In this work, the amination of sulfonated polystyrene resin with alkyl secondary amine is investigated. The catalytic activities of the modified resins are determined through the hydration of l-butene. The optimum cha...In this work, the amination of sulfonated polystyrene resin with alkyl secondary amine is investigated. The catalytic activities of the modified resins are determined through the hydration of l-butene. The optimum chain length and the best range of amination rate are determined. It is found that the single-pass conversion of 1 -butene was raised 2% on average, and the relative activity was increased over 30% after modification. A hypothesis about the enhancement of catalytic activities by the inclusion of alkyl chain to wrap up the butene molecule is proposed.展开更多
A dynamic mass transfer model of isobutane/butene alkylation over solid acid catalysts in a fixed bed reactor was established. In the model, a modified equation for the relationship between point activity and effectiv...A dynamic mass transfer model of isobutane/butene alkylation over solid acid catalysts in a fixed bed reactor was established. In the model, a modified equation for the relationship between point activity and effective diffusion coefficient was proposed. It is found that the simulation results fit the experimental data well and the breakthrough time of the bed layer is predicted accurately. By modeling the alkylation process, the time-space distribution of butene and point activity profiles of catalysts can be obtained. Furthermore, the reasons for the deactivation of solid acid catalysts were investigated. It indicates that the main reason for the deactivation of catalysts is the site coverage near the inlet of the reactor, while it is ascribed to the steric effect in the region far away from the inlet.展开更多
Macro-mesoporous γ-alumina support（MMA） was prepared by a sol-gel route in aqueous medium using pseudo-boehmite as aluminum source and polystyrene microspheres and Pluronic P123 as hard and soft dual templates,resp...Macro-mesoporous γ-alumina support（MMA） was prepared by a sol-gel route in aqueous medium using pseudo-boehmite as aluminum source and polystyrene microspheres and Pluronic P123 as hard and soft dual templates,respectively.MMA had a BET specific surface area of about 259 m2 g-1,total pore volume of about 1.61 cm3 g-1,macropore diameter of about 102 nm,and mesopore diameter of about 14 nm.Re2O7/MMA and conventional Re2O7/Al2O3 were prepared by a incipient-wetness impregnation method,and their catalytic performances in the metathesis of 1-butene and 2-butene were tested in a fixed-bed tubular reactor.The result showed that Re2O7/MMA possessed higher activity and far longer working life-span than conventional Re2O7/Al2O3.展开更多
A BrOnsted-Lewis (B-L) conjugated solid superacid HPW-SbF_5/SiO_2 wassynthesized by a two-step method. This B-L acid shows high acid strength, high activity, goodselectivity and moderate stability in alkylation of iso...A BrOnsted-Lewis (B-L) conjugated solid superacid HPW-SbF_5/SiO_2 wassynthesized by a two-step method. This B-L acid shows high acid strength, high activity, goodselectivity and moderate stability in alkylation of isobutane/butene due to strong interactionbetween the BrOnsted acid and the Lewis acid, as confirmed by the results of IR, NMR and XPS. Undera mild reaction condition (30℃, 15-35xl0~5 Pa), the conversion of butene was maintained at 100% for110 hours on stream and the main products were C_8 and TMP. The results of alkylation conductedunder various operating conditions indicated that the activity was improved by increasing theloading content of HPW and SbF_5. The selectivity of TMP in the products was enhanced when theisobutane/butene ratio in the feedstock was increased. The existence of some intermediates was alsoreported.展开更多
Mesoporous γ-aluminas with large pore size （up to 19 nm, denoted as MAI9） are prepared from dispersed pseudo-boehmite using pluronic P123 as template. It is found that these mesoporous alumina supported rhenium oxi...Mesoporous γ-aluminas with large pore size （up to 19 nm, denoted as MAI9） are prepared from dispersed pseudo-boehmite using pluronic P123 as template. It is found that these mesoporous alumina supported rhenium oxide catalysts were more active and have far longer working life-span in gas-phase metathesis of 1-butene and 2-butene to propene than rhenium oxide on conventional alumina with small pore size （5 nm）. At 60 ℃ and atmospheric pressure with WHSV = 1 h^-1, the similar stable conversions of butene （ca. 55%） for all the 13 wt% Re207/alumina catalysts were obtained near the chemical equilibrium, and the stable working life-spans of Re2OT/MA19 were far longer than that of Re2O7/A1203, being about 70 h and 20 h, respectively.展开更多
