Zeolite 4A is the main substitute builders for sodium tripolyphosphate in non-phosphated detergent. It can be manufactured from savageness clay and the cost may greatly be reduced by this method. In the manufacturing ...Zeolite 4A is the main substitute builders for sodium tripolyphosphate in non-phosphated detergent. It can be manufactured from savageness clay and the cost may greatly be reduced by this method. In the manufacturing process of detergent-used zeolite 4A from montmorillonite, it is important to remove quartz from clay or zeolite, otherwise the product will not qualified for detergent additive. This article provides two methods, the calibration curve method of quartz content by XRD and the calibration curve method of aluminium ion concentration in synthetic system, to determine the quartz content. Then three methods of removing quartz were studied on, including the methods of whirlwind during the mill run, filtration after alkalinization of silicic acid gel and sedimentation of zeolite.展开更多
Exchange rates of calcium ion with high aluminum zeolites used in detergent, such as NaA, MAP and MAX zeolites, were measured by using a improved calcium ion selective electrode method (ISE). The calcium exchange kine...Exchange rates of calcium ion with high aluminum zeolites used in detergent, such as NaA, MAP and MAX zeolites, were measured by using a improved calcium ion selective electrode method (ISE). The calcium exchange kinetics of zeolites was studies by using Body Reichenberg diffusion equation. The effects of the particle size, pore structure of zeolites and the ion exchange temperature on the calcium ion exchange kinetics were also investigated. Results showed that the diffusion coefficients at room temperature were 2.33×10-15m2·s-1, 4.28×10-16m2· s-1 and 7.73×10-17m2·s-1 for zeolite MAX, NaA and MAP, respectively. The activation energy of diffusion was 48kJ·mol-1, 65kJ·mol-1 and 91kJ·mol-1 for zeolite MAX, NaA and MAP, respectively.展开更多
Modification of KL zeolite by chemical vapour deposition (CVD) of Si(OEt)4 and (CH3)3SiOSi(CH3)3 was used to study the influence of zeoltie support on the aromatization of n-hexane over Pt/KL catalyst. The pore size a...Modification of KL zeolite by chemical vapour deposition (CVD) of Si(OEt)4 and (CH3)3SiOSi(CH3)3 was used to study the influence of zeoltie support on the aromatization of n-hexane over Pt/KL catalyst. The pore size and pore volume of zeolite were decreased by CVD. The acidic hydroxyl groups remaining on the surface of KL zeolite were removed and thus the selectivity of non-acidic catalyzed aromatization reaction was improved. Whereas the activity of aromatiztion reaction was decreased due to the destruction of some of active sites in KL zeolite for 1,6-cyclization. Becuase of the coverage of the framework of zeolite by CVD of SiO2, Pt particles became more electron-excess.Therefore, the silica-coated catalysts were easier to be poisoned by sulphur.展开更多
The influence of second metal component (Fc) on Pt/KL zeolie catalyst was investi-gated. The catalytic properties of Pt-Fe/KL zeolite varied as the amount of Fe. When the amount of Fe was 0.3 % (mass fraction), the ca...The influence of second metal component (Fc) on Pt/KL zeolie catalyst was investi-gated. The catalytic properties of Pt-Fe/KL zeolite varied as the amount of Fe. When the amount of Fe was 0.3 % (mass fraction), the catalyst was found to show both excellent n-hexane aromati-zation reactivity and higher ability for sulphur-resistance. The dispersion of Pt particles was also found to be better in this bimetallic catalyst, whereas the electron state of Pt particles as indicated by CO-FTIR was nlodified to be more electron-deficient than that of Pt/KL zeolite, which made the bimetallic Pt-Fe/KL more tolerant to sulphur poisoning.展开更多
