The alkylation of toluene with methanol for the selective formation of p-xylene was systematically studied. Very few studies have been reported on the use of superacids such as heteropolyacids on cheap supports, such ...The alkylation of toluene with methanol for the selective formation of p-xylene was systematically studied. Very few studies have been reported on the use of superacids such as heteropolyacids on cheap supports, such as clay. This article deals with the use of different heteropoly acids (HPAs), viz, Dodeca-Tungstophosphoric acid [H3PO4.12WO3.xH2O] (TPA), Dodeca-Molyhdo phosphoric acid ammonium salt hydrate [H12Mo12N3O40P+aq] (DMAA), Dodeca-Molyhdo Phosphoric acid (PMA) on clay (MontmoriUonite, K-10) and as such plain clay. This comparative study reveals that 20%PMA/Clay shows 62% toluene conversion and 100% selectivity toward p-xylene.展开更多
The alkylation of toluene with methanol to selective formation of p-xylene has been systematically studied. ZSM-12 (MTW)/ZSM-5 co-crystalline zeolite in 40:60 proportions have been synthesized by the same molar gel...The alkylation of toluene with methanol to selective formation of p-xylene has been systematically studied. ZSM-12 (MTW)/ZSM-5 co-crystalline zeolite in 40:60 proportions have been synthesized by the same molar gel composition, but at different temperatures and periods than that of ZSM-12 and ZSM-5, separately. All the prepared samples are characterized by XRD, SEM, BET, and XRF. The activity of toluene alkylation was investigated with a mixture of toluene and methanol as a feed over the ZSM-12, ZSM-12/ZSM-5 co-crystalline, ZSM-5, and physical mixture of ZSM-12/ZSM-5. From characterization, it is observed that the ZSM-12/ZSM-5 co-crystalline material is different from that of ZSM-12, ZSM-5, and their physical mixture. Further, the ZSM-12/ZSM-5 co-crystalline zeolite produces the highest content of xylene and has better selectivity for p-xylene than ZSM-12, ZSM-5, and their physical mixture.展开更多
The global consumption of p-xylene(PX)for the production of polymers has raised serious concerns about its impact on the environment.As various reports have shown the risks that PX could pose to human health,research ...The global consumption of p-xylene(PX)for the production of polymers has raised serious concerns about its impact on the environment.As various reports have shown the risks that PX could pose to human health,research into cost-effective remedial methods to remove PX from the environment has gained attraction.In this work,a hierarchical porous crab shell biochar(KCS)was synthesized,characterized,and evaluated for its efficiency to remove PX from aqueous solution.The characterizations of KCS,including the porous structure,surface functional group,phase structure,and surface morphology,were discussed by N_(2) adsorption-desorption,FTIR,XRD,and SEM.Batch adsorption experiments showed that the maximum adsorption capacity of PX on KCS was 393 mg/g within 5 min,larger than most biological/biomass materials,mainly due to the higher specific surface area of 2046 m^(2)/g,and abundant lipophilic functional groups.Subsequent adsorption kinetics study indicated a pseudo-second-order model which implied that the adsorption of PX was due to chemisorption.Thermodynamic parameters showed that the values ofΔH°andΔG°were both negative,indicating that the PX adsorption process on KCS was spontaneous and exothermic.The performance of KCS in delivering a cost-effective,fast,and efficient solution for the removal of PX from aqueous solution would greatly benefit current environmental remediation efforts.展开更多
Vapor-liquid equilibrium composition and temperature were measured for binary andternary mixtures of benzene,toluene and p-xylene at 101.33 kPa The equilibrium cell of Boubliketal.was modified for the present study.Th...Vapor-liquid equilibrium composition and temperature were measured for binary andternary mixtures of benzene,toluene and p-xylene at 101.33 kPa The equilibrium cell of Boubliketal.was modified for the present study.The experimental vapor-liquid equilibrium data were corre-lated with the Wilson equation.展开更多
文摘The alkylation of toluene with methanol for the selective formation of p-xylene was systematically studied. Very few studies have been reported on the use of superacids such as heteropolyacids on cheap supports, such as clay. This article deals with the use of different heteropoly acids (HPAs), viz, Dodeca-Tungstophosphoric acid [H3PO4.12WO3.xH2O] (TPA), Dodeca-Molyhdo phosphoric acid ammonium salt hydrate [H12Mo12N3O40P+aq] (DMAA), Dodeca-Molyhdo Phosphoric acid (PMA) on clay (MontmoriUonite, K-10) and as such plain clay. This comparative study reveals that 20%PMA/Clay shows 62% toluene conversion and 100% selectivity toward p-xylene.
文摘The alkylation of toluene with methanol to selective formation of p-xylene has been systematically studied. ZSM-12 (MTW)/ZSM-5 co-crystalline zeolite in 40:60 proportions have been synthesized by the same molar gel composition, but at different temperatures and periods than that of ZSM-12 and ZSM-5, separately. All the prepared samples are characterized by XRD, SEM, BET, and XRF. The activity of toluene alkylation was investigated with a mixture of toluene and methanol as a feed over the ZSM-12, ZSM-12/ZSM-5 co-crystalline, ZSM-5, and physical mixture of ZSM-12/ZSM-5. From characterization, it is observed that the ZSM-12/ZSM-5 co-crystalline material is different from that of ZSM-12, ZSM-5, and their physical mixture. Further, the ZSM-12/ZSM-5 co-crystalline zeolite produces the highest content of xylene and has better selectivity for p-xylene than ZSM-12, ZSM-5, and their physical mixture.
基金supported by the Natural Science Foundation of Zhejiang Province of China(No.LQ16D060004)Key Research and Development Projects of Zhejiang Province of China(No.2018C02043)+1 种基金Demonstration Project of Marine Economic Innovation and Development of Zhoushan City of ChinaDemonstration Project of Marine Economic Innovation and Development of Yantai City of China(No.YHCX-SW-L-201705).
文摘The global consumption of p-xylene(PX)for the production of polymers has raised serious concerns about its impact on the environment.As various reports have shown the risks that PX could pose to human health,research into cost-effective remedial methods to remove PX from the environment has gained attraction.In this work,a hierarchical porous crab shell biochar(KCS)was synthesized,characterized,and evaluated for its efficiency to remove PX from aqueous solution.The characterizations of KCS,including the porous structure,surface functional group,phase structure,and surface morphology,were discussed by N_(2) adsorption-desorption,FTIR,XRD,and SEM.Batch adsorption experiments showed that the maximum adsorption capacity of PX on KCS was 393 mg/g within 5 min,larger than most biological/biomass materials,mainly due to the higher specific surface area of 2046 m^(2)/g,and abundant lipophilic functional groups.Subsequent adsorption kinetics study indicated a pseudo-second-order model which implied that the adsorption of PX was due to chemisorption.Thermodynamic parameters showed that the values ofΔH°andΔG°were both negative,indicating that the PX adsorption process on KCS was spontaneous and exothermic.The performance of KCS in delivering a cost-effective,fast,and efficient solution for the removal of PX from aqueous solution would greatly benefit current environmental remediation efforts.
文摘Vapor-liquid equilibrium composition and temperature were measured for binary andternary mixtures of benzene,toluene and p-xylene at 101.33 kPa The equilibrium cell of Boubliketal.was modified for the present study.The experimental vapor-liquid equilibrium data were corre-lated with the Wilson equation.