Fe-Al catalysts with hollow nano-spherical structures were synthesized following the hard template method using self-made carbon spheres as templates.The catalytic performance of these catalysts in the production of c...Fe-Al catalysts with hollow nano-spherical structures were synthesized following the hard template method using self-made carbon spheres as templates.The catalytic performance of these catalysts in the production of carbon nanotubes(CNTs)was evaluated through ethane catalytic cracking on a fixed bed reactor.Furthermore,the influence of these hollow nanospheres on the yield and quality of CNTs was investigated.The results showed that compared to the irregular-shaped catalyst synthesized by coprecipitation and the catalyst with micro-spherical structures prepared by the impregnation method,the Fe-Al hollow nano-spherical catalysts exhibited significantly enhanced specific surface area and pore volume,reaching 236 m^(2)/g and 0.77 cm^(3)/g,respectively.At a reaction temperature of 700℃ and an ethane feed rate of 90 mL/min,the CNTs yield of Fe-Al hollow nano-spherical catalyst reached as high as 48.6 gCNT/gcat,which was 1.8 and 4.6 times higher than the yield of irregular-shaped(27.7 gCNT/gcat)and micro-spherical(10.5 gCNT/gcat)catalysts,respectively.This was mainly attributed to the hollow cavity structure of Fe-Al catalyst providing sufficient space for the CNTs growth.As a result,the blockage of catalyst internal pores was prevented by the formed CNTs,which isolated ethane molecules from the active sites and lead to catalyst deactivation.Furthermore,the CNTs synthesized by Fe-Al hollow nano-spherical catalyst exhibited a uniform diameter distribution and a higher degree of graphitization.展开更多
A novel porous binder was obtained from acid-treated kaolin. This new binder possessed abundant meso/macropores, good hydrothermal stability and heavy metal resistance. The prepared catalyst using new binder featured ...A novel porous binder was obtained from acid-treated kaolin. This new binder possessed abundant meso/macropores, good hydrothermal stability and heavy metal resistance. The prepared catalyst using new binder featured low attrition index and large pore volume. The catalysts were contaminated with Ni, V, and tested in a fixed-fluidized bed reactor unit. In comparison with the reference sample, the oil conversion achieved by the above-mentioned catalyst increased by 3.50 percentage points, and heavy oil yield decreased by 2.86 percentage points, while the total liquid yield and light oil yield increased by 2.82 percentage points and 0.79 percentage points, respectively. The perfect pore structure, good hydrothermal stability and heavy metal resistant performance of new binder were the possible causes leading to its outstanding performance.展开更多
A new silica sol binder was obtained by mixing the acid-modified aluminium sulfate and water glass. The effect of SiO2 concentration in sodium silicate, pH value and polymerization was investigated. The new silica sol...A new silica sol binder was obtained by mixing the acid-modified aluminium sulfate and water glass. The effect of SiO2 concentration in sodium silicate, pH value and polymerization was investigated. The new silica sol binder, which possessed abundant pore volume and suitable acid amount, was an ideal component for preparing cracking catalyst. As a result, the corresponding catalyst comprising the new binder showed excellent performance. Compared with the reference sample, the liquefied petroleum gas(LPG) and propylene yield obtained over this catalyst increased by 3.49 and 1.20 percentage points, respectively. The perfect pore structure and suitable Lewis acid amount of new silica sol were the possible reason leading to its outstanding performance.展开更多
In this work,Saudi heavy crude oil(SHCO)was upgraded by the hydrodynamic cavitation technique.The collapse of cavitation bubbles instantly produces extreme conditions such as high temperature,pressure,and jet flow and...In this work,Saudi heavy crude oil(SHCO)was upgraded by the hydrodynamic cavitation technique.The collapse of cavitation bubbles instantly produces extreme conditions such as high temperature,pressure,and jet flow and strong shear forces,which can play a significant role in the upgradation process.The results revealed that the viscosity and Conradson carbon residue of SHCO decreased from 13.61 to 7.22 mm^(2)/s and from 7.16%to 6.48%,respectively.True boiling point distillation findings showed that the vacuum residue(VR)decreased by 1%.Atmospheric-pressure photoionization Fourier-transform ion cyclotron resonance mass spectrometry,X-ray diffraction,dynamic light scattering,Fourier-transform infrared spectroscopy,and scanning electron microscopy were employed to characterize the molecular composition,crystalline structure,asphaltene aggregate particle size distribution,functional groups,and morphology,respectively,to understand the effects of hydrodynamic cavitation on asphaltenes.The obtained results demonstrate that hydrodynamic cavitation upgradation reduced the interaction forces between the asphaltene molecules,weakening the crystalline structure of the asphaltene aggregates,reducing the degree of association of the aromatic compounds in SHCO and asphaltenes,and decreasing the average particle size.The delayed coking properties of the VR were further investigated,and the cavitation treatment was found to decrease the coke yield by 1.85%and increase the liquid and gas yields by 1.52%and 0.33%,respectively.Hence,hydrodynamic cavitation can effectively enhance the processing performance of crude oil by improving the properties and structural characteristics of asphaltenes.展开更多
