A C_(9)H_(10)O_(2):0.5ZnCl_(2)/SG catalyst was synthesized using a one-step sol-gel method with silica gel(SG)as the carrier and C_(9)H_(10)O_(2):0.5ZnCl_(2)deep eutectic solvent(DES)as active component.The structure ...A C_(9)H_(10)O_(2):0.5ZnCl_(2)/SG catalyst was synthesized using a one-step sol-gel method with silica gel(SG)as the carrier and C_(9)H_(10)O_(2):0.5ZnCl_(2)deep eutectic solvent(DES)as active component.The structure of the supported catalyst was characterized by FT-IR,XRD,SEM,and N2 adsorption-desorption,and the DES was found to have successfully permeated the SG through its pores.The removal of dibenzothiophene(DBT)in model diesel was studied using C_(9)H_(10)O_(2):0.5ZnCl_(2)/SG as a catalyst and H_(2)O_(2)as an oxidant.The influence of loading dose of DES,reaction temperature,catalyst dosage,O/S molar ratio,and sulfide type on the desulfurization rate was investigated.The removal rates of DBT,4,6-dimethyldibenzothiophene(4,6-DMDBT),and benzothiophene(BT)under optimal reaction conditions were 99.4%,96%,and 78.2%,respectively.C_(9)H_(10)O_(2):0.5ZnCl_(2)/SG catalyst could be recycled five times with a little decrease of oxidative desulfurization activity,and the adsorption-oxidation desulfurization mechanism was examined.展开更多
柔性多状态开关(soft open point,SOP)作为可在配电网中替代传统联络开关的新型柔性一次设备,已成为主动配电网领域的研究热点。针对基于模块化多电平变流器(modularmultilevelconverter,MMC)的SOP装置,提出了一种改进型下垂控制策略,...柔性多状态开关(soft open point,SOP)作为可在配电网中替代传统联络开关的新型柔性一次设备,已成为主动配电网领域的研究热点。针对基于模块化多电平变流器(modularmultilevelconverter,MMC)的SOP装置,提出了一种改进型下垂控制策略,将具有功率分配特性的可调下垂系数与基于虚拟惯量的惯性下垂系数相结合。该控制策略可以根据换流站输出功率的变化相应地改变可调下垂系数以改善各端换流站的功率分配能力,提高系统稳定性。此外,该改进型下垂控制策略通过直流电容动态方程将系统频率与直流电压进行耦合,通过快速调整下垂系数调节各端MMC的输出功率,实现对弱交流电网的频率支撑,提高系统可靠性。最后,基于PSCAD/EMTDC仿真软件搭建了四端SOP系统模型,验证了所提控制策略的正确性与有效性。展开更多
The WO_3/C composite was successfully prepared by calcination of a mixture of WO_3 and g-C_3N_4 at 520 ℃. The as-synthesized samples were analyzed by X-ray diffraction(XRD), electronic differential system(EDS), scann...The WO_3/C composite was successfully prepared by calcination of a mixture of WO_3 and g-C_3N_4 at 520 ℃. The as-synthesized samples were analyzed by X-ray diffraction(XRD), electronic differential system(EDS), scanning electron microscopy(SEM), infrared spectrometry(IR) and the Brunner-Emmet-Teller(BET) techniques. The WO_3/C composite, in comparison with the WO_3 and C_3N_4, features smaller particle size, bigger surface area and higher desulphurization performance. The influence of the reaction temperature, the catalyst dosage, the reaction time, the oxidant dosage, the sulfide type and the extractant dose on desulfurization reaction was studied. The results showed that the WO_3/C composite revealed a higher desulfurization activity than the WO_3. The desulfurization rate could reach up to 95.8% under optimal conditions covering a catalyst dosage of 0.02 g, a H_2O_2 amount of 0.2 mL, a 1-ethyl-3-methylimidazolium ethyl sulfate(EMIES) amount of 1.0 mL, a reaction temperature of 70 ℃ and a reaction time of 180 min. After five recycles, the desulfurization activity of catalyst did not significantly decline.展开更多
H_(2)WO_(4)/GO catalyst was synthesized by the immersion method and was characterized by using X-ray diffraction(XRD),Fourier-transform infrared spectroscopy(FT-IR),scanning electron microscopy(SEM),and nitrogen adsor...H_(2)WO_(4)/GO catalyst was synthesized by the immersion method and was characterized by using X-ray diffraction(XRD),Fourier-transform infrared spectroscopy(FT-IR),scanning electron microscopy(SEM),and nitrogen adsorptiondesorption measurements(BET).The characterization results show that H_(2)WO_(4) has been dispersed on GO(grapheme