Calcium ion exchange behavior of Zeolites used in detergent such as NaA, NaX and NaP was studied by Ion Selective Electrode Method (ISE). The linear relationship between calcium ion exchange capacity and framework alu...Calcium ion exchange behavior of Zeolites used in detergent such as NaA, NaX and NaP was studied by Ion Selective Electrode Method (ISE). The linear relationship between calcium ion exchange capacity and framework aluminum content of zeolite NaX was found, and the effects of exchange temperature, concentration of zeolite and other cations on calcium ion exchange behavior were also investigated. The sequence of the calcium ion exchange selectivity of zeolite MAP, NaA and NaP was determined. The framework structure of zeolite NaA, NaX and NaP significantly influence the cation exchange behavior of these three zeolites.展开更多
文摘Zeolite 4A is the main substitute builders for sodium tripolyphosphate in non-phosphated detergent. It can be manufactured from savageness clay and the cost may greatly be reduced by this method. In the manufacturing process of detergent-used zeolite 4A from montmorillonite, it is important to remove quartz from clay or zeolite, otherwise the product will not qualified for detergent additive. This article provides two methods, the calibration curve method of quartz content by XRD and the calibration curve method of aluminium ion concentration in synthetic system, to determine the quartz content. Then three methods of removing quartz were studied on, including the methods of whirlwind during the mill run, filtration after alkalinization of silicic acid gel and sedimentation of zeolite.
文摘Exchange rates of calcium ion with high aluminum zeolites used in detergent, such as NaA, MAP and MAX zeolites, were measured by using a improved calcium ion selective electrode method (ISE). The calcium exchange kinetics of zeolites was studies by using Body Reichenberg diffusion equation. The effects of the particle size, pore structure of zeolites and the ion exchange temperature on the calcium ion exchange kinetics were also investigated. Results showed that the diffusion coefficients at room temperature were 2.33×10-15m2·s-1, 4.28×10-16m2· s-1 and 7.73×10-17m2·s-1 for zeolite MAX, NaA and MAP, respectively. The activation energy of diffusion was 48kJ·mol-1, 65kJ·mol-1 and 91kJ·mol-1 for zeolite MAX, NaA and MAP, respectively.
文摘Modification of KL zeolite by chemical vapour deposition (CVD) of Si(OEt)4 and (CH3)3SiOSi(CH3)3 was used to study the influence of zeoltie support on the aromatization of n-hexane over Pt/KL catalyst. The pore size and pore volume of zeolite were decreased by CVD. The acidic hydroxyl groups remaining on the surface of KL zeolite were removed and thus the selectivity of non-acidic catalyzed aromatization reaction was improved. Whereas the activity of aromatiztion reaction was decreased due to the destruction of some of active sites in KL zeolite for 1,6-cyclization. Becuase of the coverage of the framework of zeolite by CVD of SiO2, Pt particles became more electron-excess.Therefore, the silica-coated catalysts were easier to be poisoned by sulphur.
文摘The influence of second metal component (Fc) on Pt/KL zeolie catalyst was investi-gated. The catalytic properties of Pt-Fe/KL zeolite varied as the amount of Fe. When the amount of Fe was 0.3 % (mass fraction), the catalyst was found to show both excellent n-hexane aromati-zation reactivity and higher ability for sulphur-resistance. The dispersion of Pt particles was also found to be better in this bimetallic catalyst, whereas the electron state of Pt particles as indicated by CO-FTIR was nlodified to be more electron-deficient than that of Pt/KL zeolite, which made the bimetallic Pt-Fe/KL more tolerant to sulphur poisoning.
文摘Calcium ion exchange behavior of Zeolites used in detergent such as NaA, NaX and NaP was studied by Ion Selective Electrode Method (ISE). The linear relationship between calcium ion exchange capacity and framework aluminum content of zeolite NaX was found, and the effects of exchange temperature, concentration of zeolite and other cations on calcium ion exchange behavior were also investigated. The sequence of the calcium ion exchange selectivity of zeolite MAP, NaA and NaP was determined. The framework structure of zeolite NaA, NaX and NaP significantly influence the cation exchange behavior of these three zeolites.