The effect of crystal size of USY zeolite on the performance of hydro-upgrading catalysts for treating catalytically cracked(FCC) LCO(light cycle oil) was studied.Three W-Ni catalysts supported on USY zeolites with di...The effect of crystal size of USY zeolite on the performance of hydro-upgrading catalysts for treating catalytically cracked(FCC) LCO(light cycle oil) was studied.Three W-Ni catalysts supported on USY zeolites with different crystal sizes and Al2O3 were prepared by impregnation method.The catalysts were characterized by XRD and BET methods,and evaluated in a micro-reactor using tetralin as the model compound and in an 100-mL hydrogenation test unit using FCC LCO as the feedstock.By contrast,catalyst made from smaller crystal-size USY zeolite had higher external surface area and shorter pore length,having more hydrogenation activity sites and short contact time of reactant molecules with acidity sites.The evaluation results showed that the catalyst prepared on the basis of small crystal-size USY zeolite had higher tetralin conversion and better hydro-upgrading performance for treating FCC LCO.展开更多
Copper nanorods have been synthe-sized in mesoporous SBA-15 by a low-temperature metal organic chemical vapor deposition (MOCVD) employing copper (II) acetylacetonate, Cu(acac)2, and hydrogen as a precursor and reacta...Copper nanorods have been synthe-sized in mesoporous SBA-15 by a low-temperature metal organic chemical vapor deposition (MOCVD) employing copper (II) acetylacetonate, Cu(acac)2, and hydrogen as a precursor and reactant gas, re- spectively. The hydrogen plays an important role in chemical reduction of oganometallic precursor which enhances mass transfer in the interior of the SBA-15 porous substrate. Such copper nanostructures are of great potentials in the semiconductor due to their unusual optical, magnetic and electronic properties. In addition, it has been found that chemically modi- fying the substrate surface by carbon deposition is crucial to such synthesis of copper nanostructures in the interior of the SBA-15, which is able to change the surface properties of SBA-15 from hydrophilic to hydrophobic to promote the adsorption of organic cupric precursor. It has also been found that the copper nanoparticles deposited on the external sur- face are almost eliminated and the copper nanorods are more distinct while the product was treated with ammonia. This approach could be achieved under a mild condition: a low temperature (400℃) and vac-uum (2 kPa) which is extremely milder than the con- ventional method. It actually sounds as a foundation which is the first time to synthesize a copper nanorod at a mild condition of a low reaction temperature and pressure.展开更多
Metallorganic chemical vapor deposition is used as a novel simple pore tailoring method to fine-tune the pore opening size of SBA-15 materials without significant loss in pore volume and surface area. By using acetyle...Metallorganic chemical vapor deposition is used as a novel simple pore tailoring method to fine-tune the pore opening size of SBA-15 materials without significant loss in pore volume and surface area. By using acetylene as carbon source and copper (II) acetylacetonate as precursor, the poremouth of SBA-15 is effectively reduced from 5.78 nm to 3.67 nm while maintaining the pore body at 5.78 nm. The effect of four pore modification factors-the ratio of acetylene/nitrogen, the feeding time of carbon precursor, the ratio of SBA-C/Cu(acac)2 and the cycles of MOCVD on the final pore structure of the SBA-15/carbon/copper composite is studied. The morphology and microstructure of the resulting product SBA-C-Cu are characterized by XRD patterns, TEM images and EDS analysis. The XRD and TEM reveal that the SBA-C-Cu composite is highly hexagonally ordered and has similar particle morphology as the original SBA-15.展开更多
Carbon nanotubes (CNTs)/mesostructured silica core-shell nanowires with a carbon nanotube core and controllable highly ordered periodic mesoporous silica shell are syntheiszed via the interfacial surfac- tant template...Carbon nanotubes (CNTs)/mesostructured silica core-shell nanowires with a carbon nanotube core and controllable highly ordered periodic mesoporous silica shell are syntheiszed via the interfacial surfac- tant template. The core-shell nanowires are characterized by transmission electron microscope (TEM), X-ray diffraction pattern (XRD) and nitrogen sorption/desorption. The results indicate that the core-shell nanowires have highly ordered periodic mesoporous silica shell (space group p6mm), high BET sur- face area and narrow pore size distribution. Moreover, the morphology of core-shell nanowires can be controlled by the pH value. The core-shell nanowires have promising applications in biosensors, nanoprobes and energy storage due to their good dispersibility in polar solvents.展开更多