With the expansion of butene production capacity,clean and efficient conversion of mixed butene attracts increasing attention.Herein we report direct co-conversion of butene and syngas to highquality gasoline enabled ...With the expansion of butene production capacity,clean and efficient conversion of mixed butene attracts increasing attention.Herein we report direct co-conversion of butene and syngas to highquality gasoline enabled by a bifunctional OXZEO catalyst comprising ZnCrO_(x) oxide and ZSM-5 zeolite.A gasoline selectivity of 71.6% at 98.1% butene conversion and 26.2% CO conversion have been obtained under the reaction conditions of 360℃,3 MPa and 3000 mL g^(-1) h^(-1).The space time yield of gasoline of0.25 g·g^(-1) h^(-1) is achieved.Interestingly,the presence of syngas can effectively facilitate iso-paraffin production while hindering the formation of aromatics.This is attributed to the prohibited hydrogen transfer aromatization process of butene on ZSM-5 in the presence of H2.Fu rthermore,the formation of isomers of gasoline range hydrocarbons is favored because the active intermediates generated from CO/H_(2) activation over ZnCrO_(x) oxide could react with butene over ZSM-5 zeolite.Thus,the product distribution among gasoline range hydrocarbons is modulated with reduced heavy aromatics and improved iso-paraffins,which is desirable for application as fuels.This provides an alternative environmentally friendly technology to utilize still increasing mixed butene.展开更多
VOx/SiO2 catalysts prepared by impregnation method were used for catalytic dehydrogenation of n-butane to butenes and characterized by X-ray diffraction, FT-IR, UV-vis, Raman, and BET measurements. The effects of VOx ...VOx/SiO2 catalysts prepared by impregnation method were used for catalytic dehydrogenation of n-butane to butenes and characterized by X-ray diffraction, FT-IR, UV-vis, Raman, and BET measurements. The effects of VOx loading and the reaction temperature on the VOx/SiO2 catalysts and their catalytic performances for the dehydrogenation of n-butane were studied. When the VOx loading was 12% g/gcat and reaction temperature was between 590 ℃ and 600℃, n-butane conversion and butenes yields reached the highest value under H2 flux of 10 ml/min and n-butane flux of 10 ml/min. Product distribution, such as the ratio of 2-butene to 1-butene and the ratio of cis-2-butene to trans-2-butene, was mainly influenced by the reaction temperature.展开更多
The aromatization of light alkenes in liquefied petroleum gas (LPG) with and without dimethyl ether (DME) addition in the feed was investigated on a modified ZSM-5 catalyst.The results showed that under the given reac...The aromatization of light alkenes in liquefied petroleum gas (LPG) with and without dimethyl ether (DME) addition in the feed was investigated on a modified ZSM-5 catalyst.The results showed that under the given reaction conditions the selectivity of alkenes to high-octane gasoline blending components was markedly enhanced and the formation of propane and butanes was greatly suppressed with the addition of DME.It was also found that the distribution of C5+ components was changed a lot with DME addition into the LPG feed.The formation of branched hydrocarbons (mainly C6 C8 i-paraffin) and multi-methyl substituted aromatics,which are high octane number gasoline blending components,was promoted significantly,while the content of n-paraffins and olefins in C5+ components was decreased obviously,indicating that in addition to the oligomerization,cracking,hydrogen-transfer and dehydrogenation-cyclization of alkenes,the methylation of the formed aromatics and olefins intermediates also plays an important role in determining the product distribution due to the high reactivity of surface methoxy groups formed by DME.And this process,in combination with the syngas-to-methanol/DME technology,provides an alternative way to the production of high-octane gasoline from coal,natural gas or renewable raw materials.展开更多
V/SiO2 catalysts compared to Cr/SiO2 catalysts were studied for dehydrogenation of n-butane to butenes. Several methods for characterization of catalysts such as FT-IR, UV-vis and Raman spectroscopies were used. Some ...V/SiO2 catalysts compared to Cr/SiO2 catalysts were studied for dehydrogenation of n-butane to butenes. Several methods for characterization of catalysts such as FT-IR, UV-vis and Raman spectroscopies were used. Some differences between two catalysts were showed, including the performances of catalysts, distribution of products and mechanism of reactions. The results showed that prepared catalysts with 12m% of active component loading all demonstrated best conversion of n-butane to butene at a reaction temperature of around 590 ℃. Two different reaction mechanisms were mentioned to well explain why iso-butene was produced on V/SiO2 catalysts but not on Cr/SiO2 catalysts.展开更多
文摘In this work, the amination of sulfonated polystyrene resin with alkyl secondary amine is investigated. The catalytic activities of the modified resins are determined through the hydration of l-butene. The optimum chain length and the best range of amination rate are determined. It is found that the single-pass conversion of 1 -butene was raised 2% on average, and the relative activity was increased over 30% after modification. A hypothesis about the enhancement of catalytic activities by the inclusion of alkyl chain to wrap up the butene molecule is proposed.