oxide).H_(2)WO_(4)/GO was used as catalyst in the oxidative desulfurization of dibenzothiophene(DBT),with H2O2 acting as oxidant and acetonitrile acting as extraction agent.The experimental results show that the sulfur removal rate for DBT reach 99.2%,that for 4,6-dimethyldibenzothiophene(4,6-DMDBT)reach 95%and that for benzothiophene(BT)reach 42.8%under the optimal reaction conditions.Meanwhile,the recycled catalysts still exhibits good desulfurization performance after four operating cycles.The high activity and stability of catalysis is attributed to a small dose of H_(2)WO_(4),which is highly dispersed inside the layers of GO.This desulfurization reaction follows the pseudo-first-order kinetics,and the apparent activation energy of the desulfurization reaction is 18.515 kJ/mol,which indicates that the H_(2)WO_(4)/GO used as desulfurization catalyst has demonstrated good desulfurization property for DBT.展开更多
The polycrystalline phase WO_3/g-C_3N_4 was synthesized under stirring using tungstenic acid(H_2WO_4) and graphitic carbon nitride(g-C_3N_4) as raw materials. The catalyst was characterized by X-ray diffraction(XRD), ...The polycrystalline phase WO_3/g-C_3N_4 was synthesized under stirring using tungstenic acid(H_2WO_4) and graphitic carbon nitride(g-C_3N_4) as raw materials. The catalyst was characterized by X-ray diffraction(XRD), scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS),the Fourier transform infrared spectroscopy(FT-IR),and the Brunauer-Emmett-Teller analysis(BET). The polycrystalline phase WO_3/g-C_3N_4 was determined by XRD technique. The oxidative desulfurization process was investigated using WO_3/g-C_3N_4 as the catalyst, 30% hydrogen peroxide(H202) as the oxidant, and 1-butyl-3-methylimidazolium tetrafluoroborate([bmim]BF4) ionic liquids(ILs) as the extractant. The operating conditions, including H_2WO_4 amount, IL dose, H_2 O_2 volume, temperature, catalyst dosage, and types of sulfur compounds,were systematically researched. The desulfurization rate could reach 98.46% for removing dibenzothiophene(DBT) from the model oil under optimal reaction conditions. In addition, the catalytic activity was slightly decreased after five recycles of catalysts. The reaction kinetics analysis shows that the oxidative desulfurization system was in accord with the first-order reaction kinetics equation. The mechanism of oxidative desulfurization was proposed.展开更多
The micro-spheric Bi_2WO_6 was synthesized by a simple one-step hydrothermal method. Bi_2WO_6 crystals were characterized using XRD, SEM, EDS and BET techniques. Bi_2WO_6, H_2O_2 and [HMIM][BF_4] served as catalyst, o...The micro-spheric Bi_2WO_6 was synthesized by a simple one-step hydrothermal method. Bi_2WO_6 crystals were characterized using XRD, SEM, EDS and BET techniques. Bi_2WO_6, H_2O_2 and [HMIM][BF_4] served as catalyst, oxidant and extracting agent in the oxidative desulfurization system(ODS), respectively. The influence of extraction agent type, oxidant usage, catalyst dosage, temperature, sulfur compound type and other factors on the oxidative desulfurization was studied in the present work. The experimental results demonstrate that Bi_2WO_6 possesses high activity for desulfurization of dibenzothiophene(DBT) and benzothiophene(BT). The desulfurization rate of DBT and BT in model oil could reach 98.1% in 80 minutes and 96.2% in 120min at 70℃, respectively. Moreover, the desulfurization performance of catalyst for DBT hardly changed after being recycled for 10 times.展开更多
基金the financial support of the Natural Science Foundation of Liaoning Province(2019-ZD-0064)the Doctoral Fund of Liaoning Province(201501105).