文摘Fe-Al catalysts with hollow nano-spherical structures were synthesized following the hard template method using self-made carbon spheres as templates.The catalytic performance of these catalysts in the production of carbon nanotubes(CNTs)was evaluated through ethane catalytic cracking on a fixed bed reactor.Furthermore,the influence of these hollow nanospheres on the yield and quality of CNTs was investigated.The results showed that compared to the irregular-shaped catalyst synthesized by coprecipitation and the catalyst with micro-spherical structures prepared by the impregnation method,the Fe-Al hollow nano-spherical catalysts exhibited significantly enhanced specific surface area and pore volume,reaching 236 m^(2)/g and 0.77 cm^(3)/g,respectively.At a reaction temperature of 700℃ and an ethane feed rate of 90 mL/min,the CNTs yield of Fe-Al hollow nano-spherical catalyst reached as high as 48.6 gCNT/gcat,which was 1.8 and 4.6 times higher than the yield of irregular-shaped(27.7 gCNT/gcat)and micro-spherical(10.5 gCNT/gcat)catalysts,respectively.This was mainly attributed to the hollow cavity structure of Fe-Al catalyst providing sufficient space for the CNTs growth.As a result,the blockage of catalyst internal pores was prevented by the formed CNTs,which isolated ethane molecules from the active sites and lead to catalyst deactivation.Furthermore,the CNTs synthesized by Fe-Al hollow nano-spherical catalyst exhibited a uniform diameter distribution and a higher degree of graphitization.
基金the Department of Science and Technology Management of PetroChina for providing financial support
文摘A novel porous binder was obtained from acid-treated kaolin. This new binder possessed abundant meso/macropores, good hydrothermal stability and heavy metal resistance. The prepared catalyst using new binder featured low attrition index and large pore volume. The catalysts were contaminated with Ni, V, and tested in a fixed-fluidized bed reactor unit. In comparison with the reference sample, the oil conversion achieved by the above-mentioned catalyst increased by 3.50 percentage points, and heavy oil yield decreased by 2.86 percentage points, while the total liquid yield and light oil yield increased by 2.82 percentage points and 0.79 percentage points, respectively. The perfect pore structure, good hydrothermal stability and heavy metal resistant performance of new binder were the possible causes leading to its outstanding performance.
基金the Department of Science and Technology Management of PetroChina for providing financial support
文摘A new silica sol binder was obtained by mixing the acid-modified aluminium sulfate and water glass. The effect of SiO2 concentration in sodium silicate, pH value and polymerization was investigated. The new silica sol binder, which possessed abundant pore volume and suitable acid amount, was an ideal component for preparing cracking catalyst. As a result, the corresponding catalyst comprising the new binder showed excellent performance. Compared with the reference sample, the liquefied petroleum gas(LPG) and propylene yield obtained over this catalyst increased by 3.49 and 1.20 percentage points, respectively. The perfect pore structure and suitable Lewis acid amount of new silica sol were the possible reason leading to its outstanding performance.
基金This work was financially supported by the Research Program of China Petrochemical Corporation(SINOPEC 117017-8 and 119022-2).
文摘In this work,Saudi heavy crude oil(SHCO)was upgraded by the hydrodynamic cavitation technique.The collapse of cavitation bubbles instantly produces extreme conditions such as high temperature,pressure,and jet flow and strong shear forces,which can play a significant role in the upgradation process.The results revealed that the viscosity and Conradson carbon residue of SHCO decreased from 13.61 to 7.22 mm^(2)/s and from 7.16%to 6.48%,respectively.True boiling point distillation findings showed that the vacuum residue(VR)decreased by 1%.Atmospheric-pressure photoionization Fourier-transform ion cyclotron resonance mass spectrometry,X-ray diffraction,dynamic light scattering,Fourier-transform infrared spectroscopy,and scanning electron microscopy were employed to characterize the molecular composition,crystalline structure,asphaltene aggregate particle size distribution,functional groups,and morphology,respectively,to understand the effects of hydrodynamic cavitation on asphaltenes.The obtained results demonstrate that hydrodynamic cavitation upgradation reduced the interaction forces between the asphaltene molecules,weakening the crystalline structure of the asphaltene aggregates,reducing the degree of association of the aromatic compounds in SHCO and asphaltenes,and decreasing the average particle size.The delayed coking properties of the VR were further investigated,and the cavitation treatment was found to decrease the coke yield by 1.85%and increase the liquid and gas yields by 1.52%and 0.33%,respectively.Hence,hydrodynamic cavitation can effectively enhance the processing performance of crude oil by improving the properties and structural characteristics of asphaltenes.
