The reaction of CO2 reforming of CH4 has been investigated with y-A1203-supported platinum and ruthenium bimetallic catalysts, with the specific purpose of thermochemical energy storage. The catalysts were prepared by...The reaction of CO2 reforming of CH4 has been investigated with y-A1203-supported platinum and ruthenium bimetallic catalysts, with the specific purpose of thermochemical energy storage. The catalysts were prepared by using the wetness impregnation method. The prepared catalysts were characterized by a series of physico-chemical characterization techniques such as BET surface area, thermo-gravimetric （TG）, transmission electron microscope （TEM） and X-ray photoelectron spectroscopy （XPS）. In addition, the amount of carbon deposits on the surface of the catalysts and the type of the carbonaceous species were discussed by TG. It was found that the bimetallic Pt-Ru/7-A1203 catalysts exhibit both superior catalytic activity and remarkable stability by comparison of monometallic catalysts. During the 500 h stability test, the bimetallic catalyst showed a good performance at 800 ~C in CO2 reforming of CH4, exhibiting an excellent anti-carbon performance with the mass loss of less than 8.5%. The results also indicate that CO2 and CH4 have quite stable conversions of 96.0 % and 94.0 %, respectively. Also, the selectivity of the catalysts is excellent with the products ratio of CO/H2 maintaining at 1.02. Furthermore, it was found in TEM images that the active carbonaceous species were formed during the catalytic reaction, and well-distributed dot-shaped metallic particles with a relatively uniform size of about 3 nm as well as amorphous carbon structures were observed. Combined with BET, TG, TEM tests, it is concluded that the selected bimetallic catalysts can work continuously in a stable state at the high temperature, which has a potential to be utilized for the closed-loop cycle of the solar thermochemical energy storage in future industry applications.展开更多
Significant effort including field work has been devoted to develop a natural gas extraction technology from natural gas hydrate reservoirs through the injection of carbon dioxide. Natural gas hydrate is practically m...Significant effort including field work has been devoted to develop a natural gas extraction technology from natural gas hydrate reservoirs through the injection of carbon dioxide. Natural gas hydrate is practically methane hydrate. The hypothesis is that carbon dioxide will be stored as hydrate owing to its favorable stability conditions compared to methane hydrate. Although the dynamics of the CO2/CH4 exchange process are not entirely understood it is established that the exchange process is feasible. The extent is limited but even if the CH4 recovery is optimized there is a need for a CH4/CO2 separation plant to enable a complete cyclic sequence of CO2 capture, injection and CH4 recovery. In this paper we propose an alternative paradigm to the Inject(CO2)/Exchange with(CH4)/Recover(CH4) one namely Recover(CH4) first and then Inject(CO2) for Storage.展开更多
[目的]随着新能源的大规模应用,新能源发电并网面临的挑战不断突显,储能系统的重要性日益上升。二氧化碳储能(Carbon Dioxide Energy Storage,CES)技术是近年来兴起的一种压缩气体储能技术,具有储能密度大、寿命长、系统设计灵活等优势...[目的]随着新能源的大规模应用,新能源发电并网面临的挑战不断突显,储能系统的重要性日益上升。二氧化碳储能(Carbon Dioxide Energy Storage,CES)技术是近年来兴起的一种压缩气体储能技术,具有储能密度大、寿命长、系统设计灵活等优势。其中液态二氧化碳储能(Liquid Carbon Dioxide Energy Storage,LCES)技术在系统高压侧和低压侧均采用液相存储二氧化碳,储能密度高、运行稳定性强。[方法]文章首先介绍了LCES系统的运行原理和关键技术指标,指出二氧化碳液化的重要性和常见工艺。然后介绍了针对LCES系统低压侧CO_(2)液化的研究现状,包括采用混合储能工质、自冷凝、利用LNG冷能、采用蓄冷器,详细分析了各种方式的特点。[结果]研究表明,采用蓄冷器是最具优势的方式。进一步分析蓄冷液化面临的技术挑战及发展前景具有必要性。[结论]研究为LCES系统CO_(2)液化技术的进一步发展提供了指导。展开更多