文摘A C_(9)H_(10)O_(2):0.5ZnCl_(2)/SG catalyst was synthesized using a one-step sol-gel method with silica gel(SG)as the carrier and C_(9)H_(10)O_(2):0.5ZnCl_(2)deep eutectic solvent(DES)as active component.The structure of the supported catalyst was characterized by FT-IR,XRD,SEM,and N2 adsorption-desorption,and the DES was found to have successfully permeated the SG through its pores.The removal of dibenzothiophene(DBT)in model diesel was studied using C_(9)H_(10)O_(2):0.5ZnCl_(2)/SG as a catalyst and H_(2)O_(2)as an oxidant.The influence of loading dose of DES,reaction temperature,catalyst dosage,O/S molar ratio,and sulfide type on the desulfurization rate was investigated.The removal rates of DBT,4,6-dimethyldibenzothiophene(4,6-DMDBT),and benzothiophene(BT)under optimal reaction conditions were 99.4%,96%,and 78.2%,respectively.C_(9)H_(10)O_(2):0.5ZnCl_(2)/SG catalyst could be recycled five times with a little decrease of oxidative desulfurization activity,and the adsorption-oxidation desulfurization mechanism was examined.
文摘柔性多状态开关(soft open point,SOP)作为可在配电网中替代传统联络开关的新型柔性一次设备,已成为主动配电网领域的研究热点。针对基于模块化多电平变流器(modularmultilevelconverter,MMC)的SOP装置,提出了一种改进型下垂控制策略,将具有功率分配特性的可调下垂系数与基于虚拟惯量的惯性下垂系数相结合。该控制策略可以根据换流站输出功率的变化相应地改变可调下垂系数以改善各端换流站的功率分配能力,提高系统稳定性。此外,该改进型下垂控制策略通过直流电容动态方程将系统频率与直流电压进行耦合,通过快速调整下垂系数调节各端MMC的输出功率,实现对弱交流电网的频率支撑,提高系统可靠性。最后,基于PSCAD/EMTDC仿真软件搭建了四端SOP系统模型,验证了所提控制策略的正确性与有效性。
基金the financial support of the Natural Science Foundation of China (Project No. 21003069)the Liaoning Province Doctoral Fund (Project No.201501105)
文摘The WO_3/C composite was successfully prepared by calcination of a mixture of WO_3 and g-C_3N_4 at 520 ℃. The as-synthesized samples were analyzed by X-ray diffraction(XRD), electronic differential system(EDS), scanning electron microscopy(SEM), infrared spectrometry(IR) and the Brunner-Emmet-Teller(BET) techniques. The WO_3/C composite, in comparison with the WO_3 and C_3N_4, features smaller particle size, bigger surface area and higher desulphurization performance. The influence of the reaction temperature, the catalyst dosage, the reaction time, the oxidant dosage, the sulfide type and the extractant dose on desulfurization reaction was studied. The results showed that the WO_3/C composite revealed a higher desulfurization activity than the WO_3. The desulfurization rate could reach up to 95.8% under optimal conditions covering a catalyst dosage of 0.02 g, a H_2O_2 amount of 0.2 mL, a 1-ethyl-3-methylimidazolium ethyl sulfate(EMIES) amount of 1.0 mL, a reaction temperature of 70 ℃ and a reaction time of 180 min. After five recycles, the desulfurization activity of catalyst did not significantly decline.