基金support from the China National Petroleum Corporation (CNPC) (2011B-2304-0305)
文摘The effect of crystal size of USY zeolite on the performance of hydro-upgrading catalysts for treating catalytically cracked(FCC) LCO(light cycle oil) was studied.Three W-Ni catalysts supported on USY zeolites with different crystal sizes and Al2O3 were prepared by impregnation method.The catalysts were characterized by XRD and BET methods,and evaluated in a micro-reactor using tetralin as the model compound and in an 100-mL hydrogenation test unit using FCC LCO as the feedstock.By contrast,catalyst made from smaller crystal-size USY zeolite had higher external surface area and shorter pore length,having more hydrogenation activity sites and short contact time of reactant molecules with acidity sites.The evaluation results showed that the catalyst prepared on the basis of small crystal-size USY zeolite had higher tetralin conversion and better hydro-upgrading performance for treating FCC LCO.
文摘Copper nanorods have been synthe-sized in mesoporous SBA-15 by a low-temperature metal organic chemical vapor deposition (MOCVD) employing copper (II) acetylacetonate, Cu(acac)2, and hydrogen as a precursor and reactant gas, re- spectively. The hydrogen plays an important role in chemical reduction of oganometallic precursor which enhances mass transfer in the interior of the SBA-15 porous substrate. Such copper nanostructures are of great potentials in the semiconductor due to their unusual optical, magnetic and electronic properties. In addition, it has been found that chemically modi- fying the substrate surface by carbon deposition is crucial to such synthesis of copper nanostructures in the interior of the SBA-15, which is able to change the surface properties of SBA-15 from hydrophilic to hydrophobic to promote the adsorption of organic cupric precursor. It has also been found that the copper nanoparticles deposited on the external sur- face are almost eliminated and the copper nanorods are more distinct while the product was treated with ammonia. This approach could be achieved under a mild condition: a low temperature (400℃) and vac-uum (2 kPa) which is extremely milder than the con- ventional method. It actually sounds as a foundation which is the first time to synthesize a copper nanorod at a mild condition of a low reaction temperature and pressure.
基金supported by the Research Grants Council (RGC) of Hong Kong under the Central Allocation Vote Scheme (Grant No. CA04/05.SC02)the CERG Scheme (Grant No. 600707)
文摘Metallorganic chemical vapor deposition is used as a novel simple pore tailoring method to fine-tune the pore opening size of SBA-15 materials without significant loss in pore volume and surface area. By using acetylene as carbon source and copper (II) acetylacetonate as precursor, the poremouth of SBA-15 is effectively reduced from 5.78 nm to 3.67 nm while maintaining the pore body at 5.78 nm. The effect of four pore modification factors-the ratio of acetylene/nitrogen, the feeding time of carbon precursor, the ratio of SBA-C/Cu(acac)2 and the cycles of MOCVD on the final pore structure of the SBA-15/carbon/copper composite is studied. The morphology and microstructure of the resulting product SBA-C-Cu are characterized by XRD patterns, TEM images and EDS analysis. The XRD and TEM reveal that the SBA-C-Cu composite is highly hexagonally ordered and has similar particle morphology as the original SBA-15.
基金Supported by the Australian Research Council (ARC) through Discovery Project program (DP0452461)
文摘Carbon nanotubes (CNTs)/mesostructured silica core-shell nanowires with a carbon nanotube core and controllable highly ordered periodic mesoporous silica shell are syntheiszed via the interfacial surfac- tant template. The core-shell nanowires are characterized by transmission electron microscope (TEM), X-ray diffraction pattern (XRD) and nitrogen sorption/desorption. The results indicate that the core-shell nanowires have highly ordered periodic mesoporous silica shell (space group p6mm), high BET sur- face area and narrow pore size distribution. Moreover, the morphology of core-shell nanowires can be controlled by the pH value. The core-shell nanowires have promising applications in biosensors, nanoprobes and energy storage due to their good dispersibility in polar solvents.
