Monte Carlo method is applied to investigate the kinetics of ammonia oxidative decomposition over the commercial propylene ammoxidation catalyst(Mo-Bi). The simulation is quite in agreement with experimental results. ...Monte Carlo method is applied to investigate the kinetics of ammonia oxidative decomposition over the commercial propylene ammoxidation catalyst(Mo-Bi). The simulation is quite in agreement with experimental results. Monte Carlo simulation proves that the process of ammonia oxidation decomposition is a two-step reaction.展开更多
Removal of hydrophobic organic contaminants (HOCs) from soil of low permeability by electroremedia-tion was investigated by using phenanthrene and kaolinite as a model system. Tween 80 was added into the purging solut...Removal of hydrophobic organic contaminants (HOCs) from soil of low permeability by electroremedia-tion was investigated by using phenanthrene and kaolinite as a model system. Tween 80 was added into the purging solution in order to enhance the solubility of phenanthrene. The effects of pH on the adsorption of phenanthrene and Tween 80 on kaolinite and the magnitude of -potential of kaolinite were examined, respectively. The effects of electric field strength indicated by electric current on the electroremediation behavior, including the pH of purging solution, the conductivity, phenanthrene concentration and flow rate of effluent, were experimentally investigated, respectively. In case of an electric field of 25 mA applied for 72 hours, over 90% of phenanthrene was removed from 424 g (dry mass) of kaolinite at an energy consumption of 0.148 kW-h. The experimental results described in present study show that the addition of surfactant into purging solution greatly enhances the removal of HOCs by electroremediation.展开更多
An experimental study of vertical gas conveying of Geldart-D powder as a dilute phase is performed in a pipe of length 22m and internal diameter 0.05m using a fluidized blow tank at gas velocity ranging from 5m.S-1 to...An experimental study of vertical gas conveying of Geldart-D powder as a dilute phase is performed in a pipe of length 22m and internal diameter 0.05m using a fluidized blow tank at gas velocity ranging from 5m.S-1 to 13m.s-1 and loading ratio up to about 30. The characteristics of gas conveying, such as pressure drop, the choking velocity and the minimum primary velocity of the fluidized blow tank, are discussed in detail.展开更多
The methanol-to-olefins(MTO)process has the potential to bridge future gaps in the supply of sustainable lower olefins.Promoting the selectivity of propylene and ethylene and revealing the catalytic role of active sit...The methanol-to-olefins(MTO)process has the potential to bridge future gaps in the supply of sustainable lower olefins.Promoting the selectivity of propylene and ethylene and revealing the catalytic role of active sites are challenging goals in MTO reactions.Here,we report a novel heteroatomic silicoaluminophosphate(SAPO)zeolite,SAPO-34-Ta,which incorporates active tantalum(V)sites within the framework to afford an optimal distribution of acidity.SAPO-34-Ta exhibits a remarkable total selectivity of 85.8%for propylene and ethylene with a high selectivity of 54.9%for propylene on full conversion of methanol at 400°C.In situ and operando synchrotron powder X-ray diffraction,diffuse reflectance infrared Fourier transform spectroscopy and inelastic neutron scattering,coupled with theoretical calculations,reveal trimethyloxonium as the key reaction intermediate,promoting the formation of first carbon-carbon bonds in olefins.The tacit cooperation between tantalum(V)and Brønsted acid sites within SAPO-34 provides an efficient platform for selective production of lower olefins from methanol.展开更多
文摘Monte Carlo method is applied to investigate the kinetics of ammonia oxidative decomposition over the commercial propylene ammoxidation catalyst(Mo-Bi). The simulation is quite in agreement with experimental results. Monte Carlo simulation proves that the process of ammonia oxidation decomposition is a two-step reaction.
基金Supported by the National Natural Science Foundation (No. 29976020) and Tsinghua University Foundation.
文摘Removal of hydrophobic organic contaminants (HOCs) from soil of low permeability by electroremedia-tion was investigated by using phenanthrene and kaolinite as a model system. Tween 80 was added into the purging solution in order to enhance the solubility of phenanthrene. The effects of pH on the adsorption of phenanthrene and Tween 80 on kaolinite and the magnitude of -potential of kaolinite were examined, respectively. The effects of electric field strength indicated by electric current on the electroremediation behavior, including the pH of purging solution, the conductivity, phenanthrene concentration and flow rate of effluent, were experimentally investigated, respectively. In case of an electric field of 25 mA applied for 72 hours, over 90% of phenanthrene was removed from 424 g (dry mass) of kaolinite at an energy consumption of 0.148 kW-h. The experimental results described in present study show that the addition of surfactant into purging solution greatly enhances the removal of HOCs by electroremediation.
文摘An experimental study of vertical gas conveying of Geldart-D powder as a dilute phase is performed in a pipe of length 22m and internal diameter 0.05m using a fluidized blow tank at gas velocity ranging from 5m.S-1 to 13m.s-1 and loading ratio up to about 30. The characteristics of gas conveying, such as pressure drop, the choking velocity and the minimum primary velocity of the fluidized blow tank, are discussed in detail.
基金University of Manchester,the National Natural Science Foundation of China and BNLMS for funding,and the EPSRC for funding of the EPSRC National EPR Facility at Manchester(EP/W014532/1 and EP/X034623/1)We are grateful to the STFC/ISIS Facility and Diamond Light Source for access to the beamlines TOSCA/MAPS,and I11/B18/B22,respectively+8 种基金We are grateful to the STFC/ISIS Facility and Diamond Light Source for access to the beamlines TOSCA/MAPS,and I11/B18/B22,respectivelyWe acknowledge the UK catalysis Hub Block Allocation Group(BAG)Programme Mode Application for provision of beamtime at B18 for collection of the data presented in this work and the initial discussion of the dataThe UK Catalysis Hub is kindly thanked for resources and support provided via our membership of the UK Catalysis Hub Consortium and funded by EPSRC grant:EP/R026939,EP/R026815,EP/R026645,EP/R027129 and EP/M013219(biocatalysis)We acknowledge the support of The University of Manchester's Dalton Cumbrian Facility(DCF),a partner in the National Nuclear User FacilityWe recognise Dr.R.Edge for the assistance during the 60Co-irradiation processesWe thank M.Kibble for help at ISIS beamlinesTEM access was supported by the Henry Royce Institute for Advanced Materials,funded through EPSRC grants EP/R00661X,EP/S019367,EP/P025021 and EP/P025498Zhaodong Zhu thanks the President's Doctoral Scholar award of University of Manchester for fundingMeng He and Lutong Shan thank the China Scholarship Council(CSC)for funding.
文摘The methanol-to-olefins(MTO)process has the potential to bridge future gaps in the supply of sustainable lower olefins.Promoting the selectivity of propylene and ethylene and revealing the catalytic role of active sites are challenging goals in MTO reactions.Here,we report a novel heteroatomic silicoaluminophosphate(SAPO)zeolite,SAPO-34-Ta,which incorporates active tantalum(V)sites within the framework to afford an optimal distribution of acidity.SAPO-34-Ta exhibits a remarkable total selectivity of 85.8%for propylene and ethylene with a high selectivity of 54.9%for propylene on full conversion of methanol at 400°C.In situ and operando synchrotron powder X-ray diffraction,diffuse reflectance infrared Fourier transform spectroscopy and inelastic neutron scattering,coupled with theoretical calculations,reveal trimethyloxonium as the key reaction intermediate,promoting the formation of first carbon-carbon bonds in olefins.The tacit cooperation between tantalum(V)and Brønsted acid sites within SAPO-34 provides an efficient platform for selective production of lower olefins from methanol.
