘Low-carbon light olefins are the basic feedstocks for the petrochemical industry. Catalytic cracking of crude bio-oil and its model compounds (including methanol, ethanol, acetic acid, acetone, and phenol) to light olefins were performed by using the La/HZSM-5 catalyst. The highest olefins yield from crude bio-oil reached 0.19 kg/(kg crude bio-oil). The reaction conditions including temperature, weight hourly space velocity, and addition of La into the HZSM-5 zeolite can be used to control both olefins yield and selectivity. Moderate adjusting the acidity with a suitable ratio between the strong acid and weak acid sites through adding La to the zeolite effectively enhanced the olefins selectivity and improved the catalyst stability. The production of light olefins from crude bio-oil is closely associated with the chemical composition and hydrogen to carbon effective ratios of feedstock. The comparison between the catalytic cracking and pyrolysis of bio-oil was studied. The mechanism of the bio-oil conversion to light olefins was also discussed.
基金Supported by 863 National High Technology Development Program of China(No. 2001AA514021)
文摘Catalysts, such as HZSM-5(Si/Al=50), HZSM-5(25), zeolite 5A, CaHZSM-5(50), ZnHZSM-5(50), and Kaolin were used in upgrading of crude biomass oil from pyrolysis in a fixed-bed reactor under atmospheric pressure, in order to investigate the effects of catalyst type on the yield of desired product. A blank test was carried out in a bed of inert packings to determine the extent of non-catalytical thermal cracking. The gas produced in the reaction was analyzed by the chemical absorption method. Among those catalysts, HZSM-5(50) gave the highest yield of the desired organic distillate while Kaolin gave the least formation of coke. Regeneration of deactivated HZSM-5(50) was studied. In terms of yield of organic distillate and formation rate of coke, the catalytic activity did not change much during the first 3 times of regeneration.
文摘Driven by the increasing supply of heavy oils with deteriorating quality,a high nickel-resistant catalyst for catalytic cracking of inferior crude oils was developed by the Research Institute of Petroleum Processing(RIPP).Catalyst performance was evaluated in a laboratory fixed fluidized bed reactor.The test results showed that the high nickel resistance catalyst exhibited good bottoms crackability,good nickel resistance,and good adaptability to changes in operating parameters,which had no adverse effect on the product distribution,indicating to a most promising prospect for application of this catalyst in catalytic cracking of inferior crude oil.
文摘The catalytic cracking of 1-hexene,1-heptene,1-octene,1-nonene,1-decene,and five olefins mixed with benzene,over USY catalysts was conducted in a small fixed fluidized bed reactor to study the conversion of benzene under catalytic cracking conditions.Benzene mainly alkylated with C_(2)-C_(5)light olefins,generating monosubstituted alkylbenzenes,and the concentration of light olefins dramatically affected the alkylbenzene yield.Due to the limitation of thermodynamic equilibrium,the yield of benzene alkylation to alkylbenzene in catalytic cracking was in a relative low level.The equilibrium constant of benzene alkylation decreases with the increasing reaction temperature which resulted in reduction of alkyl benzene yield.
文摘A novel catalytic cracking process named the MIP process was developed by the Research Institute of Petroleum Processing(RIPP),SINOPEC,to manufacture clean gasoline with lower olefin contents. The MIP pro-cess features a unique riser consisting of two sequential reaction zones with different radii,in which different kinds of chemical reactions are intensified respectively to achieve better product slates and product properties. In order to fully implement the MIP potentials,a proprietary catalyst RMI tailored to the needs of the MIP process was devel-oped by adopting an AIRY zeolite having improved accessibility to active sites,which could result in better heavy oil cracking,coke selectivity and olefin reduction performance compared with the conventional REUSY zeolite. Its commercial application showed that the RMI catalyst could further reduce the olefin content in gasoline and raise the gasoline octane number while increasing the total liquid yield. On the basis of the MIP process,the MIP-CGP process was also developed to significantly reduce the olefin content in FCC naphtha and to enhance the propylene yield simultaneously. As far as the MIP-CGP process itself is concerned,both the MIP-CGP process and the MIP process have the similar reactor configuration but with different reactor size and operating parameters. The proprietary catalyst CGP-1 is also proposed to tailor for the MIP-CGP process. The specific features of the CGP-1 catalyst cover the new matrix,which possesses excellent capability to accommodate coke formation in the first reaction zone;the modified Y zeolite,which exhibits high hydrogen transfer activity in the second reaction zone;and the MFI zeolite,which has good gasoline olefin cracking activity. The commercial test results of MIP-CGP process applied along with the CGP-1 catalyst showed that the olefin content of gasoline was less than 18 v% and the propylene yield was more than 8 m%. Furthermore,as compared with the conventional FCC process,the gasoline properties were improved greatly and a higher total liquid yield was obtained. The advantages and characteristics of the MIP-CGP process were fully exploited by using the CGP-1 catalyst.
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.
文摘This article is based on the experimental data on reaction of FCC naphtha in the presence of acid catalysts. The data published in the literature were reprocessed and compared with experimental data and the relationship of hydrogen and methane contained in the dry gas with the conversion rate was identified.The similarity between the route for cracking of olefin enriched FCC gasoline and the route for reaction of individual hydrocarbons was deduced, while the route for formation of ethylene in dry gas was also proposed to identify the relationship between the reaction path for formation of ethylene and the conversion rate.