The influence of zeolite structure and process parameters (including reaction temperature and catalyst/oil ratio) on rules for formation of ethylene and propylene in the course of catalytic pyrolysis of n-heptane was ...The influence of zeolite structure and process parameters (including reaction temperature and catalyst/oil ratio) on rules for formation of ethylene and propylene in the course of catalytic pyrolysis of n-heptane was studied in a small- scale fixed fluid catalytic cracking unit. Test results have revealed that compared to the USY zeolite and Beta zeolite, the catalytic pyrolysis of n-heptane in the presence of the ZRP zeolite catalyst can result in higher yield and selectivity of ethyl- ene and propylene, while a higher reaction temperature and a higher catalyst/oil ratio can promote the formation of ethylene and propylene during catalytic pyrolysis of n-heptane. The ethylene formation reaction is more sensitive to the changes in reaction temperature, whereas the changes in catalyst/oil ratio are more influential to the propylene formation reaction. This paper has made a preliminary exploration into the different reaction pathways for formation of ethylene and propylene on zeolites with different structures.展开更多
The novel microwave catalyst MgFe204-SiC was synthesized via sol-gel method, to remove azo dye Direct Black BN （DB BN） through adsorption and microwave-induced catalytic reaction. Microwave- induced catalytic degrad...The novel microwave catalyst MgFe204-SiC was synthesized via sol-gel method, to remove azo dye Direct Black BN （DB BN） through adsorption and microwave-induced catalytic reaction. Microwave- induced catalytic degradation of DB BN, including adsorption behavior and its influencing Factors of DB BN on MgFc204-SiC were investigated. According to the obtained results, il indicated thai the pseudo-second-order kinetics model was suitable fbr the adsorption of DB BN onto MgFc204-SiC. Besides, the consequence of adsorption isotherm depicted that the adsorption of DB BN was in accordance with the Langmuir isotherm, which verified that the singer layer adsorption of MgF%O4- SiC was dominant than the multi-layer one. The excellent adsorption capacities of MgFe204-SiC were kept in the range of initial pH from 3 to 7. In addition, it could be concluded that the degradation rate of DB BN decreased over ten percent after the adsorption equilibrium had been attained, and thc results from the result of comparative experiments manitbsted that the adsorption process was not conducive to the process of microwave-induced catalytic degradation. The degradation intermediates and products of DB BN were identified and determined by GC-MS and LC-MS. Furthermore, combined with the catalytic mechanism of MgFe204-SiC, the proposed degradation pathways of DB BN were the involution of microwave-induced OH and holes in this catalytic system the breakage of azo bond, hydroxyl substitution, hydroxyl addition, nitration reaction, dcamination reaction, dcsorbate reaction, dehydroxy group and ring-opening reaction.展开更多
文摘The influence of zeolite structure and process parameters (including reaction temperature and catalyst/oil ratio) on rules for formation of ethylene and propylene in the course of catalytic pyrolysis of n-heptane was studied in a small- scale fixed fluid catalytic cracking unit. Test results have revealed that compared to the USY zeolite and Beta zeolite, the catalytic pyrolysis of n-heptane in the presence of the ZRP zeolite catalyst can result in higher yield and selectivity of ethyl- ene and propylene, while a higher reaction temperature and a higher catalyst/oil ratio can promote the formation of ethylene and propylene during catalytic pyrolysis of n-heptane. The ethylene formation reaction is more sensitive to the changes in reaction temperature, whereas the changes in catalyst/oil ratio are more influential to the propylene formation reaction. This paper has made a preliminary exploration into the different reaction pathways for formation of ethylene and propylene on zeolites with different structures.
文摘The novel microwave catalyst MgFe204-SiC was synthesized via sol-gel method, to remove azo dye Direct Black BN （DB BN） through adsorption and microwave-induced catalytic reaction. Microwave- induced catalytic degradation of DB BN, including adsorption behavior and its influencing Factors of DB BN on MgFc204-SiC were investigated. According to the obtained results, il indicated thai the pseudo-second-order kinetics model was suitable fbr the adsorption of DB BN onto MgFc204-SiC. Besides, the consequence of adsorption isotherm depicted that the adsorption of DB BN was in accordance with the Langmuir isotherm, which verified that the singer layer adsorption of MgF%O4- SiC was dominant than the multi-layer one. The excellent adsorption capacities of MgFe204-SiC were kept in the range of initial pH from 3 to 7. In addition, it could be concluded that the degradation rate of DB BN decreased over ten percent after the adsorption equilibrium had been attained, and thc results from the result of comparative experiments manitbsted that the adsorption process was not conducive to the process of microwave-induced catalytic degradation. The degradation intermediates and products of DB BN were identified and determined by GC-MS and LC-MS. Furthermore, combined with the catalytic mechanism of MgFe204-SiC, the proposed degradation pathways of DB BN were the involution of microwave-induced OH and holes in this catalytic system the breakage of azo bond, hydroxyl substitution, hydroxyl addition, nitration reaction, dcamination reaction, dcsorbate reaction, dehydroxy group and ring-opening reaction.