文摘A dynamic mass transfer model of isobutane/butene alkylation over solid acid catalysts in a fixed bed reactor was established. In the model, a modified equation for the relationship between point activity and effective diffusion coefficient was proposed. It is found that the simulation results fit the experimental data well and the breakthrough time of the bed layer is predicted accurately. By modeling the alkylation process, the time-space distribution of butene and point activity profiles of catalysts can be obtained. Furthermore, the reasons for the deactivation of solid acid catalysts were investigated. It indicates that the main reason for the deactivation of catalysts is the site coverage near the inlet of the reactor, while it is ascribed to the steric effect in the region far away from the inlet.
基金supported by the National Natural Science Foundation of China (Grant No:20976192)SINOPEC Jiujiang Petrochemical Company (G2810-09-ZS-0027)
文摘Macro-mesoporous γ-alumina support（MMA） was prepared by a sol-gel route in aqueous medium using pseudo-boehmite as aluminum source and polystyrene microspheres and Pluronic P123 as hard and soft dual templates,respectively.MMA had a BET specific surface area of about 259 m2 g-1,total pore volume of about 1.61 cm3 g-1,macropore diameter of about 102 nm,and mesopore diameter of about 14 nm.Re2O7/MMA and conventional Re2O7/Al2O3 were prepared by a incipient-wetness impregnation method,and their catalytic performances in the metathesis of 1-butene and 2-butene were tested in a fixed-bed tubular reactor.The result showed that Re2O7/MMA possessed higher activity and far longer working life-span than conventional Re2O7/Al2O3.
基金supports from the National Natural Science Foundation of China and SINOPEC are acknowledged
文摘A BrOnsted-Lewis (B-L) conjugated solid superacid HPW-SbF_5/SiO_2 wassynthesized by a two-step method. This B-L acid shows high acid strength, high activity, goodselectivity and moderate stability in alkylation of isobutane/butene due to strong interactionbetween the BrOnsted acid and the Lewis acid, as confirmed by the results of IR, NMR and XPS. Undera mild reaction condition (30℃, 15-35xl0~5 Pa), the conversion of butene was maintained at 100% for110 hours on stream and the main products were C_8 and TMP. The results of alkylation conductedunder various operating conditions indicated that the activity was improved by increasing theloading content of HPW and SbF_5. The selectivity of TMP in the products was enhanced when theisobutane/butene ratio in the feedstock was increased. The existence of some intermediates was alsoreported.
基金financially supported by SINOPEC Jiujiang Petrochemical Company and from the National Nature Science Foundation of China (No.20976192)
文摘Mesoporous γ-aluminas with large pore size （up to 19 nm, denoted as MAI9） are prepared from dispersed pseudo-boehmite using pluronic P123 as template. It is found that these mesoporous alumina supported rhenium oxide catalysts were more active and have far longer working life-span in gas-phase metathesis of 1-butene and 2-butene to propene than rhenium oxide on conventional alumina with small pore size （5 nm）. At 60 ℃ and atmospheric pressure with WHSV = 1 h^-1, the similar stable conversions of butene （ca. 55%） for all the 13 wt% Re207/alumina catalysts were obtained near the chemical equilibrium, and the stable working life-spans of Re2OT/MA19 were far longer than that of Re2O7/A1203, being about 70 h and 20 h, respectively.
