Introducing reduced metal and nitrogen species is a powerful strategy to improve the reactivity of carbon-based materials for selective catalytic reduction of NO_(x) with NH_(3).To further improve the NH_(3)-SCR perfo...Introducing reduced metal and nitrogen species is a powerful strategy to improve the reactivity of carbon-based materials for selective catalytic reduction of NO_(x) with NH_(3).To further improve the NH_(3)-SCR performance of non-pitch coal activated coke(NPAC),a series of metal oxides(e.g.,Co,Ce,and Ni)were loaded on nitrogen modified NPAC.The outstanding performance of NPAC-N-CoCeNi as well as the superior SO_(2)-and H_(2)O-tolerate performance are attributed to the extra electrons caused by the modification of N species,and these extra electrons are more conducive to the electron transfer.More importantly,the interaction of the major active component Co^(3+)and the promoter catalysts CeO_(2),NiOx,or CoNiO_(2) can also increase the charge transfer and produce more oxygen vacancy and unsaturated chemical bonds,leading to improving the redox performance of NPAC-N-CoCeNi.In addition,the NH3-SCR reaction is promoted after the metal oxides co-doping mainly via the Mars-van-Krevelen mechanism.展开更多
Differential scanning calorimetry(DSC)was used to investigate the thermal decomposition and thermal safety characteristics of Shuangfang-3(SF-3)gun propellant.The kinetic calculation of the DSC curve was carried out b...Differential scanning calorimetry(DSC)was used to investigate the thermal decomposition and thermal safety characteristics of Shuangfang-3(SF-3)gun propellant.The kinetic calculation of the DSC curve was carried out by Kissinger and Friedman models,and the time to the maximum rate under adiabatic conditions and the self-accelerating decomposition temperature were calculated by using the AKTS thermal analysis software in combination with the heat balance equation.The thermal history experiment was carried out to further analyze the autocatalytic properties of SF-3.The results show that the initial decomposition temperature,decomposition peak temperature,and decomposition completion temperature of SF-3 all move to the high temperature direction with the increase of heating rate,and the average decomposition heat is 1521.4 J/g.The kinetic model showcased that SF-3 has different reactions in different reaction stages,and its apparent activation energy is 168.2 kJ/mol.When the times to maximum rate under adiabatic conditions are 2.0 h,4.0 h,8.0 h,24.0 h,respectively,the corresponding temperatures are 130.7℃,124.8℃,119.2℃and 110.5℃,respectively.When the masses are 5.0 kg,15.0 kg,25.0 kg,50.0 kg,100.0 kg,respectively,the corresponding self-accelerating decomposition temperatures are 110.0℃,105.0℃,102.0℃,99.0℃and 96.0℃,respectively.As the packaging mass increases,it is more difficult to exchange the liberated heat into the surrounding environment and its safety would be further reduced.The thermal history experiment demonstrates that the thermal decomposition of SF-3 is an n-stage reaction and does not have autocatalytic properties.Therefore,the size and ventilation conditions of the sample have a certain impact on the storage stability of SF-3.In the actual production,usage,storage and transportation,sample size and ventilation conditions should be controlled,and practical and effective measures should be taken according to the actual situation.展开更多
The explosion characteristics of M15 methanol-gasoline mixture was experimental test by using FRTA explosion limit instrument.The effect of temperature on the explosion area of the sample was studied.The results show ...The explosion characteristics of M15 methanol-gasoline mixture was experimental test by using FRTA explosion limit instrument.The effect of temperature on the explosion area of the sample was studied.The results show that the lower explosion limit of M15 methanol-gasoline mixture is 1.716%and the upper explosion limit is 11.451%at the initial temperature of 80℃.The lower explosion limit of M15 methanol-gasoline is in the range of 1.711%-1.760%with the initial temperature from 25℃to 100℃,and the upper explosion limit of the sample changes between 11.253%and 11.451%.Considering experimental error and precision,it can be approximated that the temperature has little influence on the explosion area of M15 methanol-gasoline mixture.展开更多
基金This work was financially supported by the National Natural Science Foundation of China(51901209)the Postdoctoral Science Program of China(2019M660061)the Applied Basic Study Program of Shanxi Province(201801D221349).
