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Development of highly active coated monolith SCR catalyst with strong abrasion resistance for low-temperature

Lina GAN,Shan LEI,Jian YU,Hongtao MA,Yo YAMAMOTO,Yoshizo SUZUKI,Guangwen XU,Zhanguo ZHANG

《环境科学与工程前沿（英文）》 2015年 第9卷 第6期   页码 979-987 doi: 10.1007/s11783-015-0824-8

摘要： Monolith SCR catalysts coated with V O -WO /TiO were prepared by varying binder and coating thickness. Comparing with a monolith extruded with 100% V O -WO /TiO powder, a coated monolith with a catalyst-coating layer of 260 μm in thickness exhibited the similar initial NO reduction activity at 250°C. After 4 h abrasion (attrition) in an air stream containing 300 g·m fine sands (50–100 μm) at a superficial gas velocity of 10 m·s , the catalyst still has the activity as a 100% molded monolith does in a 24-h activity test and it retains about 92% of its initial activity at 250°C. Estimation of the equivalent durable hours at a fly ash concentration of 1.0 g·m in flue gas and a gas velocity of 5 m·s demonstrated that this coated monolith catalyst is capable of resisting abrasion for 13 months without losing more than 8% of its initial activity. The result suggests the great potential of the coated monolith for application to de-NO of flue gases with low fly ash concentrations from, such as glass and ceramics manufacturing processes.

关键词： coated monolith     low-temperature denitration     abrasion resistance     attrition    

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Three-dimensional stability analysis of the dam foundation at Baise

XU Qianjun, LI Xu, CHEN Zuyu

《结构与土木工程前沿（英文）》 2007年 第1卷 第2期   页码 217-221 doi: 10.1007/s11709-007-0026-y

摘要： It is usually difficult to determine the actual safety factors of rock masses in an ordinary two-dimensional stability analysis if the safety factors of the different cross sections in the rock mass vary significantly. In addition to the actual slope, arch dam abutment, and the actual foundation of a high building, another example is that the different cross sections of the foundation in the monolith of a gravity dam vary significantly, just like the condition at the overflow dam in the Baise project. A three-dimensional stability analysis method based on the upper-bound theorem was employed to solve this problem. The parameters used in the analysis were obtained from geomechanics tests, as well as continuity simulations of the randomly distributed joints. Two failure patterns against sliding are analyzed. One pattern is the foundation slide along deep-seated planes which were determined by calculations. The other pattern is the foundation slide along the planes across the bottom of the high steps in the foundation pit. The results indicate that a special overflow dam monolith can be considered to be safe in case of considering the three dimensional effect. However, a key wall with a depth of 5m must be constructed at the upper side of this monolith in order to ensure the safety of the foundation.

关键词： ordinary two-dimensional     randomly     monolith     three-dimensional stability     different    

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Pd-Fe/α-Al

Shengping WANG, Xin ZHANG, Yujun ZHAO, Yadong GE, Jing LV, Baowei WANG, Xinbin MA

《化学科学与工程前沿（英文）》 2012年 第6卷 第3期   页码 259-269 doi: 10.1007/s11705-012-1212-6

摘要： Cordierite monoliths coated with Pd-Fe/α-Al O catalysts were prepared at various calcination temperatures and characterized by thermogravimetry, temperature-programmed reduction, transmission electron microscopy, diffuse reflectance infrared Fourier transformation spectroscopy and X-ray diffraction. The performance of the catalytic monoliths for the synthesis of dimethyl oxalate (DMO) through a CO coupling reaction was evaluated. Monolithic catalysts with calcination temperatures ranging from 473 K to 673 K exhibited excellent dispersion of Pd, good CO adsorption properties, and excellent performance for the coupling reaction. The optimized monolithic catalyst exhibited a much higher Pd efficiency (denoted as DMO (g)·Pd (g) ·h ) (733 h ) than that of the granular catalyst (60.2 h ), which can be attributed to its honeycomb structure and the large pore sizes in the α-Al O washcoat which was accompanied with an even distribution of the active component in the coating layer along the monoliths channels.

关键词： dimethyl oxalate     coupling     Pd     cordierite     monolith     calcination     structure    

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Sustainable H

Ruixue GU, Guangming ZENG, Jingjing SHAO, Yuan LIU, Johannes W. Schwank, Yongdan LI

《化学科学与工程前沿（英文）》 2013年 第7卷 第3期   页码 270-278 doi: 10.1007/s11705-013-1337-2

摘要： A macro-meso-porous monolithic Ni-based catalyst was prepared via an impregnation route using polystyrene foam as the template and then used in the steam reforming of ethanol to produce a H -rich gas. The Ni/Mg-Al catalyst has a hierarchically macro-meso-porous structure as indicated by photographs and scanning electron microscopy (SEM). The surface area of the catalyst was 230 m ?g and the Ni dispersion was 5.62%. Compared to the pelletized sample that was prepared without a template, the macro-meso-porous Ni/Mg-Al monolith exhibited superior reactivity in terms of H production and also had lower CH yields at 700oC and 800oC. Furthermore, the monolithic catalyst maintained excellent activity and H selectivity after 100-h on-stream at 700 C, as well as good resistance to coking and metal sintering.