基金Project(2010CB227103) supported by the National Basic Research Program of ChinaProjects(50930007,50836005) supported by the Key Program of the National Natural Science Foundation of ChinaProject(U1034005) supported by the National Natural Science Foundation of China
文摘The reaction of CO2 reforming of CH4 has been investigated with y-A1203-supported platinum and ruthenium bimetallic catalysts, with the specific purpose of thermochemical energy storage. The catalysts were prepared by using the wetness impregnation method. The prepared catalysts were characterized by a series of physico-chemical characterization techniques such as BET surface area, thermo-gravimetric （TG）, transmission electron microscope （TEM） and X-ray photoelectron spectroscopy （XPS）. In addition, the amount of carbon deposits on the surface of the catalysts and the type of the carbonaceous species were discussed by TG. It was found that the bimetallic Pt-Ru/7-A1203 catalysts exhibit both superior catalytic activity and remarkable stability by comparison of monometallic catalysts. During the 500 h stability test, the bimetallic catalyst showed a good performance at 800 ~C in CO2 reforming of CH4, exhibiting an excellent anti-carbon performance with the mass loss of less than 8.5%. The results also indicate that CO2 and CH4 have quite stable conversions of 96.0 % and 94.0 %, respectively. Also, the selectivity of the catalysts is excellent with the products ratio of CO/H2 maintaining at 1.02. Furthermore, it was found in TEM images that the active carbonaceous species were formed during the catalytic reaction, and well-distributed dot-shaped metallic particles with a relatively uniform size of about 3 nm as well as amorphous carbon structures were observed. Combined with BET, TG, TEM tests, it is concluded that the selected bimetallic catalysts can work continuously in a stable state at the high temperature, which has a potential to be utilized for the closed-loop cycle of the solar thermochemical energy storage in future industry applications.
基金The financial support from NSERC is acknowledged
文摘Significant effort including field work has been devoted to develop a natural gas extraction technology from natural gas hydrate reservoirs through the injection of carbon dioxide. Natural gas hydrate is practically methane hydrate. The hypothesis is that carbon dioxide will be stored as hydrate owing to its favorable stability conditions compared to methane hydrate. Although the dynamics of the CO2/CH4 exchange process are not entirely understood it is established that the exchange process is feasible. The extent is limited but even if the CH4 recovery is optimized there is a need for a CH4/CO2 separation plant to enable a complete cyclic sequence of CO2 capture, injection and CH4 recovery. In this paper we propose an alternative paradigm to the Inject(CO2)/Exchange with(CH4)/Recover(CH4) one namely Recover(CH4) first and then Inject(CO2) for Storage.
文摘[目的]随着新能源的大规模应用,新能源发电并网面临的挑战不断突显,储能系统的重要性日益上升。二氧化碳储能(Carbon Dioxide Energy Storage,CES)技术是近年来兴起的一种压缩气体储能技术,具有储能密度大、寿命长、系统设计灵活等优势。其中液态二氧化碳储能(Liquid Carbon Dioxide Energy Storage,LCES)技术在系统高压侧和低压侧均采用液相存储二氧化碳,储能密度高、运行稳定性强。[方法]文章首先介绍了LCES系统的运行原理和关键技术指标,指出二氧化碳液化的重要性和常见工艺。然后介绍了针对LCES系统低压侧CO_(2)液化的研究现状,包括采用混合储能工质、自冷凝、利用LNG冷能、采用蓄冷器,详细分析了各种方式的特点。[结果]研究表明,采用蓄冷器是最具优势的方式。进一步分析蓄冷液化面临的技术挑战及发展前景具有必要性。[结论]研究为LCES系统CO_(2)液化技术的进一步发展提供了指导。