基金supported by the Ministry of Science and Technology of China (2018YFA0704503)the National Natural Science Foundation of China (Grant Nos. 22002153, 91945302)+2 种基金the Youth Innovation Promotion Association of Chinese Academy of Sciences (2019184)the Natural Science Foundation of Liaoning (2020-BS019)Dalian Science and Technology Innovation Fund (2020JJ26GX028)。
文摘With the expansion of butene production capacity,clean and efficient conversion of mixed butene attracts increasing attention.Herein we report direct co-conversion of butene and syngas to highquality gasoline enabled by a bifunctional OXZEO catalyst comprising ZnCrO_(x) oxide and ZSM-5 zeolite.A gasoline selectivity of 71.6% at 98.1% butene conversion and 26.2% CO conversion have been obtained under the reaction conditions of 360℃,3 MPa and 3000 mL g^(-1) h^(-1).The space time yield of gasoline of0.25 g·g^(-1) h^(-1) is achieved.Interestingly,the presence of syngas can effectively facilitate iso-paraffin production while hindering the formation of aromatics.This is attributed to the prohibited hydrogen transfer aromatization process of butene on ZSM-5 in the presence of H2.Fu rthermore,the formation of isomers of gasoline range hydrocarbons is favored because the active intermediates generated from CO/H_(2) activation over ZnCrO_(x) oxide could react with butene over ZSM-5 zeolite.Thus,the product distribution among gasoline range hydrocarbons is modulated with reduced heavy aromatics and improved iso-paraffins,which is desirable for application as fuels.This provides an alternative environmentally friendly technology to utilize still increasing mixed butene.
基金The project was supported by Program for New Century Excellent Talents in University (Grant No. NCET-04-0987)Doctor Fund of Science Research of Xinjiang University (Grant No. BS060101).
文摘VOx/SiO2 catalysts prepared by impregnation method were used for catalytic dehydrogenation of n-butane to butenes and characterized by X-ray diffraction, FT-IR, UV-vis, Raman, and BET measurements. The effects of VOx loading and the reaction temperature on the VOx/SiO2 catalysts and their catalytic performances for the dehydrogenation of n-butane were studied. When the VOx loading was 12% g/gcat and reaction temperature was between 590 ℃ and 600℃, n-butane conversion and butenes yields reached the highest value under H2 flux of 10 ml/min and n-butane flux of 10 ml/min. Product distribution, such as the ratio of 2-butene to 1-butene and the ratio of cis-2-butene to trans-2-butene, was mainly influenced by the reaction temperature.
基金supported by the "Action Plan of CAS to Support China’s New and Strategic Industries with Science and Technology(2012-2014)"the "Knowledge Innovation Program of the Chinese Academy of Sciences(S201041)""Youth Innovation Promotion Association CAS(2012-2015)"
文摘The aromatization of light alkenes in liquefied petroleum gas (LPG) with and without dimethyl ether (DME) addition in the feed was investigated on a modified ZSM-5 catalyst.The results showed that under the given reaction conditions the selectivity of alkenes to high-octane gasoline blending components was markedly enhanced and the formation of propane and butanes was greatly suppressed with the addition of DME.It was also found that the distribution of C5+ components was changed a lot with DME addition into the LPG feed.The formation of branched hydrocarbons (mainly C6 C8 i-paraffin) and multi-methyl substituted aromatics,which are high octane number gasoline blending components,was promoted significantly,while the content of n-paraffins and olefins in C5+ components was decreased obviously,indicating that in addition to the oligomerization,cracking,hydrogen-transfer and dehydrogenation-cyclization of alkenes,the methylation of the formed aromatics and olefins intermediates also plays an important role in determining the product distribution due to the high reactivity of surface methoxy groups formed by DME.And this process,in combination with the syngas-to-methanol/DME technology,provides an alternative way to the production of high-octane gasoline from coal,natural gas or renewable raw materials.
基金The Program for New Century Excellent Talents in University (Grant No.NCET-04-0987)Doctor Fund of Science Research of Xinjiang University (Grant No. BS060101)
文摘V/SiO2 catalysts compared to Cr/SiO2 catalysts were studied for dehydrogenation of n-butane to butenes. Several methods for characterization of catalysts such as FT-IR, UV-vis and Raman spectroscopies were used. Some differences between two catalysts were showed, including the performances of catalysts, distribution of products and mechanism of reactions. The results showed that prepared catalysts with 12m% of active component loading all demonstrated best conversion of n-butane to butene at a reaction temperature of around 590 ℃. Two different reaction mechanisms were mentioned to well explain why iso-butene was produced on V/SiO2 catalysts but not on Cr/SiO2 catalysts.
