Publications (Cited by EI)

EI论文25-29


2008-06-27
29.Accession number 05159039337

Study of catalysis oxidation of methane to methanol in liquid phase


 Gao Xiao Hua Xue Gong Cheng Xue Bao

The selective oxidation of methane in oleum was catalyzed by the iodine compounds. The effect of the catalysts kinds, catalyst concentration, reaction temperature and the amount of SO3 in oleum on the conversion of methane and the yield of methanol were investigated. The mechanism of reaction in oluent was studied and the functions of oluent were also discussed. Among the tested catalysts, I2 showed the highest activity and selectivity. Under the optimal reaction condition, that is, the concentration of I2 is 0.099 mol·L-1, reaction temperature is 473 K, pressure of methane is 3.4 MPa, reaction time is for 3 h, the content of sulfur trioxide in oleum is about 50%, the 82.65% conversion of methane and the 70.43% yield of methanol could be obtained. The mechanism analysis shows that methane is transformed into methyl bisulfate firstly, then the methyl bisulfate is hydrolyzed into methanol. The oxidation of methane follows the mechanism of electrophilic displacement intermediate. The SO3 of oluent is the key element in the oxidation of methane and the functions of strong acid are supplying the electrophilic surrounding, being the source of oxidant and the nucleophile to product a stable intermediate.

 

28.Accession number: 04438424816

Title: Studies on the kinetics of synthesis of zinc oxalate nanoparticles

Authors: He, Yong-Jun; Yang, Bo-Lun  

Serial title: Gao Xiao Hua Xue Gong Cheng Xue Bao/Journal of Chemical Engineering of Chinese Universities

Abstract: Zinc oxalate nanoparticles were synthesized from the coupling route of microemulsion and homogeneous precipitation. To probe in the kinetic features of the growth of zinc oxalate nanoparticles, the radius of the water droplet of NP-9/hexanol/heptane/zinc nitrate solution microemulsion was inspected through diluting method; the variation of the concentration of methyl oxalate with time in the precipitation reaction was tested, and the kinetic equation of the hydrolysis of methyl oxalate was established. According to the diffusion mechanism, the relation of the size of nanoparticles to reaction time was derived, and the calculated size was compared with the experimental one. The results show that the radius of water droplet of NP-9/hexanol/heptane/zinc nitrate solution microemulsion is 1.86 nm at 308 K and 2.33 nm at 318 K respectively, and such microemulsion is a good medium for the synthesis of nanoparticles. When the precipitation reaction of methyl oxalate exists, the hydrolysis of methyl oxalate is a first order reaction. The calculated size of zinc oxalate nanoparticles was 15 to 30 times smaller than the experimental value. The kinetic process of nanoparticle growth mainly followed with the collision-fusion-cleavage mechanism.

Ei controlled terms: Zinc oxide | Microemulsions | Synthesis (chemical) | Precipitation (chemical) | Reaction kinetics

 

27.Accession number: 04278253082

Title: Biological elimination of hydrogen sulfide by immobilized Thiobacillus denitrificans

Authors: Ma, Yan-Ling; Zhao, Jing-Lian; Yang, Bo-Lun 

First author affiliation: Sch. of Environ. and Chem. Eng., Xi’an Jiaotong Univ., Xi’an 710049, China

Serial title: Xiandai Huagong/Modern Chemical Industry

Abstract: Thiobacillus denitrificans was immobilized with Ca-alginate to produce pellet packing materials for a packed column biological fixed bed that controlled hydrogen sulfide emission. The effects of operating parameters, such as temperature, pH value, inlet gas concentration and flow rate, on the removal efficiency were studied. The kinds and contents of metabolic products in the biological fixed bed were measured. The results showed that the optimal temperature and pH value required to remove hydrogen sulfide were 25-40°C and pH=6.0-7.5, correspondingly the hydrogen sulfide removal efficiency greater than 90% if inlet H2S concentration was below 6×10-5 mg/L, and pH value drop was insignificant in this fixed bed. The hydrogen sulfide removal efficiency was affected dramatically by the inlet gas concentration and flow rate. The biological fixed bed had a hydrogen sulfide removal efficiency remained above 95% when the inlet hydrogen sulfide concentration was below 3×10-5 mg/L at 35 L/h of flow rate. The element sulfur as a main product prevented acidification of the biological fixed bed, which maintained the stability of the operation.

 

26.Accession number: 05068829586

Title: Catalytic dehydration of tert-butyl alcohol using cation exchange resin

Authors: Zhao, Guo-Sheng; Yang, Bo-Lun; Yang, Xiao-Hui 

Serial title: Gao Xiao Hua Xue Gong Cheng Xue Bao/Journal of Chemical Engineering of Chinese Universities

Abstract: In order to explore a new technology to produce isobutylene via reactive distillation, the kinetics of dehydration of tert-butyl alcohol was studied by using the strong acid cation exchange resin NKC-9 as the catalyst under atmosphere. Effects of the operation conditions such as particle diameter of catalyst, speed of agitation, reaction temperature and reactant concentration on the reaction rate were investigated. Experimental results show that the effect of film diffusion and intraparticle diffusion can be neglected; the dehydration rate increases with temperature; water is found to inhibit the reaction rate due to the strong selective adsorption on the active acid sites of cation exchange resin in the alcohol solution. Based on these experimental results, a kinetics model was developed in which the water inhibition was considered. The relationships of the rate constant and the inhibition coefficient of water with the temperature and the activity energy were obtained. The calculation results agree well with the experimental results.

25.Accession number: 05068829586

Title: Catalytic dehydration of tert-butyl alcohol using cation exchange resin

Authors: Zhao, Guo-Sheng; Yang, Bo-Lun; Yang, Xiao-Hui 

Serial title: Gao Xiao Hua Xue Gong Cheng Xue Bao/Journal of Chemical Engineering of Chinese Universities

Abstract: In order to explore a new technology to produce isobutylene via reactive distillation, the kinetics of dehydration of tert-butyl alcohol was studied by using the strong acid cation exchange resin NKC-9 as the catalyst under atmosphere. Effects of the operation conditions such as particle diameter of catalyst, speed of agitation, reaction temperature and reactant concentration on the reaction rate were investigated. Experimental results show that the effect of film diffusion and intraparticle diffusion can be neglected; the dehydration rate increases with temperature; water is found to inhibit the reaction rate due to the strong selective adsorption on the active acid sites of cation exchange resin in the alcohol solution. Based on these experimental results, a kinetics model was developed in which the water inhibition was considered. The relationships of the rate constant and the inhibition coefficient of water with the temperature and the activity energy were obtained. The calculation results agree well with the experimental results.