基金The authors also acknowledge the financial support of the Doctoral Fund of Liaoning Province(201501105).
文摘H_(2)WO_(4)/GO catalyst was synthesized by the immersion method and was characterized by using X-ray diffraction(XRD),Fourier-transform infrared spectroscopy(FT-IR),scanning electron microscopy(SEM),and nitrogen adsorptiondesorption measurements(BET).The characterization results show that H_(2)WO_(4) has been dispersed on GO(grapheme oxide).H_(2)WO_(4)/GO was used as catalyst in the oxidative desulfurization of dibenzothiophene(DBT),with H2O2 acting as oxidant and acetonitrile acting as extraction agent.The experimental results show that the sulfur removal rate for DBT reach 99.2%,that for 4,6-dimethyldibenzothiophene(4,6-DMDBT)reach 95%and that for benzothiophene(BT)reach 42.8%under the optimal reaction conditions.Meanwhile,the recycled catalysts still exhibits good desulfurization performance after four operating cycles.The high activity and stability of catalysis is attributed to a small dose of H_(2)WO_(4),which is highly dispersed inside the layers of GO.This desulfurization reaction follows the pseudo-first-order kinetics,and the apparent activation energy of the desulfurization reaction is 18.515 kJ/mol,which indicates that the H_(2)WO_(4)/GO used as desulfurization catalyst has demonstrated good desulfurization property for DBT.
基金the financial support of the Doctoral Fund of Liaoning Province (201501105)
文摘The polycrystalline phase WO_3/g-C_3N_4 was synthesized under stirring using tungstenic acid(H_2WO_4) and graphitic carbon nitride(g-C_3N_4) as raw materials. The catalyst was characterized by X-ray diffraction(XRD), scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS),the Fourier transform infrared spectroscopy(FT-IR),and the Brunauer-Emmett-Teller analysis(BET). The polycrystalline phase WO_3/g-C_3N_4 was determined by XRD technique. The oxidative desulfurization process was investigated using WO_3/g-C_3N_4 as the catalyst, 30% hydrogen peroxide(H202) as the oxidant, and 1-butyl-3-methylimidazolium tetrafluoroborate([bmim]BF4) ionic liquids(ILs) as the extractant. The operating conditions, including H_2WO_4 amount, IL dose, H_2 O_2 volume, temperature, catalyst dosage, and types of sulfur compounds,were systematically researched. The desulfurization rate could reach 98.46% for removing dibenzothiophene(DBT) from the model oil under optimal reaction conditions. In addition, the catalytic activity was slightly decreased after five recycles of catalysts. The reaction kinetics analysis shows that the oxidative desulfurization system was in accord with the first-order reaction kinetics equation. The mechanism of oxidative desulfurization was proposed.
基金financial support of the Natural Science Foundation of China (Project No. 21003069)the Doctoral Fund of Liaoning Province (201501105)
文摘The micro-spheric Bi_2WO_6 was synthesized by a simple one-step hydrothermal method. Bi_2WO_6 crystals were characterized using XRD, SEM, EDS and BET techniques. Bi_2WO_6, H_2O_2 and [HMIM][BF_4] served as catalyst, oxidant and extracting agent in the oxidative desulfurization system(ODS), respectively. The influence of extraction agent type, oxidant usage, catalyst dosage, temperature, sulfur compound type and other factors on the oxidative desulfurization was studied in the present work. The experimental results demonstrate that Bi_2WO_6 possesses high activity for desulfurization of dibenzothiophene(DBT) and benzothiophene(BT). The desulfurization rate of DBT and BT in model oil could reach 98.1% in 80 minutes and 96.2% in 120min at 70℃, respectively. Moreover, the desulfurization performance of catalyst for DBT hardly changed after being recycled for 10 times.