In this paper, Ce_(0.2)Zr_(0.8)O_2 composite supports were prepared by different Ce-addition methods including impregnation of cerium(CeZr-imp), impregnation of citric acid and cerium(CeZr-CA) simultaneously and depos...In this paper, Ce_(0.2)Zr_(0.8)O_2 composite supports were prepared by different Ce-addition methods including impregnation of cerium(CeZr-imp), impregnation of citric acid and cerium(CeZr-CA) simultaneously and deposition precipitation method(CeZr-DP), respectively. The as-prepared supports were applied to prepare 10 wt% MoO_3/Ce_(0.2)Zr_(0.8)O_2 catalysts for sulfur-resistant methanation. The N_2 adsorption/desorption,X-ray diffraction(XRD), Raman spectroscopy(RS), X-ray photoelectron(XPS), temperature-programmed reduction by hydrogen(H_2-TPR) were undertaken to get textural properties, morphological information and structures of the catalysts. The results showed that Mo O_3 was highly dispersed on the surface of these three supports and Ce was mostly of coexisted in Ce^(4+)/Ce^(3+) redox pairs. Compared with Mo/CeZrimp, the CO conversion increased by 10% and 15% for Mo/CeZr-CA and Mo/CeZr-DP, respectively. This was mainly attributed to the larger specific surface area, Ce^(3+) concentration and content of active MoS_2 on the surface of catalysts.展开更多
The operation of blast furnace using natural gas and oxygen enriched blast （composite blast technology） is considered in many countries to be standard operation for a modern blast furnace particularly in certain cou...The operation of blast furnace using natural gas and oxygen enriched blast （composite blast technology） is considered in many countries to be standard operation for a modern blast furnace particularly in certain countries with cheap and stable supply of natural gas. The theoretical flame temperature （TFT） of combustion and the degree of di-rect reduction of iron oxides （rd） are considered as the main controlling parameters of composite blast technology. The calculated values of these parameters are mainly dependent on the amount of air blast consumption. This amount of air blast is measured before entering into blast stoves, Actually, some of air blast is lost through valves of air stoves. Consequently, the real volume of air blast in the furnace is less than the recorded value by amounts of 5%-15% which is not considered in the estimation of rd and TFT. The purpose is to analyze the different methods for es-timation of air blast inside the blast furnaces and develop a theoretical model to calculate air blast eonsumption with high accuracy. Based on the calculation of air blast consumption, a complete roadmap is demonstrated to change the operation regime parameters of blast furnaces working on composite blast technology.展开更多
基金Financial supports from the National High Technology Research and Development Program of China (863 Project) (2015AA050504)the National Natural Science Foundation of China (21576203)
文摘In this paper, Ce_(0.2)Zr_(0.8)O_2 composite supports were prepared by different Ce-addition methods including impregnation of cerium(CeZr-imp), impregnation of citric acid and cerium(CeZr-CA) simultaneously and deposition precipitation method(CeZr-DP), respectively. The as-prepared supports were applied to prepare 10 wt% MoO_3/Ce_(0.2)Zr_(0.8)O_2 catalysts for sulfur-resistant methanation. The N_2 adsorption/desorption,X-ray diffraction(XRD), Raman spectroscopy(RS), X-ray photoelectron(XPS), temperature-programmed reduction by hydrogen(H_2-TPR) were undertaken to get textural properties, morphological information and structures of the catalysts. The results showed that Mo O_3 was highly dispersed on the surface of these three supports and Ce was mostly of coexisted in Ce^(4+)/Ce^(3+) redox pairs. Compared with Mo/CeZrimp, the CO conversion increased by 10% and 15% for Mo/CeZr-CA and Mo/CeZr-DP, respectively. This was mainly attributed to the larger specific surface area, Ce^(3+) concentration and content of active MoS_2 on the surface of catalysts.
文摘The operation of blast furnace using natural gas and oxygen enriched blast （composite blast technology） is considered in many countries to be standard operation for a modern blast furnace particularly in certain countries with cheap and stable supply of natural gas. The theoretical flame temperature （TFT） of combustion and the degree of di-rect reduction of iron oxides （rd） are considered as the main controlling parameters of composite blast technology. The calculated values of these parameters are mainly dependent on the amount of air blast consumption. This amount of air blast is measured before entering into blast stoves, Actually, some of air blast is lost through valves of air stoves. Consequently, the real volume of air blast in the furnace is less than the recorded value by amounts of 5%-15% which is not considered in the estimation of rd and TFT. The purpose is to analyze the different methods for es-timation of air blast inside the blast furnaces and develop a theoretical model to calculate air blast eonsumption with high accuracy. Based on the calculation of air blast consumption, a complete roadmap is demonstrated to change the operation regime parameters of blast furnaces working on composite blast technology.