关键词： macroporous Ni-based catalyst     monolith     hydrogen production     ethanol steam reforming    

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Upgrading of derived pyrolysis vapors for the production of biofuels from corncobs

Liaoyuan Mao, Yanxin Li, Z. Conrad Zhang

《化学科学与工程前沿（英文）》 2018年 第12卷 第1期   页码 50-58 doi: 10.1007/s11705-017-1685-4

摘要： A bubbling fluidized bed pyrolyzer was integrated with an honeycomb as a catalytic upgrading zone for the conversion of biomass to liquid fuels. In the upgrading zone, zeolite coated ceramic honeycomb (ZCCH) catalysts consisting of ZSM-5 (Si/Al=25) were stacked and N or recycled non-condensable gas was used as a carrier gas. Ground corncob particles were fast pyrolyzed in the bubbling bed using fine sand particles as a heat carrier and the resulting pyrolysis vapors were passed on-line over the catalytic upgrading zone. The influence of carrier gas, temperature, and weight hourly space velocity (WHSV) of catalyst on the oil product properties, distribution and mass balance were studied. Using ZCCH effectively increased the hydrocarbon yield and the heating value of the dry oil, especially in the presence of the recycled noncondensable gas. Even a low usage of zeolite catalyst at WSHV of 180 h was effective in upgrading the pyrolysis oil and other light olefins. The highest hydrocarbon (≥C2) and liquid aromatics yields reached to 14.23 and 4.17 wt-%, respectively. The undesirable products including light oxygenates, furans dramatically decreased in the presence of the ZCCH catalyst.

关键词： corncob     monolith     upgrading     pyrolysis    

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Mayenite supported perovskite monoliths for catalytic combustion of methyl methacrylate

Zekai ZHANG, Zhijian KONG, Huayan LIU, Yinfei CHEN

《化学科学与工程前沿（英文）》 2014年 第8卷 第1期   页码 87-94 doi: 10.1007/s11705-014-1410-5

摘要： To improve their thermal stability, La Sr MnO cordierite monoliths are washcoated with mayenite, which is a novel Al-based material with the crystal structure of 12MO·7Al O (M= Ca, Sr). The monoliths are characterized by means of nitrogen adsorption/desorption, scanning electron microscopy, and X-ray diffraction. Catalytic performances of the monoliths are tested for methyl methacrylate combustion. The results show that mayenite obviously improves both the physic-chemical properties and the catalytic performance of the monoliths. Because mayenite improves the dispersity of La Sr MnO and also prevents the interaction between La Sr MnO and cordierite or -Al O , both crystal structure and surface morphology of La Sr MnO phase can thereby be stable on the mayenite surface even at high temperature up to 1050 oC. Under the given reaction conditions, La Sr MnO monolith washcoated with 12SrO·7Al O shows the best catalytic activity for methyl methacrylate combustion among all the tested monoliths.

关键词： mayenite     perovskite     catalytic combustion     methyl methacrylate     monolith    

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标题 作者 时间 类型 操作

Development of highly active coated monolith SCR catalyst with strong abrasion resistance for low-temperature

Lina GAN,Shan LEI,Jian YU,Hongtao MA,Yo YAMAMOTO,Yoshizo SUZUKI,Guangwen XU,Zhanguo ZHANG

期刊论文

Three-dimensional stability analysis of the dam foundation at Baise

XU Qianjun, LI Xu, CHEN Zuyu

期刊论文

Pd-Fe/α-Al

Shengping WANG, Xin ZHANG, Yujun ZHAO, Yadong GE, Jing LV, Baowei WANG, Xinbin MA

期刊论文

Sustainable H

Ruixue GU, Guangming ZENG, Jingjing SHAO, Yuan LIU, Johannes W. Schwank, Yongdan LI

期刊论文

Upgrading of derived pyrolysis vapors for the production of biofuels from corncobs

Liaoyuan Mao, Yanxin Li, Z. Conrad Zhang

期刊论文

Mayenite supported perovskite monoliths for catalytic combustion of methyl methacrylate

Zekai ZHANG, Zhijian KONG, Huayan LIU, Yinfei CHEN

期刊论文