文摘Introducing reduced metal and nitrogen species is a powerful strategy to improve the reactivity of carbon-based materials for selective catalytic reduction of NO_(x) with NH_(3).To further improve the NH_(3)-SCR performance of non-pitch coal activated coke(NPAC),a series of metal oxides(e.g.,Co,Ce,and Ni)were loaded on nitrogen modified NPAC.The outstanding performance of NPAC-N-CoCeNi as well as the superior SO_(2)-and H_(2)O-tolerate performance are attributed to the extra electrons caused by the modification of N species,and these extra electrons are more conducive to the electron transfer.More importantly,the interaction of the major active component Co^(3+)and the promoter catalysts CeO_(2),NiOx,or CoNiO_(2) can also increase the charge transfer and produce more oxygen vacancy and unsaturated chemical bonds,leading to improving the redox performance of NPAC-N-CoCeNi.In addition,the NH3-SCR reaction is promoted after the metal oxides co-doping mainly via the Mars-van-Krevelen mechanism.
基金Key Research and Development Project of Shanxi Province(No.201903D121028)。
文摘Differential scanning calorimetry(DSC)was used to investigate the thermal decomposition and thermal safety characteristics of Shuangfang-3(SF-3)gun propellant.The kinetic calculation of the DSC curve was carried out by Kissinger and Friedman models,and the time to the maximum rate under adiabatic conditions and the self-accelerating decomposition temperature were calculated by using the AKTS thermal analysis software in combination with the heat balance equation.The thermal history experiment was carried out to further analyze the autocatalytic properties of SF-3.The results show that the initial decomposition temperature,decomposition peak temperature,and decomposition completion temperature of SF-3 all move to the high temperature direction with the increase of heating rate,and the average decomposition heat is 1521.4 J/g.The kinetic model showcased that SF-3 has different reactions in different reaction stages,and its apparent activation energy is 168.2 kJ/mol.When the times to maximum rate under adiabatic conditions are 2.0 h,4.0 h,8.0 h,24.0 h,respectively,the corresponding temperatures are 130.7℃,124.8℃,119.2℃and 110.5℃,respectively.When the masses are 5.0 kg,15.0 kg,25.0 kg,50.0 kg,100.0 kg,respectively,the corresponding self-accelerating decomposition temperatures are 110.0℃,105.0℃,102.0℃,99.0℃and 96.0℃,respectively.As the packaging mass increases,it is more difficult to exchange the liberated heat into the surrounding environment and its safety would be further reduced.The thermal history experiment demonstrates that the thermal decomposition of SF-3 is an n-stage reaction and does not have autocatalytic properties.Therefore,the size and ventilation conditions of the sample have a certain impact on the storage stability of SF-3.In the actual production,usage,storage and transportation,sample size and ventilation conditions should be controlled,and practical and effective measures should be taken according to the actual situation.
基金Key Research and Development(R&D)Projects of Shanxi Province(No.201903D121028)Special Foundation for Platform Base and Outstanding Talent of Shanxi Province(No.201705D211002)。
文摘The explosion characteristics of M15 methanol-gasoline mixture was experimental test by using FRTA explosion limit instrument.The effect of temperature on the explosion area of the sample was studied.The results show that the lower explosion limit of M15 methanol-gasoline mixture is 1.716%and the upper explosion limit is 11.451%at the initial temperature of 80℃.The lower explosion limit of M15 methanol-gasoline is in the range of 1.711%-1.760%with the initial temperature from 25℃to 100℃,and the upper explosion limit of the sample changes between 11.253%and 11.451%.Considering experimental error and precision,it can be approximated that the temperature has little influence on the explosion area of M15 methanol-gasoline mixture.
