利用三氯化铁改型的沸石在水中的除氟性能,对其使用条件及除氟机理进行了研究。并对洗脱、再生后的吸附剂进行了再吸附柱试验。研究表明,该吸附剂的静态饱和吸附容量可达26.57 m g/g,动态吸附容量可达16.81 m g/g,吸附平衡时间为2~3 h,...利用三氯化铁改型的沸石在水中的除氟性能,对其使用条件及除氟机理进行了研究。并对洗脱、再生后的吸附剂进行了再吸附柱试验。研究表明,该吸附剂的静态饱和吸附容量可达26.57 m g/g,动态吸附容量可达16.81 m g/g,吸附平衡时间为2~3 h,含氟水中共存阴离子对吸附几乎不产生影响,可用稀碱液进行洗脱,多次洗脱再生后的吸附剂可重复使用,吸附剂性能稳定,机械强度高。展开更多
The effects of olefins were quantified by measuring the decreased amount of thiophenes removed by modified zeolites with an increasing olefin concentration in model fuels (300 ppm) via fixed-bed adsorption technique...The effects of olefins were quantified by measuring the decreased amount of thiophenes removed by modified zeolites with an increasing olefin concentration in model fuels (300 ppm) via fixed-bed adsorption technique at room temperature and atmosphere pressure. The influence of olefins on adsorptive desulfurization of model fuel had been investigated by FT-IR techniques, which revealed that the protons in the zeolites were the sites responsible for the adsorption of olefins. On the CeY zeolite, in the presence of strong hydroxyl species in the zeolites, the adsorbed olefin compounds can attach to the protons molecularly via electrophilic interaction and undergo the opening of the C=C bonds depending on the acidity of the zeolites. The reduced desulfurization performance of CeY zeolite was attributed to the direct occupation of the absorbent's active sites by olefins. In contrast to the CeY zeolite, the NiY zeolites were unable to react directly with pure olefins. However the sulfur compounds and olefins adsorbed on the protons may subsequently undergo olefin alkylation reactions, which can block the zeolite pores and then prevent sulfide molecules from having access to super-cages to contact with the metal cations. This work demonstrates also that the NiY zeolites exhibit excellent performance for selective adsorption desulfurization of model fuel containing olefin compounds.展开更多
In order to reduce the olefin content in gasoline manufactured by the MGG (Maximizing Liquefied Gas and Gasoline) process while retaining the LPG yield, RIPP has developed a novel catalyst consisting of a more pore-...In order to reduce the olefin content in gasoline manufactured by the MGG (Maximizing Liquefied Gas and Gasoline) process while retaining the LPG yield, RIPP has developed a novel catalyst consisting of a more pore-opened matrix and the modified Y-zeolite and the ZRP zeolite modified with metal oxides. Test results have revealed that compared with the commercial catalyst RAG under comparable reaction conditions the reaction conversion rate and product distribution provided by the novel catalyst were similar, but the olefin content in gasoline obtained thereof was decreased with the octane rating unchanged along with a slight reduction of olefin content in the LPG fraction. The hydrothermal stability of the novel catalyst was better than the commercial catalyst RAG.展开更多
文摘利用三氯化铁改型的沸石在水中的除氟性能,对其使用条件及除氟机理进行了研究。并对洗脱、再生后的吸附剂进行了再吸附柱试验。研究表明,该吸附剂的静态饱和吸附容量可达26.57 m g/g,动态吸附容量可达16.81 m g/g,吸附平衡时间为2~3 h,含氟水中共存阴离子对吸附几乎不产生影响,可用稀碱液进行洗脱,多次洗脱再生后的吸附剂可重复使用,吸附剂性能稳定,机械强度高。
基金supported by the National Natural Science Foundation of China(No. 20476042 and No.20776064)the Ministry of Science and Technology of the People's Republic of China under the National Basic Research Program of China(973 Program) (2007CB216403)
文摘The effects of olefins were quantified by measuring the decreased amount of thiophenes removed by modified zeolites with an increasing olefin concentration in model fuels (300 ppm) via fixed-bed adsorption technique at room temperature and atmosphere pressure. The influence of olefins on adsorptive desulfurization of model fuel had been investigated by FT-IR techniques, which revealed that the protons in the zeolites were the sites responsible for the adsorption of olefins. On the CeY zeolite, in the presence of strong hydroxyl species in the zeolites, the adsorbed olefin compounds can attach to the protons molecularly via electrophilic interaction and undergo the opening of the C=C bonds depending on the acidity of the zeolites. The reduced desulfurization performance of CeY zeolite was attributed to the direct occupation of the absorbent's active sites by olefins. In contrast to the CeY zeolite, the NiY zeolites were unable to react directly with pure olefins. However the sulfur compounds and olefins adsorbed on the protons may subsequently undergo olefin alkylation reactions, which can block the zeolite pores and then prevent sulfide molecules from having access to super-cages to contact with the metal cations. This work demonstrates also that the NiY zeolites exhibit excellent performance for selective adsorption desulfurization of model fuel containing olefin compounds.
文摘In order to reduce the olefin content in gasoline manufactured by the MGG (Maximizing Liquefied Gas and Gasoline) process while retaining the LPG yield, RIPP has developed a novel catalyst consisting of a more pore-opened matrix and the modified Y-zeolite and the ZRP zeolite modified with metal oxides. Test results have revealed that compared with the commercial catalyst RAG under comparable reaction conditions the reaction conversion rate and product distribution provided by the novel catalyst were similar, but the olefin content in gasoline obtained thereof was decreased with the octane rating unchanged along with a slight reduction of olefin content in the LPG fraction. The hydrothermal stability of the novel catalyst was better than the commercial catalyst RAG.